Short notes on various topics

An unusual cause of death of a Stigmella-larva: a “pseudo-Bucculatrix” mine

How does Lyonetia clerkella cross a major vein?

Key to the grass-inhabiting Agromyza larvae

Key to the subgenera of the genus Cerodontha (Agromyzidae)

The cocoon of Bucculatrix

Overproduction of eggs in Ectoedemia albifasciella

The development of the agamous generation of the knopper gall

Key to the species groups within the super-genus Euura

gallers on Chaerophyllum

pub 2.iv.2020

Dichotomous table for gallers on Chaerophyllum

by Hans Roskam

1a On parts of inflorescence or fruits => 15

1b On stems or leaves => 2

2a Bulge-shaped, usually yellowish coloured or margined galls on leaves or stems, soon bearing fruiting bodies of rust fungi on their surface => 10

2b Malformations caused by animal parasites or by fungi, fruiting inside the gal => 3

3a Malformations on leaves caused by aphids => 7

3b Malformations caused by different parasites => 4

4a Leaves variously folded, curled or distorted => 5

4b ulge-like, depending on the infected plant part, variously large, compact, pale-green swellings on leaf veins, -midrib, or shoot axis, exceptionally even on young fruits. Containing fungus spores inside. Ch. hirsutum, villarsii: Protomyces macrosporus

5a Leaves disfigured on leaf blades and midrib => 6

5b Development of leaves completely stunted; midrib normal; only the leaf blade folded upward, ± curled and thickened close to midrib. Containing several white larvae. Ch. aromaticum, hirsutum: Macrolabis heraclei

6a Main- and side axis ± stunted, the ± developed leaves deflected, with their ± curled leaf blades loosely converging, nest-like. Leaf blades close to infestation deep-green. Chaerophyllum spp.: Philaenus spumarius

6b Mainly apical parts of leaves stunted and distorted, leaf blades locally swollen, curled. Malformation stunted, often inconspicuously converging, nest-like. Ch. temulum: Trioza apicalis

7a Aphids green => 8

7b Aphids black. Leaflets curled and converging; upper stem leaves slightly bleached. Ch. bulbosum: Aphis fabae

8a Aphids yellowish-green to green, siphunculi of same colour, long, slightly swollen => 9

8b Aphid greenish, siphunculi black, long, swollen. Ch. aromaticum, hirsutum, temulum: Hyadaphis foeniculi

9a Aphid with a “double” cauda; antennae not reaching the middle of body. Leaves curved and curled; the inflorescence is often simultaneously infected and distorted. Ch. temulum: Cavariella pastinacae

9b Cauda simple, antennae longer than half the body length; leaves curled, sometimes reddened at margin; usually only slightly curled. Ch. hirsutum: Myzus persicae

10a Bulges on leaves and stems caused by a fungus, developing aecia => 12

10b Fungus develops only telia; leaf axis and stem, also stalk of umbel, with 1–2 mm long pads, which often coalesce to ± conspicuous and curved, bulging swellings => 11

10c Leaves blistered, especially when young, with whitish down on underside. Ch. aromaticum, aureum, bulbosum, temulum: Plasmopara chaerophylli

11a On Ch. bulbosum and villarsii: Puccinia enormis

11b On Ch. hirsutum: Puccinia pozzii

12a Aecia on Ch. aromaticum or bulbosum, rarely aureum => 14

12b Aecia on Ch. aureum, hirsutum, temulum => 13

13a On Ch. hirsutum. Fungus develops on swollen, orange-red pads, only spermogonia and deeply countersunk, not protruding, pustule-shaped aecia: Puccinia bistortae

13b Aecia pustule-shaped, with rather weakly developed, loose peridium, with outer wall not, or weakly thickened. Chaerophyllum spp.: Puccinia chaerophylli

14a Aecia in dense groups, on leaf underside on arched spots or often in long pads on veins, midrib, stalks or on stems. Peridium weakly developed, loose, opening with an oblong slit. Ch. aromaticum: Puccinia aromatica

14b Aecia pustule-shaped, caeoma-like, opening with oblong slit, cells of peridium similar to spores. Ch. aureum, bulbosum, coloratum, hirsutum, temulum: Puccinia retifera

15a On fruits => 16

15b Centre of stalk of (partial) umbel ± swollen club-shaped or globular. Containing a red larva. Ch. aromaticum, bulbosum, temulum: Lasioptera carophila

16a Fruit bladder-like, inflated, ± globular, protruding above the umbel. Containing an orange-red larva. Ch. aromaticum: Kiefferia pericarpiicola

16b Fruit tube-like, swollen. Containing a white-yellow larva. Ch. bulbosum: Unidentified gall midge

gallers on Mentha

pub 1.iv.2020

Dichotomous table for gallers on Mentha

by Hans Roskam

1a On parts above ground => 2

1b Nodular swellings on roots bearing side roots. Mentha spp.: Meloidogyne hapla

2a On inflorescences or flowers => 12

2b On vegetative organs => 3

3a Various malformations on shoots or leaves => 7

3b Localised galls of different size on stems or leaves => 4

4a Wart- or bulge-shaped galls caused by fungi => 5

4b Egg-shaped or conical galls, 4–6 mm long, 2–3 mm thick, often reddened swellings of shoot axis, usually situated above a higher node. Containing a curved larva, yellow when mature. M. aquatica, arvensis, pulegium, suaveolens: Squamapion vicinum

5a Galls contain spores => 6

5b Strongly swollen, sometimes conspicuously curved, yellowish or brownish-green bulges on basal stem parts; pads on leaf blades protruding on underside, on upperside often ± depressed, yellow, ± red-margined. Galls soon bearing cups, with dust of reddish-yellow spores. Mentha spp.: Puccinia menthae

6a Less than 1 mm long, golden-yellow translucent, multi-cellular warts on leaf underside, on petioles and stems; often many and occasionally joined into crusts or ridges. M. aquatica, longifolia: Synchytrium aureum

= On leaves of M. aquatica small, irregular globular or oval, often reddened nodules with a central cavity may be caused by the green alga Chlorochytrium rubrum.

6b Thick, black-brown bulges on stems, rarely on leaves, containing dark brown spore masses. M. aquatica: Physoderma menthae

7a At shoot tips or on leaves => 8

7b Plants stunted. Stem at base with bases of inserted leaves strongly swollen and spongy. Gall ± pale-green, necrotic. Mentha spp.: Ditylenchus dipsaci

8a Malformations not excessively pubescent => 10

8b Malformations covered by dense, abnormal pubescence => 9

9a Leaves or, if present, also neighbouring flower buds stalked on tips of main- and side shoots; all organs with ± dense yellowish-white pubescence on all sides. Hairs multi-cellular, branched. Sometimes excessively leafy, branched. Mentha spp.: Aceria megacera

9b Leaf blades of slightly stunted leaves with dense whitish pubescence. M. aquatica, arvensis, longifolia, mollissima, spicata: Aceria mentharia

10a Malformations caused by aphids => 11

10b Clustering of several leaves on bent shoot tips, usually stunted on one side and ± rolled and curled. Mentha spp.: Philaenus spumarius

11a Leaves on shoot tip strongly curled. Aphid green. Mentha spp.: Aphis affinis

11b Leaf blades of terminal leaves strongly curved and deflected. Aphid greenish-white. Mentha spp.: Ovatus crataegarius

12a Malformations of inflorescence => 14

12b Malformations on single or several flowers => 13

13a Flower buds swollen, unopened. Inner wall with mycelium. Containing an ochre-yellow larva. Mentha spp.: Asphondylia menthae

13b Flow ers slightly disfigured, only recognisable if closely examined. Mentha spp.: Peronospora stigmaticola

14a Malformations abnormally densely pubescent => 15

14b Malformations without abnormal pubescence. Accumulations of slightly stunted bracts and severely disfigured flowers at shoot tip of Mentha spp.: Eriophyes menthae

15a Flowers, mainly of terminal inflorescences, transformed into dense, white-pubescent, greened structures. Mentha spp.: Aceria megacera

15b Similar galls on M. arvensis, longifolia: Aceria mentharia

gallers on Lolium

pub 31.iii.2020

Dichotomous table for gallers on Lolium

by Hans Roskam

1a On above-ground parts => 3

1b On roots => 2

2a Roots often with many slender galls, up to about 5 mm long and 0.5–4 mm thick, usually bent or twisted half screw-like. L. perenne: Subanguina radicicola

2b Roots from the outside hardly changed, inside with giant cells, temporarily occupied by white to brown, about poppy-seed size cysts. Lolium spp.: Heterodera avenae

3a On inflorescences, flowers or fruits => 8

3b On culms, shoot tips or leaves => 4

4a Malformations on culms, shoot tips or leaves => 5

4b Complete plant stunted, disfigured, often additionally leaf-like, shoots often reddish discoloured, especially thickened close to ground. Leaves shortened, bent and rugose. L. multiflorum, perenne: Ditylenchus dipsaci

4c Growth compact and stunted, spikes disfigured, however, many shoots remain healthy. L. perenne: Steneotarsonemus spirifex

5a Malformations on leaf blades => 7

5b Malformations on culms or shoot tips => 6

6a Saddle-shaped depressions, about 10–12 mm long, elongated, raised at the ends above the terminal node, covered by slightly swollen leaf sheaths. Each gall containing a brick-red larva. L. temulentum: Haplodiplosis marginata

6b Occasionally on L. multiflorum, perenne occurring as various malformations: Oscinella frit

6c Terminal tuft of imbricate leaves, discoloured, stem not swollen. L. perenne: Tetramesa sp.

6d Whitish, at surface yellowish or brownish patches, which envelope a large area of the upper part of stem, of which further development is stunted. Node of stem rarely swollen, encircled by fungus stroma, yellowish when mature; several nodes may be affected; flowering stunted; stroma contains narrow asci and filamentous spores. L. multiflorum, perenne: Epichloë typhina

7a Leaves rolled, plant ± severely stunted. L. multiflorum, perenne: Diuraphis frequens

7b Leaf blade, sheath and occasionally culm with long parallel stripes caused by smut. L. perenne: Urocystis bolivarii

7c Spores solitary, brown-black, globular or rotund-oval. L. perenne: Ustilago striiformis

7d Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. L. perenne: Puccinia striiformis

8a Malformations of inflorescences or their stalks => 9

8b Yellow larvae live gregariously in the inflorescences. L. perenne: Contarinia lolii

8c Ovaries distinctly swollen, transformed into a ± egg-shaped, acuminate structure, filled with a yellowish to yellowish-brown spore mass, foul-smelling when fresh. Lolium multiflorum, perenne, remotum, rigidum, temulentum: Tilletia lolii

9a Spikelets developing further, floral parts variously greened or leaf-like, in other cases bleached. L. perenne: Aceria tenuis

9b Lateral spindle-shaped swelling at base of inflorescence stalk. L. perenne: Tetramesa sp.

gallers on Lactuca

pub 30.iii.2020

Dichotomous table for gallers on Lactuca

(incl. Cicerbita, Mulgedium, Mycelis)

by Hans Roskam

1a On above-ground parts => 2

1b Mostly terminal parts of root with nodular swellings. L. perennis, sativa, serriola: Meloidogyne hapla

2a Malformations of inflorescences or capitula => 11

2b Galls on shoots or leaves => 3

3a Malformations almost exclusively on leaves => 6

3b Malformations on stems, with or without involvement of leaves => 4

4a Localised galls on shoots => 5

4b The overwintering mycelium causes a systemic infection, largely deforming the plant and inhibiting the formation of flowers. Internodes lanky, often excessively elongated, diseased stems ± prostrate; affected leaves pale green, shortened and on the underside, like the stems, with spermogonia and isolated aecia on expanded areas. Lactuca sibirica, Mulgedium tataricum: Puccinia minussensis

5a Shoots with spindle-shaped to oval or elongated bulges, with single to many depressions containing the gall causer. L. serriola, viminea: Planchonia arabidis

5b Conspicuous stem galls, about 30–45 mm long, 10–20 wide tuber- to spindle-shaped, tough. L. saligna, viminea: Timaspis phoenixopodos

6a Malformations mainly of the leaf blades => 8

6b Galls exclusively or preferentially on the petiole or on the midrib => 7

7a Conspicuous swelling of the midrib of basal leaves, especially protruding on the underside, glabrous on the surface, broad at the base, gradually narrowing, usually extending into the upper third of the leaf blade. Containing a single larva. L. serriola: Phytomyza penicilla

7b Spongy, ± spindle-shaped swellings of the midrib in different sites and of various expansion. Surface mostly rugose, inside massive. Occasionally extending into the leaf blade, which is often swollen and disfigured. L. serriola: Ditylenchus dipsaci

8a Local, ± conspicuous swellings on the leaves caused by rust fungi => 10

8b Expanded malformations of the leaf blade => 9

9a Compact, narrow upward roll of the leaf margin. L. perennis: Unidentified gall mite

9b Leaf blade ± curled and discoloured. L. sativa, serriola: Nasonovia ribisnigri

= Sometimes occurring together with the aphid Aulacorthum solani

10a Leaf blade with 5–10 (15) mm long rotund, pale green to reddish spots, usually on the underside with a vivid yellowish hardly swollen pad bearing cup-shaped aecia; with a corresponding depression on the upper side. L. perennis, quercina, sativa, serriola, virosa, etc.: Puccinia opizii

10b Aecia with pore-shaped opening, unlike the cup-shaped opening of the preceding species, the peridium very loose, rudimentary. Sori on the underside of the leaves, on the leaf blades usually rather small and little swollen; on the venation, petioles and stems united in larger groups on bulge-like swellings. L. perennis, serriola, rarer on L. perennis, quercina, sativa, serriola, viminea: Puccinia lactucarum

10c On L. viminea with similar aecia to the preceding species: Puccinia maculosa

11a Stalks of young inflorescences or the basal parts of older inflorescences markedly stunted in longitudinal direction; ± thickened; budding inflorescences in various numbers at their base ± globular or mostly obtuse cone-shaped swollen; not opening. On later infected inflorescences the stalks are less stunted; finally only some to many disfigured capitula are distributed over the inflorescences. Containing many white, jumping larvae. L. serriola: Contarinia cf. salatica

11b Capitula often completely transformed into small tufts of irregular, curved leaflets. L. saligna, sativa, serriola, virosa: Aculus lactucae

11c Flower head remaining closed, swollen and longitudinal-ovoid. L. viminea: Hypenidium graecum

gallers on Hypochaeris

pub 29.iii.2020

Dichotomous table for gallers on Hypochaeris

by Hans Roskam

1a On capitula or achenes => 14

1b On vegetative plant parts => 2

2a On leaves => 5

2b On stems => 3

2c All parts of shoot with white crusty blisters, very variable in size; shoot often distorted. H. maculata: Pustula obtusata

3a Shoot axis with tough-walled, plurilocular galls => 4

3b Shoot axis with spongy pale green galls of various shape, length and position, usually on all sides, often elongate, massive, ± twisted or curved. Close to the capitula, also extending into the receptacle. H. maculata, radicata: Ditylenchus dipsaci

4a Stem with up to 40 mm long and 7 mm thick, plurilocular, usually spindle-shaped or oblong swelling, sometimes occupying the whole shoot axis. Galls in spring; one yellow larva per chamber. H. achyrophorus, glabra, laevigata, radicata: Phanacis hypochoeridis

4b Shoot axis, often at the stem base, with one-sided callosity, up to 5 mm long with rotund larval chamber. Hypochaeris spp.: Napomyza lateralis

5a Galls on the leaf blade, not involving veins => 11

5b Galls on main- or secondary veins, partially extending to the leaf blade; massive => 6

6a The gall development expands from the midrib to the leaf blade, or affects mainly the secondary venation => 7

6b The gall formation is restricted to the vein => 7

7a Spongy, short spindle-shaped galls, but variously elongated, protruding on both sides of the vein, pale green with ± rugose surface, often extending over a wide area of the leaf blade, occasionally also running only from the major lateral veins and causing bends. Many eelworms inside the loose gall parenchyma. H. glabra, maculata, radicata, uniflora: Ditylenchus dipsaci

7b Venation of irregularly margined and pale- or yellow green upward arched areas swollen, often ± reddened, the underside protruding in relief. Many spores in the vascular tissue. H. radicata: Protomyces cf. kriegerianus

8a Elongated soft swelling, emerging at the leaf base and narrowed towards the top, is caused by fly maggots => 10

8b Up to 6 mm long swelling, especially prominent on one side of the leaf => 9

9a Closed, egg-shaped, thin- but tough-walled, unilocular swelling. H. glabra, maculata, radicata: Aulacidea andrei

9b Inconspicuous swellings, up to 2 mm long, ± egg-shaped, yellow margined with covering of cinnamon brown spores, usually on the underside of the youngest, ± curved leaves. H. glabra, radicata, maculata: Puccinia hieracii

9c Similarly has been recorded on H. uniflora the close relative: Puccinia montivaga

9d Similarly on H. achyrophorus the close relative: Puccinia marquesii

10a About 3 (5) cm long occasionally slightly reddened galls on smaller leaves which are sometimes extending to the upper side of the terminal third part of the leaf blade. H. radicata: Phytomyza cecidonomia

10b Corresponding galls in the larger leaves, hardly conspicuous, on H. maculata: Phytomyza sp.

11a Galls lacking additional pubescence => 12

11b Leaf blade folded and reddened; in the folds on the upperside white, felt-like, pubescence, might be accompanied by rolling of the leaf margin. H. glabra, radicata: Aceria hypochoerina

12a Galls on expanded leaf blade => 13

12b Leaf blade upward folded, containing apterous green aphids about 1 mm long. H. maculata, radicata: Aphis hypochoeridis

13a Leaf blade slightly deformed, with irregular, weak, one-sided open bulges. H. radicata: Craspedolepta flavipennis

13b Leaf blade with several distinctly protruding pustules on the upperside, which are surrounded by a broad yellow-green to reddish margin. On the leaf underside clearly recognizable red-yellow larva is situated in spongy parenchyma under the epidermis. H. glabra, radicata: Cystiphora sp.

14a Malformations of the capitula => 16

14b Malformations of the achenes => 15

15a Capitula disfigured, with patch of stunted florets and their achenes at side of receptacle; containing yellow, jumping larvae. H. glabra, maculata, radicata: Contarinia hypochoeridis

15b Achene deformed to a 3 mm long, rotund-oval longitudinally grooved gall. One white larva. H. radicata: Unidentified tephritid fly

16a Capitula small and not opening, swollen. H. uniflora: ? Stylia sp.

16b In ungalled capitula of Hieracium spp.: Campiglossa achyrophori

gallers on Chenopodium

pub 28.iii.2020

Dichotomous table for gallers on Chenopodium

(incl. Blitum, Chenopodiastrum, Dysphania, Lipandra, Oxybasis)

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Roots with small, nodular or spindle-shaped, compact swellings, up to about 4 mm long. Chenopodium album; Dysphania ambrosioides; Lipandra polysperma: Meloidogyne hapla

2b Outside of root unchanged, inside with giant cells. C. album: Heterodera schachtii

= On Oxybasis glauca the clover cyst eelworm Heterodera trifolii has been recorded

2c Main root close to ground surface with conspicuous, easily rupturing, 30 to 80 mm long, 5–6 mm thick, beet-like thickening, with a broad, elongate cavity usually containing several larvae. Chenopodium spp. s.l.: Bothynoderes affinis

3a Leaves with abnormal pubescence or with down-like sori of fungi => 12

3b Malformations not conspicuously pubescent or without down-like sori => 4

4a Extensive malformations caused by aphids, spittlebugs or psyllids => 9

4b Causers belong to other groups => 5

5a Single galls pearl-like, on leaves, often also on stems; sometimes, on greatly disfigured organs, coalescing into ± expanded ridge- or crust-like groups => 8

5b Malformations extensive, of indefinite shape => 6

6 Galls predominantly on stem parts => 7

6b Infected shoots or complete plants growing abnormally, ± crippled, almost witches’ broom-like. Leaves ± erect and distorted, narrower than those on healthy plants. Flower buds slightly inflated, at first unopened, often densely aggregated, their ovaries soon filled with a grey-brown, later on dusty spore mass. Chenopodium album, strictum; Dysphania ambrosioides: Thecaphora leptideum

7a Shoot axis, depending on grade of infestation, ± bulge-like swollen over various lengths; with rotund-oval, rimmed depressions containing causer. Chenopodiastrum hybridum: Planchonia arabidis

7b Galls broad spindle-shaped or narrowing barrel-shaped; up to hazelnut-size. Inside are several oblong larval chambers. Each chamber contains a single yolk-yellow or red larva. C. album: Aplonyx chenopodii

7c Stem parts of young plants distinctly shortened, spongy, swollen. Inserted leaves with shortened, thickened stalks and veins, leaf blades variously disfigured. Chenopodium album, foliosum, Lipandra polysperma: Ditylenchus dipsaci

= Terminally bushy, compact plants of Chenopodiastrum murale with oblong, slightly spindle-shaped stem galls with an expanded frass-containing pith channel. Cf. Scrobipalpa obsoletella

8a Leaves and stems, rarely also perigone, with 1–2 mm long or more expanded, multicellular, wart-like, ± hemispherical, watery- or yellow-green, curly galls which in the case of more dense infestation, join into larger bulges on the often conspicuously distorted axial leaf parts or margins, as well as on stem parts. Chenopodium spp. s.l.: Physoderma pulposum

8b Single galls hardly 1 mm across, golden-yellow translucent, on underside of basal leaves, their stalks and stems. Chenopodium album, Lipandra glauca, Oxybasis rubra: Synchytrium aureum

9a Malformations contain aphids => 11

9b Malformations caused by psyllids or spittlebugs => 10

10a Leaf blades with irregular leaf folds, caused by froth-covered nymphs of psyllids. Chenopodium spp. s.l.: Trioza chenopodii/p>

10b Leaf blades variously ± nest-like deflected, hunch-backed curled, dark green close to the froth-covered nymph. C. bonus-henricus, etc.: Philaenus spumarius

11a eaves on the ± shortened shoot tips converging, their leaf blades stunted, variously also deflected over their tip; infected inflorescences clustered, globular. Aphid black. Chenopodium spp. s.l.: Aphis fabae

11b Leaves upwardly folded along midrib or rolled, often distinctly thickened and severely discoloured. Aphid about 1.5 mm long, green, conspicuously frosted with white powdery wax. Chenopodium spp. s.l.: Hayhurstia atriplicis

12a Leaves lacking bladder-like swellings, abnormally pubescent. Hairs simple, not branched fork-like. C. album: Unidentified gall mite

12b Leaf blade with ± expanded, sometimes considerably, pale green, occasionally violet discoloured, bladder-like, partially distinctly thickened swellings, on underside a dense dirty-violet down of multiple fork-like branched conidiophores. Fungi belong to the species complex of Peronospora farinosa

gallers on Matricaria

pub 27.iii.2020

Dichotomous table for gallers on Matricaria

(incl. Tripleurospermum)

by Hans Roskam

1a On above-ground parts => 2

1b Roots with spindle- to nodule- shaped swellings, bearing several lateral roots. Matricaria chamomilla, Tripleurospermum inodorum: Meloidogyne hapla

2a On inflorescences or their organs => 9

2b On vegetative parts => 3

3a Localised galls on leaflets => 8

3b Malformations of leaves, single shoots or the complete plant => 4

4a Various malformations of leaves and shoots => 7

4b Development of entire plant or large parts of it stunted and variously disfigured; caused by aphids => 5

5a Aphids black => 6

5b Aphid yellow to yellow-green, 1.5–2 mm long. Matricaria chamomilla, Tripleurospermum inodorum: Brachycaudus helichrysi

6a More frequent inhabitant of disfigured plants. Matricaria chamomilla, Tripleurospermum inodorum: Aphis fabae

6b Similar development and only distinguished by microscopical characters. Matricaria chamomilla, Tripleurospermum inodorum: Aphis fabae subsp. solanella

6c Dense bushy growth. Matricaria chamomilla: Didymaria matricariae

7a Stems variously spongy, swollen, pale green, with ± rugose surface. Tripleurospermum inodorum: Ditylenchus dipsaci

7b Galls in apical meristems of rosettes and bolting plants, axillary leaf buds. Tripleurospermum inodorum: Rhopalomyia tripleurospermi

7c Downward bend, ± disfigured, locally dark green coloured leaves clustered in sometimes unilaterally curved terminal shoots. Matricaria chamomilla, Tripleurospermum inodorum: Philaenus spumarius

8a Hyaline, pale green, clearly protruding bulges on the leaflets. Tripleurospermum inodorum: Protomyces matricariae

8b Small rotund to oblong, diffuse or coalescing sometimes slightly thickened spots on leaves, conspicuous by their initially white, later on yellow to brown colour. Matricaria chamomilla; Tripleurospermum inodorum, maritimum: Entyloma matricariae

9a Galls in single florets or achenes => 14

9b Malformations on more substantial parts of the capitula => 10

10a Malformations predominantly of the receptacle => 12

10b Malformations predominantly of the florets => 11

10c Galls in different meristematic tissues of flower heads. Tripleurospermum inodorum: Rhopalomyia tripleurospermi

11a Ligules not developed. Flower head transformed into a semi-globular or elongated, 5–50 mm long greened and leafy tuft. Matricaria chamomilla; Tripleurospermum inodorum: cf. Aceria matricariae

11b Ligules elongated and variously curved; tubular florets ± withered. Organs soon covered with a loose grey cover of conidiophores. Matricaria chamomilla, discoidea; Tripleurospermum inodorum, maritimum: Peronospora radii

12a Considerable swelling of the receptacle => 13

12b Receptacle only slightly swollen, ± disfigured, hardened by a beetle larva. Matricaria chamomilla: Microplontus rugulosus

= Larvae of the leafminer Napomyza lateralis are rather frequent in receptacles of Tripleurospermum inodorum

13a Receptacle enlarged, thickened and arched. A yellowish-white maggot. Matricaria chamomilla, discoidea; Tripleurospermum inodorum, maritimum: Trupanea stellata

13b Similar, globular to egg-shaped receptacle gall inhabited by a beetle larva. Matricaria chamomilla; Tripleurospermum inodorum: Omphalapion laevigatum

= Also in capitula of chamomiles the larvae of other snout beetles develop, e.g., Omphalapion hookerorum

14a Single florets transformed into a hard barrel-shaped, glabrous gall, firmly attached to, or embedded in the receptacle, apically opening by a lid. Often several in a flower head. Containing a single larva. Tripleurospermum inodorum: Rhopalomyia syngenesiae

14b Achene swollen and base of corolla enlarged, often several affected in one flower head; each containing a yellow larva. Tripleurospermum inodorum: Ozirhincus longicollis

14c Similar malformations and biology similar to that of O. longicollis. Tripleurospermum inodorum: Ozirhincus hungaricus

gallers on Genista

pub 26.iii.2020

Dichotomous table for gallers on Genista

(incl. Chamaespartium, Cytisanthus, Echinospartium)

by Hans Roskam

1a On parts above ground => 2

1b Rotund-oval to cylindrical, about 8 (10) mm long, apically ± forked or fan-shaped broadened, laterally attached nodules on main- and adventitious roots. Genista spp.: Rhizobium leguminosarum

2a On inflorescences, flowers or fruits => 15

2b On vegetative parts => 3

3a On shoot tip or -axis => 9

3b On lateral buds or leaves => 4

4a On buds => 7

4b On leaf blades => 5

5a Wart- or pustule-shaped galls on leaf blade => 6

5b Leaflet rolled over its length, slightly thickened and enlarged, ± yellowish or reddish, strongly pubescent. Galls usually with several terminally on non-flowering shoots. Containing a single white larva. G. pilosa: Dasineura genistarum

6a Compact, ± yellowish translucent warts on basal leaves; infestation encroaching onto young axial parts. G. tinctoria: Synchytrium aureum

6b Soft egg-shaped pustules, up to 2 mm long, ± yellowish-green. The emerged larva leaves the ‘procecidium’ (oviposition scar, not a true gall, which collapses soon afterwards) and feeds freely on the leaf blade. G. pilosa, tinctoria, etc.: Unidentified sawfly

7a Relatively small midge galls, up to 7 mm long, rather constant in shape, glabrous or sometimes in young stage ± strongly white pubescent => 8

7b The buds develop into small, ± witches’ broom-like structures bearing clustered, almost scale-shaped, strongly pubescent leaves. Genista spp.: Aceria genistae

8a Axillary leaf bud transformed into a glabrous gall, about 7 mm long, 4 mm thick, with large central chamber. Inner wall covered with mycelium. Containing a single larva. Genista spp.: Asphondylia genistae

8b Buds enlarged, transformed into an egg-shaped to oblong-oval tuft; with external white pubescence, at first bud-like, then apically spreading; containing one to several, at first white, later on pale pink-coloured larvae. Genista spp.: Jaapiella genisticola

8c Globular galls covered with long snow-white hairs at shoot tip or in leaf axil. G. scorpius: Dasineura scorpii

9a Galls exclusively or mainly on the buds or leaves of apical shoots => 10

9b The terminal axial parts are transformed over several, ± strongly shortened internodes into a broad, long-, rarely rotund-oval, irregular bulging, spongy, sparsely haired swelling; usually multiple-, rarely single-chambered. Tips of terminal and, if present, lateral shoots often with tuft-like clustered, ± reduced, basally thickened leaves. Larvae flesh-coloured, jumping. G. corsica, depressa, germanica, tinctoria: Contarinia melanocera

9c Terminal internodes shortened, excessively branched, bearing clustered tufts of small leaves, up to 3 mm long, underside pubescent, leaf blade wrinkled at top or curved, spoon-like. Malformation up to 20 mm across. Genista spp.: Aceria genistae

9d One-sided swelling of twig (10 x 3 mm), crazed at surface, with oblong larval chamber inside. G. aetnensis, tinctoria: Hexomyza cf. sarothamni

9e Internodes shortened, bearing enlarged, densely white pubescent leaves which are clustered in a rosette. G. scorpius: Dasineura scorpii

9f Subterranean part of stem with one-sided, discoloured malformations of variable length and shape, single or clustered in irregular complexes due to expansion of parenchyma; compact. Caused by large numbers of black aphids. Genista spp.: Aphis cytisorum

10a Tufts of leaves on G. sagittalis => 14

10b Tufts of leaves on other Genista species => 11

11a Tufts abnormally haired => 12

11b Leaves of tufts glabrous, basally thickened and broadened. Many larvae. G. germanica, tinctoria: Dasineura sp.

12a Malformations caused by gall midges => 13

12b Axis of shoot tip distinctly shortened. Apical- and usually some lateral buds developing into stub-shaped, partially branched shoots bearing markedly reduced, almost scale-shaped and densely haired clustered leaves. Genista spp.: Aceria genistae

13a Oblong, abnormally haired tuft of leaves on G. januensis, pilosa, tintoria. Leaves ± keel-shaped rolled inwards. Containing orange-coloured larvae: Jaapiella genistamtorquens

13b Acuminate rotund to oblong-oval, about 10 (15) mm long tufts of leaves with ± thickened, partially almost mussel-like broadened leaves and sometimes densely, short, white pubescent. Larvae at first white, then pale pink. Genista spp.: Jaapiella genisticola

14a Dense white or grey pubescent tufts of leaves. The upper leaves ± keel-shaped. Winged ridges of stem undulately bent: Aculus acraspis

14b Upper leaf enlarged and curved, enveloping a cluster of disfigured leaves, less strongly pubescent and mainly enveloped by a larger leaf: Dasineura cytisi

15a Fruit galls => 18

15b Galls on single flower buds or on ± expanded parts of inflorescence => 16

16a Several up to all flowers disfigured => 17

16b Flower buds swollen, unopened, calyx swollen. Corolla and anthers aborted. 4–5 yellowish-white larvae. G. sagittalis: Dasineura sp.

16c Similar galls, contain jumping midge larvae. G. hirsuta, sagittalis: Contarinia sp.

17a Caused by gall midges. Usually only a part of the flower bud is galled. This is swollen, unopened; strongly pubescent, like the enlarged bracts. Larvae at first white, then pink-coloured. Genista spp.: Jaapiella genisticola

17b Caused by gall mites. Inflorescence distinctly shortened. Flowers largely leafy, with abnormal white pubescence. G. sagittalis: Aculus acraspis

17c Caused by gall mites. Flowers greened. G. tinctoria: Phyllocoptes genistae

18a No layer of mycelium inside fruit galls => 19

18b Fruit galls caused by midges, with layer of mycelium inside. Pod swollen, egg-shaped to cylindrical. Seeds aborted. Containing 1 (‒3) orange-red larvae. Genista spp.: Asphondylia genistae

= Similar gall on G. sagittalis is caused by Aspondylia bitensis. One to three red larvae, or pupae, in the galled pods. Inner wall of gall chamber lined with mycelium

19a On G. pilosa. The pods are of almost normal size but infestation is indicated by weak, discoloured tubercles. Larvae bone-coloured: Contarinia pulchripes

19b On G. tinctoria, sagittalis. The young pod is distinctly swollen and often remains hidden in the hypertrophied, unopened flower. Containing a single larva: Tychius parallelus

= Swollen pods may be caused by weevil larvae of Exapion difficile and E. genistae; it is not known whether these are true galls

gallers on Erigeron

pub 25.iii.2020

Dichotomous table for gallers on Erigeron

(incl. Chiliodenus, Conyza)

by Hans Roskam

1a Malformations locally => 2

1b Whole plant stunted in development, bushy, terminal part of stems stunted; leaves clustered, white-spotted, sometimes ± curved. Erigeron spp.:
Brachycaudus helichrysi

2a In capitula and fruits => 12

2b On vegetative parts => 3

3a Swellings of the stem, not in the terminal parts => 11

3b Galls in basal rosettes, in buds, growing points or leaves => 4

4a On shoot tips or leaves => 6

4b Galls of various kinds in stunted or on stunted rosettes or lateral buds; tuft of leaves variously developed or even missing => 5

5a Galls ± onion-like, swellings succulent, predominantly, at least in the rosettes, with tuft of leaves and sometimes lateral shoot. E. acris, uniflorus: Rhopalomyia ruebsaameni

5b Inner rosette leaves converted into a rotund or long-oval, up to 10 mm long, spongy gall. E. acris, uniflorus: Rhopalomyia ruebsaameni

6a Leaves with localised galls or occurring over larger areas with several galls, malformed predominantly in the terminal part of the shoot => 7

6b Leaves accumulated on the shoot tips tuft-like, at the base ± shell-like broadened, pale, the outer ones often reddened, their terminal parts ± stunted, but not conspicuously deformed or discoloured. E. acris: Dasineura erigerontis

7a Leaf blade over large parts rolled, curved or curled => 9

7b Leaves with restricted, wart- or bulge-shaped swellings => 8

8a Galls often many, less than 1 mm long, yellowish, sometimes coalescing. E. canadensis: Synchytrium aureum

8b Leaf veins and stems with black-brown dusty sori on weakly swollen bulges. Erigeron spp.: Puccinia dovrensis

9a Leaf blade loosely rolled inwards and curled; by aphids => 10

9b Top and margin of the leaf blades of the larger basal leaves bent together; stem leaves with several correspondingly deformed and often nest-like clusters on the locally stunted and ± curved stem. Close to the froth-covered nymph curled and dark green. Erigeron spp.: Philaenus spumarius

10a Margin of leaf blade rolled, slightly curled, with minor paler, upward bulges. E. acris, annuus, canadensis: Brachycaudus helichrysi

10b Similar, slight curling of leaves. Erigeron spp.: Aulacorthum solani

10c Leaves swollen and curled. E. acris: Acuticauda erigerontis

11a Development of young stems severely stunted; basal internodes on all sides with perforating shoots ± one-sided spongy, swollen and bent. Inserted leaves at the sites of infestation deformed to various extents. E. canadensis: Ditylenchus dipsaci

11b Basal shoot stem with rugose embossments; one larva inside. E. acris: Cause unknown – ? beetle

12a Malformations of single or several capitula => 13

12b Fruit aborted, larva bright yellow. E. acris: Cause unknown – ? gall midge

13a Malformation of single capitula by gall midge larvae => 15

13b Malformation of inflorescence extended over several capitula => 14

14a Capitula deformed, ± sprouting and abnormally pubescent. E. annuus: Cause unknown – ? gall mite

14b Capitula stunted, small, only opening a little. Flowers ± withered, ovaries malformed, styles often elongated and discoloured violet. E. acris, uniflorus: Aceria puculosa

15a Galls caused by gall midges => 16

15b Receptacles swollen, tephritid inducers. Chiliadenus glutinosus: Myopites jasoniae

16a Terminal capitula basally slightly swollen, often remaining closed. Larvae red, non-jumping. E. acris: Dasineura socialis

16b Similar malformations. Heads on shortened stalks, shrivelled, hardened and dying off prematurely. Larvae yellow, jumping. E. acris: Contarinia erigeronis

gallers on Galeopsis

pub 24.iii.2020

Dichotomous table for gallers on Galeopsis

by Hans Roskam

1a On plant parts above ground => 3

1b On roots => 2

2a Roots with nodular swellings. G. tetrahit: Meloidogyne hapla

2b Roots unaltered externally; inside with giant cells. The bodies of developing female eelworms break through the host tissue and are attached to the root as at first white, then yellowish, eventually partially brown, about poppy-seed sized cysts. G. tetrahit: Heterodera schachtii

3a Galls at tip of vegetative or generative shoots => 11

3b Galls on shoot axis, leaves or flowers => 4

4a Malformations of vegetative organs => 5

4b Flower buds globular, swollen and discoloured, unopened. Containing a white or pale reddish-yellow larva. G. bifida, ladanum, tetrahit: Dasineura tetrahit

5a Galls on leaves distant from shoot tip => 7

5b Galls on axial parts of stem => 6

6a Oblong swelling of upper parts of shoot axis. Shoot tip above swelling usually soon withered. Pith containing many larvae. G. ladanum: Thamnurgus kaltenbachii

6b Conspicuous, usually pale green swelling of basal axial parts; tissue spongy; plant severely stunted. On stems, infected after ± completed longitudinal growth and also on higher situated parts, develop variously shaped galls, on one or all sides, often associated with distortions, ± reddened, spongy. Such galls develop ± locally also on petioles and leaf blades. Galeopsis spp.: Ditylenchus dipsaci

7a Downward roll and distortion of leaves caused by aphids => 8

7b Basal leaf blades with many small, multicellular, wart-shaped, yellowish translucent warts; infestation also encroaching into petioles and stems. G. tetrahit: Synchytrium aureum

8a Aphids up to 2 mm long, dark green, with black siphunculi => 10

8b Aphids yellowish-white or yellow to pale green, or yellow-green with same-coloured siphunculi => 9

9a Aphid 1–1.5 mm long, yellow to pale or yellow-green. Galeopsis spp.: Aphis nasturtii

9 Aphid 2–2.6 mm long, yellowish-white to pale green, with siphunculi of the same colour. Galeopsis spp.: Cryptomyzus galeopsidis subsp. galeopsidis

10a Cauda and siphunculi of the 1.5–2 mm long aphid black, antennae slightly longer than half the body length. Siphunculi and cauda almost of same length. Galeopsis spp.: Aphis frangulae subsp. beccabungae

10b Cauda of the up to 2 mm long aphid green, lighter than siphunculi. Antennae half the body length. Siphunculi twice as long as cauda. Galeopsis spp.: Aphis gossypii

11a Malformations caused by aphids or spittlebugs => 14

11b Galls caused by gall midges, eelworms or gall mites => 12

12a Galls lacking abnormal pubescence => 13

12b Leaves, also flower buds, stunted, clustered on shoot tips; densely pubescent. G. ladanum: Unidentified gall mite

13a Upper leaf pair of shoot tip substantially undeveloped, erect, ± rolled together with the margins, curled. Petiole and leaf blade base markedly stunted, thickened and discoloured with several midge larvae in between. Soon shrivelling after departure of larva, e.g. G. segetum, tetrahit: Macrolabis sp.

13b Stem below inflorescence, also midrib, shortened, spongy, swollen, sometimes severely distorted, ± reddened. Galeopsis spp.: Ditylenchus dipsaci

14a Shoot axis usually terminally infected, stunted and distorted close to infestation site, inserted leaves variously curled and rolled. Galeopsis spp.: Philaenus spumarius

14b Three of the aphid species recorded previously also occasionally colonise the young shoot tips, the axis of which remains ± undeveloped, resulting in a ± nest-like clustering of distorted and paler leaves. Galeopsis spp.:

a Cryptomyzus galeopsidis subsp. galeopsidis

b Aphis frangulae subsp. beccabungae

c Aphis gossypii

gallers on Pinus

pub 23.iii.2020

Dichotomous table for gallers on Pinus

by Hans Roskam

1a On above-ground parts => 2

1b Roots of seedlings distinctly shortened, with nodular swellings or proliferations. Bark loose around central cylinder with eelworms in between. Parts above ground shrivelled. P. sylvestris: Unidentified root eelworm

2a On shoots or needles => 4

2b On cones => 3

3a Cones shrivelled, bent, stone hard, not opening, always ± acuminate. Irregular tunnels in scale bases; already dropping 8–10. Usually a single, sometimes 2 or 3 larvae. P. cembra, mugo, nigra, pinea, ponderosa, sylvestris: Pissodes validirostris

3b One-sided curved cones, with resin and frass, containing caterpillars. P. nigra, sylvestris: Cydia conicolana

3c Cone scales inside with elongated wart-like swellings. P. sylvestris, strobus: Kaltenbachiola strobi

3d Blister-like swellings on cone scales caused by spermogonia and aecia of rust. P. densiflora, sylvestris, virginiana: Cronartium quercuum

4a On shoot axial parts => 7

4b On needles => 5

5a Needles swollen at base => 6

5b Needles accumulated terminally on young shoots, development stunted, undulately curved or bent screw-like, not thickened. Pinus spp.: Pineus pini

5c Fungus. Both surfaces of needles with cylindrical projections of aecia, 1–5 mm long; spermogonia present. Pinus spp.: Coleosporium tussilaginis

6a Infestation of developing needles. They are severely shortened, their bases ± fused over a length of 2–3 mm, swollen, sometimes slightly twisted, erect and in autumn often golden-yellow. Larvae 2–3.5 mm long, orange-reddish to red, lacking sternal spatula; one or occasionally more larvae per gall. P. halepensis, mugo & subsp. rotundata, nigra, pinaster, pinea, sylvestris: Thecodiplosis brachyntera

= The pine needle buckling gall midge Contarinia baeri causes needles constricted at base and bend like walking sticks, dropping already in autumn

6b Needles remain linked, with yellowish, bulging thickenings, shortened, often ± twisted screw-like; a basal, expanded, bag-like widening containing a whitish to yellow beetle larva. P. sylvestris, uncinata: Brachonyx pineti

7a On stems, older branches or several year old twig => 10

7b On young shoots => 8

8a Galls caused by animals => 9

8b Bark of young twigs usually with narrow erupting pads on one side 10–30 mm long, with dusting of reddish-yellow spores. Shoots stunted at infestation site, continuing to grow on healthy side and so deflected. Terminal parts become erect subsequently making s-shaped curves. Pinus spp.: Melampsora populnea

9a Axis gaping over a length of about 20–30 mm, ± swollen. Primary bark and resin channels enlarged; secondary bark and wood slightly thickened. Pith cavity containing a large-headed, yellow- to yellow-brown caterpillar. Open gall often covered with resin mass on one side. P. banksiana, mugo, pinaster, sylvestris: Retinia resinella

= The gall midge Cecidomyia sarae has been recorded from resin lumps and wounds caused by R. resinella

= Two more gall midges, Cecidomyia pini and C. harrisi, occur also in resin exudates of shoots and green cones of P. pinaster, sylvestris without causing malformations. The species differ in larval characters, viz., spatula, dorsal lobes on abdomen

9b Caterpillars at first in lower pith of young, stunted shoot tips or buds, sometimes thickened on one side, crooked, later on dehiscing. Pinus spp.: Rhyacionia buoliana

= the larvae of several leafrollers live as borers in the buds and young shoots of pine trees, causing rather similar damage symptoms. Of the more rare species the biology is not known in sufficient detail to enable discrimination, but at least the equally frequent Pseudococcyx turionella should be considered as a potential causer. The larva of Rh. buoliana bores a tunnel from the base of a shoot upwards; this causes the shoot to bend (“posthorn shoot”); when this happens to the main shoot this causes a permanent bend in the trunk later. The larva of P. turionella empties a terminal bud, then burrows for a short distance downwards. Lateral buds around the dead terminal bud then get the opportunity to develop into shoots, causing a splaying or forking of the branch

9c Young shoot curved and distorted, growth stunted. P. peuce, sibirica, strobus, sylvestris: Pineus strobi

10a Stems or branches with nodular swellings or with proliferations, excessive branching or witches’ brooms => 13

10b Bark of thinner plant parts usually swollen on all sides, several cm long, later on with many, pale yellow blister-shaped swellings, about pea-size, from which yellow fungus spores escape after eruption => 11

11a On P. mugo, sylvestris and other pines with paired needles => 12

11b On P. strobus and other 5-needle whorled pines: Cronartium ribicola

12a Fungus host alternating. Aecia conspicuous, often many on 10–20 cm long swellings of twigs. Galls at thickest part sometimes with twice the normal diameter. Fewer on stems and young trees than on branches. Cronartium flaccidum

= Blister-like swellings on bark caused by spermogonia and aecia of rust. P. sylvestris: Cronartium quercuum

12b Fungus not host alternating; it develops haploid aecia in its sori, which are only able to infect Pinus. Galls as for pine blister rust. P.sylvestris: Endocronartium pini

13a Malformation of complete shoots or witches’ brooms => 16

13b Nodule-, tuber- or spindle-shaped malformations => 14

14a Rotund to oblong nodules or tumours => 15

14b Spindle- or club-shaped swelling of a branch or stem part: Viscum album subsp. austriacum

15a Smaller, up to about 15 (30) mm globular, cancer-like compact nodules on the thicker twigs of P. cembra. “Twig tuberculosis”. Cause unknown – ? bacterium

15b On younger, thin twigs oblong to rotund, at first glabrous, later on rugose, up to 20 (25) mm broad and 10 mm high, yellow-brown swellings, permeated by many channels, originating from proliferation of the bark and persisting for several years. P. mugo, nigra, strobus, sylvestris: Trisetacus pini

16a Slightly extended malformation of complete shoots; proliferation and accumulation of buds. “Budding witches’ broom”. P. cembra, mugo: Trisetacus cembrae

16b Usually voluminous, loose, expanded or smaller, almost globular compact witches’ brooms, especially on P. sylvestris, as well as on some cultivated foreign pines: Inducer unknown

gallers on Pastinaca

pub 22.iii.2020

Dichotomous table for gallers on Pastinaca

by Hans Roskam

1a On parts above ground => 3

1b On root or root collar => 2

2a Roots with nodular swellings. P. sativa: Meloidogyne hapla

2b Conspicuous proliferations on root collar. “Root cancer”. P. sativa: Agrobacterium tumefaciens

3a On all parts of flowering or fruiting inflorescence => 14

3b On vegetative parts => 4

4a Malformations mainly on the leaf blades of leaflets or leaf sheaths => 8

4b Galls on stems, petioles and midrib or mainly on venation of leaflets => 5

5a Causers live inside galls => 7

5b Causers on galls or fruiting on surface => 6

6a Midrib of rosette leaves of young plants with smaller, or more expanded, sometimes arched, bulging, sometimes reddened swellings, which contain one or several scale insects in depressions on surface. P. sativa: Planchonia arabidis

6b Conspicuous yellow swellings, soon bearing spermogonia and aecia. P. sativa: Uromyces lineolatus

7a pindle-shaped, compact, glabrous, bulging swellings on axial parts. P. sativa: Protomyces macrosporus

7b Petiole often severely stunted, especially spongy at base. Surface wrinkled, sometimes with longitudinal fissures. Infected venation of leaflets ± swollen especially at base of leaf blade, leaf blade curled. P. sativa: Ditylenchus dipsaci

8a Malformation of leaflet leaf blade caused by midge larvae, aphids or cercopids => 9

8b Sheaths of younger leaves ± strongly swollen, slightly thickened. Buds ± stunted. Larvae red. P. sativa: Unidentified gall midge

9a The disfigured leaf blades show slight folds open on upper side or are mainly deflected downwards, caused by aphids or cercopids => 10

9b Depending on stage of development during infestation, the halves of leaflets remain partially or completely folded upwards; main venation ± swollen. Containing several white larvae. P. sativa: Macrolabis heraclei

10a Malformations caused by aphids => 11

10b Leaf midrib shortened and curved, the accumulated leaflets deflected, curled, locally deep green. P. sativa: Philaenus spumarius

10c Leaf, or several leaves, folded, curled or crumpled, often yellowish, with leaf blade and veins ± thickened; containing flattened froth-covered nymphs. P. sativa: Trioza apicalis

11a Aphids ± green => 12

11b Aphids black; leaflets deflected. Leaf blade weakly swollen. P. sativa: Aphis fabae

12a Leaflets rolled inwards and downwards => 13

12b Tips of leaflets strongly curled, at first with small folds, open on upperside; aphids inhabiting the weakly swollen leaf sheaths later on and disfiguring young side shoots as well as umbels. P. sativa: Hyadaphis foeniculi

13a Leaflets deflected downwards, partially curled. Aphid 1.8–2.8 mm long, yellowish-green. Siphunculi slightly club-shaped and pale, almost three times as long as the same coloured cauda, which has at its base a finger-like appendage. P. sativa: Cavariella pastinacae

13b Similar minor malformations. P. sativa: Cavariella theobaldi

13c Leaflets rolled downwards. Aphid lacking tail-like appendage at base of cauda. P. sativa: Semiaphis pastinacae

14a On fruits => 19

14b On inflorescences or flowers => 15

15a Malformation mainly of complete inflorescence or inflorescence stalk => 16

15b Flowers swollen, unopened; inflorescence often ball-like. White larvae inside flower. P. sativa: Contarinia sp.

16a Galls locally on stalks of inflorescence => 18

16b Variable malformations of complete inflorescence => 17

17a Caused by aphids. P. sativa: Hyadaphis foeniculi

17b Ball-like malformations of inflorescence associated with greening on P. sativa, further growth of flowers and stronger pubescence caused by an unidentified gall mite

17c Strong clustering of inflorescence caused by maggots. P. sativa: Cause unknown – ? dipteran

18a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. P. sativa: Lasioptera carophila

18b Stalk of partial umbel with club-like swelling at base. P. sativa: Unidentified gall midge

19a Fruit slightly swollen; seed aborted; containing a yellow, jumping larva. P. sativa: Contarinia pastinacae

19b Fruit strongly inflated, bladder-like; galls ± reddened, protruding above the umbel; 1 (3) orange-red larvae. P. sativa: Kiefferia pericarpiicola

gallers on Daucus

pub 21.iii.2020

Dichotomous table for gallers on Daucus

by Hans Roskam

1a On above-ground parts => 3

1b On root or root collar => 2

2a Side roots with nodular swellings, a few mm long, partially bearing adventitious roots. D. carota, sativus: Meloidogyne hapla

= A host-specific cyst eelworm, Heterodera carotae with lemon-shaped white or brown cysts on Daucus has been recorded

= Small solid swellings, often curved or twisted, at the tips of side roots, either the needle eelworm Longidorus sp. or dagger eelworm Xiphinema sp. Both are important vectors of viruses

2b The ± green root head thickened, torn open, later on dark-brown. Stalks of leaf tuft spongy, swollen at base, pale. Stem sometimes twisted and undulate with ± equally distributed, rugose pale-green, bulges on surface. D. carota: Ditylenchus dipsaci

3a On inflorescences, flowers and fruits => 13

3b On leaves and stems => 4

4a Large parts of leaves and often several whole leaves curled => 7

4b Leaves or stems with locally wart- or bulge-shaped swellings. Fungus galls => 5

5a Galls remain closed, compact => 6

5b Bulges on petioles, -midrib or on the tips of leaf blades, elongate spindle- to irregular cushion-shaped, ± yellowish to reddish, bearing aecia and spermogonia. D. carota & subsp. maximus, muricatus: Uromyces lineolatus

6a Galls smaller than 1 mm, wart-shaped, inside a ± golden-yellow translucent fungus containing nutritive cells. D. carota: Synchytrium aureum

6b Bulges compact, vitreous, pale green, glabrous, spindle-shaped, only a few mm or up to 15 mm long, depending on infected organ. Many spores close to vascular bundle. D. carota: Protomyces macrosporus

7a Various malformations caused by aphids; usually not species-specific => 9

7b Malformations caused by psyllids or cercopids => 8

8a Leaf midrib and side stems curved, deflected, forming a loose nest of ± curled leaflets. Usually only a few leaves disfigured. D. carota & subsp. sativus: Philaenus spumarius

8b Leaf tip downwardly deflected, upwardly ± swollen, tuberculate, not discoloured. Froth-covered nymphs usually on many strongly curled and stunted leaves. D. carota & subsp. sativus: Trioza apicalis

9a phids green in various gradations => 10

9b Aphids black. Leaf blades weakly curled and deflected. D. carota & subsp. sativus: Aphis fabae

10a Siphunculi distinctly longer than cauda => 11

10b Siphunculi very short on pale green, slightly powdered aphid. Rosette leaves usually strongly curled and densely converging, nest-like, sometimes partially reddened. D. carota & subsp. maximus + sativus: Semiaphis dauci

11a Siphunculi and cauda dark. Antennae as long as half the body length or longer => 12

11b Siphunculi and cauda in wingless aphids pale green translucent. Antennae shorter than half the body length. Aphid pale green, wax absent, distinguished by a finger-shaped tubercle above the cauda. Malformation of leaf much looser than in previous species; slightly discoloured. D. carota & subspp. maximus + sativus: Cavariella aegopodii

12a Aphid up to 2 mm long, yellowish- or greenish-white, posterior with black transverse ligatures. Plant severely stunted, partially with basally inserted severely disfigured inflorescences over all parts. Leaves strongly curled. D. carota & subsp. sativus: Dysaphis crataegi

12b Aphid about 2 mm long, greenish, often blackish-brown. Antennae exceeding the middle of body, but sometimes only a third of body length. Siphunculi distinctly club-shaped, black, about as long as the dark cauda. Usually on ± curled to the stem attached leaves as well as on inflorescence. D. carota & subsp. sativus: Hyadaphis passerinii

13a Complete or partial malformation of inflorescence => 14

13b Fruits swollen, bladder-like, protruding above the umbel. Wall thickened, usually glabrous, the outside often violet-coloured. Containing 1 (‒ 3) orange-red larvae. D. carota & subsp sativus: Kiefferia pericarpiicola

= From similar fruit galls on several umbellifers has been reared Amerapha gracilis, an inquiline of Kiefferia. Another, very rare, inquiline is Trotteria umbelliferarum.

14a Malformations involving many parts of inflorescence => 15

14b Centre of stalk of (partial) umbel swollen, club-shaped to globular. Galls single or multi-chambered; wall tough, covered with whitish-grey mycelium inside. Each chamber contains a red larva. D. carota & subsp. sativus: Lasioptera carophila

15a Inflorescence disfigured by aphids in a very irregular manner. Stalks of partial umbels ± stunted; flowers stunted; developed petals sometimes ± greened or reddened D. carota & subspp. maximus + sativus: Semiaphis dauci

15b Inflorescence usually less stunted; flowers leafy, partially developing new umbels. D. carota & subsp. sativus: Aceria carvi

gallers on Beta

pub 20.iii.2020

Dichotomous table for gallers on Beta

by Hans Roskam

1a On parts above ground of young plants or on leaves => 8

1b On roots or on beet => 2

= The occurrence of Rhodococcus fascians has been recorded on sugar beet. This bacterium causes the formation of “leafy galls”.

2a On beet => 4

2b On side roots => 3

3a Roots often with many nodular, barrel- or spindle-shaped swellings, usually not exceeding 3–4 mm long, sometimes joining and usually developing side roots. Causer inside gall. B. vulgaris: Meloidogyne hapla

3b All parts of plant severely disfigured. Development of roots stunted, their tips pale yellowish-white, thickened and ± crooked. B. vulgaris: Paralongidorus maximus

3c Similar swellings on root tips. B. vulgaris: Pratylenchus pratensis

3d Roots from the outside not or only slightly swollen; inside with giant cells. Females rupturing from rind, temporarily attached to the root with whitish, later on brown, about poppy seed-size, lemon-shaped egg capsules. Beet corpus usually remaining thin, often densely covered with side roots, so called “hunger roots”. Plant disfigured. B. vulgaris: Heterodera schachtii

4a Root body with ± conspicuous proliferations => 5

4b Young beet gall-like thickened, usually densely provided with adventitious roots. Contains a single larva. B. vulgaris: Bothynoderes affinis

5a Proliferations only rarely exceeding 10 mm => 7

5b Swellings in full-grown condition at least partially much larger than 10 mm => 6

6a Proliferations succulent, with uniform tissue, laterally attached to the upper part of the beet, of variable size ranging from hazelnut to child head; surface glabrous, rarely partitioned into smaller, 4–10 mm thick, usually rotund, deep compartmented single protuberances. Older galls ± browned. B. vulgaris: Agrobacterium tumefaciens

6b Smaller or more expanded, bean-, rarely also fist-sized proliferations, sometimes basally ± constricted, cancer-like, with cavities inside. At first ± orange-coloured, later on browned and with cracked surface. Usually on upper part of beet, sometimes apically elongated. “Beet cancer”. On B. vulgaris: Physoderma leproides

7a Upper part of sometimes many-headed beet body with scab- to cancer-like, cracked parts, which show ± concentric rings in cross-section; skin often detached; underlying tissue spongy, swollen, contains eelworms. B. vulgaris: Ditylenchus dipsaci

= In many aspects a similar, very variable infestation pattern is caused by the proteobacterium Actinomyces scabies; the proliferations usually develop in girdle-shaped arrangements of parasite-free, soon browned, dead, uniform cell complexes which are not true galls. The apically neighbouring area is often depressed and locally replenished with scabby remains of tissue.

7b Up to 10 mm high and about 10–30 mm broad, cracked surface, single or sometimes joined into groups mainly on upper beet part. B. vulgaris: Xanthomonas beticola

8a On larger leaves without distinct involvement of venation => 9

8b Axial parts of shoot, as well as stalks, midrib and lower parts of ± stunted juvenile- or rosette leaves stunted and spongy, swollen. Galls very variable in position and size, pale green, ± wrinkled on surface. B. vulgaris: Ditylenchus dipsaci

9a Malformations caused by fungi which fruit at surface => 14

9b Malformations caused by animals or fungi which fruit inside the gall => 10

10a Leaf blade curled or rolled by animal causers => 11

10b Leaves of young plants, especially basal part of leaf blade, often with many rotund or oblong glabrous galls, pad- or bulge-like, at surface. Leaf blades often stunted, narrowed, pale green, also the margins ± curled. Galls soon decaying. B. vulgaris: Physoderma leproides

11a Leaf blade curls caused by aphids, plant bugs or thrips => 12

11b Leaf blade usually obliquely folded downwards, also over the tip, ± nest-like or with strong, loose rolling. Strongly curled and deep green close to the froth-covered nymph on the underside. B. vulgaris: Philaenus spumarius

12a Malformations caused by aphids => 13

12b Petiole and leaf venation curved upwards, thickened and brittle; leaf blades strongly curled; inner rosette leaves if strongly infected often ± clustered-like head of lettuce. Caused by the virus Savoia betae and transmitted by the bug Parapiesma quadratum

13a Aphids black; often in large colonies on leaf underside. Leaf blades of basal- or stem leaves bent downwards and curled to a great extent. B. vulgaris: Aphis fabae

13b Aphid green. Leaf blade primarily slightly curled. B. vulgaris: Myzus persicae

14a Young leaves stunted, often shorter stalked; several in centre of rosette diseased, ± fleshy thickened, brittle; leaf margin rolled downwards and strongly curled, on underside soon covered with a woolly, dirty violet down of forked conidiophores. B. vulgaris: Peronospora farinosa

14b Leaf blades with rotund, slightly depressed yellowish pads on upper side, bulging on underside, bearing pale yellow aecia on underside, and honey-yellow spermogonia on upper side. Sori on veins or stalks often oblong spindle-shaped. B. vulgaris: Uromyces beticola

14c On various above ground, ± swollen parts of Beta species may occur the often densely grouped, whitish spermogonia and aecia of Puccinia isiacae

gallers on Capsella

pub 18.iii.2020

Dichotomous table for gallers on Capsella

by Hans Roskam

1a On parts above ground => 5

1b On root collar or on roots => 2

2a On roots => 3

2b Root collar with rotund, 5–7 mm long, succulent, one-chambered gall. Containing a single larva. C. bursa-pastoris: Ceutorhynchus assimilis

3a Outside of roots hardly changed or with small, ± nodular swellings => 4

3b Conspicuous, succulent, spindle-shaped to expanded barrel-shaped, compact swellings of variable size on main- and side roots. C. bursa-pastoris: Plasmodiophora brassicae

4a Side roots with small, nodule- or spindle-shaped swellings. C. bursa-pastoris: Meloidogyne hapla

4b Outside of roots not noticeably changed; giant cells inside; temporarily with at first white, later on partially browned lemon-shaped cysts, about poppy seed size. C. bursa-pastoris: Heterodera cruciferae and/or H. schachtii

5a Galls on various parts caused by fungi sporulating at surface => 18

5b Malformations caused by animals => 6

6a Malformation of ± extensive parts caused by aphids or spittlebugs => 10

6b Galls caused by other parasites => 7

7a On stems or leaf midrib => 8

7b Phyllanthy, flowers greened or leafy; infestation encroaching also on vegetative parts. Stalk of inflorescence stunted; leaves stunted, ± rolled inwards and twisted. All diseased parts densely pubescent, hairs branched and 3–4 times longer than the normal ones. C. bursa-pastoris: Aceria drabae

7c Swollen flower bud, preventing development of fruits; each attacked flower bud with 1‒3 larvae; pupation in soil, more generations. Capsella bursa-pastoris: Gephyraulus capsellae

7d Young siliques slightly disfigured. Contain several (1) 3 (6) white larvae. C. bursa-pastoris: Dasineura napi

= The gall midge Contarinia nasturtii has been reported from on C. bursa-pastoris.

8a Inducers inside the galls => 9

8b Stem spindle-shaped to irregularly bulging; rind with rotund-oval, sometimes rimmed depressions containing a froth-covered nymph of the polyphagous inducer. C. bursa-pastoris: Planchonia arabidis

9a Spindle-shaped glabrous galls, 10–40 mm long swellings or oblong-oval, flattened, compact, at first succulent, also deep green inside, on petioles and leaf veins. Containing a single, curved larva. C. bursa-pastoris: Ceutorhynchus chalybaeus

9b Stems of young plants severely stunted and spongy thickened; leaves stunted; especially basal parts swollen; infestation of older plants results in ± expanded, local, sometimes strongly curved swellings on stems and leaves. Gall always pale green, brittle, ± wrinkled at surface. C. bursa-pastoris: Ditylenchus dipsaci

10a Malformations caused by aphids => 11

10b Inflorescence stunted, flowers of sometimes one-sided curved midrib clustered, ± stunted. With a froth-covered nymph. C. bursa-pastoris: Philaenus spumarius

11a Malformations of various shape and expansion; atypical for this causer. Aphid green => 12

11b Shoot tips ± stunted; leaves, and flowers clustered; leaf blades deflected, slightly curled. Flowers disfigured, ± greened. Aphids black. C. bursa-pastoris: Aphis fabae and/or Aphis fabae subsp. evonymi

12a Malformations usually restricted to some parts terminally on shoots or on leaves => 13

12b Infected young plants with severely stunted shoots, leaves rolled inwards and curled; plant often completely disfigured. Axis of inflorescence and flower peduncles shortened, ± curved. Flower parts stunted and disfigured, ± discoloured, also greened or violet; siliques disfigured, bent. Aphid 1.5–2 mm, grey-green to grey-yellowish, antennae half the body length, siphunculi yellow, cauda oblong, pale greenish. C. bursa-pastoris: Lipaphis erysimi

13a Aphid not covered with wax powder => 14

13b Aphid 2–2.5 mm long, yellowish–green, with two longitudinal rows of small cross stripes, densely white powdered C. bursa-pastoris: Brevicoryne brassicae

14a Aphid yellow to green => 15

14b Aphid dark green, up to 2 mm long, antennae half the body length. Siphunculi black, cauda oblong, pale green to yellowish-white. C. bursa-pastoris: Aphis gossypii

15a Aphid yellow to greenish-yellow or pale green => 16

15b Aphid green; siphunculi black, cauda oblong, brown. C. bursa-pastoris: Aphis gossypii subsp. capsellae

16a Cauda of aphid oblong => 17

16b Cauda short, broad and rounded. Aphid hardly 2 mm long, greenish to yellowish; mainly on basal leaves on slightly rolled leaves. C. bursa-pastoris: Brachycaudus cardui subsp. lateralis

17a Antennae of the about 2–3 mm long aphid longer than the mainly yellowish-green to straw-coloured body, darker green at the insertion of siphunculi; these yellow to orange-coloured, with blackish tip. Leaves weakly rolled downwards or curved and slightly arched. C. bursa-pastoris: Aulacorthum solani

17b Antennae of the about 1–1.5 mm long, yellowish to pale green aphid surpassing the anterior half of the body, siphunculi and cauda same colour as body. Inflorescence stunted, bearing more densely clustered flowers. Leaves ± downwards deflected, sometimes bulging. C. bursa-pastoris: Aphis nasturtii

18a Bulge-like, at first closed, glossy, porcelain-like, after rupturing mealy dusting sori of variable size on all green parts. Often causing diverse swellings and distortions. Infestation of flowers results in often conspicuous malformations of ovaries. C. bursa-pastoris: Albugo candida

18b Stem and also axis of inflorescence usually with expanded, conspicuous, often distorted swellings, soon covered with a down of branched conidiophores. Flowers of diseased inflorescences severely stunted. Leaves of axillary shoots if infected early, ± spoon-like arched, thickened, brittle, pale green; with a dense down of conidiophores on underside. C. bursa-pastoris: Hyaloperonospora parasitica

18c Leaf with hard gregarious pustules, less than 0.5 mm across; contain fungi. C. bursa-pastoris: Synchytrium aureum

gallers on Poa

pub 17.iii.2020

Dichotomous table for gallers on Poa

incl. Ochlopoa

by Hans Roskam

1a On above-ground parts => 3

1b On roots => 2

2a Roots with several curved swellings, about 0.5-6 mm long, crooked or half screw-shaped. Ochlopoa annua, P. pratensis, trivialis: Subanguina radicicola

2b Poppy seed size, white to brown cysts, on outside of roots. Poa spp.: Heterodera avenae

3a Galls on inflorescences or their parts => 19

3b Malformations on vegetative parts => 4

3c Whitish, at surface yellowish or brownish patches, which envelope a large area of the upper part of stem, of which further development is stunted. Node of stem rarely swollen, encircled by fungus stroma, yellowish when mature; several nodes may be affected; flowering stunted; stroma contains narrow asci and filamentous spores. P. nemoralis, pratensis, stiriaca, trivialis: Epichloë typhina

4a Malformations on leaves or localised galls on culms => 6

4b Whole plant disfigured => 5

5a Plant withered all parts especially at base ± spongy, thickened. Ochlopoa annua, Poa trivialis: Ditylenchus dipsaci

5b Plant, especially culm, severely stunted; panicle bleached. Ochlopoa annua: Unidentified dipteran

6a Galls on culm => 10

6b Malformations on leaf blades and sheath => 7

7a Expanded malformations => 8

7b Leaf blade at base with oval or elongated bulge-shaped, usually dark violet swellings several mm long; occasionally occurring on leaf sheaths. P. nemoralis, palustris, pratensis: Anguina sp.

8a Leaf blades, partially also sheaths, with several long, parallel bleached stripes of smut, later on with dusting of spores. Fungus exceptionally also on panicle => 9

8b Leaf blade spirally rolled or twisted. P. nemoralis: Inducer unknown

9a Spores 1–2 (3) enveloped by a tight layer of sterile auxiliary cells. Poa palustris: Urocystis-poae-palustris

9b Spores similar, on other Poa spp., Ochlopoa annua: Urocystis poae

9c Spores single, without sterile envelope. Poa spp.: Ustilago striiformis species complex

10a Galls bulge-like or spindle- to club-shaped, glabrous or grooved => 12

10b Galls occupied with many rootlets, up to 10 mm long => 11

11a Stem in the middle or upper part of the culm above a node locally weakly swollen, with many, at first whitish, then pale brown rootlets, in longitudinal direction at either side of furrow, ± appressed to culm, protruding from leaf sheath. Larvae white, between the flattened shoot axis and leaf sheath. P. alpina, cenisia, nemoralis, pratensis, trivialis: Mayetiola graminis

11b Similar galls with development of closely crowded adventitious rootlets mostly on above-ground or subterranean nodes on culm; rootlets however not separated by longitudinal furrow, but irregularly growing in a tangled mass. P. nemoralis: Mayetiola radicifica

12a Less or more distinct spindle-shaped swellings on culm; containing larvae => 16

12b Larvae on culm underneath the often somewhat inflated leaf sheath => 13

13a Larvae in distinct depressions of culm, usually situated above the upper node => 15

13b Shoot axis weakly swollen above the second or third node => 14

14a The basal part of the stem, above the 2nd or 3rd node, is more or less swollen. Between the leaf sheath and the stem live here a variable number of white larvae, each in an oval shallow depression of the stem. Pupation within the gall, in a puparium. Larval spatula present, hastiformous. P. nemoralis, occasionally P. pratensis: Mayetiola joannisi

14b The basal part of the stem is more or less swollen. Larval spatula absent. Furthermore, see Mayetiola joannisi. P. pratensis: Mayetiola schoberi

15a Culm usually above the last node with elongated, one-sided, black-walled depression; containing a single larva. P. pratensis: Hybolasioptera fasciata

15b Culm above the last node with one or several slender, saddle-shaped rimmed depressions. Each containing a brick red larva. P. palustris, pratensis: Haplodiplosis marginata

16a Galls on P. palustris, bulbosa => 18

16b On P. nemoralis => 17

17a Grain-like swellings protruding from the sheaths, spindle-shaped, up to 5 mm long; at first pale green, then brownish, longitudinally grooved. Containing a single white larva: Tetramesa poae

17b Culm distinctly shortened; slightly spindle-shaped thickened above a node below the not spreading sheath; panicle remains covered by sheath. Containing a single larva: Tetramesa sp.

18a On P. palustris; weak, discoloured swelling on the shoot axis above the 3rd, 4th or 5th node: Tetramesa sp.

18b On P. alpina, bulbosa. Swelling up to 18 mm long, 2 mm broad above the first node below the panicle, protruding from the leaf sheath on one side. Tetramesa sp.

19a Malformations of spikelets => 21

19b Galls emerge from ovary => 20

19c Several larvae develop in inflorescences. P. pratensis: Contarinia floricola

= Ditto, mainly P. trivialis: Sitodiplosis cambriensis

20a Ovaries slender, bottle-shaped, enlarged, usually discoloured violet. Ochlopoa annua, Poa alpina, nemoralis, palustris, pratensis: Anguina agrostis

20b Similar galls; glumes sometimes conspicuously elongated. P. alpina, pratensis: Unknown eelworm

20c Infected ears and panicles appear normal. Since the larvae inside the flowers feed on the flowering parts they prevent seed formation. The result is wrinkled seed or sterile ears. P. pratensis: Dasineura poae

21a Spikelets leaf-like, not transformed into bulbils. Flowers thickened at base and ± reddened. P. bulbosa: ? Anguina sp.

21b Spikelets variously disfigured, often withering prematurely, with symptoms of bleaching. Poa spp.: Aceria tenuis and/or Aceria cornuta

gallers on Dianthus

pub 16.iii.2020

Dichotomous table for gallers on Dianthus

by Hans Roskam

1a On parts above ground => 2

1b Roots with small, ± spindle-shaped swellings which bear side roots. D. barbatus, caryophyllus: Meloidogyne hapla

= The cyst developing eelworms Heterodera schachtii and H. trifolii have been recorded on carnations

1c “Leafy gall” on root collar. D. barbatus, caryophyllus: Rhodococcus fascians

2a On flower buds and flowers => 9

2b On vegetative plant parts => 3

3a Malformations of shoot tips or locally defined swellings on leaves or stems => 6

3b Malformation of several plant organs => 4

4a Malformations caused by eelworms or mites => 5

4b Stem conspicuously stunted, leaves accumulated and strongly rolled downwards by activities of usually brown aphids. D. arenarius, barbatus, caryophyllus, deltoides, x lorberi, plumarius: Myzus certus

5a Complete plant disfigured; shoots shortened, leaves ± accumulated and discoloured. Leaf rosette enlarged. Organs not distinctly swollen. D. deltoides: Aceria dianthi

5b Shoots ± shortened, thickened, leaf blades clustered, in narrow-leafed species often partially broadened, swollen, especially at base, spongy, pale, undulate or wrinkled. On young single shoots rosette- or pineapple- tuft-like accumulated. “Pineapple disease”. Dianthus spp.: Ditylenchus dipsaci

6a Galls on stems or leaves => 7

6b Side shoots stunted; upper pair of leaves and the following lower pair shortened, converging and swollen. Containing a single yellowish larva. D. deltoides: Unidentified gall midge

7a The inducer is enclosed by the gall => 8

7b Yellowish pads on leaf blades countersunk on upperside, protruding on underside; on more narrow organs ± elongate bulges, bearing compact telia. Dianthus spp.: Puccinia arenariae

8a Stem distinctly shortened, slightly swollen. Galls glabrous or rough-walled. Leaves clustered, distorted and ± thickened. Containing a single larva in a large cavity. D. arenarius, carthusianorum, lusitanus, sylvestris: Caryocolum schleichi

8b Stem with swellings ± expanded, on one or on all sides, in the latter case accompanied by distortions, pale, wrinkled, spongy; similar swellings also on leaves penetrating from main venation into the leaf blade. Dianthus spp.: Ditylenchus dipsaci

9a Flowers conspicuously disfigured => 10

9b Flowers outwardly not conspicuously disfigured. Malformation usually limited to the temporarily swollen anthers, soon filled with a violet-tinged spore mass. Dianthus spp.: Microbotryum violaceum species complex

10a The swollen flower buds remain closed and are hardened. D. carthusianorum: Dasineura dianthi

10b Flower buds transformed into an often conspicuously swollen, ± globular to cone-shaped structure. Receptacle and adjacent organs ± temporarily swollen, later on filled with pale brown balls consisting of coarse-granular spores. Dianthus spp.: Thecaphora saponariae species complex

gallers on Cerastium

pub 15.iii.2020

Dichotomous table for gallers on Cerastium

by Hans Roskam

1a On inflorescences, flowers or fruits => 16

1b On vegetative organs => 2

2a Plant completely or largely etiolated. Internodes elongated and lanky; leaf blades narrowed and pale green; with expanded sori of fungus on undersides => 15

2b Malformations otherwise => 3

3a Galls at tip of shoots => 8

3b Malformations of lower parts or leaves with locally defined gall => 4

4a Galls mainly on stems => 7

4b Galls wart- or pad-shaped, mainly on leaves => 5

5a Many galls, hardly 1 mm long, multicellular, ± hemispherical, usually on underside of basal leaves, also on stems; sometimes ± coalescing ridge- or crust-like => 6

5b Leaf blades with rotund, usually circularly arranged, sometimes slightly arched sori on underside of leaf veins. Petiole or stem with more densely arranged pads on oblong-oval bulges, about 3–6 mm long, compact, often yellow margined, weak, sometimes curved. Sori usually compact, bearing brown telia. Cerastium spp.: Puccinia arenariae

= Puccinia hysteriiformis has also been reported from Cerastium. This rust has black telia

6a Small pearl-like warts, with central, golden-yellow translucent nutritive cells. C. fontanum subsp. vulgare: Synchytrium aureum

6b Small warts greenish, multicellular, later on usually yellow-red or brown. C. glomeratum: Synchytrium stellariae

7a Stem with localised swellings. C. semidecandrum: Unidentified gall midge

7b Stem swollen and spongy from base over several internodes; adjacent leaves stunted, the basal parts often galled similarly. Infestation of older plants often results in ± expanded, curved swellings of stem. Galls always pale green, with ± rugose surface. Cerastium spp.: Ditylenchus dipsaci

8a Galls on shoot tips. Midge- or fungus galls => 13

8b Malformations expanded over ± substantial parts of terminal parts of shoot => 9

9a Galls lacking conspicuous pubescence => 10

9b Leaves clustered on shortened shoot tip, ± adpressed to the stem, abnormally pubescent. Sometimes branching excessively. C. arvense, diffusum, fontanum & subsp. vulgare, glomeratum, sylvaticum: Aceria cerastii

10a Several leaf pairs enlarged, keel- or spoon-like, curved, on shortened shoot axis clustered; galls rotund to oblong-oval, tuft- or almost cone-shaped => 12

10b Leaves with several disfigured, not clustered cone-like => 11

11a Upper part of stem locally severely stunted, sometimes curved, leaves accumulated; variously converging, nest-like ± curled and deep green. Cerastium spp.: Philaenus spumarius

11b Many leaves at the end of weakly stunted shoots deflected; ± curled. Cerastium spp.: Myzus certus

12a Gall frail, oblong-oval to spindle-shaped; up to about 20 mm long. Cerastium spp.: Trioza cerastii

12b Tuft-like malformations of shoot tips. C. fontanum & subsp. vulgare, glomeratum, moesiacum: Dasineura cerastii

12c Galls similar, often paler, yellowish, more rotund or egg-shaped; at first with green, white powdered aphids, about 2 mm long on the inner side of leaves. Aphid free-living later on the terminal shoot parts. Cerastium spp.: Brachycolus cerastii

13a Upper leaf pair folded together, containing a single or several midge larvae => 14

13b hoot tip markedly stunted. Leaves bushy, clustered together, ± disfigured, pale, rudiments of flowers, if present, ± largely atrophied; transforming the whole tip into a ± closed gall; pale red-brown spore masses develop in its tissue. C. arvense: Thecaphora alsinearum

14a Terminal pair of leaves enlarged, thickened, bulging. Larva red or orange. C. alpinum, arvense, fontanum subsp. vulgare, glomeratum, grandiflorum: Dasineura lotharingiae

14b Terminal pair of leaves folded together, remaining small; containing a single larva. C. arvense: Unidentified gall midge

15a Leaves, also stem parts, as well as exceptionally developed inflorescence stems and calyx leaves with many, scattered, small orange-yellow uredinia. Cerastium spp.: Melampsorella caryophyllacearum

15b Systemic diseased shoots growing erect, etiolated. Leaves pale green, development stunted, sometimes appearing slightly thickened, covered on underside with branched conidiophores. Rudiments of inflorescences, if present, stunted in all their parts. Flower buds ± globularly swollen, unopened, loosely covered externally with conidiophores. Fungus present during whole vegetative period, mainly in spring and autumn. Cerastium spp.: Peronospora sp.

16a On inflorescences or flowers => 17

16b Capsule weakly swollen. Larvae orange-coloured. C. fontanum subsp. vulgare, pumilum, semidecandrum. Dasineura fructum

17a Inflorescence ± disfigured; flowers greened or leafy Axis shortened; flowers ± leafy; stamens and ovaries crumpled or sometimes transformed into a ± rotund ball of leafy organs. Cerastium spp.: Trioza cerastii

17b Axis of inflorescence stunted; flower buds or fruits globularly swollen, unopened => 18

18a Malformations caused by fungi => 19

18b Globular swollen bud, contains a single red midge larva. C. arvense, fontanum subsp. vulgare, glomeratum, pumilum, semidecandrum: Dasineura lotharingiae

18c Fruit swollen, also the petiole is thickened; containing a weevil larva. C. fontanum subsp. vulgare: Sibinia subtriangulifera

19a Flower buds or flowers usually distinctly stalked => 20

19b Flower buds with very short, strongly swollen stalk, only slightly protruding from the often tuft-like disfigured shoot tip, stunted early and swollen; pale red-brown spore masses inside the swollen tissue. C. arvense: Thecaphora alsinearum

20a Inflorescence unchanged and flowers outwardly only slightly changed. Ovaries slightly disfigured. Seed rudiments, also -stalks and ridges at first slightly swollen, soon containing brownish-violet spore masses, dusting when capsule opens. Cerastium spp.: Microbotryum duriaeanum

20b Flower buds on ± shortened stalks distinctly stunted and swollen, at surface soon covered with conidiophores; corresponding down usually simultaneously occurring on adjacent vegetative organs. Cerastium spp.: Peronospora sp.

gallers on Calamagrostis

pub 14.iii.2020

Dichotomous table for gallers on Calamagrostis

by Hans Roskam

1a On panicles or flowers => 14

1b On vegetative parts => 2

2a Leaves with long stripes of smut or similar fungus patches on culms; shoot ± etiolated, usually remaining sterile => 12

2b Malformations caused by animals => 3

3a On shoot tips or leaves => 9

3b On culms => 4

4a Inducers in depressions on the outside of the culm underneath the sheaths => 6

4b Swelling of the shoot axis. Culm contains larva => 5

5a Culm above the second or third node with weak swelling, with one or several chambers one above the other, each contains a single larva. C. arundinacea, canescens, epigeios: Tetramesa calamagrostidis

5b Swelling absent, several chambers one above the other. C. epigeios: Tetramesa eximia

5c Slight, weak spindle-shaped swelling above a node. C. canescens: Tetramesa sp.

6a Galls on C. canescens => 7

6b On C. epigeios. Culm underneath the sheath above a node often with weak, slightly rimmed depressions on all sides. Larva orange-yellow: Lasioptera calamagrostidis

= Between culm and leaf sheath also live the orange-red cecidomyiid larvae of Asynapta thuraui which do not induce malformations

7a Depressions not or only slightly swollen at margins => 8

7b Saddle-shaped, sometimes brown, depressions shouldered at the ends by nodular thickenings. Gall 10–12 mm long, solitary or up to 4 on culm arranged upon one another or screw-like. Leaf sheath gaping. C. canescens, epigeios: Mayetiola bimaculata

8a Depressions about 3–4 mm long, ± covered with a thin, brittle, glossy black skin. Larva orange-yellow or brick-red. C. canescens: Hybolasioptera fasciata

8b Galls lacking black cover. Larvae in a weak depression beneath the leaf sheath on higher internodes:

a Larval spatula bifid. C. canescens, epigeios: Lasioptera calamagrostidis

b Larval spatula with only one tooth. C. canescens, epigeios: Mayetiola bimaculata

c Larval spatula with only one tooth. C. canescens: Mayetiola culacera or Mayetiola bifida

9a On shoot tips => 11

9b On leaf sheaths or leaf blades => 10

10a Upper leaf swollen, bladder-like, discoloured. Aphid up to 2 mm long, slim, yellow to brownish-green. C. arundinacea, epigeios, villosa: Laingia psammae

10b Leaf sheaths more or less swollen. Inside the sheaths are pale-yellowish aphids 1.5–2.5 mm long, and covered with wax powder. C. canescens, purpurea: Diuraphis calamagrostis

10c Leaf blades, mainly at base, often with several yellowish-green, later on reddish to dark violet, spindle-shaped rough swellings, smaller or up to 10 (15) mm long, slender cylindrical, often more prominent on underside. C. arundinacea, canescens, villosa: Subanguina graminophila

10d As inducer of similar, rotund-oval, up to 8 mm long and 2 mm broad galls on C. canadensis, epigeios has been suspected: Anguina graminis

11a Tip of shoot tuft-shaped, up to 35 mm long and 5 mm thick. Outer leaves with ± curled leaf blades, the inner ones lacking leaf blades; sheaths with their margins firmly appressed. Containing one to many white larvae with one-toothed spatula. C. canescens, epigeios, villosa: Mayetiola lanceolatae

11b Tip of shoot especially in underground shoots with shortened axis. Leaf sheaths widened and thickened. Leaves stunted, yellowish, often only ± scale-like. C. canescens: Unidentified chloropid

12a Spores solitary => 13

12b Spores in black balls with 1–4 (6), enveloped by many sterile cells. Long stripes of smut on leaf blades. C arundinacea, epigeios, neglecta, villosa: Urocystis calamagrostidis

13a Leaves with black patches of smut. Spores thick-walled, glabrous; 4–7 x 3–6 µm large. Patches mainly on culms, underneath sheaths. C. epigeios: Tranzscheliella hypodytes

13b Spore wall spiny or warty. Spores in the middle about (9) 14–16 (20) µm across. Patches on leaves, more rarely on sheaths. Closely related fungi, distinguished by their spore walls and sizes:

a Spore wall irregularly spiny; the appendages running into a discontinuous reticulate pattern at base. C. arundinacea, epigeios: Ustilago scrobiculata

b Spore wall with low rotund warts, up to 0.5 µm high, distinctly separated. C. canescens, lapponica, purpurea, stricta, villosa: Ustilago striiformis

c Spore wall with higher, conical warts about 1 µm high. C. canescens, epigeios, lapponica, purpurea, purpurea subsp. phragmitoides, stricta, villosa:
Ustilago calamagrostidis

13c Leaves with long stripes of smut. Uredinia mostly on upperside leaf, orange brown, with many capitate paraphyses. Telia on both sides, black, long covered by the epidermis; spores on a short pedicel, two-celled, top cell with the apical wall thickened. C. arundinacea, canescens, epigeios, pseudophragmites, varia, villosa: Puccinia pygmaea

13d Similar stripes of chlorotic tissue. C. epigeios: Puccinia striiformis

14a Complete panicle disfigured; flowers if weakly infected ± greened, if strongly infected often largely aborted, glumes markedly shortened, irregularly twisted and rolled; eventually bleached. C. arundinacea, canescens, epigeios, neglecta, purpurea incl. subsp. phragmitoides: Aceria tenuis

14b lower primordia with galls, containing many eelworms. C. ? canadensis, lapponica, Calamagrostis sp.: Anguina agrostis

gallers on Arabis

pub 13.iii.2020

Dichotomous table for gallers on Arabis

by Hans Roskam

A gallers on Arabis glabra (= Turritis glabra): see special key below

B gallers on other Arabis species => 1

1a On parts above ground => 3

1b On roots or root collar => 2

2a Roots with conspicuous, mostly all-sided, spindle-shaped to cylindrical, succulent compact swellings, up to 15 mm long, 8 mm broad. Inside the galls are many cells containing dense masses of minute spores. “Clubroot”. Arabis spp.: Plasmodiophora brassicae

= Two cyst-forming eelworms occur on Arabis species, viz., Heterodera schachtii and H. cruciferae

2b Root collar with one to several rotund succulent, one-chambered galls, up to 7 mm long, with a curved larva inside. A. alpina subsp. caucasica: Ceutorhynchus assimilis

3a On flowers or fruits => 16

3b On vegetative parts => 4

4a Malformations caused by fungi fruiting at surface => 13

4b Malformations by animal causers => 5

5a Malformations on terminal parts of shoots or on leaves => 6

5b Stem bulging especially close to ground, variously distorted, outside with single or several rimmed depressions containing a scale insect. A. collina, rosea: Planchonia arabidis

6a Malformations on single to many already ± developed leaves => 7

6b Developing shoots already stunted in the rosettes. Leaves not unfolding, shortened, spoon-shaped, with ± thickened veins; clustered, bud-like; gall more densely pubescent, up to about 6 mm long; occasionally enclosed by some spreading leaves, only thickened at base and ± abnormally pubescent or etiolated ± tuft-like side shoots. Larvae many, flesh-coloured to red. Mainly on A. albida, alpina subsp. caucasica, more rare on A. aubretioides, hirsuta, stelleri: Dasineura alpestris

7a Leaves folded, bulging or rolled at margin => 10

7b Leaves disfigured differently => 8

8a Leaves conspicuously clustered => 9

8b Rosette leaves stunted; stalk and basal part of midrib spongy, swollen, pale green: Ditylenchus dipsaci

9a Main- and lateral shoots terminally stunted, densely occupied by small leaves, transformed into branched, almost witches’ broom-like tufts. A. procurrens: Unidentified aphid

9b Leaves at base of thickened stem disfigured, less pubescent, enveloping the stem in a globular, whorled cluster. A. ciliata, hirsuta: Inducer unidentified

10a Leaf blades at margin rolled or with localised swellings; mite galls => 11

10b Leaf blades of many inner rosette leaves ± pod-like folded upwards, slightly thickened, brittle, pale green. Inside the silique are many white powdered, grey-green aphids. A. hirsuta, parviflora: Lipaphis rossi

= Similar malformations on Arabis have also been attributed to Brevicoryne brassicae

10c On upper sides of leaves, causing lateral parts of leaves to fold upwards towards midrib. A. alpina: Pseudobrevicoryne leclanti

11a Rolls or bulge-like swellings with abnormal pubescence => 12

11b Leaves partially yellowed; rolled at margin. A. pumila: Unidentified gall mite

12a Rosette leaves abnormal pubescent, usually curved upwards at margin. A. alpina: Unidentified gall mite

12b Leaves curled, ± rolled inwards or with irregular, sometimes violet-red swellings; infected areas more pubescent. A. hirsuta: Aceria drabae

13a Malformations caused by fungi with white fruiting bodies => 14

13b Shoot with ± distinct etiolations, sterile. Stem leaves thickened, disfigured, pale green, stunted; usually large areas on underside with small, scattered, red-brown telia. Arabis spp.: Puccinia thlaspeos

13c Rotund- to oblong, often coalescing, dark brown sori on the upper part of inflorescence, flower peduncles and siliques. A. pumila: Puccinia paulii

14a Sori consisting of loose, ± mealy down of branched conidiophores => 15

14b Sori dense, pad- or bulge-like, at first glossy, porcelain-like, dusty after rupturing; conidia in rows. On the underside of leaf blades rotund, on upperside sometimes violet-margined, rarely to distinctly swollen; on stem parts ± elongated spindle-shaped, often strongly swollen and curved. Arabis spp.: Albugo candida

15a Stem sometimes infected over large area, swollen, sometimes strongly bent. Early infected leaves smaller, pale green, margins ± spoon-like arched because of deflection downwards; cover dispersed on underside. Partial infestation usually does not induce galls. A. alpina, alpina subsp. caucasica: Hyaloperonospora arabidis-alpinae

15b Similar, but usually weaker malformations on stems and leaves. Arabis spp.: Peronospora arabidis-hirsutae

16a On inflorescences or flowers => 17

16b Siliques a little shortened and only slightly swollen. Ovaries containing yellowish to grey-violet spore masses. A. alpina, ciliata, hirsuta: Thecaphora thlaspeos

17a Malformations caused by animal inducers => 18

17b Malformations by fungi. Rachis of inflorescence stunted over large parts, ± swollen and bent, bearing many white-glossy bulges. Flowers conspicuously disfigured; calyx and corolla strongly enlarged; calyx leaves stunted or stronger developed and greened; anthers ± reduced, the filaments sometimes pillar-shaped swollen, greened. Arabis spp.: Albugo candida

18a Inflorescence largely or completely stunted. Flowers densely, bushy clustered, largely disfigured. Calyx and corolla, as well as stamens often irregularly swollen, elongated and greened; anthers hardly developed; ovaries ± puffed up (turgid), sometimes leafy transformations. A. hirsuta, parviflora: Lipaphis rossi

18b Terminal flowers of raceme clustered, all parts disfigured; organs greened, partially ± leafy, more densely pubescent. A. hirsuta: Aceria drabae

Gallers on Arabis glabra

1a Malformations on parts above ground => 3

1b Succulent galls on roots => 2

2a Malformations of very variable size, a few mm up to several cm, spindle-shaped to elongate-cylindrical, branched only exceptionally. Inside the nutritive cells are masses of minute, not conspicuously discoloured spores. “Clubroot”: Plasmodiophora brassicae

2b Almost similar, but lead-grey discoloured, sometimes on the side roots coralloid branched galls developing blackish spore balls: Urocystis coralloides

3a Localised or expanded malformations, usually on vegetative parts, caused by fungi which fruit at the gall surface => 5

3b Malformations caused by aphids which may encroach into the flowering shoots => 4

4a Usually only minor curl or folds on the leaf blades of several leaves, caused by mealy powdered aphids: Brevicoryne brassicae

4b Malformations very variable on usually many clustered leaves, at the end of main- and side shoots. Leaf blades deflected on all sides, ± curled. Infected inflorescence rachis severely stunted, densely crowded; some parts of older ones conspicuously enlarged, disfigured and greened: Lipaphis turritella

5a Plant diseased in often expanded parts. Young shoots with shortened and thickened internodes. Leaves pale green, leaf blade thickened, ± bladder-like, swollen and deflected at the margins. With extensive down of branched conidiophores on undersides. Infected rachis of inflorescence stunted to slightly swollen, bearing clustered, atrophied flower buds or flowers. Peronospora arabidis-glabrae

5b Leaf blades on underside with locally restricted, rotund, slightly swollen pads, at first white porcelain-like, then rupturing and with mealy dusting. Similar ± spindle-shaped bulges on leaf veins, stem parts and inflorescence rachis. Diseased flowers usually only with conspicuously enlarged, bulging calyx and ovaries. Corolla and stamens only sometimes enlarged and greened. Albugo candida

gallers on Fagus

pub 12.iii.2020

Dichotomous table for gallers on Fagus

by Hans Roskam

1a On stems or branches => 2

1b On buds or leaves => 6

2a Witches’ broom-like malformations on branches and twigs => 3

2b Smaller nodules or larger cancer-like proliferations in the bark of stems and branches => 4

3a Smaller witches’ broom, about 4–5 cm across. F. sylvatica: Inducer unidentified

3b More frequently much larger witches’ brooms occur on beech; again
Inducer unidentified

= Viscum album is doubtful on beech; all records involve confusion with witches’ brooms

4a Extensive cancer formations caused by fungi, predominantly on older stems. F. sylvatica: Neonectria ditissima and/or Neonectria coccinea

4b Lenticular or pock-shaped nodules in the bark of young shoots, which may secondarily partially develop into cancer-like formations => 5

5a Young, already woody stems with swellings, up to 3 mm thick, partially arranged in rows, up to more than 10 cm long, predominantly on the underside of lateral shoots. The bark tears open later on in a lateral direction, developing a loose succulent wound callus or also dries out ± soon. Similarly on branches and stems. F. sylvatica: Lachnus pallipes

5b On the bark of younger axial parts somewhat lenticular, shallow- to nodular swellings, which rupture the cork layer later on and cause cancer-like proliferations. F. sylvatica: Cryptococcus fagisuga

6a On leaves => 8

6b On buds => 7

7a Buds not opening, up to 30 mm long and 12 mm wide, or developing into a short, stunted, shoot. All new parts of the unfolding bud severely stunted. Leaves folded, like the usually undulate venation, densely covered with silver-grey hairs. F. sylvatica, x taurica: Acalitus stenaspis

7b Similar malformation; between the sometimes slightly thickened leaves, which remain small and folded upwards, several whitish to grey-yellow jumping, glossy larvae. F. sylvatica: Contarinia fagi

= Inquiline non jumping dull larvae in galls of Contarinia fagi: Macrolabis fagicola

8a Galls on the leaf blade, not exclusively on the margin => 9

8b Narrow and tight leaf roll, shorter than or often as long as leaf blade; with short, stiff, acuminate hairs inside. F. sylvatica, x taurica: Acalitus stenaspis

9a Galls of a distinctive shape, on or in the leaf blades => 15

9b Leaf folds, -curls or erinea of various kinds on the leaf blad => 10

10a Leaf curls or flat erinea => 12

10b Malformations associated with leaf folds => 11

11a Leaf blade with single or several, yellow- to reddish discoloured, ± pod-like, thickened, glabrous folds along a ridge-like downwardly protruding lateral vein. Usually initiated on the midrib, on small leaves extending to the margin. Containing 2–3 reddish larvae. F. sylvatica: Phegomyia fagicola

11b Hypertrophied, yellowish to reddish, downward folds of the leaf blade. Gall as well as inducer relatively unknown, larvae gregarious. F. sylvatica: Mikiola cristata

11c Whole leaf blade or apical segment remaining folded. Sites of infestation markedly pubescent, ± thickened and sometimes reddened; in case of weak infestation curled later on. F. sylvatica: Acalitus plicans

12a Erinea => 14

12b Curls => 13

13a Spool- to tube-shaped malformation on the deflected leaf underside caused by many bluish-white aphids, covered with woolly wax exudations; malformation variously discoloured and curled. F. orientalis, sylvatica: Phyllaphis fagi

13b Curl associated with additional curling and arching of stunted leaves. F. sylvatica: Acalitus plicans

14a Linear elongated erineum along the side veins; hairs short club-shaped. F. sylvatica, x taurica: Aceria nervisequa

14b Erinea not associated with the veins, almost exclusively on underside of leaf and on several segments (between lateral veins). F. sylvatica, x taurica: Aceria nervisequa

= In the modern literature no distinction is made between the erinea that strictly follow the veins, and the more or less rounded erinea that are independent of the leaf venation. In the older literature the latter is named Aceria maculifer; possibly also an inquiline of galls made by Aceria nervisequa

15a Glabrous galls of mostly constant shape in or on the leaf blade => 17

15b Heavily pubescent galls on the leaf upperside => 16

16a Gall slender, obtuse-cylindrical or barrel-shaped, leathery-woody, up to 3 (4) mm long, densely covered with brownish hairs. Containing a single white larva. F. orientalis, sylvatica: Hartigiola annulipes

16b Gall situated close to the midrib, rotund, on the underside flat disc-shaped, on the upper side ± globular, about 1 mm (up to 1.5 mm) large. With red-brown hairs at the tip, soon deflected, with their ends contacting the leaf, hence enveloping the gall. Narrow opening on the underside, containing a single larva. F. sylvatica: Unidentified gall midge

17a Galls pouch- to pustule-shaped or groove-like => 19

17b Galls acuminated, egg-shaped or blunt cylindrical, always on the venation, often in a corner between two main veins => 18

18a Galls slim cylindrical, up to 4 (5) mm long and 1.5 mm wide, tough-walled, initially pale green, brown later on; underside slightly arched. Containing a single larva. F. orientalis, sylvatica: Hartigiola annulipes

18b Galls alongside the venation, often on the midrib, acuminated, egg-shaped, pale green or often ± reddened; underside slightly arched, thick-walled woody, with large larval chamber. Larva white, solitary. F. orientalis, sylvatica, x taurica: Mikiola fagi

18c On F. orientalis, resembles the gall of Mikiola fagi, but has a blunt tip . Larva orange, solitary: Mikiola orientalis

19a Pustule- or groove-shaped galls, various locations on the leaf blade => 20

19b Slightly bumpy, ± discoloured protrusions in the vein axils on the midrib, rarely also on the main side veins, with hair tufts on the underside. F. sylvatica: Monochetus sulcatus

20a Rotund centrally non-umbicular galls, with nodular protrusions, often hardly 1 mm long, predominantly on the underside; usually surrounded by a yellowish to reddish, sometimes marginally more intensively discoloured border, up to 3 (4) mm wide, later yellowing. Containing a single white larva. F. sylvatica: Unidentified gall midge

20b Furthermore on leaves of developing spring- and lammas shoots on indefinite places single or several, inconspicuous arched parenchyma galls, about 1.5–2 mm wide, similarly on both leaf sides containing a single white larva. F. sylvatica: Hartigiola annulipes

20c Rotund, about 0.5 mm wide grooves on the leaf underside, corresponding, initially with hardly discoloured, later on anaemic protrusions on the upperside, soon surrounded by a yellowing, later on pale browning border, up to 3 mm wide. F. sylvatica: Unidentified gall midge

gallers on Leontodon

pub 10.iii.2020

Dichotomous table for gallers on Leontodon

incl. Scorzoneroides, Thrincia

by Hans Roskam

1a On above-ground parts => 2

1b Nodule-shaped swellings of roots. L. alpinus, hispidus incl. subsp. hastilis: Meloidogyne hapla

2a On capitula => 16

2b On vegetative parts => 3

3a On leaves => 6

3b On stems => 4

3c All parts of shoot with white crusty blisters, very variable in size; shoot often distorted; L. hispidus, saxatilis: Pustula obtusata

4a More or less spindle-shaped and massive swellings, occasionally coalescing => 5

4b Shoots usually with expanded, spongy, swollen, ± bent or twisted pale green, massive galls of various size and position. On various occasions, basal parts of the capitula may be incorporated in the gall formation. Also on other organs. L. hispidus incl. subsp. hastilis, incanus; Scorzoneroides autumnalis, pyrenaica: Ditylenchus dipsaci

5a Shoot with weak, one-sided, one-chambered swelling. L. taraxacoides subsp. taraxacoides: Unidentified leafminer

5b Spindle-shaped or lenticular, enclosed by a ridge, depressions on ± swollen leaflets. L. hispidus; Scorzoneroides autumnalis: Planchonia arabidis

6a Galls exclusively on the main- or lateral veins, sometimes secondarily extending into the leaf blade => 13

6b Gall formation on the leaf blade or leaf margin independent of the venation => 7

7a Malformation without extensive involvement of the leaf margin => 9

7b Leaf margin rolled => 8

8a Leaf margins rolled upwards to different degrees, glabrous or ± abnormally pubescent, curled and rugose; also with localised swellings. Scorzoneroides autumnalis: Aceria anthocoptes

8b Leaf blades usually with discoloured marginal roll, as well as several groove-like protrusions each with a flat, white-margined froth-covered nymph. L. alpinus, hispidus incl. subsp. hastilis: Trioza dispar

8c Malformations on the underside of variously curved, sometimes ± twisted leaves. L. alpinus, hispidus incl. subsp. hastilis; Scorzoneroides autumnalis: Craspedolepta flavipennis

9a Galls without conspicuous additional pubescence => 10

9b Leaf blade on the upper surface or on the margin with abnormal formation of reddened hairs or protrusions. Sometimes weak upward marginal roll. L. hirtus: Unidentified gall mite

10a Galls compact, lacking cavities, caused by internally fruiting fungi => 11

10b Rounded pustule on upperside of leaf, about 4 mm across, purple-edged; usually several present; each containing an orange larva which can be seen through the transparent epidermis. L. crispus, hispidus incl. subsp. hastilis; Scorzoneroides autumnalis: Cystiphora leontodontis

11a Galls on the leaf blade flat wart-like, about 1.5–4 mm long; alongside sometimes spindle-shaped bulges on the midribs. Spores developing terminally on an intercellular mycelium, many, predominantly outside the vascular bundle => 12

11b Isolated galls less than 1 mm long, curved wart-shaped, yellowish translucent, consisting of a central fungus cell inside a nutritive host cell surrounded by a number of likewise strongly enlarged auxiliary cells; often coalescing to a larger, conspicuously reddish-yellow crust. On the rosette leaves, also solitary or in ± ridge-like bulges on the stem base. L. alpinus, hispidus incl. subsp. hastilis; Scorzoneroides autumnalis: Synchytrium aureum

= A similar fungus, Synchytrium saxifragae induces galls which are smaller and inconspicuous.

12a Flat, rotund, initially whitish hyaline, later on almost dark brown bulges on the underside of leaf blades, reddish in heavy infestations; alongside occasionally spindle-shaped swellings on the underside of main veins. Spores dark brown, ± rotund-oval, developing terminally on the leaf blade outside the vascular bundle. L. hispidus incl. subsp. hastilis; Scorzoneroides autumnalis: Protomycopsis leontodontis

12b Leaf underside with rotund swellings, 1.5–3.0 mm across, rarely elongated, flat, partially black-brown; alongside variously spindle-shaped bulges, up to 5 mm long on the underside of the midrib. Galls and surroundings sometimes bright red coloured. Spores dark brown. Scorzoneroides montana, pseudotaraxaci: Protomycopsis arnoldii

13a Gall causers not recognizable from the outside => 15

13b Malformations bearing brown sori => 14

14a Sori in irregular configurations predominantly on often strongly deformed petioles or stems as well as on yellowish to violet discoloured patches up to 8 mm wide, in crust-shaped groups on the leaf blades, displaying on the upperside honey-yellow spermogonia and on both sides red- to chestnut brown uredinia. Scorzoneroides helvetica, pyrenaica: Puccinia mayorii-eugenei

14b Small, initially yellow, later reddish coloured oblong bulges, usually on the underside on the main veins of the rosette leaves. Leontodon spp.: Puccinia hieracii var. hieracii

15a Affected venation swollen; leaf blade at site of infection usually yellowish discoloured and conspicuously pervaded by irregular thickness, intensively reddened, galled veins. Leaf blade slightly undulate deformed, at the margin sometimes ± downward curved. Stronger swellings of the midrib rare. Spores develop close to the vascular bundle. Leontodon hispidus incl. subsp. hastilis: Protomyces kriegerianus

15b Elongated spindle-shaped, also converging, pale green, spongy swellings of petiole as well as on midrib and main veins, locally similarly extending into the ± curved leaf blades. L. alpinus, hispidus incl. subsp. hastilis, incanus, Scorzoneroides autumnalis, pyrenaica: Ditylenchus dipsaci

16a Capitula swollen and variously disfigured => 18

16b Malformations associated with greening of florets => 17

17a apitula deformed to a pale grey, woolly, rotund structure. Florets greened and abnormally haired. Scorzoneroides autumnalis: Cause unknown – ? gall mite

17b Flower parts greened to a varied extent; capitula disfigured, sometimes bearing smaller disfigured capitula. Scorzoneroides autumnalis: Unidentified gall mite

18a The inducers are in the receptacles of disfigured capitula => 19

18b Capitula swollen, remaining closed. Several white larvae on the receptacle between the ± stunted florets. L. hispidus; Scorzoneroides autumnalis: ? Macrolabis sp.

19a Receptacle of swollen and variously distorted capitula containing 1–3 white larvae or brown puparia. L. hispidus, saxatilis; Scorzoneroides autumnalis, helvetica: Tephritis leontodontis

19b In capitula of L. alpinus, hispidus incl. subsp. hastilis: Campiglossa misella

19c Capitula often together with neighbouring stalks often spongy, swollen and curved. Inside the compact galls are many eelworms: Ditylenchus dipsaci

gallers on Linaria

pub 9.iii.2020

Dichotomous table for gallers on Linaria

(incl. Cymbalaria muralis [= L. cymbalaria], Misopates)

by Hans Roskam

1a On parts above ground => 3

1b On subterranean parts => 2

2a Roots with small, nodular compact swellings. L. vulgaris: Meloidogyne hapla

2b Conspicuous, rotund galls, up to 4 mm long, succulent, one-chambered on root parts close to surface or on subterranean runners; often clustered and/or coalescing. Each chamber containing a single, pale-headed beetle larva. L. genistifolia, loeselii, odora, repens, vulgaris: Rhinusa linariae

= Inquiline in galls of R. linariae; larvae with brown-yellow head: Rhinusa collina

3a Flowers or fruits disfigured => 14

3b Malformation of vegetative parts => 4

4a Malformation of single leaves or of many organs terminally on shoots => 10

4b Galls on axial parts of shoot => 5

5a Causers are inside galls => 6

5b Shoot axis locally ± bulging, with rimmed depressions which contain a single froth-covered nymph. Linaria spp.: Planchonia arabidis

6a Locally defined galls contain causer in chambers or feeding tunnels => 7

6b Mycelium penetrates the whole plant and disfigures the shortened stems which are quill-like over large areas. The black sori, also occurring in leaf bases, are lead-grey translucent before rupturing. L. genistifolia, repens, vulgaris: Melanotaenium cingens

6c Spongy swelling of basal organs. L. arvensis: Ditylenchus dipsaci

7a Distinct rotund or oblong swellings => 8

7b Axis with weak, inconspicuous, spindle-shaped swelling caused by several tunneling larvae. L. genistifolia, repens, vulgaris: Mecinus janthinus

7c Ditto. L. genistifolia, vulgaris: Mecinus heydeni

7d Inconspicuous unilocular swelling at the root collar. L. saxatilis, simplex, supina, thymifolia: Mecinus dorsalis

7e Weak swelling in the lower part of a young shoot; the section above the gall becomes stunted. In the gall several larvae. L. genistifolia subsp. dalmatica: Mecinus peterharrisi

7f On L. purpurea; gall undescribed. Mecinus raphaelis

8a Gall wall fleshy => 9

8b In the oblong, multi-chambered swelling the single chambers have tough, leathery-woody walls. L. vulgaris: ? Aulacidea sp.

9a Up to 8 mm long, one-chambered oblong-cylindrical to pointed barrel-shaped galls develop solitarily or are joined into oblong, multichambered, usually conspicuous tuberculate hunchbacked swellings, up to 30 mm long and 12 mm broad. L. heterophylla, purpurea, simplex, vulgaris: Rhinusa pilosa

= Inquiline in galls of Rhinusa pilosa: Rhinusa collina

9b Multichambered swelling, 20–30 mm long, usually weakly hunchbacked. L. vulgaris, ? genistifolia: Rhinusa thapsicola

9c Oblong, spindle-shaped swelling, 15 x 1.7 mm, usually discoloured violet. L. purpurea, reflexa, repens, supina; Misopates orontium: Mecinus barbarus

9d On similar galls. L. genistifolia incl. subsp. dalmatica, repens, vulgaris; Misopates orontium: Rhinusa neta

= Breeding of Mecinus and Rhinusa species mentioned in leads 7 and 9 is necessary for reliable identification

10a Galls mainly on leaves => 13

10b Malformations involve stem parts => 11

11a Malformation, with involvement of axial parts of expanded shoot parts => 12

11b The distinctly shortened and broadened, thickened terminal leaves are transformed into an oblong, often bud-like tuft containing ivory-white midge larvae. L. genistifolia, purpurea, vulgaris: Diodaulus linariae

12a Complete plant disfigured, excessive branching, young flowers variously greened. L. vulgaris: Cause unknown – ? gall mite

12b Shoot axis stunted, sometimes one-sided ± bent, inserted leaves deflected, locally deep green, ± accumulated, nest-like. Linaria spp.: Philaenus spumarius

12c Leaves curled. Cymbalaria muralis: Aphis gossypii

13a On basal leaves, usually on underside, many warts, less than 1 mm long, multi-cellular, yellow translucent, also on basal stem parts; sometimes joined into crusts or ridges. L. vulgaris: Synchytrium aureum

13b Many leaves on shoot tip ± stunted, wrinkled, the curly margin deflected or ± rolled; leaf blade wrinkled, irregularly curved and twisted, occasionally excessive budding or branching. L. vulgaris: Unidentified gall mite

14a Malformation mainly of ovary or capsule => 16

14b Malformation mainly of several flower parts => 15

15a Flower buds swollen, all parts ± disfigured and unfolding buds greened. Larvae ivory-white. L. genistifolia, purpurea, vulgaris: Diodaulus linariae

15b Gall-like malformation on flowers and inflorescences. L. arvensis: Unidentified thrips

15c Flowers are swollen; with a weevil larva or pupa inside. L. genistifolia: Rhinusa florum

16a Ovary swollen, often already in unopened, swollen flower, or disfigured after flowering, compact, often with irregular proliferations; caused by whitish beetle larvae. L. genistifolia incl. subsp. dalmatica, repens, vulgaris; Misopates orontium: Rhinusa neta

16b On L. genistifolia incl. subsp. dalmatica, repens, vulgaris live in similar, less conspicuous malformations the brown- to dark-brown headed larvae of Rhinusa antirrhini

16c On L. vulgaris, in similar galls lives also Rhinusa tetra and/or Rhinusa collina

16d Capsule galls, two or more times as large as healthy capsules. Containing a single larva. L. vulgaris, ? genistifolia: Rhinusa thapsicola

16e Similar malformations caused by a yellow-green caterpillar with angular transverse stripes on body segments. L. vulgaris: Eupithecia linariata

gallers on Lamium

pub 8.iii.2020

Dichotomous table for gallers on Lamium

(incl. Galeobdolon, Lamiastrum)

by Hans Roskam

1a On plant parts above ground => 6

1b On subterranean organs => 2

2a On subterranean stem parts or buds => 4

2b On roots => 3

3a Nodular swellings. Lamium spp.: Meloidogyne hapla

3b Root body normal in external appearance, inside with giant cells; temporarily bearing poppy-seed size white, partially brown cysts. Lamium spp.: Heterodera spp.

3c Rounded pea-size gall on shoot tip or on stolon. L. album, maculatum, purpureum: Dasineura lamiicola

4a Galls predominantly on subterranean buds; caused by gall midges => 5

4b Shoot axis close to or just below ground with ± expanded, strongly swollen galls, up to 10 mm broad, containing black masses of spores. L. album: Melanotaenium jaapii

5a erminal scale-like pairs of leaves of buds of subterranean runners folded together, joined and transformed into a rotund or oblong gall, up to 5 (7) mm long, densely covered with long, white-felt-like hairs. Containing several white larvae. L. galeobdolon: Dasineura strumosa

5b Similar, but larger and occasionally more strongly pubescent galls on subterranean buds, less on side- and end buds of stem. Larvae white, jumping. L. maculatum: Contarinia lamiicola

6a Galls only on flowers => 19

6b Malformation of vegetative organs => 7

7a Malformation of leaves, partially with involvement of shoot => 8

7b Oblong swelling on upper parts of shoot axis; organs inserted above the gall ± shrivelling. Pith containing many larvae. L. album: Thamnurgus kaltenbachii

8a Malformations of leaf, with involvement of expanded parts of terminal shoots => 12

8b Galls only of shoot tips or basal organs => 9

9a Galls of shoot tips => 10

9b Complete plant stunted. The basal stem parts are especially ± markedly shortened, spongy, swollen and pale green. Leaves inserted at infestation site with their stalks and main veins similarly galled. L. amplexicaule, purpureum: Ditylenchus dipsaci

10a Terminal pair of leaves with ± sessile, reduced, erect leaf blades; with several midge larvae between the soon necrotic malformations => 11

10b The terminal, little developed, sometimes ± joined pairs of leaves are transformed into a bud-like, oblong, whitish to yellowish, sometimes ± pubescent shoot tip gall. Containing several white larvae. L. album, flexuosum, maculatum, orvala, purpureum: Macrolabis lamii

11a Shoot tip with erect pairs of leaves with margins rolled inwards and upwards into an elongated, pale-green gall. Containing several white larvae. L. galeobdolon: Contarinia galeobdolontis

11b Between upward folded, curled and thickened leaves occur white larvae. L. maculatum: Contarinia lamii

12a Malformations of undefined shape => 13

12b Corniculate protrusions, up to about 6–8 mm long, tough-walled, pubescent at tip; usually many on leaf upperside. L. album: Dasineura corniculata

13a Malformations caused by aphids => 15

13b Malformations caused by other animals => 14

14a As causer of sometimes ± distinctly swollen leaves, which bend upwards if strongly infected and soon discolour yellowish, then brownish, on L. album, purpureum, has been recorded the free-living gall mite: Aceria lamii

14b Terminal internodes often ± stunted on one side, resulting in ± clustered leaves. Leaf blades at margin ± deflected, curled and dark green close to infestation. Lamium spp.: Philaenus spumarius

15a Malformations by aphids in all gradations of green are so variable that assignment is only possible according to characters of aphids => 16

15b Similar malformations caused by black aphids. Lamium spp.: Unidentified aphid

16a Aphids yellowish-green to dark-green, rotund-oval. Antennae shorter than body. Siphunculi very dark. Surface of wingless forms dull => 18

15b Aphid translucent greenish-white, dorsally with green longitudinal stripes, oblong-oval, glossy. Antennae longer than body. Siphunculi colourless => 17

17a Siphunculi twice as long as cauda. Migrates to Ribes species as primary hosts. L. album, amplexicaule, galeobdolon, maculatum, purpureum: Cryptomyzus galeopsidis

17b Siphunculi as long as cauda or slightly longer. Host alternation absent. Males wingless. L. album, occasionally on L. amplexicaule, maculatum, purpureum: Cryptomyzus alboapicalis

18a Siphunculi as long as cauda. Body yellowish-green. Lamium spp.: Aphis frangulae subsp. beccabungae

18b Siphunculi distinctly longer than cauda. Body dark-green. Host-alternation absent. L. album, amplexicaule, galeobdolon, maculatum, purpureum: Aphis lamiorum

19a Flower buds ± swollen, unopened, up to 7 mm across. Larvae white. L. maculatum: Dasineura lamii

19b Similar galls on L. album. Larvae white to grey. Unidentified gall midge

gallers on Cytisus

pub 7.iii.2020

Dichotomous table for gallers on Cytisus

by Hans Roskam

A Leaves 1- or 3-foliate, flowers in leafy racemes => Subgenus Sarothamnus

B Leaves 3-foliate; flowers in leafless racemes => Subgenus Cytisus

Subgenus Cytisus, incl. Cytisophyllum, Lembotropis

1a On parts above ground => 2

1b Roots with rotund, cylindrical, also hand-shaped or coralloid branched, usually laterally inserted nodules. Cytisus spp.: Rhizobium leguminosarum

2a On shoot axis or leaves => 4

2b On shoot tips or lateral buds => 3

3a Lateral buds developed into compact, ± half globular tufts of leaves; leaves stunted, rolled upwards, strongly pubescent. C. aetnensis, albus: Aceria genistae

3b Axillary bud transformed into an acuminate, densely pubescent egg-shaped gall (8 x 4 mm long) with large larval chamber. C. tridentatus: Asphondylia pterosparti

3c Rotund or egg-shaped, bud-like closed, greenish, abnormally pubescent galls on shoot tip or in leaf axils. Inner wall covered with fungus. Containing a single larva. Cytisus spp.: Asphondylia cytisi

4a Slightly bulging swellings on stems and leaves, soon covered with sori => 7

4b Malformations caused by animals => 5

5a Galls on shoot axis => 6

5b Leaflets rolled or folded upwards, pod-shaped. Larvae orange-red. C. supinus; Lembotropis nigricans: Wachtliella niebleri

5c Leaves and usually shoot tip disfigured. Leaf margin rolled upwards. Cytisophyllum sessilifolius; Lembotropis nigricans: Aceria cytisi and/or Aceria grandipennis

6a Bulges on young axial parts, bearing aecia. Only hypophyllous telia. Telia, light brown, 1 mm, in circles on yellowish swollen leaf spots. Teliospores smooth, apically thickened; pedicel hyaline, persistent. Cytisus spp.; Lembotropis nigricans: Uromyces pallidus

6b Malformations similar but aecia rare. Spermogonia and aecia hypophyllous, also on the stems. Telia dark brown; spores coarsely verrucose; top with a low hyaline papilla; pedicel hyaline, deciduous, short. Cytisus spp.; Lembotropis nigricans: Uromyces fulgens

Subgenus Sarothamnus

1a On parts above ground => 2

1b Root with many, laterally inserted globular, cylindrical or terminally hand-shaped to coralloid partitioned nodules. Sarothamnus spp.: Rhizobium leguminosarum

2a Galls on flowers and fruits => 15

2b Malformations on vegetative organs => 3

3a On buds, shoot tips or leaves => 9

3b On shoot axis => 4

4a Swellings longer than 5 mm => 7

4b Swellings smaller, sometimes ± coalescing => 5

5a Inducers inside galls => 6

5b Young stems often with many, rotund-oval, rimmed depressions containing the inducer. Sometimes coalescing and distorting the axis. Sarothamnus spp.: Chionaspis salicis

5c Sporadically has been observed: Viscum album

6a Up to 2 mm long, one-sided, often many swellings close to shoot tip, often situated below a bud and associated with a shortening of the axis. Containing a single orange-red larva. C. scoparius, striatus: Janetiella tuberculi

6b Galls 2–3 mm long, oval to spindle-shaped; terminally on main- and side shoots. Larvae sometimes occurring simultaneously in inconspicuous swellings on petioles and leaf veins. Containing orange-yellow larvae. C. grandiflorus, scoparius, striatus: Contarinia scoparii

6c Terminal swelling of twigs, usually one-sided, one-chambered with fleshy walls, 3.5 x 3.0 mm long. Containing a single red larva. C. patens, scoparius, striatus: Dasineura trotteri

7a Gall contains a larva with head capsule => 8

7b Larva lacking head capsule; at first whitish, later on greenish; solitary in one-sided, spindle-shaped swelling, 10–25 mm long and about 4 mm high, at first pale green, later on yellow-grey with exit hole provided swelling on thinner twigs. C. scoparius: Hexomyza sarothamni

7c One-sided stem gall, subcylindrical, up to 15 x 4 mm long, larval chamber oblong provided with exit hole. C. patens: Agromyza kiefferi

8a Root parts close to surface, also lower twigs up to about 25 cm above surface with rotund-oval swelling. The older larva bores a screw-like tunnel above the gall between bark and wood. Containing a single larva. C. scoparius: Agrilus cinctus

8b Expanded, 40–80 mm long, up to 5 mm high, multi-chambered swelling on 2- to 3-years old twigs. Containing many larvae. C. scoparius: Pirapion immune

8c Twig galls, sometimes very slight swelling. C. scoparius: Protopirapion atratulum

8d Twig galls. Minor rotund or spindle-shaped swelling, usually crazed on one side with central larval chamber. C. grandiflorus: Protopirapion kraatzii

9a Galls restricted to a malformation of the unopened axillary buds, or develop as localised swelling of petioles and veins => 12

9b More expanded, strongly pubescent malformations on ± unfolding lateral buds or curling of many leaves on shoot tips => 10

10a Malformations strongly pubescent => 11

10b Several leaves at the tip of young shoots rolled downwards. C. scoparius: Acyrthosiphon pisum subsp. spartii

10c Terminal bud. Gall egg-shaped (3–4 x 2.5–3 mm long), green, rather thick, fleshy wall made by the fused scales. In central larval chamber lives a single brick-red larva. C. patens: Janetiella maculata

11a Lateral buds ± swollen, with grey-felt-like pubescence, rotund, transformed into a cauliflower-like tuft, up to 15 mm long. Shoot axis succulent, thickened. Leaflets atrophied, abnormally pubescent, their margins bent upwards. Sarothamnus spp.: Aceria genistae

11b Side shoots swollen, clustered, tuft-like, shortened and lanky; ± discoloured and abnormally white pubescent. Leaves stunted, glabrous. C. scoparius:
Unidentified gall mite

11c Terminal internodes shortened and leaves inserted in tuft-like clusters. C. scoparius: Unidentified gall midge

12a Malformations of lateral buds => 13

12b Stalks of leaves or leaflets, and leaf veins often with inconspicuous, oblong-oval or spindle-shaped swellings, up to 2 mm long, one-chambered, yellowish. Containing a single orange-coloured larva. C. grandiflorus, scoparius, striatus: Contarinia scoparii

12c Leaflet folded upwards, transformed into a fleshy inflated pod, hooked behind, red-tinged. Containing several red larvae. C. scoparius: Dasineura vallisumbrosae

13a Galls glabrous => 14

13b Galls ± distinctly white pubescent; about 8–12 mm long; ± egg-shaped, with ± long acuminate distal extension. Inner wall with mycelium. Containing a single larva. C. scoparius: Asphondylia pilosa

14a Galls acuminate egg-shaped, ± short stalked, succulent, 7–10 (12) mm long, one-chambered; tip often oblique. Inner wall with mycelium. Contains a yolk-yellow larva. C. grandiflorus, scoparius: Asphondylia sarothamni

14b Galls ± tube-shaped, up to 10 mm long and 2–3 mm broad, one-chambered; tip opening, enveloped by 3–6, slightly diverging slender lobes, above the larva; inside with long, white, ± rigidly upwardly directed hairs. Containing a single orange-yellow or -reddish larva. C. eriocarpus, grandifloras, patens, scoparius, striatus welwitschi: Dasineura tubicoloides

15a Fruit galls => 19

15b Flowers ± swollen and unopened => 16

16a The gall inducing larvae occur in the cavity within the flower parts; head capsule absent; midge galls => 17

16b Flower ± pouch-like, swollen, unopened, soon drying. In the weakly or almost globularly swollen, stunted ovary a beetle larva develops. C. scoparius: Tychius parallelus

17a nner gall wall without mycelium => 18

17b Swollen bud remains unopened but sometimes displaying the yellowish-orange corolla parts. Inner wall of gall with dense, white-grey mycelium. Containing a yolk-yellow larva. C. scoparius: Asphondylia sarothamni

18a Flower buds swollen, often allowing the upwardly curved styles to protrude. Containing a pale red larva. C. scoparius: Jaapiella sarothamni

18b Flower bud weakly swollen, unopened or half opened. Later on blackening and drying. Larva white to yellowish, jumping. C. scoparius: Contarinia anthonoma

19a Malformations caused by gall midge larvae => 20

19b Pod ± stunted; with rotund-oval swelling, almost lenticular; sometimes laterally bent. Containing a single larva. C. scoparius: Tychius parallelus

20a Pod ± stunted; with rotund- to oblong oval swelling, 10–12 x 3–5 mm long, ± yellowish, usually situated in proximal part. Inner wall with grey-white mycelium. Containing a single yolk-yellow larva. C. scoparius: Asphondylia sarothamni

20b Pod developing almost normally; with several weak, yellowish tubercles, about 2 mm long. Contains several ivory-white, jumping larvae. C. scoparius: Contarinia pulchripes

gallers on Sisymbrium

pub 5.iii.2020

Dichotomous table for gallers on Sisymbrium

(incl. Murbeckiella)

by Hans Roskam

1a On parts above ground => 5

1b On roots or root collar => 2

2a Galls on roots => 3

2b Whitish, rotund, one-chambered swellings on root collar, up to about 6 mm long. sometimes with several and ± coalescing. Each chamber containing a single white larva. S. altissimum, austriacum, loeselii, officinale: Ceutorhynchus assimilis

3a Galls conspicuous, of very variable size, usually much larger than 5 mm => 4

3b Swellings nodular, or slender spindle-shaped, up to about 5 mm long and 3 mm broad. S. altissimum: Meloidogyne hapla

= The cyst forming eelworms Heterodera cruciferae and H. schachtii have also been recorded.

4a Galls on thinner roots slender-spindle-shaped, on thicker roots acuminated, oblong-oval to cylindrical; succulent. With masses of minute spores inside cells. “Clubroot”. Sisymbrium spp.: Plasmodiophora brassicae

4b Main- or lateral roots with ± pronounced, also twisted, many-chambered swelling. S. officinale, etc.: ? snout beetle

5a Malformation is limited to a single organ or its parts => 11

5b Malformations include the complete plant or large parts, including buds, and terminal or lateral vegetative or generative shoot => 6

6a Malformations caused by aphids, spittlebugs or fungi => 9

6b Malformations caused by larvae of gall midges => 7

7a Gall lacking conspicuous pubescence => 8

7b Large part of axis of plant stunted. Main- and side shoots severely stunted. Leaves reduced, clustered, ± depressed, together with disfigured flowers, transformed into a strongly pubescent, dense tuft-like gall. Containing many ivory-coloured larvae. S. altissimum, austriacum, loeselii, orientale: Dasineura bayeri

8a Organs densely clustered terminally on shoots or in leaf axils; swollen at base and transformed into a fleshy gall, which variously is overtopped by ± severely stunted to healthy organs. Leaves thickened and pale, especially at base. Infected flower buds turgid, ± unopened, with thickened, sometimes adnate stalks and swollen corolla and stamens. Already present siliques basally, like their stalks, swollen, ± stunted and distorted. Larvae white to pale yellow, jumping. Sisymbrium spp.: Contarinia nasturtii

8b Galls mostly similar, almost as variable as the previous species. Larvae white or yellow, non-jumping. S. irio, officinale, orientale, volgense: Dasineura sisymbrii

9a Malformations caused by animals => 10

9b Lateral shoots stunted, thickened, ± curved; often growing in opposite directions. The inserted organs stunted and disfigured. All parts soon covered with white down of branched conidiophores. S. altissimum, irio, loeselii, luteum, officinale, volgense: Hyaloperonospora sisymbrii-loeselii

10a Whole plant mostly stunted, compact and variously disfigured. Leaves ± curved, spoon-like, curled, often paler green, violet-tinged. Flower buds or flowers clustered, disfigured; similarly discoloured. S. altissimum, loeselii, officinale: Lipaphis erysimi

= Apparently the mealy cabbage aphid Brevicoryne brassicae occurs temporarily and sparsely on Sisymbrium. Galls induced by this species are not definitely known.

10b Young shoot axial parts locally stunted and slightly bent; the ± clustered leaves deflected, leaf blades curved and curled. Similar stunting and occasionally clusters of disfigured young inflorescences bearing flowers as well as fruits. Sisymbrium spp.: Philaenus spumarius

11a Galls on inflorescences or flowers => 21

11b Stem- or leaf galls => 12

12a On leaves => 17

12b On stems => 13

13a The inducers or their fructifications occur on the outside of galls => 15

13b Larvae inside galls => 14

14a Younger stems with spindle-shaped swelling, up to 20 mm long and about 4 mm thick. Containing a single beetle larva inside the green tissue. S. altissimum, officinale, orientale: Ceutorhynchus chalybaeus

14b Stem irregularly swollen over several cm length, often bent and ± stunted. The increased pith containing several beetle larvae. S. altissimum, officinale: Ceutorhynchus napi

15a Swelling covered with white fruiting bodies => 16

15b Irregular bulging swellings, which bear several small rimmed depressions. S. altissimum: Planchonia arabidis

16a Localised to expanded, one- or all-sided, ± curved swellings on stems of vegetative or flowering shoot. Inserted leaves stunted, bent over their length, pale green, thickened and brittle, inserted flowers ± atrophied in all their parts. Down loose, conidiophores branched. Sisymbrium spp.: Hyaloperonospora sisymbrii-loeselii

16b Similar, usually more conspicuous malformations with sori of variable size, spindle-shaped, at first glossy white, porcelain-like, later on ruptured and dusty. If on inflorescences, causing conspicuous malformation of flowers. Sisymbrium spp.: Albugo candida

17a Pad-, spindle- or bladder-shaped swellings caused by fungi => 20

17b Malformations caused by animals => 18

18a Galls on petioles or leaf veins => 19

18b Leaf tip rolled upwards at margin, irregularly thickened, abnormally haired. S. altissimum, loeselii. officinale, orientale: Aceria drabae

19a Spindle-shaped or acuminate oblong-oval swellings on petiole or midrib, about 10–15 mm long, ± flattened, also deep green inside. Containing a single beetle larva. S. altissimum, officinale, orientale: Ceutorhynchus chalybaeus

19b Leaf blade folded together to varied extent over the locally thickened midrib, at the base of the infestation swollen, pouch-like, ± discoloured; containing several white to pale yellow, jumping larvae. Sisymbrium spp.: Contarinia nasturtii

19c Small gall terminally on young plant, consisting of 4 or 5 disfigured leaves, succulent, pubescent. Containing several reddish larvae. Murbeckiella zanonii: Dasineura sisymbrii

20a White, at first glossy, porcelain-like, then rupturing and with white dusting, leaf blade rotund on underside, on veins and petioles forming ± spindle-shaped pads. Leaf blades of S. officinale deep violet-red close to the often ± discoloured sori. Albugo candida

20b Leaf blades locally slightly swollen and discoloured; completely infected leaves stunted, pale green, deflected at margin and venation especially distinctly thickened. On underside with white down of branched conidiophores. Sisymbrium spp.: Hyaloperonospora sisymbrii-loeselii

= Very similar is Peronospora sisymbrii-orientalis on S. orientale, which may facultatively induce similar gall-like malformations on its host.

21a Flower galls, usually at same time with malformations of inflorescence stalk => 22

21b Single flower swollen, unopened. Larvae white, non-jumping. S. altissimum: Gephyraulus raphanistri

21c Silique swollen, containing white midge larvae. S. loeselii: Dasineura rostratae

22a Flower buds or flowers disfigured, clustered at the tip of panicles => 23

22b Axial parts slightly changed or locally swollen, bearing single or several severely disfigured flowers. Calyx leaves hypertrophied, corolla leaves transformed into elongated green tongues, stamens ± leafy; ovary developing into an elongated, sometimes bent tube; on all parts often several ± rotund-oval, white sori of fungus. S. altissimum, officinale: Albugo candida

23a Several swollen and unopened flower buds in loose or dense sequences at the tip of ± stunted and swollen, terminal- or axillary racemes. Larvae white to pale yellow, jumping. Sisymbrium spp.: Contarinia nasturtii

23b Similar gall, contain non-jumping larvae. Sisymbrium spp.: Dasineura sisymbrii

23c Axis shortened; ± greened or leafy, bearing abnormally pubescent flowers. S. altissimum, loeselii. officinale, orientale: Aceria drabae

gallers on Hordeum

pub 4.iii.2020

Dichotomous table for gallers on Hordeum

by Hans Roskam

1a On above-ground parts => 4

1b On roots => 2

2a Galls are distinct swellings =>3

2b Roots outwardly not markedly galled, tissue of infected sites containing ‘giant cells’. Developing females erupting from the root bark, occupy it for a while like poppy-seed sized cysts, at first white, then yellowish, eventually brownish. On cultivated barley and close relatives. Hordeum spp.: Heterodera avenae

= Oblong expanded, weak root thickenings on barley predominantly at the tips caused by the partially free-living meadow eelworm Pratylenchus pratensis have been reported.

= From the second half of the summer apterae of the aphid Tetraneura ulmi live on the roots of various grasses, incl. Hordeum.

3a Roots often with many broad swellings, half screw-like curved spindle-shaped, 0.5–6 x 0.5–5 mm. Hordeum spp.: Subanguina radicicola

3b Galls slender spindle-shaped, not curved screw-like. H. vulgare: Meloidogyne hapla

= Furthermore there are records of the occurrence of other Meloidogyne species. The galls of these species are usually thicker and larger than those of M. hapla and never have lateral roots, which is characteristic for M. hapla.

4a On inflorescences or flowers => 12

4b On tips of younger or older shoots, on culms or leaves => 5

5a Malformations on shoot tips caused by dipteran maggots => 9

5b Malformations caused by aphids or eelworms => 6

5c Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. H. bulbosum, distichon: Puccinia striiformis

5d Infected stems at first developing quickly, later on stunted, often remaining sterile, extensively covered with brown-black patches with spores. H. secalinum: Tranzscheliella hypodytes

6a Malformations by aphids => 8

6b Malformations by eelworms => 7

7a Plant compact, especially thickened at base. Leaves curled, sometimes undulate at margin. H. vulgare: Ditylenchus dipsaci

7b Young leaves folded and rolled, the sheaths at base sometimes slightly thickened. Hordeum spp: Anguina tritici

8a Leaf sheath swollen and discoloured, leaf blade ± spirally rolled. Aphid 2.0–2.75 mm long, oblong, olive-green, reddish close to the short, slightly swollen siphunculi. H. distichon, murinum incl. subsp. leporinum, vulgare: Rhopalosiphum padi

8b Similar malformations: H. murinum, vulgare: Diuraphis noxia

8c Also as an inducer of gall-like malformations on shoots. H. murinum, vulgare: Sitobion avenae

9a Malformations caused by fly maggots, which are situated at the shoot tip; maggots with buccal hooks => 11

9b Malformations caused by midge larvae, which reside in galls on culms in developed plants or live between leaf sheaths in young plants. Larvae without buccal hooks, but with sternal spatula => 10

10a Culm underneath the slightly swollen leaf sheath usually below the final node with several rimmed depressions, ca. 10–12 mm long, elongated, saddle-shaped, at the ends. Each gall containing a bright red larva. H. vulgare: Haplodiplosis marginata

10b Shoots of excessively leaf-like young plants with slender onion-like swelling at base. Leaves initially more erect, darker green, shorter and broader than in healthy plants; central leaves yellowing later and dying off. Later in development, shoots on first and second node with weak swellings. Culm here buckling easily. Underneath the sheaths are several 3–5 mm long, whitish-greenish larvae or flax seed-like brown puparia. H. vulgare: Mayetiola hordei

= Mayetiola destructor is also found on barley, but is far less common than on wheat or rye.

11a Growth of young plants stunted; axis of shoot shortened; inner leaves yellowed, outer ones remaining green. H. murinum: Oscinella frit

11b Similar damage might also be caused on same host by: Delia coarctata

11c On young plants the shoot tip is shortened and sometimes slightly thickened, cigar-shaped. At the terminal bud is an oblong cavity containing a maggot or a brown-yellow puparium up to 7 (9) mm long, yellowish- to greenish-white, weakly flattened, parallel sided. H. distichon, murinum, vulgare: Chlorops pumilionis

12a Malformations predominantly in ovaries or fruits of single flowers, only rarely in other parts; galls caused by smut fungi or eelworms => 16

12b Malformation of axis of inflorescence, expanded parts of the inflorescence or many parts of several single flowers => 13

13a Expanded parts of ± stunted inflorescence greened or leaf-like. Mite galls => 15

13b Malformations mainly on axis of inflorescence => 14

14a On dwarfed plants the axis of the inflorescence, which is usually hidden in the leaf sheath, is largely atrophied and bent, stair-like. H. murinum, vulgare: tarsonemid mite

14b Developing plants remain shorter. Terminal leaves clustered, yellowish or also normally coloured, basally slightly curled, sometimes appearing broadened and thickened. Above the upper node of the undeveloped culm are long yellowish- to greenish-white maggots or brown-yellow puparia, up to 7 (9) mm long. H. distichon, murinum, vulgare: Chlorops pumilionis

15a Spike severely stunted, hardly 1 cm long. From the basal part and also from the upper culm new nodes develop, up to 13 cm long with leaf-like shoots and rolled leaves. H. murinum: Unidentified gall mite

15b Several to many flowers of the spike greening and becoming leaf-like. H. murinum, vulgare: Aceria tenuis

16a Malformation by smut fungi of all flowers of a spike => 17

16b The infected ovary develops into a reduced, black-brown, thick-walled grain, containing many eelworms. H. vulgare: Anguina tritici

17a The fungus usually infests all ovaries of a spike and destroys them early, covering completely with dusting of spores during sporulation => 18

17b The sori are not completely covered by dusting of spores, but remain enclosed by the glumes. Usually all spikelets of spike are diseased. On cultivated barley and related species during maturation of grain. H. distichon, spontaneum vulgare: Ustilago hordei

18a Spores not foul-smelling, smaller => 19

18b On cultivated barley. Spore mass dark violet-brown, spores globular, 20–24 µm large or egg-shaped to rotund-oval 22–28 x 18–22 µm; with high reticulate pattern at surface. H. bulbosum, marinum, murinum incl. subsp. leporinum, vulgare: Tilletia controversa

19a Usually the diseased plants develop faster than the healthy ones, resulting in smut-infected spikes surmounting healthy ones. Spores globular to oblong-oval, The spores are solitary, long-oval, 6-9 µm long, yellowish brown, darker at one side; wall scattered finely echinulate H. distichon, jubatum, murinum subsp. leporinum, vulgare: Ustilago nuda

19b Spores smaller, c. 6 µm long, olive brown when ripe; then the spores are lighter at one side; wall spinulose. H. ? distichon, murinum, vulgare: Ustilago avenae

= The gall midge Sitodiplosis mosellana with orange larvae, lives in yellow-spotted, sterile spikelets on H. vulgare, destroying grain. The midge is very harmful but does not induce galls

gallers on Angelica

pub 3.iii.2020

Dichotomous table for gallers on Angelica

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodule-shaped swellings. A. archangelica, sylvestris: Meloidogyne hapla

2a On inflorescences, flowers or fruits => 16

2b On vegetative plant parts => 3

3a Malformations bearing fructifications of fungi on their surface => 12

3b Malformations caused by animal inducers or by fungi with fructifications inside => 4

4a Malformations mainly on leaf blades => 6

4b Galls mainly on petiole, rachis, or leaf veins => 5

5a Swellings of variable expansion, spongy, pale-green and blunt, ± undulately wrinkled at surface. Containing many eelworms. A. archangelica: Ditylenchus dipsaci

5b Galls compact, glabrous, vitreous. Many spores develop close to vascular bundle. A. archangelica, sylvestris: Protomyces macrosporus

6a Leaf blades curled, rolled, folded or with swellings caused by animal parasites => 7

6b Basal leaves on the underside of leaf blades with many, ± golden-yellow translucent warts, less than 1 mm long; sometimes coalescing, also on leaf rachis. A. sylvestris: Synchytrium aureum

7a Curling or extensive rolling of leaves caused by aphids or cercopids => 10

7b Leaf blades narrowly rolled, or folded or swollen, bladder-like => 8

8a Leaf blade rolled inwards or swollen => 9

8b Leaflets ± pouch-like converging upwards or curved; curled, thickened at base, ± discoloured; the folds contain several white larvae. A. sylvestris: Macrolabis heraclei

9a Leaf blade segments strongly curled, locally swollen, curved downwards at margin; many larvae on underside. A. sylvestris: Trioza apicalis

9b Leaf tips rolled, ± discoloured. A. sylvestris: Unidentified gall mite

10a Malformations caused by aphids => 11

10b Larger parts of leaf blade ± nest- or roll-like converged; strongly curled and deep-green close to the froth-covered nymph. Angelica spp.: Philaenus spumarius

11a Leaf tips at margin usually weakly bent downwards, curled, sometimes slightly discoloured. Aphid black. A. archangelica, sylvestris: Aphis fabae

11b Similar, sometimes more distinct and deep-green, malformations caused by green aphids. A. archangelica, sylvestris: Cavariella archangelicae

12a Malformations bearing yellowish aecia => 14

12b Bulges often only minor; with sori containing brown spores => 13

13a Swellings in the leaf blade ± rotund, on leaf veins, leaf rachis or stem ± spindle-shaped, yellowish margined, bearing 2-celled telia. A. sylvestris: Puccinia karstenii

13b Minor, often conspicuously yellow-margined and coloured swellings on underside of leaf vein or -rachis, bearing spermogonia and soon browned uredinia. A. archangelica, sylvestris and relatives: Puccinia angelicae

14a Fungi living on A. sylvestris => 15

14b Aecia on A. palustris on variously large bulges usually leaning against the venation, arched on underside, upper side ± countersunk and browned: Puccinia rigensis

15a Bulges ± elongated, leaf rachis and stems usually distinct. Aecia clustered, cup-shaped; peridium protruding, deflected, with very regularly arranged, ± orthogonal cells, thickened outside as well as inside. A. sylvestris: Puccinia angelicae-mammillata

15b Bulges rather uniform, sometimes more compact and more strongly arched. Aecia only pustule-, not cup-shaped. Peridium not protruding, opening with a round hole, outer wall distinctly thickened. A. sylvestris: Puccinia bistortae

16a On inflorescences or flowers => 17

16b Ovaries bladder-like inflated, surmounting the umbel. Containing a single orange-red larva. A. archangelica, sylvestris: Kiefferia pericarpiicola

17a Malformations on single- or several flowers; caused by gall midge larvae => 20

17b Galls on stalks of inflorescences or on expanded parts of inflorescence => 18

18a Inflorescence and flowers variously disfigured => 19

18b Centre of umbel- or partial umbel stalk ± swollen, club-shaped or globular; galls one- to several chambered, sometimes also on one or all sides of the stalks of umbels or partial umbels; inner wall covered with mycelium. Containing a red larva. A. archangelica, palustris, sylvestris: Lasioptera carophila

19a Inflorescence, including flowers, variously stunted and disfigured. Stalks of partial umbels shortened, clustered, bearing aphids. A. sylvestris: Unidentified aphid

= Also Cavariella aegopodii and/or C. konoi might cause such malformations

19b Tangle-like accumulation of unopened, slightly thickened flowers, caused by midge larvae. A. sylvestris: Contarinia baggendorfi

20a Flower buds slightly swollen, not opening. Larvae greenish- to lemon-yellow, jumping. A. sylvestris: Diodaulus traili

= according to W.N. Ellis not on Angelica, but only on Pimpinella

20b Galls usually larger than those of previous midge. Calyx, corolla, ovary distinctly enlarged, these sometimes swollen, hood-like. Larva orange-red. A. archangelica, sylvestris: Dasineura angelicae

gallers on Picea

pub 2.iii.2020

Dichotomous table for gallers on Picea

by Hans Roskam

1a On above-ground part => 2

1b Young stunted plants with main root atrophied, excessively branched; broom-like occurrence of shortened lateral rootlets at nodular places. P. abies: Unidentified root eelworm

2a On or in cones => 20

2b On vegetative parts => 3

2c Old resin masses contain gall midge larvae. P. abies: Cecidomyia magna

3a On buds or young shoots => 7

3b On perennial stem parts => 4

4a Club- or spindle-shaped swellings on branches or twigs => 6

4b Cancer-like malformations on stem or thicker branches => 5

5a Local, closed tumours on P. abies: Cause unknown – ? bacterium

5b Cancer-like rimmed wounds. P. abies, sitchensis: Neonectria fuckeliana

6a Branches with club- to spindle-shaped swellings, bearing Viscum album subsp. austriacum

6b Two-year or older twigs with swellings. P. abies: Unidentified lepidopteran

7a Galls on young shoots => 8

7b Buds distinctly swollen, remaining closed; mite gall. P. abies, etc.: ? Tricetacus sp.

7c Buds distinctly swollen, shoot often deformed, fungus gall. P. abies, engelmannii, pungens: Cucurbitaria piceae

8a Galls ± locally. Originate on young shoots, may partially persist on lignified ends of twigs after inducers have left; caused by animals => 9

8b Complete young shoot stunted by a perennial mycelium, becoming almost cone-like. Needles pale, shortened and thickened, ± divaricate, densely covered with erupting golden-yellow aecia. P. abies, glauca, mariana, pungens: Chrysomyxa woroninii

= Conspicuous bending of terminal shoots, infected by a rust fungus, have been attributed to Pucciniastrum areolatum

9a Galls develop with predominant involvement of needles => 10

9b Shoot axis usually with multi-chambered swelling, up to 9 mm long and 6 mm thick, especially of the bark; if severely infected ± stunted and bent. Each chamber with inner rough wall and containing a bright red larva. P. abies: Piceacecis abietiperda

10a Conspicuous, egg-shaped to elongate cylindrical galls originating from swelling of basal needle parts; caused by aphids => 11

10b Needles of unfurling shoots densely clustered, swollen at base, vitreous, ± yellowing, then often falling prematurely; many depressions in bark often accumulated, 6–9 mm long, 4–6 mm wide. Marked stunting of growth and conspicuous basal swelling in cases of severe infestation. Larvae 2–2.5 mm, bright red; often gregariously on opened scale whorls of severely stunted shoots. P. abies: Piceacecis abietiperda

11a Gall compact, usually less than 20 mm => 14

11b Cylindrical galls on only slightly shortened spring shoots, measuring several cm => 12

12a Gall chamber without cross walls, mutually connected; the gall scales not fused, spreading at maturity => 13

12b Gall chambers separated by cross walls; mainly at base of needles; hence the mutually closely fused gall scales are surmounted with long needles. Gall with 100–150 chambers, pale green to purple, 2.5–6 (10) cm long, often one-sided, crooked. Maturity from end 6 onwards. P. abies, alcoquiana, engelmannii, mariana, orientalis, pungens, sitchensis: Gilletteella cooleyi

12c Gall similar, however, the thickened bases of the needles are not fused to axis of shoot, forming a loose structure 1–4 cm long; galled needles pale green or yellowish; adelgids only partially enclosed in gall (adult has 4 pairs of spiracles) P. sitchensis: Pineus similis

13a Galls often crooked, barrel-shaped or short conical, up to about 5 cm long, with remains of needles of variable length; scales at surface rhomboidally arranged. Mature already at beginning June. Galls ± one-sided. Mainly on P. abies, also on P. glehnii, jezoensis, koraiensis, orientalis: Pineus cembrae

13b Galls similar to previous ones, but often smaller and thinner, sometimes ± egg-shaped, with narrow- or free scales, usually on all-sides. Mature end June, beginning July. Mainly on P. orientalis, also on P. jezoensis, pungens, torano: Pineus orientalis

14a Galls mainly terminally and on all-sides, strawberry- or pineapple-like; scales glabrous on outside, needles not- or only slightly protruding. Top of gall with or without tuft => 16

14b Gall predominantly one-sided at base of new shoots, surmounted by the ± stunted tip of shoot, often deflected from growth direction; ± egg-shaped, 15–25 (30) mm long, green. Scales usually very short pubescent, especially on the often reddened exit slits; provided with longer needles => 15

15a Galls mature mid to end June. Aphid host alternating. P. abies, occasionally on P. engelmannii, glauca, koraiensis, mariana, obovata, omorika, orientalis, pungens, sitchensis, smithiana: Sacchiphantes viridis

15b Similar galls, mainly mature in August. Aphid anholocyclic, no host alternation. P. abies and forms; occasionally on P. engelmannii, glauca, jezoensis, koyamae, mariana, omorika, orientalis, pungens, schrenkiana, sitchensis, smithiana:
Sacchiphantes abietis

16a Galls on P. abies and related species => 18

16b Galls only on P. orientalis => 17

17a Galls occupy the complete lateral shoots; ± blunt conical or cone-like, up to 22 mm long, chambered, strawberry-coloured, with minute, broad stub-shaped remains of needles but no tufts: Dreyfusia nordmannianae and/ or Dreyfusia merkeri

17b Galls similar, rotund to oblong, 6–20 x 8–15 mm, dull bluish to dark green, appearing weakly frosted, chambered. Develop from lateral shoots. Needles already in the galled buds, running ahead to the normal ones, transformed into narrow scales, ± fused at base. Tips of scales present only as remains of the regularly patterned, always tuft-less gall. Mature mid-June, beginning August: Dreyfusia prelli

18a Many galls ± egg-shaped, up to hazelnut size, pale green or whitish; scales partially provided with stub-shaped, distinctly recognisable needle stumps. Usually on top of shaded lanky lateral shoots, only exceptionally surmounted by a tuft of needles or a short atrophied shoot => 19

18b Galls on lateral buds of shoots wild strawberry-size, green, lacking tuft of needles. Scales on chambers fused, endings blunt-pyramidal. Picea spp.: Aphrastasia pectinatae

19a Aphid holocyclic, migrating to Larix decidua. Galls mature in June. Picea spp.: Adelges laricis

19b Galls similar, but mature in late-summer, August-October. Aphid especially biologically distinct from the previous one, anholocyclic, not alternating. P. abies, glauca, pungens, sitchensis: Adelges tardus

19c In similar galls, P. abies, live the following closely related species: Adelges tardoides and/ or, P. abies, glauca, jezoensis, mariana, pungens, sitchensis: Adelges lapponicus

20a On cone scales => 21

20b Seeds narrowed, oblong, acuminate, ± twisted and bent, discoloured. Wings of seed absent, seed often falling prematurely. Containing a yellow- to orange-red larva. P. abies, glauca, obovata, pungens: Plemeliella abietina

21a Warts bearing aecia at base of scales => 22

21b Inside the scales with 1–3 weak, ± wart-shaped, lighter swellings. Cone remains closed for a longer time. Each gall containing a single red larva, often many per cone. P. abies, glauca, omorika, pungens: Kaltenbachiola strobi

= Gall midge larvae develop inside the growing cones; damaging the basal part of the scale where the resin mass arise. P. abies: Resseliella ingrica

= The introduction of the N-Am gall midge Resseliella conicola on P. sitchensis has been reported

22a All scales of a cone at first covered on upper side with small warts caused by many, clustered, rough-walled, brown aecia, which become exposed, also in disfigured cones, during dry weather in summer. P. abies: Pucciniastrum areolatum

22b Outside of scale, usually at both sides of the midrib with two to several, swellings up to pea-size, sometimes with coalescing flat aecia. P. abies, engelmannii, glauca, mariana, obovata, pungens, rubens: Chrysomyxa pyrolae

22b Bisexual cones, observed in many Picea species are teratomata, and cannot be attributed to parasitic agents

gallers on Lonicera

pub 1.iii.2020

Dichotomous table for gallers on Lonicera

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular galls. Lonicera spp.: Meloidogyne div. spp.

2a On inflorescences or flowers => 19

2b On vegetative parts => 3

3a On shoot tips or leaves => 6

3b On axial parts of shoots => 4

4a On young shoots => 5

4b Conspicuous proliferations mainly on the nodes of older axial parts of shoot. “Bacterial cancer”. Lonicera spp.: Agrobacterium tumefaciens

5a Oblong oval, one-chambered gall, swelling on one or all sides, extending over 2–3 internodes below the stunted shoot tip. Pith containing a white larva. L. caerulea, nigra, xylosteum: Hoplocampoides xylostei

5b Shoot axis at some distance from shoot tip with weak, sometimes twisted, 20–30 mm long spindle-shaped swelling. Pith containing a reddish-yellow caterpillar. L. caerulea, xylosteum: Pterotopteryx dodecadactyla

6a Galls on terminal parts of shoot => 18

6b Localised or expanded malformations on single or several leaves => 7

7a Locally defined galls on leaf blade, petioles or leaf veins => 16

7b Malformations on leaf margins or on large parts of leaf blade => 8

8a Cartilaginous or ± fleshy roll of leaf margin caused by gall mites or -midges => 14

8b Loose fold or spoon-like deflection of leaf blade, often with associated curling roll of margin, caused by aphids => 9

9a With less conspicuous additional malformations connected downward folds or rolls of margin => 12

9b Leaves discoloured, folded or rolled upwards, distorted on the ± stunted shoot tips; extensive infestation followed by colonisation of many leaves, which are partially bent or rolled upwards => 10

10a Galls inhabited during May, June, soon decaying. Aphids migrating to Apiaceae => 11

10b Upwards curled leaves bearing aphids still in early summer and even later. L. caprifolium, etrusca, implexa, periclymenum, tatarica: Hyadaphis passerinii

11a Shoot tips, as well as several neighbouring, prematurely developed side shoots, transformed into a drooping, densely leafed, 15–25 (40) cm long bushy bundle with ± whitish axial parts. Leaf blades strongly reduced, bent upwards along midrib, irregular pale-green. L. x bella, caprifolium, involucrata, ligustrina subsp. yunnanensis, x purpusii, tatarica, xylosteum: Hyadaphis tataricae

11b Similar malformations, on many leaves of often severely disfigured and strongly deflected lammas shoots on L. nigra, bearing several aphids: Hyadaphis sp.

11c On L. xylosteum and also on many other climbing species: Hyadaphis foeniculi

11d In upwardly-rolled leaves of L. nigra: Hyadaphis bicincta

12a Aphids sometimes ± frosted, however lacking conspicuous white-woolly covering of wax => 13

12b Aphid strongly white-woolly. L. alpigena, tatarica, xylosteum: Prociphilus xylostei

13a On L. alpigena: Rhopalomyzus poae

13b Aphid rolling leaves towards undersides and causing yellow and red spots. L. nigra, tatarica, xylosteum and relatives: Rhopalomyzus lonicerae

14a Narrow, ± succulent, but soft, usually glabrous roll of leaf margin caused by gall midge larvae => 15

14b Narrow, compact, upwards partial roll of leaf blade usually associated with undulate curling, sometimes red-margined, cartilaginous; occasionally, if strongly infected, together with downward protrusions. Lonicera spp.: Aculus xylostei

14c Narrow tight roll, usually downwards, often reddish, clearly thickened and causing crinkling of the leaf margin, or a pleat parallel to the leaf margin, about 2‒3 mm long or affect most of both margins; roll often lines with hairs. L. periclymenum: cf. Aculus xylostei

15a More or less soft, succulent, pale-green upwards rolls, mainly on the leaf margins of one- or both sides on a developing shoot. Containing several white or yellow-red larvae. L. etrusca, implexa, nigra, periclymenum: Dasineura periclymeni

15b Roll only slightly thickened, containing several milk- to yellowish-white larvae. L. caprifolium, etrusca, implexa, nigra, periclymenum, xylosteum: Macrolabis lonicerae

= The larvae might also live as inquilines in galls of previous midge

16a Parenchyma- or groove galls caused by gall midge larvae, often many per leaf => 17

16b Rotund yellow sori of fungus, on main leaf veins, -stalks, also on young stems sometimes joined to slightly swollen, also distorted pads. Lonicera spp.: Puccinia festucae

16c On the young leaves develop chlorotic spots, that turn yellow, then brown, finally they dry out and are silvery. The veins remain green. On the underside a white bloom of basidia. L. tatarica, xylosteum: Insolibasidium deformans

17a The whitish larvae develop at first in inconspicuous pustule-shaped galls in leaf parenchyma, later on ± yellow, up to 3 (5) mm long. L. xylosteum: Dasineura xylostei

17b Spindle-shaped, slender and flat, 5–7 (9) mm long galls. Larvae in tissue of main veins. L. xylosteum: Unidentified gall midge

17c Leaf blade with many grooves, arched on upper side, 1 mm long surrounded by an about 4–7 mm broad lighter area, each containing a white, often succulent enveloped larva. L. caerulea, periclymenum, xylosteum: Dasineura excavans

18a Often only slightly stunted shoot tip with some completely or only basally stunted, thickened, ± discoloured erect leaves. Leaf blades completely rolled inwards, transformed into a pale-green cone or leaf blades of leaf pairs rolled over one another on only one side, spreading their free, usually normal halves. Containing several to many white larvae. L. xylosteum: Unidentified gall midge

18b Similar, more closed galls with strongly developed thickening of leaf. L. caerulea: Contarinia lonicerae

19a Gall development of single or several separate flowers => 20

19b Complete inflorescence variously stunted and disfigured by aphids. Bracts distorted. Flower reduced, ± greenish or disfigured; stamens reduced, not extending; the discoloured corolla and bracts are irregularly distorted or rolled upwards. L. caprifolium, etrusca, implexa, periclymenum, tatarica: Hyadaphis passerinii and/or Hyadaphis foeniculi

20a Malformations caused by gall midge larvae => 21

20b Flower buds unopened, facultatively slightly swollen, containing a yellow caterpillar with dark dorsal stripe. L. caprifolium, periclymenum, xylosteum: Alucita hexadactyla

21a Flower buds shortened, ± strongly swollen. Corolla inflated, ± leather-like and thickened. Stamens and ovaries ± distorted. Containing several yellow, jumping larvae. [S]. L. caerulea, nigra, xylosteum, tatarica and other cultivated species: Contarinia lonicerearum

21b Similar galls, containing orange, non-jumping larvae. L. xylosteum: Placochela nigripes

21c In flower galls of Lonicera spp. occur also the white, non-jumping larvae of Arnoldiola sambuci

gallers on Aster

pub 29.ii.2020

Dichotomous table for gallers on Aster

by Hans Roskam

incl. Bellidiastrum, Chrysocoma, Galetella, Symphiotrichum, Tripolium

“Asters” are here incidentally without further designation indicated as hosts for many parasites, especially Meloidogyne-species. It is often not clear which Aster-species, Callistephus [= Aster] chinensis or even cultivated Chrysanthemum-species have been meant by many authors

1a On capitula => 21

1b On vegetative parts => 2

2a Galls less than 1 mm long or with fruiting fungi on the surface => 15

2b Other kinds of malformations caused by animals (or bacteria) => 3

3a Malformations mainly on leaves => 8

3b Galls at the top of main- and lateral shoots or on stems => 4

4a Terminally on plants the growth of which is not stunted => 6

4b Swellings of lower stem parts => 5

5a Stem with considerable, one-sided, ± blistered, smooth-walled, unilocular swelling, Larva without head capsule or legs. Bellidiastrum michelii: Tephritis arnicae

5b Spongy, pale, often massive stem galls with rugose surface. “Aster”: Ditylenchus dipsaci

5c Stem base, still above the underground root collar, swollen; in other areas one-sided, oval, about 10–12 mm long, 3 mm wide; almost on all sides of the thin stems. A yellow caterpillar up to 10 mm with a yellow-brown head capsule. Galetella linosyris: Caulastrocecis furfurella

= Root cankers, caused by Agrobacterium tumefaciens, and “leafy galls” of Rhodococcus fascians have been reported

6a Malformations without conspicuous swellings of the stem => 7

6b Plant growth stunted in longitudinal direction, shoot tip swollen, curved and reddened. One caterpillar. Galetella linosyris, Tripolium pannonicum subsp. tripolium: Eucosma aspidiscana

6c Very conspicuous swelling of twig, containing one caterpillar. Galetella sedifolia: Caulastrocecis gypsella

7a Shoot stem shortened. Abnormal twig- and leaf development on long- or short shoots. Galetella linosyris: Aceria linosyrina

7b On the stunted shoots a rotund gall encased by several leaves, up to 10 mm long, greenish. Larvae between the inner leaves. A. alpinus: Rhopalomyia astericola

8a Leaf blade rolled, folded or curled => 11

8b Leaves with local, ± constant shaped, galls => 9

9a Galls glabrous => 10

9b Whitish pubescent, rotund, spongy, uni- or multilocular galls, up to 16 mm long, yellowish, often many on ± stunted plants, mainly close to basal leaves, more rarely on stem leaves or even on the scales of the capitula. A. alpinus: Unidentified gall midge

10a Leaf blade with greenish-yellow galls, 3–5 mm long, bulging on the underside, about 1.5 mm thick, ± spindle-shaped; often spreading from midrib and occupying or even surmounting the whole leaf blade; sometimes several per leaf, occasionally coalescing. One dark orange-yellow larva per gall. On Galatella linosyris; Tripolium pannonicum: Dasineura linosyridis

10b Cylindrical, up to 20 mm long, 5 mm wide, very thick-walled, tough, multilocular, tubercular gall on leaf base, including the midrib. The upper leaf part folded along the midrib. Tripolium pannonicum: Inducer unidentified – ? gall wasp

11a Leaf blade curved and curled by aphids or cercopids => 14

11b Leaf blade folded or rolled; midge- or mite galls => 12

12a Leaf margin rolled => 13

12b Leaf blade folded downwards, ± bleached. Galatella linosyris: Unidentified gall midge

13a Leaf margin upwardly curved or folded, thickened and bleached. Larvae on upper side. A. alpinus: Unidentified gall midge

13b Leaf blade with loose, weakly thickened leaf margin roll without abnormal pubescence. Bellidiastrum michelii: Aceria opistholia

14a Leaf blade at the margins downwardly curved or rolled, ± strongly curled. Sometimes several leaves densely bunched at the compressed shoot tips. Aphids on the underside. A. amellus and cultivated forms, Bellidiastrum michelii, Tripolium: Brachycaudus helichrysi

14b Leaves, depending on their condition, differently ± strongly curved downwards and curled. Tissue close to the froth-covered nymph dark green. Sometimes several leaves converging spoon- or clump-like on compressed, ± curved stems. A. amellus, Symphiotrichum novae-angliae, novi-belgii including the cultivated forms, S. lanceolatum, Tripolium, etc.: Philaenus spumarius

15a Fungus, infected area larger than 1 mm => 16

15b Many golden-yellow warts, hardly 1 mm long, mainly on the underside of basal leaves. Bellidiastrum michelii: Synchytrium aureum

16a Minor swellings, occupied by brown-black telia => 19

16b Sporangia containing aecia => 17

17a On Bellidiastrum michelii, Tripolium => 18

17b On Galatella linosyris. Sporangia mainly on the underside of the leaves, yellowish, hardly swollen, sometimes bulging the leaf out laterally; also indistinctly swollen callus on the stems about 5–7 mm long: Puccinia linosyridis-caricis

18a On Tripolium. Sori on leaves and stem hardly cecidogenic. Visible malformations only reported laterally on the base of the capitula slightly swollen, ± bent flower head buds. Puccinia extensicola

18b On A. bellidiastrum, hardly cecidogenic aecia: Puccinia firma

19a On A. alpinus, Bellidiastrum michelii => 20

19b On other asters. Sori on the leaf veins or stem parts rotund-oval to spindle-shaped, on sometimes slightly swollen pads. A. amellus, Galatella linosyris, Tripolium, etc.: Puccinia cnici-oleracei

20a Similar sori on A. alpinus: Puccinia asteris-alpini

20b Sori usually in converging, callus-like groups on curved petioles and leaf veins; occasionally on rotund, usually violet-red bordered pads on the leaf undersides. Bellidiastrum michelii: Puccinia bellidiastri

21a Capitula deformed. Receptacle swollen, all- or one-sided. Larvae in receptacle, cylindrically shaped, with black mandibles => 22

21b Capitula hardly swollen. Larvae without conspicuous mouth parts, between flowers. Galatella linosyris: Dasineura procera

= In capitula of Bellidiastrum michelii midge larvae of an undescribed Dasineura have been mentioned.

21c Florets forming a compact rosette of green leaves (phyllanthy); contains mites with four pairs of legs. Symphyotrichum novi-belgii: Phytonemus pallidus

22a Galls preferentially when unilaterally affected ± bent downwards; marginal flowers partially not developed. Tripolium: Campiglossa plantaginis

22b Similar malformations Tripolium: Trupanea stellata

22c In Germany, J. Haase collected inflorescences of Tripolium with many widely extending capitula, of which the flowers were largely reduced and deformed. Cause unknown; similar malformations also known from other Asteraceae, especially Liguliflorae and Cynareae. Might be caused by viruses.

gallers on Fraxinus

pub 26.ii.2020

Dichotomous table for gallers on Fraxinus

by Hans Roskam

1a On buds, leaves, inflorescences or fruits => 6

1b On axial parts of shoot => 2

1c Root with rounded or spindle-shaped swelling, 2–5 mm across; containing eelworms, some may be glistening white pear-shaped females with eggs: Meloidogyne ardenensis

2a On thicker stems and branches => 4

2b On younger twigs => 3

3a Shoot axis with irregular rimmed depressions, containing the causer under a pear-shaped scale, about 2.5–3 mm long. F. excelsior: Chionaspis salicis

3b Younger shoots with cauliflower-like proliferations, about 5–20 mm across. F. americana, angustifolia, excelsior, ornus: Aceria fraxinivora

4a Malformations caused by inconspicuous parasites invisible from the outside or on younger stems or thicker branches => 5

4b Thicker axial parts with spindle-, club-shaped, or nodular swellings bearing: Viscum album

5a Proliferations develop, mainly on nodes, usually closed, rotund, at first glabrous, later on cracked and ruptured, up to about 30 mm long, later on discoloured brown to black. “Bacterial cancer”. F. excelsior: Pseudomonas savastanoi pv. fraxini

= In many areas similar proliferations due to Agrobacterium tumefaciens have been reported.

= So-called bark roses on ash, rather similar proliferations, should not be confused with previous malformations. They occur mainly on thicker axial parts and differ from basally usually distinctly narrowed bacterial cancer by being broadly attached to the host. These proliferations, often cracked, ± rosette-like are responses to wounds caused by feeding of the scolytid beetle Hylesinus fraxini.

5b Open cancer, mainly on branches, usually arranged according to the bearing organ, provided with conspicuously glabrous to warty rims surrounded to varied extent; perennial. “Nectria-cancer”. F. excelsior: cf. Neonectria ditissima

= Apparent “cancers” on ash are often caused by freezing and not by parasites

6a On buds or leaves => 8

6b On inflorescences or fruits => 7

7a Fruit irregularly slightly swollen; gall surface usually strongly undulate, becoming brown and cracked. Containing several to many lemon-yellow larvae. F. excelsior, ornus: Contarinia marchali

7b Inflorescences transformed into at first green, soon browned, tuberculate, cauliflower-like masses. Flower peduncles disfigured, ± cauliflower-like distorted. “Klunkern” in German. F. excelsior, ornus, etc. Aceria fraxinivora

8a On leaves => 9

8b Buds disfigured, scales of buds soon dropping. F. excelsior: Unidentified gall mite

9a Galls confined to single leaves or parts of leaves => 12

9b Malformations extend to several leaves => 10

10a Nest-like clustering of disfigured leaves on shoot tip, caused by aphids => 11

10b Some, usually laterally inserted leaves ± converging, nest-like. Leaf blades curled. Deeper green at site of infestation. Containing a froth-covered nymph. F. excelsior: Philaenus spumarius

11a Petioles, as well as -midrib, severely stunted and distorted, densely clustered. Aphid mainly on midrib and leaf underside, also in much lower numbers on shoot axis. F. angustifolia incl. subsp. oxycarpa; excelsior: Prociphilus fraxini

11b More loosely arranged clustered leaves; aphids mainly on shoot axis and petioles. F. angustifolia, excelsior, mandshurica, pennsylvanica: Prociphilus bumeliae

12a Galls on leaf midrib or -blade => 15

12b Roll of leaf margin => 13

13a Expanded, loose, greenish or pale, partially reddish discoloured, soft to brittle downward rolls => 14

13b Very narrow, cartilaginous downward roll of leaf margin; the rolls are abnormally haired inside. F. angustifolia, excelsior: Aculus fraxini

14a Loose, usually normal, rarely ± pale-green discoloured, soft rolls of leaf margin; containing several midge larvae. F. excelsior: Unidentified gall midge

14b Bladder-like swollen, loose ± thickened roll of leaf margin; brittle, largely discoloured, often with reddish or violet marbling; caused by white-woolly psyllids. F. angustifolia incl. subsp. oxycarpa; excelsior: Psyllopsis fraxini

14c In similar galls also lives Psyllopsis discrepans

14d Leaf roll gall with shallow depression, discoloured bulge above. F. angustifolia incl. subsp. oxycarpa, excelsior, ornus: Psyllopsis fraxinicola

15a Galls on leaf blades, without particular involvement of venation => 17

15b Galls on leaf midrib or leaf veins => 16

16a Leaflets along midrib folded upwards, pod-like, strongly thickened and hardened. Leaf blade not developed or only as a narrow rim. Often all leaflets infected on young leaves. Containing several white larvae with bluish-green gut. F. angustifolia incl. subsp. oxycarpa, americana, excelsior, ornus, pallisiae: Dasineura acrophila

= The yellowish larvae of Contarinia invocata occur as inquilines of D. acrophila as well as the whitish, never greenish translucent larvae of Macrolabis pavida. Reddish-yellow larvae of Clinodiplosis botularia also occur in these galls

16b From similar galls on F. ornus: Trigonodiplosis fraxini

16c On leaf underside bulging, sometimes reddish discoloured pouches on midrib of leaflets, also on midrib and sometimes on petioles, up to 30 (50) mm long. Later with distinctly protruding longitudinal slit on upperside, surrounded by a stronger pubescent rim; often many galls per leaf blade. Each containing a single orange-coloured larva. F. angustifolia incl. subsp. oxycarpa, excelsior, ornus: Dasineura fraxini

17a Variously shaped small grooves, protrusions or pubescence of leaf blade => 20

17b Warts, nodules or parenchyma galls, mostly of constant shape => 18

18a Wart-like or nodular galls => 19

18b Pustule-shaped flat parenchyma galls, hardly 1 mm high, especially protruding on underside with margin, at first red-violet or pale-green, later on brown, up to 8 mm wide. Containing a single yellowish-white larva with green translucent gut. F. angustifolia incl. subsp. oxycarpa, excelsior: Dasineura fraxinea

19a Golden-yellow translucent warts on underside of basal leaves of seedlings, 1 mm across. F. excelsior: Synchytrium aureum

19b Corniculate, or ± hemispherical nodules, up to 1.5 mm high, glabrous, yellowish or reddish, protruding more strongly on one side of leaf. The irregular glabrous tunnels inside the galls usually open on leaf underside. Galls occasionally on leaf midrib and -stalks. F angustifolia, excelsior, ornus: Aceria fraxinicola

20a Flat, irregular, 1–2 mm long, sometimes coalescing yellowish protrusions on upperside of leaf blade, often soon ± browned. F. angustifolia subsp. oxycarpa, excelsior, ornus, pennsylvanica: Aculus epiphyllus

20b Abnormal, at first reddish, then ± brownish pubescence on underside of leaflets, especially along midrib. Hairs multi-cellular, with acuminate or obtuse tip. F. excelsior, ornus, angustifolia subsp. oxycarpa: Aculus epiphyllus

gallers on Avena

pub 25.ii.2020

Dichotomous table for gallers on Avena

incl. Avenula

by Hans Roskam

1a On above-ground parts => 4

1b On roots => 2

2a Roots with conspicuous, localised swellings, a few mm long => 3

2b Roots stunted in longitudinal growth, branched bush-like (“hunger roots”). In many cases weakly thickened, sometimes bent, usually darker coloured; inside giant cells. From mid-June onwards with lemon-shaped, at first milky-white, later on brown, soon dropping cysts. Above-ground parts severely stunted. A. fatua, sativa: Heterodera avenae

3a Root tips or young roots swollen and curved. Tissue without particular cavities, containing roundly swollen, immobile eelworms; formation of adventitious roots increased. A. sativa: Meloidogyne cf. artiellia

0b Roots with slender, screw-like bent swellings; inside distinct cavities; containing a few vivid eelworms. Avena spp.: Subanguina radicicola

4a On inflorescences or flowers => 13

4b On vegetative parts => 5

5a On plants with at most rudiments of panicles => 9

5b On plants developing- or with panicles => 6

6a Malformations of stem caused by fly- or midge larvae => 7

6b Leaf sheaths inflated, discoloured. Leaf blade twisted and rolled inwards. Development of panicles often soon stunted, sometimes bleached later on. A. barbata, fatua, sativa incl. ssp. orientalis, strigosa, sterilis: Rhopalosiphum padi

6c Similar, but hardly gall-like malformations may be caused by the following aphids: Sitobion avenae, S. fragariae and Sipha maydis

7a Larvae living between stem and leaf sheaths, without legs, but with sternal spatula => 8

7b Stem stunted at base of the inflorescence, ± slightly swollen. Panicles occasionally severely stunted, often bleached. Larvae feeding on the developing seeds. A. fatua, sativa: Oscinella frit

7c Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. A. caryophyllea: Puccinia striiformis

8a Stem above a node ± slender, swollen, onion-like, sometimes bent. Under the leaf sheath are several 3–4 (5) mm long, vitreous to greenish-white larvae with arrow-shaped sternal spatula. Caudal part conically tapering. The larva develops into a flattened, flax seed-like, glossy brown puparium. A. fatua, sativa: Mayetiola avenae

8b Stem below the slightly swollen sheaths with several 10–15 mm long, elongated, saddle-shaped depressions, apically rimmed; each gall contains a blood red larva. A. sativa: Haplodiplosis marginata

8c On A. sativa and A. fatua, a similar, but not saddle-shaped swollen, expanded, blackened depressions of the culm, covered by the leaf sheath are possibly induced by Hybolasioptera fasciata

9a Plants usually excessively leafy, ± distinctly swollen at base => 10

9b Leaves of young plants slightly thickened, ± rolled inwards or folded. A. sativa: Anguina tritici

10a Shoots shortened, swollen at base, plants usually excessively leafy. Leaves usually not or only slightly discoloured => 12

10b Shoots shortened, usually less distinctly swollen, at least the inner leaves yellowed; often surmounted by additionally developing, uninfected new shoots => 11

11a Inner leaves yellowed and withered, the outer ones green, central part destroyed; shoot slightly swollen. New shoots often similarly affected, bushy clustered, later surmounted by healthy shoots. Inside is an at first vitreous, then yellowish-white cylindrical maggot, about 3–4 (5) mm long, provided with mandibles [buccal hooks] and tunneling into the root neck; with 2 caudal cone-like spiracles; pupa pale brown. A. fatua, sativa: Oscinella frit

11b Infected shoots usually sessile, at base sometimes slightly thickened. Plants usually very leafy, with many shoots which also become infected later on; leaves yellowing, starting at their margins. Between the outer, later ± browned sheaths are several, 3–4 (5) mm long, vitreous- to yellowish-white larvae or flattened flax seed-like, brown puparia. A. fatua, sativa: Mayetiola avenae

12a Single or several shoots of already developed plants stunted, predominantly at terminal parts; enveloped primordia of plant parts accumulated to ± spindle- or almost cigar-shaped galls. Larvae up to 7 (9) mm long, glossy white-yellow, with mandibles [buccal hooks], with 2 small caudal conical spiracles. Feeding on the central shoot or on upper internode. Pupa yellow-brown, ± flattened. A. sativa: Chlorops pumilionis

12b Plants very leafy, severely stunted, hardly developing shoots; infected shoots ± distinctly swollen at base, onion-like. Leaves short, thickened, undulately curved; becoming yellow and brown prematurely. Containing many eelworms in ± spongy parts. A. fatua, sativa: Ditylenchus dipsaci

13a Ovaries temporarily slightly swollen, soon occupied by a black mass of spores => 16

13b Malformation of large parts or of inflorescence, caused by animal parasites => 14

14a Malformations caused by gall mites => 15

14b Axis of the inflorescence distinctly narrow-undulately curved; panicle clustered; malformations caused by aphids. A. fatua, sativa incl. orientalis, strigosa: Sitobion avenae

14c Flowers swollen, contain yellow midge larvae. Avenula pubescens: Contarinia avenae

15a Spikelets incompletely developed. Panicle often remains largely hidden in leaf sheaths of the generally stunted plant; stalk of inflorescence shortened, ± undulate to screw-like compressed sheaths and the slightly swollen, protruding glumes often carmine- to blue-red. Terminal part of stem or panicle inside the sheath often twisted like corkscrew, covered with many mites which look like crumbly meal. A. sativa: Steneotarsonemus spirifex

15b Spikelets elongated, stalk often surmounting the flower and developing new spikelets. A. sativa: Cause unknown – ? gall mite

16a Diseased shoots develop accelerated longitudinal growth and surmount the healthy ones for a short period; infected spikelets broader and shorter, soon completely destroyed by a black-brown mass of spores, which during eruption turns the unfolding panicle to dust with only the midrib remaining. A. barbata, fatua, nuda, sativa, sterilis incl. subsp. ludoviciana, strigosa: Ustilago avenae

16b From stripes of smut on leaves of A. barbata, sativa incl. ssp. orientalis, Avenula pubescens is furthermore recorded the exceedingly rare Ustilago striiformis

16c Similar infestation, the spore mass, however, develops between two intact valves as a closed, rather compact, non-dusty smut grain. A. barbata, fatua, nuda, sativa, sterilis incl. subsp. ludoviciana, strigosa: Ustilago avenae

gallers on Tilia

pub 21.ii.2020

Dichotomous table for gallers on Tilia

by Hans Roskam

1a Galls on leaves, inflorescences or flowers => 7

1b Galls on axial parts such as twigs, branches and stems => 2

2a Galls on young shoots => 4

2b Malformations on stems or branches => 3

3a Rimmed wounds caused by cancers on branches, rarely on younger stems. “Nectria-cancer”. T. cordata, platyphyllos: cf. Neonectria ditissima

3b Older axial parts often with well-developed, oblong-spindle-shaped or compact oval swellings: Viscum album

4a Gall causers live outside the malformations => 6

4b Gall causers develop inside the galls => 5

5a Up to 8 mm wide swellings on all sides or one-sided, ± globular on the one-year old twigs. Inside is an expanded tunnel containing a caterpillar with distinct head capsule. Tilia spp.: Unidentified lepidopteran

5b Galls on young shoots ± globular to acuminated, barrel-shaped, succulent, up to 10 (20) mm across; at various locations, usually on suckers, especially the buds, which are often ± extensively involved in the gall formation. Each chamber containing a single sulphur- to lemon-yellow larva. Tilia spp.: Contarinia tiliarum

5c Plurilocular swellings on young shoots. T. cordata, platyphyllos: Contarinia ramicola

6a Axial parts of the younger shoots with slightly rimmed depressions containing a pear-shaped, 2.5–3 mm scale: Chionaspis salicis

6b Furthermore, with similar biology: Diaspidiotus gigas

6c Depressed gall-like grooves, occurring predominantly in branch axils. Tilia spp.: Xylococcus filiferus

6d Spring shoots terminally twisted. Leaves clustered nest-like, leaf blades rolled, curved and curled round each other. T. cordata, platyphyllos: Patchiella reaumuri

7a On inflorescences or flowers => 23

7b On leaves => 8

8a On developing, already unfolding or mature leaves => 9

8b The more or less developed young leaf blades terminally on stunted shoots remain irregularly crumpled and upwardly folded. Venation undulately disfigured, slightly thickened, sometimes more pubescent. The folds contain several at first white, then orange-yellow to reddish larvae. Tilia spp.: Dasineura thomasiana

9a Leaf blades browned, curled or with rolled margins and sometimes with abnormally felt-like pubescence, on the petioles and even extending onto the shoot => 16

9b Leaves with different, more or less constant localised galls => 10

10a Galls semiglobular, nodular or horn-like, always often with only narrow opening, towards the underside of the leaf => 13

10b Galls closed, ± globular to egg-shaped or flat pustule-shaped => 11

11a Galls irregular rotund to acuminate rotund-oval => 12

11b Leaf blade usually with several to sometimes many flat, circle-shaped parenchyma galls, hardly protruding on the upper side, on the underside slightly arched, pustule-shaped, sometimes reddish or yellowish brown rimmed. Containing a single white larva. Tilia spp.: Physemocecis hartigi

12a Galls dispersed on the leaf blade, often many per leaf; tough-walled, rotund, up to 8 mm wide and about 4 mm high; on one side arched-conical, on the other side rather bulging disc-shaped; predominantly protruding more on the upperside; often yellowish or reddish rimmed later on. From the conical part separates centrally at maturity an often differently coloured, brownish, cylindrical-conical, longitudinally grooved inner gall, containing a glossy white to pale yellow larva. Tilia spp.: Didymomyia tiliacea

12b Galls on petioles or veins; acuminated, rotund-oval, about 4–6 mm long, succulent, pale green; one-, more rarely more-chambers; each chamber containing a single sulphur- to lemon-yellow larva. Tilia spp.: Contarinia tiliarum

13a Galls nodule-shaped or wart-like => 14

13b Leaf blade on upperside with slender, about 5 up to even 10 (15) mm long horn-like, so called “nail galls”. Galls scattered on leaf blade, at first green, eventually yellowish, reddened or browned, glabrous or ± pubescent, acuminate, partially also rounded. Underside with narrow, pubescent opening; inner wall with loose, cylindrical pointed hairs of various length. Similar galls with rather host-specific mites:

a On T. cordata, platyphyllos, tomentosa: Eriophyes tiliae

b On T. argentea: Aculus argenteae

14a Galls at any place on the leaf blade => 15/p>

14b Leaf blade often with many almost semiglobular upward protrusions in the vein axils. Galls at first often strongly pubescent, eventually ± glabrous. Cavity open on underside and clothed often with prominent tufts of 1-celled, cylindrical, acuminate hairs. Tilia spp.: Eriophyes exilis

= In the vein axils of many woody plants occur hair formations, tuft-like, or arranged in rows, which may sometimes be even slightly bulged on the upperside of especially young leaves of lime trees. These “acarodomatia” or “mite pubs” may secondarily be inhabited by free-living mites, but are not true galls

15a Scattered nodular pouch galls; occurring on both sides of leaf; often many per leaf blade. Up to 3 mm long, up to 1.5 mm wide. Outside at first finely haired, eventually becoming glabrous, often with only some rigid hairs at base. Opening slit-like, densely pubescent. Cavity with tufts of simple hairs. T. platyphyllos: Phytoptus bursarius

15b Similar, flatter wart-shaped pouch galls, densely haired inside. T. cordata, platyphyllos: Phytoptus stenoporus

16a Leaves and additionally sometimes also the petioles with abnormal pubescence => 20

16b Leaf blades arched and curled or rolled at their margins => 17

16c Leaf blade browned. True gall? T. platyphyllos, cordata: Aculus ballei

17a Rolls of leaf margin => 18

17b Leaf blade variously ± irregular spoon- or trowel-like downwardly deflected, curled and locally coloured dark green. Tilia spp.: Philaenus spumarius

18a Roll in cross section larger than 2 mm; of varied length => 19

18b Roll narrow, compact, undulately-nodular thickening; ± pale green, usually rolled downward, occasionally upward. They often occur either with several per leaf blade and only a few mm long, or are sometimes coalescing and widely expanded. The inside is clothed with simple, pointed hairs. Tilia spp.: Phytoptus tetratrichus

19a Margin rolled upwards. Roll compact, succulent-cartilaginous thickening, brittle, wall almost glabrous, ± pubescent, yellow-green or often crimson- to violet red. Inside glabrous; often with several yellow-red larvae. Tilia spp.: Dasineura tiliae

19b Margin often on both sides of leaf with widely expanded, loose, not thickened, usually distantly-undulate upward roll. The leaf parenchyma is blotch-like mined inside the rolls up to both epidermises. Containing a single larva. Tilia spp.: Parna tenella

20a Erinea at various locations on the leaf blade => 22

20b Abnormal hair formations in the vein axils or along the venation => 21

21a Erinea flaky, white, sometimes slightly reddened, extending along the veins. On the upperside often coalescing at the branching of the veins; on the underside usually developed more sparsely. Tilia spp.: Eriophyes exilis and/or: Eriophyes nervalis

21b On the upper side in the vein axils almost semiglobular arched, haired protrusions, which eventually become glabrous. The cavities on the underside are often clothed with projecting dense tufts of 1-celled acuminate cylindrical, soon browned hairs. Tilia spp.: Eriophyes exilis

22a Densely pubescent erinea, situated between the veins, at first whitish to reddish to violet, finally brownish. Making oblong-oval patches on the upperside and/or underside, which may coalesce in various ways. Hairs cylindrical, at top often club-shaped, also bent or slightly twisted. T. cordata, platyphyllos: Eriophyes exilis

22b Similar erinea on the underside consisting of cylindrical hairs, rarely on upperside. Occur in distinctly margined, up to 5 mm, rotund- to oblong-oval patches which are clearly arched on the opposite side. T. tomentosa: Phytoptus erinotes

23a Bracts with horn-like, or felt-like galls or with rolled margins => 24

23b Globular or ± acuminated, oval, 5–8 mm, succulent swellings of flower buds, on midrib of the bracts or on the stalks of the inflorescence. Tilia spp.: Contarinia tiliarum

24a Leaf blades with erinea or horn-like- to nodular galls => 26

24b Leaf rolls => 25

25a Roll arched upward, succulent, brittle; often extending onto midrib; with uniform surface, glabrous or haired, often conspicuously reddened. Larvae yellow-red. Tilia spp.: Dasineura tiliae

25b Margin with narrow, leathery, undulate-nodular galls caused by mites These are pale green, up to 1 mm high, about 2–10 mm long, may coalesce into larger stripes, glabrous or haired rolls. Tilia spp.: Phytoptus tetratrichus

26a Leaf blades with erinea of various expansions. Erinea sometimes extending onto galls of other origin. Tilia spp.: Eriophyes exilis and/or: Eriophyes nervalis

26b Leaf blade with horn-like galls. Tilia spp.: Eriophyes tiliae

gallers on Stellaria

pub 20.ii.2020

Dichotomous table for gallers on Stellaria

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular or spindle-shaped swellings, up to 4 mm long. S. media: Meloidogyne hapla

= Cyst eelworms on roots belong to Heterodera schachtii, H. galeopsidis or H. trifolii.

2a On inflorescences, flowers or fruits => 19

2b On stems, buds or leaves => 3

3a Malformations on shoot tips, or extending over large areas of plant => 5

3b Galls defined locally, solitary or with several to many on leaves and stems => 4

4a Galls multi-cellular, flat hemispherical, wart-shaped; nutritive cell depressed at top up to 1 mm across; at first yellow-red. In large numbers on leaves, stems, flower peduncles and even calyx; solitary or coalescing into later on brownish, ± expanded, inconspicuous ridges or crusts. S. media, nemorum:
Synchytrium stellariae

4b Leaf blades with rotund, veins, stalks and stems with oblong-oval or spindle-shaped, up to 6 mm long, ± yellow margined, sometimes conspicuously arched bulges, soon covered with ring-shaped arrangement or ± coalescing groups of dark-brown, 2-celled teliospores. Stellaria spp.: Puccinia arenariae

5a Galls confined to shoot tips or lateral buds => 15

5b Malformations more extensive => 6

6a Stem is only secondarily involved in gall development => 7

6b Stem severely stunted, conspicuously spongy and thickened, especially at base, – distorted, pale green. Lateral organs clustered, ± stunted, partially similarly swollen and accordingly bent. Occasionally localised galls on well-developed stems, usually strongly curved. Leaf blades occasionally basally ± distorted. S. media: Ditylenchus dipsaci

7a Malformations caused by animals => 10

7b Malformations caused by fungi fructifying at surface => 8

8a More strongly infected shoots elongated, slightly hypertrophied, inserted leaves pale, slightly thickened; often bent, spoon-like, or irregularly curved; later on with down of branched conidiophores. Galls facultative => 9

8b Shoots etiolated; internodes lanky, elongated; leaves pale, leaf blades reduced, with expanded, scattered, golden-yellow sori on underside. Stellaria spp.: Melampsorella caryophyllacearum

9a On S. alsine, calycantha, graminea, holostea: Peronospora parva

b9 On. S. media, neglecta, nemorum, pallida: Peronospora alsinearum

10a Many terminal leaves disfigured on otherwise normal shoots => 11

10b At infestation site one or several internodes are slightly shortened on one side and ± curved. Leaves accordingly clustered; leaf blades usually arched, spoon-like, curled and locally deep green. Stellaria spp.: Philaenus spumarius

11a Malformations caused by aphids => 13

11b Malformations caused by mites or thrips => 12

12a Leaf blades ± curved; narrowly rolled upwards at margin. Usually on many terminally, clustered, sometimes ± discoloured leaves. S. alsine, graminea, holostea, palustris: Cecidophyopsis atrichus

12b Leaf blades of many terminal leaves± disfigured, rolled upwards and twisted; tissue inside stunted and undifferentiated. Whole plant, and inflorescences if present, atrophied. S. alsine, graminea, holostea, media: Taeniothrips atratus

13a Leaves variously loosely rolled downwards => 14

13b Leaves conspicuously pod-like, folded upwards over the midrib, sometimes ± discoloured and curved, sickle-shaped. Leaves accumulated close to the ± stunted shoot tip. S. graminea, holostea: Brachycolus stellariae

14a Shoot stunted at tip; leaves rolled inwards. Aphid 2–2.5 mm long, red-brown. S. media, nemorum: Myzus certus

14b Roll of leaf margin on S. media, nemorum caused by green aphids, 2–3 mm long: Aulacorthum solani

15a Galls longer than 5 mm, mainly on tips of main- and side shoots => 16

15b Side-, sometimes also terminal buds of S. alsine, graminea transformed into an elongate-oval or acuminate egg-shaped capsule-like gall, about 2–3 (4) mm broad and 3–5 mm long, consisting of two stunted, thickened leaf primordia: Ametrodiplosis duclosii

16a On S. holostea => 18

16b On other Stellaria species => 17

17a The severely stunted terminal outer pair of leaves on shoot are sessile, directed upwards and converging, mussel-like. Swollen at base, thickened and discoloured. Browning and rapidly decaying after departure of larvae. Containing several at first white, then lemon-yellow larvae. S. holostea, media: Macrolabis stellariae

17b Similar galls on S. nemorum. Larvae white to cream-coloured: Macrolabis buhri

18a Terminal ± severely stunted leaves on shoot transformed into an erect, ± pale green, soft, acuminate conical, basally slightly thickened, rapidly necrotic gall. Containing white-yellow larvae: Macrolabis holosteae

18b Terminal leaves on shoot severely stunted, transformed into conspicuously dark-brown, tough-walled, acuminate egg- to spindle-shaped, galls. Containing white larvae: Dasineura stellariae

18c Axillary leaf bud galls contain white larvae: Dasineura silvicola

19a Malformations of several parts of developing flowers or anthers => 20

19b Ovaries are not developed in disfigured capsules which remain small. Containing a single white larva. S. holostea: Dasineura holosteae

20a Flower buds of different age bloated on usually stunted stalks; ± unopened => 21

20b Corolla- and calyx leaves atrophied on usually bloated, infected flowers, often in large numbers per plant, spreading later on, with dusting of spores. S. alsine, calycantha, graminea, holostea, longifolia, media, palustris: Microbotryum stellariae

21a Spores inside early stunted buds, interiorly soon largely destroyed, ± globular to blunt conical. Spores united in balls discoloured ± red-brown in various gradations. Belonging to the smut fungus Thecaphora saponariae species complex => 22

21b Fungus with spores on branched conidiophores, developing on outside of calyx of globularly bloated, sometimes normally fruiting flowers => 9

22a On S. graminea: Thecaphora saponariae

22b On S. holostea, media: Thecaphora alsinearum

gallers on Sorbus

pub 19.ii.2020

Dichotomous table for gallers on Sorbus

by Hans Roskam

1a Malformations on inflorescences or flower => 23

1b Malformations on leaves or stem parts => 2

2a Galls on single or several terminal leaves => 5

2b Malformations exclusively or mainly on stems => 3

3a Pock-shaped galls on stems caused by scale insects or cancer-like proliferations on older organs => 4

3b Branches with spindle- to club-shaped swellings bearing: Viscum album

4a Woody stems with ± expanded cancer-like proliferations. Sorbus spp.: Eriosoma lanigerum

4b Closed, ± rotund galls, mainly on root collar. Sorbus spp.: Agrobacterium tumefaciens

4c Young shoots sometimes ± stunted or crippled often with many, centrally depressed rotund-oval pocks; containing scale below. Sorbus spp.: Chionaspis salicis

4d Dirty-grey rotund scale insects, about 1.2–1.6 mm long, live in irregular, usually rimmed depressions on bark of young stems of e.g., S. aucuparia: Epidiaspis leperii

5a Expanded curls or similar malformations on several mainly terminal leaves => 15

5b Leaf folds or -rolls, hair felts or local, sometimes clustered malformations on younger or older leaves => 6

6a Swellings caused by fungi, to varied extents on underside, yellow, also red, often yellow margined with conspicuous cylindrical to cornicular aecia protruding from the galls => 12

6b Malformations caused by animals => 7

7a Leaf blades folded, rolled or with pock-like swellings => 9

7b Leaf blades with abnormal pubescence => 8

8a Abnormal pubescence on leaf underside, mainly following venation. S. aucuparia, domestica, intermedia, etc.: Eriophyes sorbi

8b Expanded, at first whitish, then reddish to brownish erinea on under- or also on upper side of leaves, without close association with venation. Infected leaf blades are, if strongly infected, occasionally additionally disfigured during their development. Hairs compact, blunt-cylindrical or globular. S. aria, aucuparia, torminalis, etc.: Phyllocoptes sorbeus

9a Leaf blades with ± distinct rolls of margin => 11

9b Leaf blades folded along midrib or with pock-like swellings => 10

10a Leaflets on S. aucuparia completely or partially folded upwards along the ± curved, hardly thickened midrib, forming almost pod-like galls ± discoloured at base. Similar malformations on S. torminalis in only partially galled leaf blades. Containing several white larvae: Contarinia sorbi

10b Leaf blades with many pocks with narrow exit hole on undersides, weakly protruding on both sides, often less than 2 mm across, sometimes variously coalescing, at first pale-green, then browned. Sorbus spp.: Eriophyes sorbi

= a further subdivision according to host:

a On S. aucuparia: Eriophyes sorbi

b On S. aria: Eriophyes arianus

c On S. torminalis: Eriophyes torminalis

11a Leaf blades of almost unfolded leaves rolled upwards. Roll slightly thickened, ± discoloured. S. aucuparia: Unidentified gall midge

11b Leaf blade bent upwards, curved and crumpled. Larvae reddish-yellow. S. aria: Dasineura sp.

12a Wall of aecia at maturity thread-like rupturing up to base => 13

12b Peridium long horn-shaped; about 3‒4 mm long, up to 0.5 mm broad; its margin not, or only slightly, rupturing at maturity. Single cells broad, about 31–35 µm across. Inner- and side walls provided with fine or short, obliquely running ridge-like tubercles. Swellings usually weak cushion-like swollen. Sorbus spp.: Gymnosporangium cornutum

13a Galls like those of previous fungus; usually only flat cushion-shaped. Peridium cylindrical, only up to 0.5 mm broad; cells distinctly narrower than those of previous and next fungus; the wall thickenings consist at least of only smaller ridges => 14

13b Swellings usually strongly bumpy arched. Peridium cylindrical, 0.5–1 mm broad and protruding up to 3 mm; cells about 31–35 µm large, tough-walled, minute-warty. Sorbus spp.: Gymnosporangium tremelloides

14a Pseudoperidia remarkably slender, only up to about 0.25 mm broad, up to 2 mm high. Cells 18–25 µm broad; side walls with robust, transversely and obliquely running oblong tubercles and short ridges. Aeciospores 21–29 x 17–21 µm. Usually distinctly developed galls. S. torminalis, latifolia: Gymnosporangium confusum

14b Pseudoperidia up to about 0.5 mm wide and 2–3 mm long. Cells 14–20 µm wide; the strongly thickened side walls with many tubercles of unequal size and irregular shape. Aeciospores 26–32 x 22–25 µm large. Fungus on S. aucuparia, latifolia, torminalis on usually hardly swollen patches, often only developing spermogonia. Gymnosporangium clavariiforme

15a Malformations caused by spittlebugs or psyllids => 22

15b Malformations caused by aphids or fungi => 16

16a Malformations by aphids => 17

16b Leaf blade with conspicuous, bladder-shaped swellings of fungus, at maturity appearing frosted by filamentous erinea which consist of asci. S. chamaemespilus: Taphrina aff. deformans

16c s causer of small disfiguring spots or more expanded curlings on leaves. S. torminalis: Taphrina sorbi

17a Leaves ± disfigured, accumulated nest-like at shoot tips, only slightly discoloured => 18

17b Similar accumulations of usually soon conspicuously yellow or red discoloured, bladder-like swollen leaves, bent over at their tips. S. torminalis: Dysaphis aucupariae

18a Aphids yellowish-green or green => 19

18b In leaf-roll galls on S. aria. Aphids yellowish-white, furthermore close to Dysaphis plantaginea: Dysaphis ariae

19a Leaves not conspicuously curved, ± strongly curled => 20

19b Leaves on stunted shoots, strongly rolled, usually over the tip, accumulated into loose clusters, dropping in autumn; not discoloured and curled. Aphid foliage-green, with rather long, black, siphunculi Sorbus spp.: Aphis pomi

20a Aphid green to olive-brownish or darker and in that case with thick wax covering; distinguished by marginal tubercles on all body segments and the very short triangular cauda => 21

20b Aphid 1.5–2.5 mm long, green. Cauda tongue-shaped, siphunculi pale with dark tip; antennae slightly shorter than half the body length. S. aria, aucuparia, torminalis: Rhopalosiphum oxyacanthae

21a On S. aucuparia, hybrida. Leaves rolled downwards over their tips, disfigured and curled. The dense nest-like, globose accumulations dry out and often remain on the tree until the following spring. Dysaphis sorbi

21b On S. torminalis, rarely on S. aucuparia. Usually the terminal leaves show a yellowish to reddish discolouration of the venation. Dysaphis aucupariae

22a Leaves developing in spring stunted, variously disfigured, usually with several flat yellowish larvae on underside. S. aucuparia, aria and relatives : Cacopsylla sorbi

22b Usually several flatted froth-covered nymphs on the underside of the leaves, each in a shallow depression. S. aria, aucuparia, domestica, torminalis: Cacopsylla albipes

22c Similar malformation. S. aria: Cacopsylla breviantennata

23a Parasite inside disfigured flowers => 25

23b Inflorescence ± stunted, compact; flowers stunted and disfigured => 24

24a Organs of young inflorescences sometimes with the neighbouring disfigured leaves ± densely bunched together. S. aucuparia: Dysaphis sorbi

24b All parts of young inflorescence stunted. Buds clustered into irregular pseudo-umbels or into squarrose panicles. All green parts densely pubescent. S. aucuparia: Phyllocoptes sorbeus

25a Flower buds swollen, unopened, yellowish-green. Corolla at first not discoloured. Inside are several pale yellow, jumping larvae. S. aria, aucuparia: Contarinia floriperda

25b Flower buds slightly enlarged; corolla unopened, soon browned. With a beetle larva inside. S. aucuparia: Anthonomus conspersus

= Also Anthonomus pomorum may occasionally occur on S. aucuparia

gallers on Solanum

pub 18.ii.2020

Dichotomous table for gallers on Solanum

incl. Lycopersicon

by Hans Roskam

1a Malformations on higher situated parts above ground => 9

1b Variously shaped malformations on roots, stolons, tubers, root collar => 2

1c White, velvet cover on all parts of the plant, even underground. Attacked parts turn brown and wither. The conidia (in fact, sporangia) are ovoid or lemon-shaped, with an indistinct apical papilla. They are formed at the tip of seemingly undifferentiated hyphae, that here and there show irregular swellings. S. dulcamara, melongana, nigrum, physalifolium, tuberosum; also on Lycopersicon: Phytophthora infestans

2a Malformations only or mainly on roots => 7

2b Malformations on runners, tubers or on root collar, on other organs only under particular conditions and usually occurring simultaneously with previously reported malformations => 3

3a Malformations on stolons or tubers => 5

3b Malformations on root collar or on basally situated buds => 4

4a Gall formation not exclusively dependent on buds. Proliferations ± compact; rugose from outside, soon enclosed in tougher, corky tissue. Cavities inside many, running up to periphery. Inducer hardly microscopically detectable. Never on tubers and only exceptionally on stolons. “Bacterial-cancer|”. S. tuberosum: Agrobacterium tumefaciens

4b Proliferations usually close to ground; only developing from buds; soft at surface. Spores distinctly detectable in tissue. Galls very variable, depending on kind of host and developmental stage, time and degree of infestation; ± fissured, often coral-like; with strongly reduced primordia of organs. Pale below ground, above ground buds greened. Mainly on tubers, exceptionally on stolons or leaf parts; in potatoes never occurring on roots. “Potato-cancer”. S. tuberosum: Synchytrium endobioticum

5a Swellings usually less than 10 mm, flat; usually no connection with buds; on stolons or also on tubers => 6

5b Galls expanded, only developing from buds of tubers; at surface coral- or cauliflower-like, incised; at first white and compact, later on dark brown and rotting. On single or many buds, sometimes enveloping the complete tuber. “Potato-cancer”. On S. tuberosum and many tuber bearing relatives: Synchytrium endobioticum

6a The galls, about 3–6 mm long, rotund to oval, wart-like, mainly developing on tubers and on stolons, occasionally occurring mainly also on roots, at first white, later on dark-brown are ± rotund-oval, bladder-shaped and contain in the strongly hypertrophied nutritive cells of the swollen parenchyma masses of ball-like accumulated, rotund spores, made conspicuous by their dark colour. “Powder scab”. S. tuberosum as well as many, especially tuber bearing relatives: Spongospora subterranea

6b Developing tubers, almost only close to lenticels, with partially strongly arched swellings, also encroaching into the tissue, consisting of living cells, which contain many eelworms in between; weaker, mainly one-sided swellings sometimes simultaneously on stolons. S. tuberosum: Ditylenchus dipsaci

= Damage of tubers, known as “worm rot” has been caused by Ditylenchus destructor

7a Gall development inconspicuous from the outside, of irregular shape => 8

7b Roots with swellings usually on all sides, 2–5 mm long, slender spindle-shaped or ± conspicuous nodular, smooth-walled, sometimes joining, containing eelworms. S. dulcamara, melongena, nigrum, tuberosum, villosum: Meloidogyne spp.

7c Conspicuous, usually one-sided, sometimes fissured, almost cancer-like proliferations on thicker roots are caused by “Powder scab”: Spongospora subterranea

8a Roots externally not galled, or only on particular substrates, with slightly spindle-shaped galls. The temporarily about poppy-seed size, at first white, later on yellow, eventually brown, soon dropping cysts with giant cells developed inside roots. The healthy parts above the infestation site usually develop many “starvation roots”. On S. tuberosum and many wild potatoes, occasionally on S. dulcamara, luteum, melongena, also several forms of S. nigrum, etc.: Globodera rostochiensis

8b Roots with smaller, at first pale, later on brown galls, about 1–2.5 (4) mm long, wart-like, at surface often ± fissured, sometimes densely arranged or coalescing; similar infestation sometimes also on subterranean stem internodes. S. dulcamara, villosum, nigrum as well as several varieties and forms: Synchytrium endobioticum

9a Galls on stems, shoot tips or leaves => 11

9b Malformations on inflorescences or flowers => 10

10a Inflorescence largely stunted; flower primordia clustered into often long, ± raceme-like arranged galls. Flowers leafy in variously shaped, often densely haired rosettes. S. dulcamara: Aceria lycopersici

10b Flower buds strongly swollen, unopened. Galls greenish or ± violet tinged. Stamens and ovaries thickened and ± curved. Containing several ivory-white larvae. S. dulcamara: Contarinia solani

= Orange-yellow midge larvae of Macrolabis dulcamarae live as inquilines in galls on S. dulcamara

10c Berry disfigured and ± bumpy. Containing a single or several larvae. S. nigrum, tuberosum: Asphondylia trabuti

11a Malformations mainly on leaves or on shoot tips => 12

11b Gall development mainly on stems, occasionally over two or more internodes ± strongly shortened, curved, spongy, swollen and discoloured pale green. Leaves clustered at infestation site; development stunted; usually stalks, and midrib similarly galled; leaflets stunted and ± disfigured. Diseased parts usually prematurely withered. S. robustum, villosum, memphiticum, nigrum, tuberosum: Ditylenchus dipsaci

12a Expanded malformation of several organs on tips or terminally on shoots => 13

12b Leaf blade underside usually with many ± golden-yellow wart-like galls, less than 1 mm long. Also on petioles and basal stem parts; sometimes joined into ridges or crusts. S. dulcamara: Synchytrium aureum

13a Malformations caused by aphids => 15

13b Malformations caused by spittlebugs or mites => 14

14a All organs in often expanded arrangement terminally on apical or lateral shoots, and -buds ± stunted, bearing strongly reduced, often densely clustered, whitish or grey pubescent leaflets. Malformations sometimes up to 60 mm long and 40 mm wide; also encroaching into inflorescence. Lycopersicum esculentum; Solanum dulcamara, nigrum: Aceria lycopersici

14b Internodes close to shoot tip locally stunted and curved. Inserted leaves clustered, axial parts and margins curved; locally deep green. Similar malformations on larger leaves without involvement of axial parts. Lycopersicon esculentum, Solanum spp.: Philaenus spumarius

15a Aphids yellow or green => 17

= Many aphids, especially the host alternating species, inhabit not only potatoes, but also other hosts, during summer, preferably on leaves of varying age, which become variously disfigured. Aphids of some species may, in the later vegetative period, develop more luxuriously on plants already diseased by virus. It may be difficult to determine whether malformations are primarily the result of virus, making aphids secondary inhabitants, or primarily caused by aphids

15b Aphids almost black => 16

16a Leaves of ± stunted shoot tips clustered; ± deflected and curled over their top. Aphid only separable from the next species by microscopic characters, but preferentially colonising S. nigrum: Aphis fabae solanella

16b Similar malformations. S. nigrum, tuberosum: Aphis fabae fabae

17a Antennae longer than body => 18

17b Antennae of apterae not exceeding tip of abdomen, distinctly shorter than body => 19

18a Apterae pale yellowish to green, with a darker green spot at insertion of each siphunculus. Body pear-shaped, broadest at abdomen. 1.8–2.9 mm. Siphunculi pale, with darker tip, 1/5–1/4 body length, about twice as long as cauda. Alates green, with yellowish-brown to black-brown thorax, and with dark transverse stripes on abdomen. Lycopersicon esculentum, Solanum dulcamara, nigrum, tuberosum, villosum: Aulacorthum solani

18b Aphid green, often with a dark, green longitudinal stripe on back. Body spindle-shaped oval, glossy in adults, frosted in froth-covered nymphs. 2.5–3.6 mm. Siphunculi brownish, ¼–⅓ of body length, twice as long as cauda. Alates with pale brownish-yellow thorax, otherwise lacking pigmentation on back. Lycopersicon esculentum, Solanum dulcamara, melongena, nigrum, tuberosum: Macrosiphum euphorbiae

19a No tubercles on head. Siphunculi cylindrical or slightly conical. Abdomen of alates without dark median patch => 20

19b Head with tubercles at antennal bases. Apterae pale green, rarely reddish. Siphunculi pale, slightly club-shaped. Alates with head, thorax, a large median patch on abdomen, dark brown-black. Lycopersicon esculentum, Solanum dulcamara, melongena, pseudocapsicum, tuberosum: Myzus persicae

20a Apterae yellow to greenish-yellow. Siphunculi yellowish-green with brownish tips. S. dulcamara, melongena, tuberosum: Aphis nasturtii

20b Apterae dark-green spotted to dirty yellow. Siphunculi black, slightly conical. Lycopersicon esculentum; Solanum laxum, melongena, tuberosum: Species complex of Aphis gossypii

gallers on Sinapis

pub 17.ii.2020

Dichotomous table for gallers on Sinapis

(incl. Coincya)

by Hans Roskam

1a On parts above ground => 5

1b On roots or root collar => 2

2a Galls on roots => 3

2b Whitish, rotund, one-chambered swellings on root collar, up to about 6 mm long, sometimes with several and ± coalescing. Each chamber containing a single white larva. S. alba, arvensis: Ceutorhynchus assimilis

3a Malformations mainly on lateral roots, only exceptionally more than 5 mm long and 3 mm wide => 4

3b Galls of very variable size, conspicuous on main- lateral roots; spindle-shaped to cylindrical, usually more than 10 mm, up to even 20 mm long and about 4–8 mm wide; sometimes encroaching from the main root onto the branchings, also coalesced into larger groups; succulent. Inside are masses of minute spores. “Clubroot”. S. alba, arvensis & subsp. allionii: Plasmodiophora brassicae

4a Roots with small nodular to elongate cylindrical, usually many swellings bearing several lateral roots. S. alba, arvensis: Meloidogyne hapla

4b Outside of roots unchanged; inside with giant cells, bearing poppy seed-sized white to brown cysts. S. alba, arvensis: Heterodera sp.

= Scattered reports of damage by H. schachtii, H. trifolii and H. cruciferae

5a Malformations on inflorescences, flowers or siliques => 16

5b Galls on leaves, axial buds or stems, in the latter case sometimes encroaching onto inflorescences => 6

6a Gall formations ± delimited in expansion, usually only on parts of infected organs => 10

6b Malformations of irregular shape and expansion; usually on various organs => 7

7a On organs of ± fully developed plants => 8

7b Young plants severely stunted and disfigured. Petioles and main venation as well as shoots stunted, pale green, spongy. S. alba, arvensis: Ditylenchus dipsaci

8a The inducers develop on the outside of mostly terminal malformations => 9

8b Stem slightly swollen to large extent. In the increased pith of the ± disfigured, stunted and sometimes distorted plants live several beetle larvae. S. arvensis: Ceutorhynchus napi

9a Axis of the tips of vegetative- or developing flowering shoots ± stunted; the inserted organs clustered, development stunted. Leaf blades curved, curled. Flower buds or flowers variously disfigured. S. alba, arvensis: Brevicoryne brassicae

9b Stem locally stunted, sometimes bent; the inserted leaves clustered; the leaf blade arched, at the infestation site ± curled and discoloured deep green. S. alba, arvensis: Philaenus spumarius

10a Galls on well-developed stems or leaves => 11

10b Terminal, also lateral shoots, and axillary buds severely stunted in longitudinal growth. Leaves clustered, the inner ones developing into rosette- to bud-like galls, especially thickened at base. Containing several whitish to pale yellow, jumping larvae. S. alba, arvensis: Contarinia nasturtii

11a Malformations caused by fungi => 15

11b Malformations caused by animals => 12

12a Causers inside entirely deep green galls => 14

12b Causers develop outside the malformations => 13

13a Leaf blade with small, localised swellings. S. arvensis: Inducer unidentified – ? psyllid

13b Leaf blade ± folded, or variously deflected or bent upwards at margin, usually pale green, sometimes reddish marbled. S. alba, arvensis: Brevicoryne brassicae

= Lipaphis erysimi, which is facultatively cecidogenic on several crucifers, also occurs on Sinapis.

14a Galls flat spindle-shaped, 10–15 mm long; mainly on midrib, midrib or petioles, occasionally on stems. Containing a single larva. S. alba, arvensis: Ceutorhynchus chalybaeus

14b Galls flat rotund-oval, including the finer venation situated in the leaf blade. S. arvensis: Ceutorhynchus leprieuri

15a Leaf blade on underside with rotund bulges, up to 10 mm wide, or young stem parts ± spindle-shaped, often expanded, which are at first glossy, porcelain-like, later rupturing and with mealy dusted sori. S. arvensis, rarely S. alba: Albugo candida s. lat.

15b Leaf blade with weak bladder-like swellings; young stem sometimes with conspicuous, usually one-sided, ± distorted bulge-like swellings, soon covered with a whitish down of branched conidiophores. S. alba & subsp. dissecta, arvensis & subsp. allionii: Hyaloperonospora brassicae

16a Malformations on inflorescences or flowers => 17

16b Siliques usually only insignificantly stunted and disfigured; ± sterile, early (prematurely) maturing; contain several white larvae. S. alba, arvensis: Dasineura napi

17a Malformations caused by fungi => 22

17b Malformations caused by other inducers => 18

18a Galls on single or several flowers of inflorescences that are not additionally conspicuously stunted => 21

18b Axis usually ± stunted with clustered flower buds => 19

19a Malformations not abnormally pubescent => 20

19b Calyx little changed; inner flower parts transformed into ± leaf-like organs or greened; infected parts excessively pubescent. S. arvensis: Unidentified gall mite

20a Flower buds clustered on the stunted, hardly swollen axial parts. Containing several white to pale yellow jumping larvae. S. alba, arvensis: Contarinia nasturtii

20b Flowers largely stunted; at terminal parts of racemes sometimes normally arranged or more clustered; only the sterile remaining ovary is greatly enlarged. S. arvensis: Inducer unidentified – ? aphid

21a Flower buds enlarged, inflated, unopened. Corolla ± stunted. Stamens shortened and thickened. Containing several white, non-jumping larvae. S. alba, arvensis: Gephyraulus raphanistri

21b Galls similar. Larvae whitish to lemon-yellow, jumping. S. alba, arvensis: Contarinia nasturtii

22a Diseased flowers, with exception of stamens, often conspicuously enlarged. At first glossy, porcelain-like, soon bearing mealy dusted sori. Mainly occurring on single flowers; sometimes flower peduncle and midrib of galled inflorescence is also often elongated. S. alba, arvensis & subsp. allionii: Albugo candida

22b In the infected flowers, often inserted on short stalks, only the ovaries are hypertrophied, later on bearing down of branched conidiophores. All other organs ± strongly atrophied. Usually several to many flowers on the ± swollen and distorted axis of inflorescences are similarly galled, also covered with conidiophores. Galls partially contain oospores. S. alba & subsp. dissecta, arvensis & subsp. allionii: Hyaloperonospora brassicae

gallers on Pimpinella

pub 16.ii.2020

Dichotomous table for gallers on Pimpinella

by Hans Roskam

1a Malformations on parts above ground => 2

1b Lateral roots usually with several nodule- to spindle-shaped swellings from which originate some lateral roots. P. anisum: Meloidogyne hapla

2a On flowering or fruiting inflorescences => 17

2b On vegetative parts => 3

3a Gall formations primarily affect leaf sheaths of leaf blades of leaflets => 8

3b Galls primarily on petioles, midrib, leaf veins or on stems => 4

4 Fungi live inside galls; but fruiting bodies develop at gall surface => 5

4b The scale-covered nymphs develop in rimmed depressions on spindle- to barrel-shaped or bulging swellings of leaf sheaths or basal stem parts. P. saxifraga: Planchonia arabidis

4c Spindle-shaped one-chambered swelling of stem or rays of umbel, 5–8 x 3–5 mm; surface green, longitudinally striate; thick-walled. P. villosa: Contarinia pimpinellae

5a Galls- bulging, soon bearing sori of rust fungi => 6

5b Galls as small, closed warts on the leaf axis, also on leaflets and stems. P. major, saxifraga: Physoderma hemisphaericum

5c Galls elongate spindle-shaped, a few to several (15) mm long; glabrous, at first vitreous, yellow-green, then ± browned. On the veins and axis of leaves, also on stem parts, usually close to ground. Many spores close to vascular bundle. P. major, saxifraga: Protomyces macrosporus

6a Galls bearing countersunk aecia and spermogonia => 7

6b Ridges on leaves with variable long, yellow-margined slight bulges, from which erupt cinnamon-to dark brown telia. P. major, siifolia: Puccinia corvarensis

7a Expanded or smaller, ± spindle-shaped, yellow bulges on petioles, midrib, leaf veins; occasionally on young stems; bearing pale yellow, pustule-shaped opening aecia. Peridium not or slightly protruding, if so then glossy white and irregularly frayed. Pimpinella spp.: Puccinia pimpinellae

7b Bulges similar, but usually smaller and more strongly swollen, often vivid reddish-yellow. Aecia deeply countersunk, sometimes remaining enclosed by tissue, globular or flat, not cup-shaped. Peridium not protruding. P. anisum, major, peregrina, saxifraga: Puccinia bistortae species complex.

8a Malformations on leaflets, with or without involvement of midrib => 9

8b Leaf sheath, especially close to umbel, inflated, bulging and swollen, succulent, often lacking leaf blade, enclosing the etiolated side shoot, sometimes inducing a cone-shaped acuminate gall. Larvae orange-red. P. major, saxifraga: Jaapiella hedickei

8c Occasionally, in very similar malformations, on P. major, peregrina, saxifraga, also develops: Semiaphis pimpinellae

9a Malformations affect leaflet leaf blades as well as leaf midrib => 15

9b Malformations on leaf blades, usually without stunting of midrib => 10

10a Leaf blades folded, as in buds => 12

10b Malformation on at least partially ± unfolded leaf blades => 11

11a Apart from often only a few normal leaflets, many are rolled at margin, thickened, ± frayed, twisted and distorted, weakly pubescent. P. major, saxifraga: Aceria peucedani

11b Leaf blades that are infected during their development show pale-green, weakly inflated upward arches, covered on underside with a dense cover of white conidiophores. P. major: Plasmopara nivea

12a Rolls or folds of leaflets => 14

12b Halves of leaflets do not unfold => 13

13a The folded leaf blade is ± shortened and curled, discoloured close to the midrib. White larvae develop between the ± distinctly thickened folds. P. major, saxifraga: Macrolabis sp.

13b Similar gall, but midrib usually bent and thickened: Contarinia sp.

14a Leaflets longitudinally rolled upwards, ± thickened. White midge larvae inside. P. saxifraga: Unidentified gall midge

14b Leaflets curled upwards or folded. Galls sometimes ± yellowish, also reddish, transversely undulate and partially twisted. P. major, peregrina, saxifraga: Semiaphis pimpinellae and/or Hyadaphis foeniculi

15a Malformations caused by aphids or psyllids => 16

15b Midrib over the tip or laterally ± conspicuously bent, with accordingly clustered, curled, deflected, locally deep green leaflets. P. anisum, major, saxifraga: Philaenus spumarius

16a Midrib of young leaves stunted. Leaf segments deflected, ± curled, slightly discoloured; with black aphids on underside. P. anisum, major: Aphis fabae

16b Leaf segments ± deflected at margin, with protrusions up to 5 mm wide, not discoloured, usually on upper side. Midrib of infected developing leaves severely stunted. P. anisum, major: Trioza apicalis s. l.

17a On flowers or fruits => 22

17b On ± expanded parts of inflorescence => 18

18a Malformation of large parts or complete inflorescence => 19

18b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall lined with mycelium. Containing a red larva. Pimpinella spp.: Lasioptera carophila

19a Malformations caused by aphids or thrips => 20

19b Inflorescence ± stunted, flower parts, usually with exception of aborted ovaries, greening and leafy. P. major, saxifraga: Aceria peucedani

20a Malformations associated with variously stunted axial parts or clustering of umbels. Sheaths of bracts usually ± swollen, bladder-like, and discoloured violet-red. Flowers undeveloped or ± greened; caused by aphids => 21

20b Gall-like malformations on flower buds or flowers caused by froth-covered nymphs or by very agile adult thrips. P. saxifraga: Unidentified thrips

21a Aphid green. P. major, peregrina, saxifraga: Semiaphis pimpinellae

21b Aphid black. P. saxifraga: Aphis fabae

22a On fruits => 24

22b Flowers globular, swollen, unopened => 23

23a Galls on P. saxifraga, rarely on P. major, ± globular, often reddened. Containing a sulphur- or lemon- yellow jumping midge larva: Diodaulus traili

23b On P. major, rarely on P. saxifraga. Larvae dark orange-coloured, jumping: Contarinia umbellatarum

24a Usually only one mericarp strongly inflated, bladder-like; distinctly protruding from the umbel. Wall thin, often reddened. Containing 1 (2–3) orange-red larvae. P. anisum, major, saxifraga, tragium: Kiefferia pericarpiicola

24b Young fruits slightly disfigured, shortened, rounded; mericarps not splitting up; containing pale brown-red or yellowish olive-coloured smut spores. P. saxifraga: Thecaphora pimpinellae

gallers on Cardamine

pub 15.ii.2020

Dichotomous table for gallers on Cardamine

by Hans Roskam

1a On parts above ground => 2

1b Main- and side roots with conspicuous, spindle-shaped, succulent, compact galls with length of 2–15 mm. |”Clubroot”. C. amara, parviflora, pratensis: Plasmodiophora brassicae

1c Small, half globular or irregularly shaped galls on root collar at base of basal leaves, caused by beetle larvae. Cardamine spp.: Ceutorhynchus minutus

2a Malformations caused by fungi fruiting at surface => 17

2b Malformations caused by animals or by fungi fruiting inside gall => 3

3a On flowers, fruits, and their stalks or on vegetative axillary buds => 13

3b On leaves or stems => 4

4a On stems, leaf base or on veins => 7

4b Galls exclusively or predominantly on leaf blades => 5

5a Leaf blade with grooves or warts => 6

5b Axis of leaflet stunted, leaflets clustered; leaf blades folded or (especially if leaf blades undivided), strongly rolled upwards. Leaf blades wrinkled, green, in many species additionally haired. C. alpine, bellidifolia, bellidifolia, hirsuta, impatiens pratensis, resedifolia: Aceria drabae

6a Leaf blade with scattered small grooves. C. amara, flexuosa, hirsuta, impatiens, opizii, uliginosa: Trioza rotundata

6b Leaf blades with many warts, on underside ± half globular protruding, golden-yellow translucent, less than 1 mm long; also on leaf midrib and -stalk, as well as on lower stem parts; sometimes coalescing crust- or ridge-like. C. amara, pratensis: Synchytrium aureum

7a Galls on stems, leaf base or rachis; inducer inside gall => 9

7b Malformation of stem by parasites on outside => 8

8a Stem swollen over variable length, on rind with ± rimmed, flat depressions, each containing a froth-covered nymph. C. glauca: Planchonia arabidis

8b Axial parts stunted and curved; neighbouring leaves clustered. Containing a froth-covered nymph. Cardamine spp.: Philaenus spumarius

9a Swellings glabrous; containing midge- or beetle larvae => 10

9b Shoot- or also leaf axis severely stunted, often spongy and swollen on all sides, if one-sided, then often associated with curving; galls pale green, with wrinkled surface. C. hirsuta, pratensis: Ditylenchus dipsaci

10a Galls slender, ± spindle-shaped or elongate; caused by beetle larvae => 12

10b Galls compact, oval or ± barrel-shaped => 11

11a Petiole at base, including neighbouring stem tissue, strongly swollen. Axial buds severely stunted, hardly enlarged. Caused by midge larvae. C. amara: Dasineura cardaminicola

11b Single galls ± barrel-shaped, often on stem base, also on stalks or midrib of basal or lower leaves; occasionally in shorter or longer groups, often bulging, even coalescent, up to 15–30 mm long. Each gall contains a beetle larva. C. amara, hirsuta, impatiens, pratensis: Ceutorhynchus pectoralis

12a Stem at various sites usually with slender spindle-shaped swelling on all sides or more one-sided, then often ± curved, about 10–20 mm long; the fleshy tissue contains a larva inside. C. amara, hirsuta, pratensis: Ceutorhynchus pectoralis

12b From similar, but rougher galls on C. resedifolia has been reared Ceutorhynchus chalybaeus

12c Usually lower part of shoot axis, with one-sided weak swellings. Galls and upper stem parts often slightly curved. The rind layer with narrow feeding site, containing a beetle larva. C. amara, pratensis: Psylliodes napi

13a On flower peduncles, flowers or fruits => 14

13b Lateral buds disfigured. C. flexuosa, hirsuta: Dasineura umbrosa

14a Malformations on flowers or flower peduncles => 15

14b Malformations on fruits. Siliques shortened, hardly thicker than their stalk. Diseased parts of inflorescence further developing and flowering sporadically when the healthy parts are already bearing fruits. Anthers of diseased flowers ± disfigured, dirty grey-brown, covered, and filled with conidia. Young seed soon aborted and filled with bright brown spores. C. alpina, bellidifolia: Thecaphora thlaspeos

15a On flower buds or flowers => 16

15b Flower peduncle severely swollen at base. C. amara: Dasineura cardaminicola

16a Flower buds swollen. Calyx ± normal; corolla unopened, thickened at base, greened. Stamens shortened, bent and thickened. Containing several red larvae. C. amara, flexuosa, opizii, pratensis: Dasineura cardaminis

16b Flowers filled with stamens and ovaries changing into corolla leaves. C. pratensis subsp. paludosa, pratensis: Unidentified gall mite

17a Malformations covered by brown sori => 20

17b Malformations with white sori => 18

18a Sori consisting of loose down of branched conidiophores => 19

18b Sori pad- or bulge-like, compact, at first closed, glossy, porcelain-like, after rupturing mealy dusted; in variable expansion on ± swollen, sometimes arched parts on all green organs. Cardamine spp : Albugo candida

19a On the occasionally completely infected plants or rarely also on lateral short shoots all parts are stunted, pale green, slightly thickened, the leaf blade margins ± curved. Localised infestation of stems results in slight swellings and curvings. Underside of the leaves with a whitish down, consisting of erect conidiophores that apically are branching several times, each branch ending in a conidium. C. bulbifera, heptaphylla, impatiens, parviflora, pentaphyllos: Hyaloperonospora dentariae

19b Sori similar, usually more loose, on many plant parts, only exceptionally inducing gall-like malformations. C. amara, flexuosa, heptaphylla, hirsuta, impatiens, macrophylla, pratensis, trifolia: Hyaloperonospora parasitica

19c On Cardamine enneaphyllos,? glanduligera. Infection usually systemic, plants become dwarfed, stunted and chlorotic. Underside of the leaves with a whitish down, consisting of erect conidiophores that are dichotomously branching apically several times, each branch ending in a conidium: Hyaloperonospora cardamines-enneaphyllos

19d On C. graeca. Underside of the leaves with a whitish down, consisting of erect conidiophores that apically several times are dichotomously branching, each branch ending in a conidium: Hyaloperonospora malyi

20a Sori on the sometimes slightly swollen leaf midrib, also on stems, axis of inflorescence or fruits; bearing early naked, chestnut-brown, 2-celled telia. C. alpina, bellidifolia, pratensis, resedifolia: Puccinia cruciferarum

20b Smaller or expanded swellings, only later erupting, bulge-shaped, usually associated with strong curving and twisting, up to 25 mm long, at first grey, later on brown dusted; on all green parts and even occurring on pale subterranean shoot parts. C. bulbifera, enneaphyllos, glanduligera, heptaphylla, macrophylla: Puccinia dentariae

gallers on Anemone

pub 14.ii.2020

Dichotomous table for gallers on Anemone

incl. Hepatica, Pulsatilla

by Hans Roskam

1a On above-ground plant parts => 2

1b Roots with nodule-shaped swellings. A. apennina, sylvestris, Hepatica nobilis, Pulsatilla vulgaris: Meloidogyne hapla

2a On stems, rhizomes, leaves and bracts (whorl of leaves on flower peduncle) => 5

2b On flowers and fruits => 3

3a On fruits => 4

3b Flower peduncle shortened. Flower sterile; pod atrophied, remaining on plant. Pulsatilla alpina: Unidentified gall mite

4a Fruit swollen at base, appendage abnormally pubescent, twisted. Containing yellow or reddish larvae. Pulsatilla pratensis, vernalis, vulgaris: Dasineura pulsatillae

4b Ovary or fruit disfigured. Larva yellow. Pulsatilla pratensis: Unidentified gall midge

5a Malformations of aerial parts, already displaying early sori => 15

5b Malformations without fruiting bodies at surface or bulges, rupturing later on and releasing dusting of spores => 6

6a Malformations restricted to less extensive plant parts => 7

6b Flowering or non-flowering plants usually conspicuously disfigured, in all parts ± greatly enlarged. A. nemorosa; also recorded from A. ranunculoides, trifolia: Virus disease

6c Aphids in early spring on the root collar and stem base; later on the leaves and finally on the developing fruits; no host plant alternation. P. vulgaris ssp.grandis, pratensis subsp. nigricans: Aphis pulsatillicola

7a Bulges conspicuous, often strongly arched or curved, soon translucent lead-grey, rupturing later on and releasing black dusting, or fungus sori brown, remaining closed => 14

7b Plant parts with small wart-shaped or ± expanded, pale green spongy or more compact, concave swellings, or leaf blades rolled, folded or bent => 8

8a Swellings wart- or bulge-like => 12

8b Leaf blade rolled, folded or bent => 9

9a Leaf blade ± narrowly rolled upwards => 11

9b Leaf blade folded or bent => 10

10a Tips of bracts folded, shortened. Midrib swollen, reddened. A. nemorosa: Unidentified dipteran

10b Leaf blades ± nest-like clustered downwards, bent. Containing a froth-covered nymph. A. sylvestris, Pulsatilla pratensis and several cultivated species: Philaenus spumarius

11a Single or all leaflets with loose, ±curled, rough upward roll; on younger leaves often including the major part of leaf blade. Rolls ± red coloured, sometimes twisting the leaf blade. Containing several yellow-red larvae. A. sylvestris: Unidentified gall midge

11b Leaf blades rolled upwards, sometimes ± twisted, screw-like. Anemone spp., Hepatica nobilis: Aphelenchoides fragariae

12a Galls expanded, usually ± bulging => 13

12b Small red- to black-violet warts, up to 0.5 mm long, often many and mainly on leaf underside. A. nemorosa, ranunculoides; less abundant on A. coronaria, sylvestris, Anemonoides seemenii, Pulsatilla alpina: Synchytrium anemones

13a Stem- or predominantly lower leaves spongy, swollen basally to varied extent. Surface of often pale green galls ± wrinkled. Parasites inside the galls. A. coronaria, x japonica, Hepatica nobilis: Ditylenchus dipsaci

13b Petiole or partially also rachis with an irregular spindle-shaped swelling, about 15–30 mm long, tough-walled, usually curved, having one or more depressions, containing the initially surface living gall causer. P. pratensis: Planchonia arabidis

14a Leaf blade with ± rotund bladder-like swellings of various size, protruding on upper side, more rarely on underside. Petiole, also stem, with distinctly protruding, sometimes curved, ± spindle-shaped bulges. Patches crust-shaped, initially often yellowish, soon dark-, later on black-brown; not opening. On A. sylvestris and other species. Galls 5, 6 to winter. Anemone sylvestris; Pulsatilla alpina, armena, halleri, montana, patens, pratensis, vernalis, vulgaris: Puccinia pulsatillae species complex

14b Sori conspicuous, lead-grey translucent, rupturing later on and releasing black dusting of spores; on the leaf blades rotund, usually bladder-like arched upwards; on leaf veins, -stalks and stems bulging, often accompanied by stronger curvatures; occasionally even on flower parts and on pale rhizome sections. The forms of this fungus occur on many anemones and belong to the former species complex. Urocystis anemones s.l.

a On A. apennina, nemorosa, ranunculoides and relatives: Urocystis anemones s.str.

b On A. baldensis, coronaria, sylvestris and relatives: Urocystis antipolitana

c On members of Hepatica, such as H. acutiloba, nobilis, transsilvanica: Urocystis syncocca

d On members of Pulsatilla, such as P. alpina, montana, patens, pratensis, vulgaris and relatives: Urocystis pulsatillae

15a Malformations with brown sporulating sori => 19

15b Malformations with lighter aecia and pycnidia => 16

16a Petiole conspicuously elongated, developing early. Leaf blades ± stunted; leaflets narrowed, usually less subdivided, slightly thickened, paler. Aecia scattered on the underside of leaf blade. Sometimes also ± partial but expanded infestation on flowering plants; sori then even on flowering parts. Mycelium perennial => 17

16b Sori on underside of leaves ± rotund, up to about 10 (15) mm broad, elongate-oval on veins and stalks, yellowish, often only slightly thickened. Hepatica nobilis, vulgaris: Puccinia actaeae-agropyri

17a Cups of aecia rupturing, with a few broad lobes => 18

17b On A. nemorosa. Cups whitish; peridium rupturing into many lobes. Copious, initially white, later on brownish spermogonia only on upper side. Membrane of aecia thickened at apical part: Ochropsora ariae

18a On A. ranunculoides. Peridium usually with only a few, 3–5 (6), broad lobes. Spermogonia already initially dark, on both leaf sides. Spore membrane thickened terminally: Tranzschelia pruni-spinosae

18b Aecia analogous; on severely disfigured leaves and shoots, sometimes also flower parts of ornamental anemones, such as A. blanda, coronaria, hortensis: Tranzschelia discolor

19a Mycelium and sori expanded. Diseased organs with longer stems, narrowed => 20

19b Mycelium restricted; sori compact, bulging, rotund on the underside of sometimes curled leaf blades; on distinctly thickened veins or stalks ± elongate spindle-shaped, sometimes coalescing into long ridges. A. altaica, ranunculoides: Puccinia singularis telia

20a Petiole ± elongate; leaf blades variously stunted, simplified, somewhat thickened; plants usually non-flowering. Leaf blades on underside, mainly towards margin with expanded areas of rotund, dusty sori of dark brown telia and black-brown pycnidia. Scattered also on flowering plants. Flowers stunted, disfigured. A. nemorosa, also on A. apennina, blanda, nemorosa, sylvestris, trifolia; Anemonoides seemenii: Tranzschelia anemones

20b Leaves usually longer stalked; leaf blade less expanded, narrower; sori dusting, expanded on leaf underside. P. alpina, halleri incl. subsp. styriaca, montana, patens, pratensis, vernalis, vulgaris: Tranzschelia pulsatilla

gallers on Peucedanum

pub 12.ii.2020

Dichotomous table for gallers on Peucedanum

by Hans Roskam

1a On parts of flowering or fruiting inflorescences => 21

1b On vegetative plant parts => 2

2a Malformations mainly of leaf segments => 13

2b Malformations mainly of stems, petioles and midrib or of venation of leaflets => 3

3a More or less spindle-shaped bulges caused by rust fung => 4

3b Spindle-shaped, vitreous, glabrous, yellowish-green, later brownish bulges on leaf axis and stem. Spores develop inside the galls. P. ostruthium, palustre: Protomyces macrosporus

4a Galls caused by mycelia developing uredinia or telia => 6

4b Galls caused by mycelia developing aeci => 5

5a Distinctly protruding swelling on leaf veins, -midrib or -stalks of P. ostruthium: Puccinia imperatoriae-mamillata

5b Similar malformations on P. rablense: Aecidium peucedani-raiblensis

6a Galls caused by primary mycelium developing uredinia accompanied by spermogonia. Sori with secondary uredinia or telia small, usually non-cecidogenic, often many on leaves, partially also on stems => 7

6b Fungus develops only telia on conspicuous, rather strongly swollen, rotund or elongated bulges on the leaf underside or on leaf axis. P. ostruthium: Micropuccinia imperatoriae

7a Fungi belonging to the Puccinia bullata species complex, distinguished by glabrous teliospores; morphologically partially ± similar but biologically usually distinctly different => 10

7b Teliospores covered with parallel running lines => 8

8a On P. oreoselinum or P. verticillare. Teliospores bearing loosely distributed warts => 9

8b On P. coriaceum, parisiense, ruthenicum, officinale: Puccinia rugulosa

9a On P. oreoselinum. The primary, cinnamon-brown uredinia develop on usually conspicuous, curved bulges on leaf venation, -midrib and -stalks: Puccinia oreoselini

9b On P. verticillare: Puccinia terrieri

10a On P. alsaticum, palustre, venetum => 12

10b On P austriacum, cervaria, rablense => 11

11a On P. austriacum. Malformations minor and rare: Puccinia peucedani-austriaci

11b On P. cervaria. Galls often conspicuous, on petioles and veins, up to 20 mm long, often curved, bearing spermogonia and primary uredinia: Puccinia cervariae

12a On P. alsaticum: Puccinia peucedani-alsatici

12b On P. palustre. Distinct swellings, up to several cm. long, on leaf veins, -midrib and -stalks, sometimes on stems: Puccinia semadenii

13a Leaflet with narrow marginal roll => 20

13b Leaflets with bulging swellings, curls or loose folds, or rolls of their margins => 14

14a Malformations with downwardly bent margins => 15

14b ip of leaflet folded upwards or rolled inwards, partially curled, thickened at base, discoloured ± yellowish to reddish. Containing white larvae. P. cervaria, oreoselinum: Macrolabis incognita and/or: Jaapiella buhri

15a Expanded malformations of leaf blades or conspicuously discoloured marginal roll, or fold => 16

15b Curling of tip leaflet. P. oreoselinum: Trioza sp.

15c On the leaves of P. ostruthium have been recorded the larvae of Trioza apicalis

16a Malformation caused by aphids or by surface fruiting fungi => 17

16b Leaf midrib sometimes stunted over large areas, bearing clustered, sometimes nest-like converging, locally deep green coloured leaves. Peucedanum spp.: Philaenus spumarius

17a Malformations caused by aphids => 18

17b Leaf blade pale green, swollen, bladder-like, mainly on upperside soon covered with loosely arranged fungal fruiting bodies. P. palustre: Taphridium umbelliferarum

18a Malformations on expanded leaf parts => 19

18b Terminal parts of leaflets partially or completely ± mussel-shaped, deflected downwards or loosely rolled, slightly thickened, conspicuously discoloured red and yellow. Aphid yellow to bright greenish-yellow. P. cervaria, oreoselinum: Semiaphis cervariae

19a On P. palustre. Severe stunting of midrib; leaflets, occasionally at terminal leaf part densely clustered, nest-like at tip and margin deflected: Semiaphis anthrisci

19b On P. officinale; colonising shoot tips and deforming leaves: Semiaphis horvathi

19c On P. ostruthium. Leaf blades rolled downwards or arched. Malformations sometimes expanded; leaves converged, nest-like:Semiaphis sphondylii

20a Tips of leaflets stunted, rolled at margin, ± twisted and discoloured. P. arenarium, palustre; Aceria peucedani

20b Similar malformations on P. oreoselinum: Unidentified gall mite

21a Malformations of large parts of inflorescence or galls locally on axial parts => 22

21b Fruit strongly inflated, bladder-like; galls ± reddened, protruding above the umbel; 1 (3) orange-red larvae: Kiefferia pericarpiicola

22a Malformation of expanded parts of inflorescence => 23

22b Centre of umbel or stalk of umbel ± swollen, club-shaped, sometimes also affecting the base of the stalks of umbels. Inner wall covered with mycelium. Containing a red larva: Lasioptera carophila

23a Inflorescences and ± greened flowers variously disfigured by aphids. P. palustre: Semiaphis anthrisci

23b Similar, often compact malformations caused by mites, often associated with severe greening and malformation of flowers. P. carvifolia, cervaria, oreoselinum, palustre, venetum: Aceria peucedani

gallers on Juniperus

pub 11.ii.2020

Dichotomous table for gallers on Juniperus

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodular swellings. J. communis: Meloidogyne sp.

2a On fruits => 28

2b On vegetative plant parts => 3

3a On terminal shoots, shoot tips or only on leaves => 13

3b On lower axial parts of shoot => 4

4a Shoot axis with tuberose- or elongated swellings of various length => 5

4b Bark of younger shoots with, rimmed depressions, up to 2 mm long, containing inducer. J. communis: Carulaspis juniperi

5a Elongate galls without larval cavities, at maturity with fungal structures at their surface => 9

5b Similar galls, but with tunnels caused by of lepidopteran larvae feeding => 6

6a Caterpillar white to reddish => 7

6b Caterpillar pale brown, head black, neck- and anal scale brown. J. communis: Chionodes electella

7a Caterpillar usually uniform white => 8

7b Caterpillar dirty white, often reddish tinged; head and neck scale brown. J. communis: Cydia duplicana

8 Caterpillar biannual, ivory white. J. communis: Synanthedon cephiformis

8b Caterpillar annual, whitish. J. communis: Synanthedon spuleri

8c The so-called “tuberculate disease” in twigs of Mediterranean J. communis, phoenicea as well as on Cupressus sempervirens has been attributed to: Ceratostoma juniperinum

9a Spindle-shaped to elongated cylindrical swellings of twigs and branches. Telia partially thick-, partially thin-walled, dark to pale, on ± long stalks; sori united under humid conditions into gelatinous swollen columns, tongues or pads; uredinia absent. In spring, on J. communis and relatives => 11

9b Similar galls on J. sabina and relatives. Sori of telia cornicular, thick, usually higher than wide. Telia oval to short, spindle-shaped => 10

10a Sori brown-red to chestnut brown, at first pad-shaped, then developing yellow-brown blunt-conical lobes. Galls with perennial mycelium, spindle-shaped, 6–8 cm long. Juniperus spp.: Gymnosporangium confusum

10b Sori black-brown to black. Galls with perennial mycelium, when mature about 10 (12) cm long and 3–4 cm thick. Juniperus spp.: Gymnosporangium sabinae

11a Sori flat cushion-shaped, much broader than high, swelling to a mussel-shaped body. Telia oval or short spindle-shaped, hardly twice as long as broad, partially thick-, partially thin-walled => 12

11b Sori cylindrical, band- or tongue-shaped, up to 5 mm long, 2 mm thick, orange-coloured; swelling to a pale yellow compact jelly-like body when wet, clustered on slender spindle-shaped swelling of stem parts sometimes bent, perennial. Telia oblong-spindle-shaped. Juniperus spp.: Gymnosporangium clavariiforme

12a Dry sori forming flat brown, 1–2 mm high, up to 5 mm broad and 20 mm long pads, which swell to orange-coloured, mussel- or cup-like extending jelly bodies if humid. Swellings often little pronounced; mycelium soon withering. Juniperus spp.: Gymnosporangium tremelloides

12b Witches’ broom on J. oxycedrus, microcarpa: Gymnosporangium gracile

12c Sori usually smaller, developing into yellow-red discoloured jelly bodies; distinguished by its smaller spores. Galls usually on thinner twigs as weak spindle-shaped swellings. Sori also on needles: Gymnosporangium cornutum

= In addition, a rust gall, caused by Gymnosporangium asiaticum has been recorded on introduced J. chinensis

13a On shoot tips => 17

13b On leaves => 14

14a Bulging or tongue-shaped malformations on terminal part of needles, caused by fungi => 15

14b Basal part of needle bulging, swollen. Internodia ± shortened. J. communis, etc.: Trisetacus juniperinus

15a Spores brown, predominantly 2-celled, in gall-like sori; swellings ± compact, slightly bulging => 16

15b Spores black, 1-celled in 3–6 mm long severely blister-like arched dusty sori. J. communis: Lepidoderma carestianum

16a Two-year to perennial needles on upperside with small, slightly arched, lacerate, cinnamon- to black-brown sori, also containing, apart from 1-celled ± globular brown uredinia, 2-celled teliospores, ± egg-shaped, slightly constricted in the middle. J. communis: Gymnosporangium gaeumannii

16b Similar, usually only pinhead size jelly bulges, macroscopically hardly different from previous fungus, containing only 2-celled teliospores. J. communis: Gymnosporangium cornutum and/ or Gymnosporangium tremelloides

17a Galls on tips of shoots => 19

17b Malformation of many leaves terminally on stunted shoots => 18

18a Dense accumulation of almost imbricated covered needles at top of young stunted shoots. J. communis: Cause unknown – ? aphid

Many needles accumulated at the end of a shoot; swollen at base, bulging. J. communis, chinensis: Trisetacus juniperinus

19a More or less bud-like galls caused by gall midges. On J. communis => 21

19b Similar galls on J. sabina => 20

19c Pear-shaped galls with blunt apex on J. oxycedrus, navicularis 10–12 mm long and 8–10 mm wide at base formed by an atrophied brownish inner whorl of needles enclosing a larval chamber and an outer whorl of very broad thickened needles, fused at base and slightly shortened. Containing a single larva: Oligotrophus valerii

20a Pyramid-shaped gall, up to 13 mm long and 5 mm broad, at base gradually narrowing, consisting of 3–5 (7) distinctly enlarged pairs of acuminate leaves; back of leaves rounded and weakly carinate. J. sabina, phoenicea: Etsuhoa sabinae

20b Gall consisting of several pairs of leaves, up to 5 mm long, rotund, strongly shouldered at base. Leaves thickened, their back with deep furrow. Containing a single larva. Unidentified gall midge

21a Gall is composed of two or more whorls of needles => 22

21b The small gall, up to 3 mm long, is oblong-egg-shaped and consists of only one whorl ± distinctly shortened, broadened, mutually covering leaves. Containing a single orange-coloured larva. J. communis: Oligotrophus gemmarum

22a Galls always composed of only two whorls => 25

22b Galls composed of (2) 3–4 whorls => 23

23a Galls larger than 5 mm => 24

23b Gall consists of 2–4 whorls, egg-shaped to conical, small, occasionally up to 4 mm long; outer needles scale-like broadened, composing a closed gall. Galls sometimes also in the male inflorescences. Unidentified gall midge

24a Gall composed of 3–4 whorls, up to 10 mm long, oblong, ± acuminate, terminally on main- and lateral shoots. Needles of the outer whorl ± shortened and distinctly broadened, those of the second whorl slightly longer, but narrower, the inner becoming narrower and smaller, enclosing the central larval chamber. At maturity of the gall, the needle tips are usually outwardly deflected. Containing an orange-coloured larva. J. communis: Oligotrophus sp.

24b Similar galls, containing single red larvae when mature. Unidentified gall midge

25a Needles of the outer whorl ± open or outer whorl spreading at least at maturity of gall => 26

25b Gall up to 12 mm long; ± slender conical, acuminate. Needles of the outer whorl only broadened in the basal half the upper half narrowed, enclosing completely the inner whorl of shorter, narrower needles. Containing a single orange-coloured larva. J. communis: Oligotrophus panteli

26a Galls at most 6 mm long => 27

26b Up to 12 mm long, oblong, not acuminate gall. Needles of the outer whorl broadened and thickened over their whole length. Needles of the inner whorl narrow, adpressed. Leaves of the outer whorl spreading distally at maturity. Containing a single orange-coloured larva. J. communis: Oligotrophus juniperinus

27a Gall often acuminate, up to 5 (6) mm long, ± discoloured. Needles of the ± open outer whorl mainly broadened at base, terminally distinctly narrowed, sometimes deflected outwardly, shorter than inner ones, composed of a closed whorl of converging narrow leaves. containing a red larva. J. communis: Oligotrophus schmidti

27b Open, up to 5 mm long, rarely larger gall, in which the distinctly broadened leaves of the ± spreading outer whorl are as long as, or shorter than the closed inner whorl, usually blunt- to acute-conical gall body. Containing a single red larva. Oligotrophus sp.

28a Fruit slightly swollen, slightly stunted; flesh hypertrophied, carpels incompletely fused, composing at the top a three–rayed opening. Seeds usually sterile, visible under the slits. J. communis: Trisetacus quadrisetus

28b Fruit with grooved, rimmed depressions. J. communis: Carulaspis juniperi

gallers on Filipendula

pub 10.ii.2020

Dichotomous table for gallers on Filipendula

by Hans Roskam

1a On extensively elongated stems, on buds, leaves or flowers => 2

1b Basal shoots severely stunted and transformed into a large cone-like tough, fleshy gall several cm long, reddish-grey, multi-chambered and bearing rotund lumpy proliferations. Similar but smaller galls also on petioles. F. ulmaria, vulgaris: Dasineura harrisoni

2a On inflorescences or flowers => 20

2b On vegetative parts => 3

3a Galls on stems, midrib of leaf, leaf veins or -blades, caused by animals => 10

3b Shoot axis, petiole or leaf veins with many wart-shaped nodules or with extended swellings; fungus galls => 4

4a Expanded malformations caused by rusts, smuts or mildews => 6

4b The young, still developing parts bear many wart-like galls, hardly 1 mm across, loosely arranged or ± expanded into coalesced crusts => 5

5a Warts consisting of several cells. F. ulmaria, vulgaris: Synchytrium aureum

5b Galls 1-celled, only known from F. ulmaria: Synchytrium ulmariae

6a Galls covered with orange-red spore masses, or also at first unopened with lead-grey translucent blackish spores dusting later on => 7

6b Malformations caused by a white mycelium growing on outside of host. F. ulmaria: Podosphaera aphanis

6c Similar malformations; stems, leaves and shoots thickened and sometimes twisted or otherwise distorted, covered with thick, white mycelium. F. kamtschatica, ulmaria, vulgaris: Podosphaera filipendulae

7a Galls soon covered by orange-red rust sori => 9

7b Galls caused by smuts with spores 1–8 united in easily degraded balls, enveloped by sterile auxiliary cells => 8

8a On F. ulmaria: Urocystis ulmariae

8b On. F. vulgaris: Urocystis filipendulae

9a On F. ulmaria, lobata and relatives: Triphragmium ulmariae

9b On F. vulgaris: Triphragmium filipendulae

10a Large parts of leaf blades disfigured or with localised galls => 13

10b Stems, leaf midrib or leaf veins with localised galls => 11

11a Galls on leaf midrib or leaf veins => 12

11b Weak thickening of shoot axis, mainly close to ground. F. ulmaria: Unidentified lepidopteran

12a Galls hemispherical on upperside, protruding on underside acuminate- conical; wall soft; on midrib or main veins; upperside glabrous and often reddish, underside yellowish, ± pubescent, with terminal, pubescence, narrow exit hole, one-chambered. Containing a single whitish-yellow larva. F. lobata, ulmaria: Dasineura ulmaria

= Various aberrant galls have been described in literature; attributed to either D. ulmaria or undescribed other gall midges. D. harrisoni causes on F. ulmaria in various wet biotopes expanded galls close to the ground.

12b Galls only conspicuous on one side of leaf. Midrib of leaf blade swollen. F. ulmaria: Epitrimerus filipendulae

13a Malformations on leaf blade of leaf => 14

13b Leaf blade deeply dissected at margin, indented, teeth ± narrow fimbriate. F. ulmaria: Unidentified gall mite

14a Leaf blade curled or otherwise extensively disfigured => 16

14b Small grooves or erinea on otherwise unchanged leaf blade => 15

15a On the underside of the slightly disfigured leaf blade occur 1 mm deep grooves in rotund, pale green spots, yellowish margined up to 5 (6) mm across with corresponding archings on upperside. Often many per leaf blade, sometimes coalescing. Each containing a single vitreous, white to greenish larva. F. ulmaria, vulgaris: Dasineura pustulans

= Small grooved galls on F. ulmaria, arched on upper side, which display eggs in the underside cavity, have been attributed to an unidentified psyllid, which may, in strong infestations, also cause a ± distinct curl or upward roll of the leaf margin.

15b On leaf underside between veins, usually close to margin irregular erinea of various dimension with white, club-like hairs. F. ulmaria: Unidentified gall mite

16a Curling or rolling of leaf blade, caused by aphids or spittlebugs => 18

16b Leaf blade with buckled archings or folds, caused by gall midges => 17

17a Bulging yellowish-green to often reddish folds or swellings of the leaf blade, usually elongated and bumpy, often coalescing. Development varies. In cases of strong infestation the leaf blade is strongly curled; occasionally at margin with thickened rolls. Each depression on the underside containing a larva that is at first white, then pale red. F. lobata, ulmaria, vulgaris: Dasineura engstfeldi

17b Leaf blade folded downwards along a lateral vein, white larvae on upper side. F. ulmaria: Dasineura engstfeldi

18a Malformations caused by aphids => 19

18b Shortening of leaf midrib and curling of leaf blade. Filipendula spp.: Philaenus spumarius

= Spiral rolls of stunted basal leaves. The leaflets are densely clustered on the stunted midrib. On the midrib occur bluish-grey, black-headed larvae of an unidentified sawfly

19a Weak arching or curling of leaf tip. F. ulmaria, vulgaris: Macrosiphum cholodkovskyi

19b Various expanded curvings, folds, rolls. F. ulmaria, vulgaris: Aphis ulmariae

20a Flower galls => 22

20b Malformations of inflorescence => 21

21a Often conspicuously disfigured inflorescence covered with a white mycelium: Podosphaera aphanis

21b Stalks of inflorescence distinctly shortened. Buds, and flowers therefore clustered. F. ulmaria, vulgaris: Aphis ulmariae

21c Malformations are also caused by froth-covered nymphs of
Philaenus spumarius

22a Flowers unopened, containing midge larvae => 23

22b Galls on buds and stems of the midge that usually lives on leaves have been attributed to Dasineura ulmaria

23a On F. ulmaria. Flowers swollen on one side in an irregular manner, here densely pubescent, discoloured pale to dark-red; stamens and stem etiolated, galled flowers 1.5–2 mm across, distinguished from healthy flowers by their small size. Larvae white, pale red later on: Dasineura engstfeldi

23b On F. ulmaria. Slightly swollen, unopened red-violet discoloured flower buds: Dasineura spiraeae

23c On F. hexapetala, vulgaris. Flowers unopened, swollen and ± reddened. Larvae red: Dasineura filipendulae

gallers on Astragalus

pub 8.ii.2020

Dichotomous table for gallers on Astragalus

by Hans Roskam

1a On parts above ground => 2

1b Side roots with smaller egg-shaped nodules, about 7 mm long, cylindrical or terminally broadened and branched to coralloid: Rhizobium leguminosarum

2a On inflorescences, flowers or fruits => 17

2b On vegetative organs => 3

3a Malformations caused by mycelium of rust fungus bearing aecia and telia => 16

3b Malformations by animal causers => 4

4a On leaves => 11

4b On buds, shoots, stems or thorns => 5

5a Galls on stems or thorns => 8

5b Galls on shoot tips or lateral buds => 6

6a Malformations with ± conspicuous abnormal pubescence; on small-leafed Astragalus species => 7

6b Tip of main shoot or of ± stalked side shoots severely stunted. The still unfolded vegetative or also generative parts restricted in further development and completely stunted, ± thickened. The marginal leaves in all basal parts swollen, towards the exterior increasingly unfolding, the free part partially towards midrib rolled inwards or also folded and strongly narrowly curled. In the middle of the malformation are several white larvae. A. glycyphyllos: Contarinia sp.

7a Shoot tip or lateral bud as result of ± expanded thickening of stipules, petioles and leaflets transformed into a whitish densely pubescent, rotund, tuft-like mass. A. arenarius: Unidentified gall midge

7b Top of main- and side shoots severely stunted; younger organs clustered into a rotund to egg-shaped ± closed gall. The marginal leaves ± stunted, all parts close to gall thickened, pale green and more pubescent, at their tips sometimes almost normal. The centre of the gall contains a single orange-yellow larva. A. danicus: Dasineura rossi

8a Single galls ± spindle-shaped, sometimes clustered into conspicuous irregular nodular structures => 9

8b Galls globular or barrel-shaped, acuminate, about 3–5 mm across, with thick, compact, glabrous wall. Containing a single or several larvae. Inducer unidentified – ? gall midge, ? eulophid chalcid

9a All-sided spindle-shaped galls on stems => 10

9b Galls usually one-sided on internodes, spindle-shaped to oblong-oval, about 4–6 mm long and 2 mm wide, bulging, pale green or browned; chambers in woody part, each contains a single larva. Galls usually with several per internode, sometimes closely alongside or behind one another and coalescing. Close to nodes usually densely clustered, conspicuous, ± oblong, sometimes consisting of almost all-sided brown-tubercular gall complexes, measuring 10–25 mm in length and 10–15 mm in width. A. arenarius, cicer, glycyphyllos: Inducer unidentified – ? gall midge, ? eulophid chalcid

9c Stem galls of various size on A. glycyphyllos, up to even finger size, as well as about cherry-sized axillary galls on A. arenarius which on this host contained several yellow midge larvae in a large central cavity: Dasineura astragalorum

9d Large galls on stems. A. lagopoides: Asphondylia anatolica

10a Stem with all sided swelling, regular, wide spindle-shaped, tough- and thin-walled. A large chamber in pith containing several white chalcid larvae. A. danicus: Inducer unidentified – ? gall midge, ? eulophid chalcid

10b Stem close below the top swollen bottle-shaped; inside a cavity contains several white larvae. A. alpinus: Inducer unidentified – ? gall midge, ? eulophid chalcid

11a Malformations on leaflets or without conspicuous malformation of axial parts => 13

11b Galls mainly on petioles or midrib => 12

12a Petioles mainly at base often with several, usually separated, hard, spindle-shaped to oblong-oval one-chambered swellings, about 3–4 mm long. Containing a single larva. A. exscapus. Inducer unidentified – ? gall midge, ? eulophid chalcid

12b Leaf midrib stunted; leaflets clustered, along midrib and base thickened. A. alpinus: Dasineura cf. viciae

13a Leaflets folded upwards pod-like => 14

13b Leaf blades of leaflets rolled downwards. A. alpinus, arenarius, glycyphyllos: Aceria astragali

14a On A. danicus, exscapus, frigidus => 15

14b On many other Astragalus species. The leaflets of younger leaves are completely galled, strongly thickened and ± pale green, also reddish. In older leaves sometimes only some leaflets are distorted, in large-leafed species with only locally pod-like swellings, remaining with a ± broad margin of normally developed leaf blade; the leaflets may also be rolled upwards and thickened at margin. Older leaves brownish-yellow. A. cicer, glycyphyllos, monspessulanus: Dasineura glyciphylli

14c Inflated, yellowish green leaflets or terminal swellings on young stems. A. alpinus: Dasineura berti

14d Pod-like folded leaflets on A. lusitanicus: Dasineura mariae

15a Single or all leaflets of larger leaves pod-like, rolled upwards, strongly thickened, pale green or reddened. Each gall contains an orange-yellow larva. A. danicus, onobrychis: Dasineura rossi

15b Pod-like folded leaflets on A. lusitanicus: Dasineura mariae

15c Inflated, yellowish green leaflets or terminal swellings on young stems. A. alpinus: Dasineura berti

16a Mycelium perennial; leaves of infected shoots disfigured, shorter and tougher than the healthy ones. Often completely covered with telia on underside. A. frigidus: Uromyces phacae-frigidae

16b Shoots completely infected with mycelium, made conspicuous by its pale colour, all parts ± etiolated. Aecia mainly on underside, often completely affecting all leaf blades; III often also on leaf midrib and -stalks. A. alpinus, australis, frigidus; also on Oxytropis: Uromyces lapponicus

16c Similar malformations on A. leontinus, norvegicus. Spermogonia absent: Uromyces splendens

17a On inflorescences or on single flowers (for spindle-shaped galls on stalk => 18

17b Fruit hardly swollen, shortened, disfigured. Containing a single larva. A. asper. Asphondylia sp.

18a Single or several flowers disfigured => 19

18b Developing young inflorescences severely stunted; their stalks ± thickened. Flower buds variously swollen, globular, arranged in ± dense balls. A. glycyphyllos: Contarinia sp.

18c Usually all flowers of several inflorescences are already disfigured in bud stage and slightly swollen. Ovules at first swollen, later on filled with masses of red-brown spore balls: Thecaphora affinis

19a Flowers swollen, unopened; with midge larvae inside => 20

19b Flowers disfigured, containing a larva with head capsule. A. arenarius, austriacus, cicer, danicus, glycyphyllos, onobrychis, sempervirens: Mesotrichapion punctirostre

19c Similar malformations on A. glyciphyllos, varius, virgatus contain larvae of Pseudoprotapion astragali

20a Calyx strongly swollen, almost enveloping all organs. Corolla shortened, thickened, greened. Stamens and ovaries mostly moribund. Containing several orange-yellow larvae. A. arenarius, austriacus: Contarinia sp.

20b Similar galls, but with a dense layer of mycelium inside. A. glycyphyllos: Asphondylia sp.

gallers on Festuca

pub 7.ii.2020

Dichotomous table for gallers on Festuca

incl. Schedonorus, Vulpia

by Hans Roskam

1a Galls on restricted organs and parts of organs => 3

1b Malformation of expanded parts of the above-ground plant => 2

1c Red midge larvae living on roots. Schedonorus pratensis: Lasioptera auricincta

1d Roots with aphids. Festuca spp.: Tetraneura caerulescens

2a Complete plant stunted, only a few cm high; shoots at base onion-like, swollen. Leaf sheaths accordingly shortened, weakly swollen and broadened. Schedonorus pratensis: Chlorops sp.

= In severely stunted, over expanded spongy, swollen areas of young plants the polyphagous stem eelworm Ditylenchus dipsaci has occasionally been found.

2b Complete plant stunted. Upper leaf sheath distinctly widened, transversely folded and bulging. F. rubra: Unidentified tarsonemid mite

= Malformations attributed to the polyphagous mite Steneotarsonemus spirifex has been reported by for several fescues.

3a On above-ground plant parts => 4

3b Roots with swellings about 0.5–3 mm long, slender, screw-shaped or crooked. Festuca ovina, Schedonorus pratensis: Subanguina radicicola

= Also the cyst developing oat eelworm Heterodera avenae has been recorded on fescue

4a On leaves, inflorescences or flowers => 11

4b On culms => 5

4c Node of stem rarely swollen, encircled by fungus stroma, yellowish when mature; several nodes may be affected; flowering stunted; stroma containing narrow asci and filamentous spores. Festuca rubra: Epichloë festucae

5a Larvae are inside the galls => 10

5b Larvae between culm and leaf sheath => 6

6a Larvae in shallow covered depressions of the culm near the leaf sheaths => 7

6b Shoot severely stunted. Inflorescence often largely hidden in sheath. Culm at base of inflorescence sometimes ± swollen. Containing a single larva. Festuca rubra, Schedonorus arundinaceus, pratensis: Oscinella frit

= On Festuca rubra, Schedonorus pratensis lives the similar Oscinella vastator. On F. rubra, O. nitidissimaoccurs. On the culms of Schedonorus arundinaceus subsp. orientalis and Schedonorus pratensis, the closely related polyphagous Oscinella pusilla, and on Schedonorus arundinaceus, giganteus, pratensis, also recorded from Leymus, the widely distributed rarer Oscinella festucae

= On Festuca ovina, rubra stem galls incorporating leaf sheaths have been reported caused by Tetramesa brevicornis.

7a Depressions not conspicuously discoloured => 8

7b Black-coated, one-sided, expanded, irregular depression with orange-yellow larva, usually above the last node. F. rubra: Hybolasioptera fasciata

8a Depressions evenly weakly rimmed all around => 9

8b Depression particularly saddle-like, thickened at the ends, single or with several above the higher situated, predominantly last node. Each gall containing a bright red larva. Schedonorus pratensis: Haplodiplosis marginata

9a One to several laterally hardly swollen depressions of the culm. Each containing a single larva. Schedonorus arundinaceus: Lasioptera calamagrostidis

9b Base of young shoots sometimes, if many larvae or puparia present, slightly swollen. Larvae yellowish-white, ± 3 mm long; puparia flax seed-like; within a leaf sheath. F. rubra: Mayetiola festucae

10a Galls tapering at both ends, spindle-shaped, wall rugose, surface glabrous. Festuca spp.: Tetramesa brevicollis

10b Irregular, yellowish-green swellings of culm above the nodes. Festuca spp.: Tetramesa longicornis

11a Malformations on inflorescences, flowers or young fruits => 16

11b Malformations on leaf sheaths or -blades => 12

12a The malformations extend over substantial parts of the leaf => 13

12b Leaf blade with 1–2 mm broad, slender egg-shaped to bulging swellings, mainly on underside, often discoloured red- to blue-violet. Festuca spp.: Anguina graminis

= From Festuca ovina, rubra, Schedonorus pratensis the sac fungus Dilophospora alopecuri, which is associated with eelworms on several grasses, has been recorded.

13a Stripes caused by black-sporulating smut on leaf blade, occasionally also on sheath => 14

13b Malformations caused by aphids. Leaf sheaths ± bulging and swollen, leaf blades variously twisted and rolled inwards. Schedonorus pratensis: cf. Rhopalosiphum padi

14a Spores single => 15

14b Spores single or more rarely 2–3 in balls enveloped by sterile auxiliary cells. F. ovina, rubra: Urocystis ulei

15a Stripes of smut very long, fine; at first lead-grey, then yellowish-grey. Spore mass black-brown. Spores globular to rotund-oval, 20–30 x 18–24 μm. Wall yellowish-brown, with lighter patches. F. ovina: Tilletia sterilis

15b Patches of smut long, linear. Mass of spores almost black. Spores globular to rotund-oval, 10–16 x 8–14 μm; densely covered with small blunt warts. Festuca spp.: Ustilago festucarum

16a Malformations mainly on large parts of the inflorescence => 17

16b Single or several ovaries per inflorescence are distinguished by a pronounced bottle- or tube-shaped, often purple-red elongation; containing eelworms. Festuca spp.: Anguina agrostis

16c Red midge larvae develop in florets and seed cases without inducing galls. Festuca rubra, Schedonorus arundinaceus: Dasineura festucae

17a Stem parts of the exposed panicle shortened apically, or over the whole inflorescence, bearing ± disfigured flowers or spikelets. Festuca spp.: Aceria tenuis

17b Gall midge larvae live in the inflorescences. Festuca rubra, Schedonorus arundinaceus: Contarinia festucae

gallers on Rhamnus

pub 16.xii.2019

Dichotomous table for gallers on Rhamnus

by Hans Roskam

Incl. Frangula

1a Galls only on flowers or fruits => 23

1b Malformations on vegetative organs => 2

2a Buds thickened, not opening; or galls only on leaves => 15

2b On leaves, ± including shoot axis or on shoot axis and sometimes additionally on axis of inflorescence => 3

3a Malformation of several leaves terminally on young, ± stunted shoots, caused by aphids => 11

3b Witches’ broom -like malformations or localised galls on various parts => 4

4a Conspicuous, ± expanded thickenings and distortions caused by scale insects or rust fungi => 5

4b Buds on woody parts developing into several short shoots, which in turn develop many lateral buds, which are severely stunted. Witches’ broom-like malformations. R. cathartica: Unidentified gall mite

4c On Frangula alnus and Rhamnus cathartica have been reported: Viscum album

5a Galls caused by rust fungi => 6

5b Bark of young axial parts swollen, with rimmed depressions, each containing a flattened froth-covered nymph under a pear-shaped scale. Frangula alnus; Rhamnus alpina subsp. fallax: Chionaspis salicis

6a Young shoot axis with variously curved, yellowish swellings, up to several cm long. Similar, ± spindle-shaped smaller galls on petioles and leaf veins; ± rotund swellings on leaf underside, on calyx, greened flower parts or on young fruits. On R. alpina, pumila, saxatilis, also on cultivated introduced species => 7

6b Similar malformations on Frangula alnus; Rhamnus alaternus, alpina, cathartica, lycioides subsp. graeca, pumila, saxatilis; species-complex of Puccinia coronata

7a Swellings bearing aecia on R. alpina, pumila, saxatilis => 8

7b On Frangula alnus: Puccinia coronata

8a Aecia on R. alpina, pumila => 10

8b Aecia on R. saxatilis => 9

9a Fungus alternating with several grasses; telia apically with lateral or upwardly directed appendages; species-complex of Puccinia coronata

9b Fungus alternating with Sesleria albicans. Telia without appendages: Puccinia sesleriae

10a Aecia recorded on R. alpina in the Alps:

a uredinia, telia mainly on Calamagrostis varia: Puccinia alpinae-coronata

b uredinia, telia on Sesleria caerulea: Puccinia sesleriae-caeruleae

10b Aecia in alpine areas on R. pumila:

a uredinia, telia mainly on Calamagrostis varia: Puccinia alpinae-coronata

b uredinia, telia mainly on Sesleria caerulea: Puccinia sesleriae-caeruleae

11a Leaf blades of inconspicuously clustered terminal leaves rolled or conspicuously converging upwards => 13

11b The variously arched or deflected terminal leaves are clustered, nest-like => 12

12a Shoot tips stunted, Leaves loosely arched, ± slightly discoloured. Aphid 1.5 mm long, marbled dark-green. Siphunculi black, twice as long as the oblong cauda. Frangula alnus; Rhamnus alaternus, alpina, lycioides incl. subsp. oleoides: Aphis frangulae

12b eaves rolled backwards, making loose tufts. Aphid 1.5 mm long, greenish-grey. Siphunculi dark, at least at base and tip, twice as long as the short conical cauda. Antennae half the body length. Body laterally with conspicuous small tubercles. R. alpina, cathartica, saxatilis subsp. tinctoria: Aphis mammulata

13a Margins of leaves are loosely rolled downwards, ± bulging => 14

13b Leaves along the midrib and partially also the side veins folded upwards and margins ± strongly rolled. Underside of main venation conspicuously protruding. R. cathartica: Aphis commensalis

14a Mainly on R. cathartica and close relatives, on leaves, margin of which is loosely rolled backwards. Aphid pale green. R. alaternus, alnifolia, cathartica, davurica, imeritina, ludovici-salvatoris, lycioides: Aphis nasturtii

14b Mainly on Frangula alnus in slightly rolled leaves. Aphid marbled dark green. Frangula alnus; Rhamnus alaternus, cathartica, lycioides incl. subsp. oleoides: Aphis frangulae

15a Malformations on leaves => 16

15b Buds swollen. Frangula alnus: Unidentified gall midge

16a Leaf blade abnormally pubescent or margin sometimes with expanded, hardly swollen or with thick succulent folds or rolls => 21

16b Leaf blade with protrusions or lenticular parenchyma galls => 17

16c Small pit-like depressions on underside of leaf. R. alaternus: Trioza marginepunctata

= Two rare Psylla species also cause pit galls on leaves: Cacopsylla rhamnicola on R. alpina incl. subsp. fallax, cathartica, saxatilis and C. alaterni on R. alaternus.

17a Golden-yellow warts or parenchyma galls => 20

17b Protrusions on upper side => 18

18a Mainly on R. cathartica => 19

18b Mainly on R. alpina; corniculate or pouch-shaped protrusions, up to 5 mm long, pale coloured with exit hole on underside. R. alaternus, alpina, lycioides subsp. oleoides, pumila: Trioza kiefferi

19a Small dome-shaped protrusions. A depression on underside containing a flat froth-covered nymph. Also on R. pallasii: Trioza rhamni

19b Protrusions small, ± pinhead-shaped: Aceria rhamni

= On Rhamnus alpinus and Frangula alnus the gall mite Calepitrimerus rhamni causes small finger galls on the upper surface of leaves

20a Underside of basal leaves with many warts, sometimes joining, multi-cellular, ± golden-yellow, less than 1 mm long. Frangula alnus: Synchytrium aureum

20b Inconspicuous parenchyma galls, up to about 5 mm broad, rotund, pale green, protruding and flattened on both sides, soon narrowed towards margins. Manifest as brown spots after departure of larvae. Each containing a single larva. R. cathartica: Unidentified gall midge

21a Underside of leaf with abnormal pubescence => 22

21b Leaf margin curved upwards over a length of 10–20 mm, more rarely rolled. Strongly succulent-cartilaginously thickened; often with abnormal pubescence. in the peripheral, not thickened parts. Rhamnus cathartica, ? Frangula alnus; Rhamnus alpina, erythroxylon, saxatilis: Trichochermes walkeri

21c ne to two pairs of terminal leaves conspicuously folded, often over their complete length, along the midrib and side veins and from margin to the middle part of leaf, or more rolled inwards and upwards. Containing many grey- to blackish-green aphids. R. cathartica: Aphis commensalis

22a Felt-like grey-green pubescence on underside, often emerging from veins. Hairs simple, thread-like or weakly club-shaped. R. alaternus, cathartica: Aequsomatus annulatus

22b Reddish erinea on underside; hairs multi-cellular, acute or obtuse. Frangula alnus: Unidentified gall mite

22c Vein axil along midrib ± discoloured. Abnormal white pubescence on underside in axils and on vein between axils. Frangula alnus: Unidentified gall mite

23a Flower galls => 24

23b Fruit weakly swollen and disfigured. R. cathartica: Wachtliella krumbholzi

24a Flowers swollen, unopened. Stamens and pistil aborted. Containing several whitish, later on sulphur yellow jumping larvae. Frangula alnus; Rhamnus pallasii: Contarinia rhamni

24b Similar galls with reddish-yellow, non-jumping larvae. Frangula alnus: Dasineura frangulae

= May not be independent gall causer, but inquiline in galls of previous midge.

24c Flower buds swollen, club-shaped, calyx green with ash-coloured pubescence, with reddish longitudinal ridges and distal part. Mature gall 5–6 mm long, 2 mm in diameter, coloured brownish when dried. Containing a single white larva. R. alaternus, ludovici-salvatoris: Asphondylia borzi

gallers on Potentilla

pub 15.xii.2019

Dichotomous table for gallers on Potentilla

by Hans Roskam

(incl. Argentina anserina, Drymocallis rupestris)

1a On above-ground parts => 2

1b Root collar, also root- or shoot parts close to surface with rotund galls, up to 5 mm across, single to multi-chambered, sometimes coalesced into conspicuous, tuberculate complexes of various extent. Each oval tough-walled chamber, about 2.5 mm across, containing a single larva. Potentilla spp.: Xestophanes potentillae

1c Nodular swellings without chambers on roots of Argentina anserina: Meloidogyne hapla

2a Galls conspicuous => 8

2b Extended erinea or very small, sometimes coalescing pustules or warts on all above-ground parts => 3

3a Leaf blades, -stalks and stems with small wart-like galls => 4

3b Erinea especially on the underside of sometimes hardly unfolded leaves, also on petioles, on stems and even on calyx. Hairs acuminate-cylindrical. Potentilla spp.: Phyllocoptes parvulus

4a Content of galls and warts yellow-red or pale coloured => 6

4b Content of galls colourless or warts dull-brown to black => 5

4c Underside of the leaves with a greyish white fungal bloom, consisting of erect, distally several times dichotomously branched conidiophores, each one ending in a conidium that is wider than long. P. chrysantha, supina incl.subsp. paradoxa, thuringiaca; also on Aphanes microcarpa: Peronospora oblatispora

5a Warts usually in groups, with colourless content. P. reptans: Synchytrium globosum

5b Pustules dull-brown to black; sometimes coalesced at curved infestation sites to ± expanded bulges. Argentina anserina; Potentilla reptans: Physoderma vagans

6a Warts clearly delineated; hemispherical to short-cylindrical arched => 7

6b Warts simple. P. argentea, heptaphylla: Synchytrium potentillae

7a Warts glabrous. P. reptans: Synchytrium aureum

7b Many (20–40) epidermis cells develop into strongly arched long, acute, white hairs. Plants conspicuously stunted if strongly infected. P. erecta: Synchytrium pilificum

8a On vegetative plant parts => 11

8b On inflorescences or flowers => 9

9a Galls caused by midge larvae or mites living inside flowers => 10

9b Apical shoots, possibly including inflorescences, disfigured, ± clustered, tuft-like. Potentilla spp.: Philaenus spumarius

10a Flowers unopened, abnormally pubescent. Calyx leaves ± elongated, stalk shortened, resulting in ± hidden flowers. Larvae many, orange-yellow to red. P. argentea, inclinata: Dasineura potentillae

10b Calyx of diseased flowers unchanged. Corolla and stamens etiolated, in P. norvegica ± greened. Receptacle elongated, with many stalked fruit primordia. The oblong, or more rotund bundle of young ovaries, if protruding from the flower s are long haired and bear long, ± curved styles. P. argentea, norvegica: Unidentified gall mite

11a Local, also ± expanded, galls on shoot stems, and on the stems of tillers, sometimes also additionally or exceptionally on petiole and even on midrib => 19

11b Malformations on leaf blades or on several disfigured leaves, mainly at, or close to, the shoot tip => 12

11c Small leaf rosette. P. grandiflora, pusilla, tabernaemontani: Guignonia potentillae

= From western Turkey on P. recta leaf bud galls have been reported which are caused by the gall midge Janetiella potentillogemmae. Several larvae live together; subsequent development of galls on lateral buds prevents the formation of side shoots with new inflorescence

12a Predominantly on single, not clustered leaves => 15

12b Mainly on clustered leaves => 13

13a Malformations caused by aphids or spittlebugs => 14

13b Leaves clustered at shoot tip, strongly pubescent. Larvae reddish. P. incana: Unidentified gall midge

13c Middle part of plant transformed into a rosette directly attached to rhizome. The rosette consists of many, 10–15 mm long, usually pale green, linear to lanceolate leaf-like structures. Between the inner linear leaves, still 5–6 mm long and with pale base, a single larva, spinning a snow white cocoon. P. tabernaemontani: Unidentified gall midge

14a Leaves, and also sometimes disfigured flowers ± clustered at the shoot tips. Leaf blades crumpled, deflected, locally intense green. Potentilla Philaenus spumarius

14b Branches and flower peduncles curved. Leaves variously disfigured. Argentina anserina; Potentilla erecta, reptans: Aphis tormentillae

15a Leaves curved, curled, folded or swollen, bladder-like => 16

15b Leaf blade with yellowish pustules. Drymocallis rupestris: Unidentified psyllid

16a Leaves rolled, folded or ± crumpled and curved => 17

16b Leaf blades with fleshy swollen spots or buckled and bladder-like to greater extent. Galls ± pale-green, on underside or both sides and soon covered with a dirty-grey layer of club-shaped, 8-spored asci. Infestation occasionally also on leaf midrib, -stalk or stem, which are swollen, and sometimes also elongated and ± bent. Drymocallis rupestris; Potentilla anglica, erecta, recta, x suberecta: Taphrina potentillae

17a Malformations without conspicuous pubescence => 18

17b Leaf blade contracted, curled, with stronger pubescence. P. argentea: Unidentified gall mite

18a Leaf midrib strongly deflected. Leaf blade at infestation site crumpled and sometimes deep-green, clustered. Potentilla Philaenus spumarius

18b Leaf midrib stunted, ± bent. Leaflets, ± rolled inwards, containing aphids. Argentina anserina: Unidentified aphid

18c Leaf blade rolled or folded at margin, curved, no abnormal pubescence. Argentina anserina; Potentilla crantzii: Cecidophyes potentillae

19a Galls closed, causers inside the tissue or in distinct chambers => 23

19b Galls open, causers living on surface or fruiting there => 20

20a Malformations contain fungus spores => 21

20b Petioles, also shoot axis, with cylindrical, ± discoloured yellowish, ± buckled swellings, often associated with bending; occasionally several scales solitary in irregularly rimmed depressions on same organ. P. argentea, erecta, grandiflora, hirta, recta: Planchonia arabidis

21a Leaf veins or -stalks with oblong, facultatively sometimes slightly swollen, yellowish spermogonia and orange-coloured caeoma-like aecia bearing pads. [Caeoma is an aecium in which the spores are formed in chains and not enclosed in a peridium]. Fungus monoecious, morphologically distinguished by its telia. Stalk of telia distinctly contrasting. 2–4 germ pores per cell, often situated in the middle or the side-walls => 22

21b Instead of caeoma-like aecia patches, with stalked, solitary primary uredinia. Stalks of telia indistinctly contrasted. Germ pores not apical. Teliospores 2–7 celled, each cell with a single germ pore. Rotund, developing sometimes reddened, with yellow spores occupying small swellings on leaf upperside. P. anglica, argentea, aurea subsp. chrysocraspeda, erecta, x mixta, recta, reptans: Frommeëlla tormentillae

22a Teliospores mainly 4-celled, rounded at apex, papilla absent. Aecia and uredinia with dense, broad warts. Potentilla Phragmidium fragariae

22b Teliospores 5–6 celled, with weak papilla. Aecia and uredinia with fine, loosely arranged warts. Potentilla Phragmidium potentillae

23a Malformations caused by animal inducers => 24

23b Small pustules or bulges on runners, petioles and also leaves. Strongly infected organs often etiolated or distorted. Argentina anserina; Potentilla reptans: Physoderma vagans

24a The inducers occur in larval chambers => 25

24b Soft, compact, spongy galls on the stems of Argentina anserina: Ditylenchus dipsaci

25a Chambers with tough, ± lignified wall => 26

25b Stems with small, rotund, one-sided swellings. Containing a single gall midge larva. P. erecta: Unidentified gall midge

26a Galls at least partially single, ± globular, ± coalesced into larger complexes => 27

26b Swelling spindle-shaped, about 10–30 mm long and 7–15 mm thick, mainly many-chambered and accordingly irregular tuberculate; especially on terminal parts of shoot axis. Each chamber containing a single larva. P. argentea, grandiflora, heptaphylla, inclinata, supina, wimanniana: Diastrophus mayri

27a Single galls about 2–3 mm long => 28

27b Axis of tiller, and more rarely the petiole, with rotund, one-chambered swellings, up to 6 mm thick; sometimes arranged like string of beads or mainly at first slightly bumpy, many-chambered, united groups up to 35 (80) mm long ± fused. Later on the rind bursts open and the single galls emerge more distinctly. Each chamber containing a single larva. Potentilla spp.: Xestophanes potentillae

28a Shoot axis, petiole and midrib with thin-walled, oblong-oval swellings, up to 3 (4) mm long, one-chambered; galls sometimes arranged in rows or groups Potentilla spp.: Xestophanes potentillae

28b Initially green, then brown, about 2 mm long, rotund swellings. One-chambered, mainly solitary or occasionally arranged in groups of various size; single galls however remain distinct and are hardly coalesced. Often close to ground, ± hidden in vegetation, sometimes solitary on petiole. P. anglica, erecta, grandiflora, heptaphylla, incana, inclinata. tabernaemontani: Xestophanes brevitarsis

gallers on Ulmus

pub 14.xii.2019

Dichotomous table for gallers on Ulmus

by Hans Roskam

1a On plant parts above ground => 2

1b Young roots with many, 1–2 mm swellings, variously coalescing and may eventually cover the root as a thick layer. U. minor: Mimeuria ulmiphila

2a In vegetative plant parts => 3

2b Flower buds containing many whitish, rarely yellow, larvae. U. glabra, laevis, minor: Coniophora autumnalis

3a On leaves => 7

3b On axial parts (twigs, branches, stems) => 4

4a On thicker branches => 6

4b On thinner twigs => 5

5a Bark of young shoot axial parts with blunt conical swellings, up to about 3 mm long, at first succulent, later tough-walled. Containing a yolk-yellow larva. U. glabra, laevis, minor.: Janetiella lemeei

5b Thinner stems, particularly of young hosts, with shallow, rimmed bulges, containing an about 3 mm long pear-shaped scale. Ulmus spp.: Chionaspis salicis

6a Bark of stems or thicker branches with conspicuous nodular swellings, at first closed, which ± tear open later on and change into open, irregularly rimmed cancer wounds. Rare on Ulmus spp.: Neonectria ditissima

= Tumors caused by Agrobacterium tumefaciens have also been observed on elm

= Proliferations on elms, so called “bark roses” are caused by the damage of the bark beetle Pteleobius vittatus, which tunnels in the bark anticipating its resting period. The proliferation develops after the feeding of the beetle has been completed, hence it is regenerating tissue, not a true gall

6a Spindle- or barrel-shaped thickenings on branches. Exceptionally on Ulmus spp.: Viscum album

7a Localised or extensive malformations of the leaf blades => 9

7b Galls on leaf veins or petioles => 8

8a Midrib, often at the base of the leaf blade, with a broadly attached swelling up to 15 mm long and 10 (15) mm wide, protruding on the upperside, distorting the leaf; gall wall thick, felt haired, pale sometimes reddened. Opening on underside but dark green aphids leave through a ± star-shaped cleft hole in top of gall. U. glabra, x hollandica, laevis, minor: Kaltenbachiella pallida

8b Midrib, or first order side veins, swollen; mainly on underside, with blunt conical to cylindrical swellings, up to 3 mm long, succulent and single -chambered. Only slightly protruding on opposite side of leaf. Opens at apical part of gall. Also on petioles and young shoots. Containing a single yolk-yellow larva. U. glabra, laevis, minor: Janetiella lemeei

9a Various, small to expanded, localised malformations of unfolded leaves => 12

9b Margins of leaf blade rolled or curled over substantial areas. Aphid galls => 10

10a Aphids pale green to brownish, powdered with wax => 11

10b Aphids black, without wax. Leaves of young shoots curled and loosely deflected, hardly discoloured. Ulmus spp.: Aphis fabae

11a Leaf blade, often only one half, loosely rolled downwards over its length into a bladder-like swollen, slightly thickened, pale green to yellowish tube; often passing over the midrib, especially the terminal part. Surface undulately rugose; veins protruding at the outside, keel-shaped. U. glabra, minor, scabra, according to many authors absent from U americana, glabra, minor, pumila, thomasii: Eriosoma ulmi

11b Open, green to yellow curled-leaf galls containing non-waxy aphids. U. americana, glabra, minor: Eriosoma grossulariae

11c Similar leaf rolls on the lower leaves of young shoots. The developing brood migrates partially to the younger leaves of the same, or neighbouring, shoots, inducing extensive curls and downward rolls but no discolouration. Galled leaves on the ± stunted short shoots clustered later on, nest-like. U. glabra, minor, pumila: Eriosoma patchiae

11d Rolls by inward curling of both edges of leaves, which become blistered, yellow or pale green, or sometimes bright red on younger trees and often considerably distorted. U. minor: Eriosoma anncharlotteae

12a Malformations of various shape, flat or only a few mm high => 15

12b Galls bag- or pouch-shaped, hollow, always higher than 5 mm. Aphid galls => 13

13a Galls pouch- or bag-shaped, about 7–15 mm high => 14

13b Bladder-shaped, 30-80 mm long, irregular enlargements on upperside, usually mostly closed on underside usually developing from a complete leaf. Surface uneven to rugose, densely short-haired, pale green or reddish. Rupturing with irregular slits when mature, then drying out, persisting after leaf fall. Containing waxy aphids. U. glabra, minor incl. subsp. canescens: Eriosoma lanuginosum

13c Leaf blade blistered and raised upwards between veins, green, becoming pinkish brown; containing waxy aphids. U. glabra, minor: Eriosoma flavum

14a Galls laterally flattened, up to 10 mm high; often in the vein axils at the base of the leaf blade; usually slightly grooved, on top cockscomb-like dentate. Often conspicuously red, more rarely yellowish; solitary or with 2–3, more rarely with several broadly attached to the leaf blade. Opening at maturity with a round exit hole on a flattened side. U. laevis, exceptionally U. glabra, laevis, minor: Colopha compressa

14b Galls egg-, pear-, or club-shaped, 7–15 mm long, laterally not flattened, distinctly stalked, mainly on upperside, often ± obliquely protruding, on underside with haired, eventually closed entrance. Surface glabrous, pale green, ± tarnished red. Leaf blade close to the gall discoloured and thickened; often many on a ± distorted leaf. Opens at maturity in the lower part of the swelling, with a lateral crack on the upperside of the leaf. “Fig gall”. U. glabra, laevis, minor; rarely on U. americana, davidiana: Tetraneura ulmi

14c Galls rotund, short stalked, more globular, pea- to walnut-size, often strongly reddened, thin-walled and, in contrast to the former species, short-haired. U. glabra, minor, pumila: Tetraneura caerulescens

14d Galls spindle- or pouch-shaped, hairy, 15‒40 mm high, with pointed apex and usually green and rose-red when mature. U. glabra, minor incl. subsp. canescens, procera, pumila: Tetraneura nigriabdominalis

15a Malformations without conspicuous expanded abnormal pubescence => 16

15b Veins on the leaf underside, especially at the branching points, strongly white haired. Erinea flaky, occasionally restricted to the vein axils. Hairs longer than the normal ones. U. glabra, laevis, minor: Unidentified gall mite

16a Malformations arched, more than 3 mm long, bladder-, groove-, or pustule-like => 20

16b Galls pock-like, wart- or nodule-shaped, about 2 (3) mm => 17

17a Swellings protruding only on one side of leaf => 18

17b Galls nodular, rotund, protruding about equally on both sides, semiglobular on the upperside, more or less conical on the underside, up to 1 mm across, ± short-haired; at first yellowish, eventually brownish. Exit on underside, surrounded by a glabrous rim. Often many per leaf blade. U. glabra, x hollandica, laevis, minor: Aceria campestricola

18a Swellings pock- or wart-like, mainly protruding on underside => 19

18b Pimples, up to 2 mm, rotund, constricted at base, ± rough-haired and pale green pouch galls on the upper side of leaf. On the underside with a small, haired exit hole. U. glabra, x hollandica, laevis, minor: Aceria campestricola

18c Additionally in both previous galls: Aceria multistriata and/ or Anthocoptes galeatus

18d Froth-covered nymphs on underside of leaf produce much honeydew. Leaves wither and become disfigured. U. glabra, laevis, minor: Cacopsylla ulmi

19a Basal leaves on the underside with many, multicellular warts, less than 1 mm across, golden-yellow translucent, distinctly margined. U. minor: Synchytrium aureum

19b Higher situated leaves with many irregularly margined, 1.5‒2.5 (3) mm wide, flat, at first pale-green, eventually brown pocks, predominantly recognisable by their discolouration. Swelling only distinct on the underside. U. glabra, x hollandica, laevis, minor: Aceria ulmi

20a Galls caused by midge larvae, residing in groove-like dimples or in the tissue of flat, rotund malformations, up to about 5 mm wide => 21

20b Leaf blades with few to many, diffuse patches, 2–10 mm long and larger, rotund, sometimes coalescing, usually flat but may be swollen slightly bladder-like to distinctly bulge-like, fungus when mature mainly on underside with ± conspicuous tufts of asci. U. glabra, laevis, minor: Taphrina ulmi

21a Larvae inside the tissue => 22

21b Small grooves, swollen on top, less than 5 mm long, on the leaf underside; surrounded by a discoloured area; often several per leaf. Each groove containing a white larva. U. minor: Dasineura ulmicola

22a Rotund, 3–4 (5) mm wide pustules, situated in the leaf parenchyma, slightly bulging on the upperside, darker or yellowish-green to deep yellow coloured, not protruding on the underside. Containing a single white larva. U. glabra, laevis, minor incl. subsp. canescens: Physemocecis ulmi

22b pperside with very weak, at first yellowish, later on brownish bulges; on the underside a narrow exit hole which is surrounded by a ring of raised cells. Gall chamber is situated below the epidermis and containing a single larva. Ulmus spp.: Unidentified gall midge

gallers on Medicago

pub 12.xii.2019

Dichotomous table for gallers on Medicago

by Hans Roskam

1a Malformations of parts above ground => 4

1b Galls on roots or on root collar => 2

2a Galls less than 10 mm, mainly on deeply situated roots => 3

2b Compound up to pea- or walnut-, even fist-sized outgrowths on root collar; above ground as well as subterranean. M. falcata, lupulina, rotata, sativa, x varia: Physoderma alfalfae

3a Spindle-shaped or nodular swellings of the root body. Medicago spp.: Meloidogyne hapla

= Root infestations by Heterodera goettingiana or by unassigned species of the schachtii group have sporadically been attributed to Meloidogyne spp.

3b Small, oval or elongate-cylindrical nodules, up to about 5 mm long, terminally broadened and forked; laterally attached to the root. Medicago spp.: Sinorhizobium meliloti

4a On flowers or fruits => 21

4b On vegetative plant parts => 5

5a Locally delimited galls on buds, stems or leaves => 9

5b Malformations of undefined shape on extended parts of shoot => 6

6a On shoot tips => 7

6b Young plants often substantially atrophied; shoots shortened; strongly swollen, spongy; inserted leaves often severely stunted, their midrib also swollen. Galls necrotic. Medicago spp., especially M. sativa: Ditylenchus dipsaci

7a Malformations with ± strong abnormal pubescence, conspicuous on many hosts, ± colourful, caused by gall mites => 8

7b Systemically infected young plants severely stunted, infected shoots often irregularly bent, also slightly thickened; diseased young leaves ± arched, slightly thickened and pale green; soon covered by a grey-violet, dense mould of conidiophores on undersides. M. falcata, intertexta subsp. ciliaris, littoralis, polymorpha, sativa, truncatula, x varia: Peronospora aestivalis

8a Leaflets folded, ± twisted, also thickened, often discoloured violet, on many hosts with ± abnormal pubescence. Often extensive malformation of plant parts. M. carstiensis, falcata, littoralis, lupulina, minima, sativa: Aceria plicator

8b Shoots terminally stunted, bearing clustered, short stalked, reduced, upwardly arched, undulate, strongly white pubescent leaves. M. lupulina: Unidentified gall mite

9a On lateral-, and occasionally also on terminal buds => 19

9b On stems or leaves => 10

10a On leaf midrib or leaf blade => 12

10b On stems => 11

11a Axis with spindle-shaped, thin-walled, one-chambered swelling. Containing a curved beetle larva. Medicago spp.: Catapion seniculus

11b In similar stem galls on M. falcata, lupulina, sativa also develops: Holotrichapion pullum subsp. aestimatum

11c Globular one-chambered pea-size gall on stem. M. minima: Catapion burdigalense

= Larvae of the snout beetle Protapion filirostre may tunnel in ungalled stems of Medicago species.

11d Stem with smaller spindle-shaped, bent or expanded bulging, usually curved swelling, with rimmed depressions containing a single froth-covered nymph. M. falcata, lupulina: Planchonia arabidis

12a Galls larger than 1 mm => 13

12b Galls hardly 1 mm long, wart-shaped, composite; the content of the strongly enlarged nutritive cell translucent. Warts often many on the underside of basal leaves, on petioles, also on stems, sometimes coalescing, crust- or ridge-like. M. lupulina: Synchytrium aureum

13a Galls with leaf blade parts involved => 15

13b Galls mainly of petiole or main venation => 14

14a Midrib of a leaflet with one or more short, oblong-oval or spindle-shaped swellings, each with a larval chamber. M. sativa: Tychius meliloti

14b Up to 5 mm long, ± oval, yellow-margined, occasionally coalescing, weak bulges on sometimes slightly bent petioles and leaf veins, soon covered by ± dusting of cinnamon- to dark brown sori. M. cyparissias, seguieriana, esula subsp. tommasiniana: Uromyces striatus

15a Leaf blade without conspicuous involvement of midrib folded upwards on both sides, caused by gall midges => 16

15b Nodular to spindle-shaped swelling, extending from midrib into the connate leaf blade halves, with central larval chamber. Containing a single larva. M. falcata, sativa. Tychius crassirostris

16a Gall wall fleshly thickened => 18

16b Gall wall only slightly thickened => 17

17a Gall tightly folded, surface glabrous, discoloured yellowish to reddish. Gall chamber narrow slit-shaped. Larva white- to pale yellow. M. lupulina, minima, sativa, truncatula: Jaapiella jaapiana

17b Galls similar to previous ones, leaflets slightly enlarged, often undulate. Larvae red. M. doliata, falcata, lupulina, sativa, incl. subsp. varia: Jaapiella medicaginis

= In similar galls on M. falcata, prostrata in SE-Eu the yellow larvae of the gall midge Wachtliella dalmatica occur

= On M. sativa red larvae of the gall midge Anabremia medicaginis are inquilinous in leaf fold galls

= From northern Italy the gall midge Diplosiola bursaria has been described on Medicago sativa. Its yellow-orange larvae cause folded leaflets.

18a The galled leaflets are enlarged, forming a pod-like, ± sickle-shaped gall containing orange-coloured larvae. M. falcata, ? lupulina: Dasineura sp.

18b Leaf blade shortened, broader at base, veins on underside strongly thickened. M. prostrata: Wachtliella sp.

19a Galls mainly on M. lupulina => 20

19b Buds swollen, onion-like; gall usually on lateral buds, soft, rotund or oblong, glabrous, ± yellowish, also reddish. Stipules strongly enlarged. Opening at top at maturity, containing several orange-red larvae. M. falcata, littoralis, minima, prostrata, sativa, truncatula, x varia: Dasineura medicaginis

20a Similar, tough-walled galls ± pubescent, often situated terminally, opening by a slit at maturity. Larva maize-yellow. M. falcata, lupulina, minima, orbicularis, polymorpha, sativa subsp. varia: Dasineura lupulinae

20b Up to 5 mm long and 4 mm broad, rotund or ± egg-shaped, closed galls, often overtopped by an atrophied stalked mid leaflet. Sometimes ± enveloped by the swollen stipules. Inner wall with mycelium. Containing a single larva. M. lupulina, minima: Asphondylia lupulinae

21a On fruits => 24

21b On flowers => 22

22a On single flowers => 23

22b Usually all flowers of a raceme are variously greened or leafy, depending on their response ability. M. carstiensis, falcata, littoralis, lupulina, minima, sativa: Aceria plicator

23a Flower buds more or less swollen, onion-like, up to 8 mm long; calyx yellowish. Corolla unopened, its parts ± coalesced, terminal part often beak-shaped. Larvae at first white, later on lemon yellow; gregarious; jumping. M. arabica, falcata, sativa incl. subsp. varia: Contarinia medicaginis

23b Buds soon stunted, ± curved. Occasionally slightly swollen; containing a compact, narrow- and brown-headed, dark cream yellow, strongly bent beetle larva. M. arborea, falcata, lupulina, sativa, x varia: Holotrichapion pisi

24a Pod distinctly shortened, swollen (especially the mid part), often slightly curved at the top. Wall succulent, inside with fungus. M. falcata, sativa, saxatilis: Asphondylia miki

24b Pod conspicuously shortened, transformed into an egg-shaped pouch, often partially enveloped by withered corolla; wall slightly succulent, thickened, inside without fungus. Containing a dirty cream coloured beetle larva with a small brown head. M. falcata, sativa incl. subsp. varia: Tychius medicaginis

gallers on Campanula

pub 11.xii.2019

Dichotomous table for gallers on Campanula

by Hans Roskam

1a On parts above ground => 3

1b On roots or rhizomes => 2

2a Reddish, spongy bud gall on rhizome, up to 4 mm long. Contains an orange-yellow larva. C. rotundifolia: Unidentified gall midge

b Main- and side roots with many small swellings, similar to bacterium nodules of Leguminosae. C. rapunculoides: Spongospora campanulae

3a On inflorescences, flowers or fruits => 27

3b On vegetative organs => 4

4a Malformations caused by ± early fruiting fungi at surface => 25

4b Malformations without externally developing fungal fruiting bodies => 5

5a Malformations caused by animal parasites => 6

5b Hardly 1 mm long, hemispherical, ± golden-yellow translucent wart-shaped galls, usually many on underside of rosette leaves, also on stalks as well as on basal stem parts; sometimes ± coalescing. C. herminii, patula, rotundifolia, scheuchzeri: Synchytrium aureum

6a Malformations terminally on main- and side shoots, on buds or on leaves, sometimes including stem parts => 7

6b Axial parts of stem, often the lower parts with ± expanded spindle-shaped swelling with single or several rimmed depressions containing froth-covered nymphs of causers. Campanula spp.: Planchonia arabidis

7a Malformations mainly on leaves, sometimes encroaching onto stems => 14

7b Malformations on shoot tips or on buds => 8

8a Galls loose, spindle-shaped, consisting of ± unfolded leaves, also tuft-like => 11

8b Galls closed, compact, ± onion-like, usually fleshy => 9

9a Rotund or egg-shaped galls, up to 5 mm long, on shoot tips or lateral buds; on larger organs sometimes ± joined into larger complexes => 10

9b Similar, often more slender gall, up to 8 mm long. Also flower primordia severely stunted and disfigured, sometimes overtopped by calyx lobes. Containing several red larvae. C. rapunculus: Dasineura rapunculi

10a Onion-like galls in axillary buds; often overtopped by short rudiments of leaf blades; on shoot tip often united into irregularly composed groups, up to 12 mm broad. Containing one or more brick-red larvae. C. cochleariifolia, persicifolia, rotundifolia, scheuchzeri, trachelium: Geocrypta campanulae

10b Similar, more egg-shaped gall. Contains single yellow-red larva. C. rotundifolia, scheuchzeri: Unidentified gall midge

11a Malformations tuft-like or elongate spindle-shaped => 12

11b Shoot tip stunted; leaves densely clustered, broadened at base and discoloured, terminally spreading; contains several white larvae in axils. C. trachelium: Unidentified gall midge

12a Tufts ± spindle-shaped => 13

12b Tuft terminally on shoot, up to 15 mm long, egg-shaped or globular, containing yellow larvae. C. glomerata: Dasineura campanularum

13a Tufts oblong spindle-shaped, with abnormal pubescence. Leaves rolled inwards and upwards or folded, thickened, abnormally pubescent. Containing a single orange larva. C. barbata, rapunculoides, thyrsoides: Unidentified gall midge

13b Similar gall, not additionally haired. Leaves rolled, slightly thickened and discoloured. Larva whitish, translucent. C. bononiensis, rapunculoides: Dasineura acuminata

14a Leaf blade rolled inwards, curled or swollen locally => 15

14b Leaves disfigured, almost felt-like pubescent. Stem shortened. C. cochlerariifolia, rotundifolia: cf. Aceria campanulae

15a Rolling or curls of leaf blade => 17

15b Leaf blade with ± expanded swelling => 16

16a Crater-shaped, greenish, wrinkled rimmed proliferation on upper side, close to midrib or a side vein; venation disfigured and thickened. C. bononiensis: Inducer unknown

16b Midrib and shortened stalk of several variously distorted rosette leaves swollen, spongy. Tissue brittle, pale green. Galls variously encroaching into the ± stunted leaf blade. C. barbata, carpatica, persicifolia: Ditylenchus dipsaci

17a Leaf blade with margin loosely rolled inwards and ± protruding, curls, caused by aphids or spittlebugs => 22

17b Narrow marginal roll, caused by gall mites or gall midges => 18

18a Margin rolled upwards, with cartilaginous or fleshy thickening, ± discoloured. Midge galls => 21

18b Narrow roll upwards, not discoloured. Mite galls => 19

19a On species with small leaves => 20

19b On C. latifolia, trachelium: Unidentified gall mite

20a Leaf roll tubular, narrow, sometimes remarkably thickened, not conspicuously felt-like pubescent. C. cochleariifolia, rotundifolia: Aceria campanulae

20b Similar roll with abnormal, ± felt-like pubescence. C. cochleariifolia, scheuchzeri, rotundifolia: Unidentified gall mite

21a Roll usually discoloured violet; especially on upper leaves of sterile shoots, also on leaves inserted on roots. Leaf blades sometimes bulging. Usually containing only a single red larva. C. cochleariifolia, latifolia, ? rotundifolia, scheuchzeri: Dasineura thomasi

21b Leaf blade often with cartilaginous, ± wrinkled, usually discoloured upwards roll on both sides. C. bononiensis, rapunculoides: Dasineura acuminata

22a Leaf blade rolled inwards, caused by aphids => 23

22b Leaves loosely deflected, roll- or spoon-like; curled and deep green close to infestation. Contains froth-covered nymph. Sometimes several similarly curved leaves are loosely converging, nest-like, on locally ± stunted and distorted stem. Campanula spp.: Philaenus spumarius

23a Leaves rolled downwards or bent and curled => 24

23b Leaves rolled upwards; stem with shortened, twisted internodes. C. rotundifolia: Unidentified aphid

24a Leaves rolled downwards. Aphid dark red-brown, with rows of black dots, making dark red spots if crushed. Mainly on C. rapunculoides, also on C. cervaria, glomerata, patula, sibirica, trachelium: Uroleucon rapunculoides

24b Leaves deflected, ± curled. Aphids black. C. rapunculoides, trachelium: Aphis fabae

25a Leaves thickened at infestation site, yellowish-green, with whitish-grey down of branched conidiophores on underside. Often the entire plant stunted; leaves in rosettes, non-flowering. C. rapunculoides: Peronospora sp.

25b Upper side of the leaves with pale, slightly embossed patches; on the corresponding underside is a greyish white fungal bloom, consisting of erect, distally strongly branched conidiophores. C. rapunculoides, rapunculus: Peronospora erinicola

25c Sori rust-brown, usually on leaf underside; causing facultatively minor swellings and distortions on venation, on petioles and young stem parts. Telia with 2-celled teliospores, provided with minute warts. Uredinia absent. Usually rare, biologically specialised, also morphologically distinct rusts of the species complex: Puccinia campanulae s. lat.

a On C. cochleariifolia: Puccinia rytzii

b On C. rapunculus: Puccinia campanulae

c On C. rotundifolia: Puccinia campanulae-rotundifoliae

d On C. scheuchzeri: Puccinia campanulae-scheuchzeri

e On C. uniflora: Puccinia novaezemblae; distinguished by glabrous spore walls

f Rust fungi reported from C. glomerata, rapunculoides, trachelium, etc., are assigned to above-mentioned species complex

26a On flowers and inflorescences => 28

26b Ovaries or fruit, including receptacle, succulent, swollen, sometimes distorted; pistil and stigmas thickened, greened; the remaining flower parts necrotic. Contains a single or several larvae. Campanula spp.: Miarus campanulae

27a Flowers or inflorescence greened or leafy => 31

27b Malformation of inflorescence primordia or of flower buds, flowers lacking conspicuous greening => 28

28a Flowers, flower buds unopened and thickened => 29

28b Primordia of inflorescences severely stunted, ± reddened. Flower primordia clustered; especially ovaries disfigured and overtopped by the distorted calyx lobes. Containing several red larvae. C. rapunculus: Dasineura rapunculi

29a Flower buds inflated => 30

29b Flower buds transformed into a succulent, onion-like gall. Contains a single or several brick-red larvae. C. cochleariifolia, persicifolia, rotundifolia, scheuchzeri, trachelium: cf. Geocrypta campanulae

30a The unopened flowers are strongly enlarged at base. Calyx ± stunted; stamens thickened. Larvae white, jumping. C. barbata, cochleariifolia, rapunculoides, rhomboidalis, rotundifolia, scheuchzeri, trachelium: Contarinia campanulae

30b Similar malformations on C. cochleariifolia, rotundifolia, scheuchzeri containing white, non-jumping larvae: Dasineura campanulae

= The curculionid Miarus graminis causes galled flowers of C. glomerata, rotundifolia, trachelium.

31a Flowers greened. C. rotundifolia: Aceria chloranthes

31b Many flowers completely greened over large parts; stunted inflorescence excessively branched and, especially on side branches, the small leaves densely clustered, rolled and curled, often with proliferations on upper side. Host often pubescent with excessive development of hairs. Campanula spp.: Aculus schmardae

gallers on Senecio

pub 10.xii.2019

Dichotomous table for gallers on Senecio

by Hans Roskam

1a On above-ground parts => 3

1b On roots => 2

2a Roots close to the surface with an expanded weak swelling, centrally with a wide canal, protruding into the stem and containing a caterpillar. Jacobaea erucifolia, J. vulgaris: Epiblema scutulana

2b Root with small, nodule- or spindle-shaped, cylindrical galls, up to 6 mm long S. vulgaris: Meloidogyne hapla

3a On capitula => 23

3b On vegetative organs => 4

4a Extensive malformations of plant parts; or galls on shoot tips, buds or leaves => 8

4b Galls on stems => 5

4c Stem and leaves greatly swollen and distorted by vivid orange aecia; long, dark brown to black telia may rarely be found at the same time; frequent. Jacobaea vulgaris, Pallenis maritima, Pericallis hybrida, Senecio spp.: Puccinia lagenophorae

4d Stem and leaves slightly swollen and distorted; with powdery orange uredinia and waxy reddish telia; rarely recorded. Senecio Coleosporium senecionis

5a Swelling elongate, situated at different positions. A caterpillar with distinct head capsule lives in a canal in the pith, extending beyond the swelling. Stem close to the gall considerably stunted or completely degenerating, overgrown later on by lower lateral shoots => 7

5b Galls plump, inhabited by larvae lacking a distinct head capsule => 6

6a Stem with padding, often developed on one side, distinctly curved swelling. Galls predominantly in upper stem part, sometimes with several, ± amalgamating. Several yellowish-white jumping larvae. Jacobaea aquatica, erratica, erucifolia, paludosa, vulgaris; Senecio leucanthemifolius subsp. vernalis, sylvaticus, viscosus, vulgaris: Contarinia jacobaeae

= White, non-jumpin, larvae of the gall midge Jaapiella crinita develop as inquilines in galls of Contarinia jacobaeae

6b Stem swollen immediately under the inflorescence. One yellow larva. Jacobaea vulgaris, Senecio sylvaticus: Unidentified dipteran

6c Several rotund galls, up to 10 mm long variously shaped and situated terminally on main- and lateral shoots; also in the inflorescences as well as in buds, petioles and capitula; often extending into neighbouring organs. Centrally one or several large larval chambers with pale yellow to flesh-coloured larvae. Jacobaea vulgaris; Senecio nemorensis, ovatus incl. subsp. stabianus, sarracenicus, sylvaticus: Contarinia aequalis

7a Stem over the galled part ± irregularly thickened, with spindle- to almost nodule-shaped bulges. Galls up to 30 mm long, predominantly on apical sites, with an ejection hole for frass, sometimes bursting. Leaves degenerating. One ivory- to dirty olive-green, black-headed caterpillar. Jacobaea aquatica; Senecio nemorensis, ovatus incl. subsp. stabianus, sarracenicus, sylvaticus: Platyptilia nemoralis

7b Stem in upper third, sometimes immediately below the inflorescence, over a length of 25–35 mm, spindle-shaped to cylindrically swollen. One reddish-yellow caterpillar, the underside paler, with pale brown head capsule. Jacobaea erucifolia, vulgaris; ? Senecio sylvaticus.: Cochylis atricapitana

7c Similar stem gall, in Jacobaea aquatica, vulgaris; Senecio nemorensis, sarracenicus: Platyptilia isodactylus

8a Wart- bulge- or cup-shaped galls on leaves, induced by fungi or psyllids => 16

8b Malformations of large plant parts or galls on shoot tips or lateral buds => 9

9a Malformations on buds or on shoot tips => 15

9b Extensive malformation of the complete plant or malformation of several leaves on the shoot tips => 10

10a Malformations by aphids or cercopids => 11

10b Early infected stems markedly stunted; basally over large extension spongy, swollen, pale green, with rugose, partially undulating surface. Later infestation results in locally expanded one- or often all-sided stem swellings, in conjunction with twisting and curving. Involved organs severely stunted; sometimes also irregularly thickened at the base. Senecio vulgaris, viscosus: Ditylenchus dipsaci

11a Malformations of various kind, usually not specific for the inducer; aphids => 12

11b Large areas on the intensively green site of infestation, strongly bent at leaf apex and ± deflected at margin, curled. Infestation of young stem parts results in stunting and bending of the internodes with ± clustering of disfigured leaves. Senecio Philaenus spumarius

12a Aphids dark green to black => 14

12b Aphids brighter => 13

13a Leaves ± stunted, margins loosely deflected or rolled, curled. Often many per plant, resulting sometimes in conspicuous malformations. Aphid 1.1–2 mm long, bright- to yellow-green. Senecio Brachycaudus helichrysi

13b Leaf blades curled, margins deflected; similar malformations on often many, ± clustered leaves on tips of shoots. Aphid 2–2⅓ mm, greenish to yellowish with large glossy black dorsal patch. Jacobaea aquatica, vulgaris; Senecio spp: Brachycaudus cardui

14a Leaves clustered at tips of shoots and young inflorescence compact, strongly malformed. Leaf blades bent, loosely rolled or curled; capitula ± stunted and disfigured. Aphid 1.5–2 mm long, dirty green to black. Antennae a little longer than half the body length; tibiae black. Jacobaea aquatica, vulgaris; Senecio gallicus, ovatus subsp. stabianus, vulgaris: Aphis jacobaeae

14b Terminal leaves clustered on stunted shoots, deformed, loosely curved downwards and curled. Young plants sometimes completely disfigured. Aphid about 2.5 mm long, dark grey-green to dull black. Antennae half the body length. Legs yellowish annulated. Jacobaea maritima, vulgaris; Senecio spp.: Aphis fabae

15a Shoot tips or lateral buds stunted; Leaves markedly stunted in their development. ± wrinkled and discoloured, heavily whitish pubescent, clustered into an elongated, bud-like shoot. Jacobaea aquatica, vulgaris; Senecio sylvaticus, vulgaris: Aceria leioprocta

15b Terminal- or lateral buds transformed into an irregular, rotund-barrel-shaped, succulent gall. A large chamber inside containing pale-yellow to flesh-coloured larvae. Jacobaea vulgaris; Senecio nemorensis, ovatus incl. subsp. stabianus, sarracenicus, sylvaticus: Contarinia aequalis

16a Wart- or bulge-shaped fungus galls => 17

16b Leaf blade curled, with weak embossment protruding on the upper side. S. nemorensis, ovatus: Trioza senecionis

17a Galls conspicuous; occupied at an early stage by a dusting of sori => 18

17b Galls wart-shaped, coalesced, almost 1 mm long; golden yellow; often many on the underside of basal leaves or on the base of young stems. Senecio vulgaris: Synchytrium aureum

18a Sori ± clearly thickened, bearing aecia => 20

18b Leaf blade often with rotund, bulging pads on the underside or leaf veins, petioles and axial parts with ± spindle-shaped, telia bearing elevations => 19

19a Dark brown, small sori, often occurring on the underside of the leaves, sometimes clustering into larger groups, in that case clearly cecidogenic. Jacobaea alpina, aquatica, subalpina, vulgaris; Senecio spp.: Puccinia expansa

19b Rotund, only slightly- or not thickened, ± yellowish margined sori, 5–10 mm wide, on leaf underside. Senecio ovatus, sarracenicus: Puccinia uralensis

20a Host-alternating fungi, which develop yellowish swellings on Senecio species, bearing their aecia and partially pycnidia => 21

20b Fungus host-specific; on the host only sori with telia develop, besides aecia. Swellings often insignificant. Aecia with whitish peridium; in irregular, loose, smaller groups, rarely extended, on the leaf underside. Jacobaea alpina, aquatica, subalpina, vulgaris; Senecio spp.: Puccinia expansa

21a Aecia on Tephroseris spp. => 22

21b Various rust fungi; recorded from:

a Senecio viscosus, vulgaris: Puccinia opizii

b Jacobaea vulgaris; Senecio viscosus, vulgaris: Puccinia schoeleriana

c Senecio nemorensis, ovatus: Puccinia silvatica

d Jacobaea alpina, aquatica, erucifolia, paludosa, vulgaris; Senecio ovatus, sylvaticus, viscosus, vulgaris: Puccinia senecionis-acutiformis

22a Aecia on the leaf undersides in rotund, often yellow-brown, violet-margined spots. Tephroseris longifolia subspp. brachychaeta, gaudini: Puccinia baldensis

22b Aecia usually on the leaf underside in rotund yellow spots. Tephroseris helenitis, palustris: Puccinia eriophori

= Aecidium senecionis-crispati has been described from Tephroseris crispa.

23a Swollen capitula on otherwise normally developed plants => 24

23b Clustered, shortened, leafy and greened capitula on ± atrophied plants. Jacobaea aquatica, J. erucifolia, J. vulgaris, Senecio sylvaticus, vulgaris: Unidentified ? gall mite

= Stunted but not greened flowers of Jacobaea vulgaris are caused by an unidentified thrips

24a Larvae inside the galls => 25

24b Larvae between the achenes. Capitula not opening, markedly swollen, rotund to broad ovoid, the base especially succulent thickened and yellowish to ± reddened there. Several yellowish-white, jumping larvae. Mainly on Jacobaea vulgaris; less frequent on Jacobaea aquatica, erratica, erucifolia, paludosa, vulgaris; Senecio leucanthemifolius subsp. vernalis, sylvaticus, viscosus, vulgaris.: Contarinia jacobaeae

24c Thickened capitula of S. ovatus containing yellowish, non-jumping larvae of Dasineura senecionis

24d Flower head only inconspicuously swollen bearing a cone of froth which covers a fly maggot. Jacobaea aquatica, incana subsp. carniolica, vulgaris; Senecio ovatus; Tephroseris crispa: Botanophila seneciella

25a Capitula usually only slightly swollen. Larvae in the thickened receptacle => 26

25b Major part of the flower head deformed to form a succulent gall. All organs more or less incorporated in the gall formation, which may extend to the stalk. Inside a large cavity containing pale yellow to succulent-red larvae. Jacobaea vulgaris; Senecio nemorensis, ovatus incl. subsp. stabianus, sarracenicus, sylvaticus: Contarinia aequalis

26a Larvae lacking distinct head capsule and legs => 27

26b Larvae with head capsule and thoracic legs in the slightly enlarged receptacle. S. viscosus: Unidentified lepidopteran

27a Capitula at base often heavily swollen on all sides and discoloured yellow-green, not opening, usually large cone-shaped. Fruits usually withered. Containing a single larva. Senecio Sphenella marginata

27b Receptacle externally only weakly swollen, often on one side, and hardened; later bulging upwards locally. Capitula not opening, mostly cylindrical to narrow cone-shaped. Containing a single larva. Senecio Trupanea stellata

gallers on Crataegus

pub 9.xii.2019

Dichotomous table for gallers on Crataegus

by Hans Roskam

1a On flowers => 23

1b On vegetative plant parts => 2

2a On buds, leaves and thinner twigs => 4

2b In root, trunk or on thicker branches => 3

3a Irregular lumpy swelling on root, 10 mm across or much larger; soft at first, later woody; contains red, purple or brown woolly aphids covered with copious white wax; gall persists long after aphids have left; rare. Crataegus spp.: Eriosoma lanigerum

3b Branches or stems often with conspicuous, club- or barrel-shaped swellings. Crataegus spp.: Viscum album

4a Malformations of various shape, soon occupied by fructifications of fungi => 20

4b Malformations caused by animals => 5

5a Aphid galls => 15

5b Other causers => 6

6a On younger stems, shoot tips or leaves => 7

6b Buds slightly swollen, not opening, occasionally abnormally pubescent. C. laevigata, monogyna: Eriophyes calycobius

6c Vegetative bud unopened, transformed into a rotund mass of small, strongly folded leaves, about 5 mm wide, the external ones making a sort of hood enveloping a shell of aggregated dying leaves. Crataegus spp.: Anthonomus bituberculatus

7a Malformations on single, or several terminal leaves, loosely arranged => 9

7b Galls on thin stems or on shoot tips => 8

8a Leaves on distinctly stunted, slightly thickened shoot tip often in many densely tuft-like clusters. Leaf blades sessile, ± stunted, rugose, occupied by many bolt-shaped or globular green or reddish proliferations. Between the inner, very small leaves are many white, later orange larvae. C. azarolus, coccinea, laevigata, monogyna, rhipidophylla: Dasineura crataegi

= Associated are the yellowish larvae of the inquiline gall midge Prolauthia circumdata.

8b Shoot axis with brown-green swelling, sometimes extending onto the petiole, with easily loosening epidermis. C. laevigata, monogyna: Unidentified gall midge

= The “Hawthorn twig gall midge” Resseliella crataegi, with larvae living gregariously under bark, has not been observed to cause galls.

8c Bark of younger twigs usually with several, ± distinctly rimmed depressions, which contain a rotund, whitish- to brownish-grey scale insect, the inducer. C. rhipidophylla: Epidiaspis leperii

9a Leaves curled or with many small swellings or pocks => 12

9b Leaf margin rolled or leaf blade abnormally pubescent => 10

10a Rolls of leaf margins => 11

10b Underside of leaf with white or violet-red erinea of slightly club-shaped hairs. C. coccinoides, laevigata, macrocarpa, monogyna, nigra, rhipidophylla, sanguinea: Phyllocoptes goniothorax

10c Upper side of leaf slightly protruding at junction of midrib and side vein; corresponding area on underside weakly pubescent. Crataegus spp.: Eriophyes albaespinae

10d Underside of leaf with a longitudinal groove, abnormal pubescence absent. C. laevigata, rhipidophylla: Aculops crataegumplicans

11a Leaf margin tightly rolled downwards, with short club-shaped, at first white, then brownish hairs sometimes extending as erinea into the leaf blade or developing there as isolated patches. C. coccinoides, laevigata, macrocarpa, monogyna, nigra, rhipidophylla, sanguinea: Phyllocoptes goniothorax

11b Leaf roll, containing several red larvae. C. monogyna, laevigata: Unidentified gall midge

12a Leaf blade with many pocks or small swellings => 13

12b Several leaves of suckers on curved stems bent together into a loose aggregation. Leaf blades ± crumpled. Containing a froth-covered nymph. Crataegus spp.: Philaenus spumarius

13a Leaf blade with one-sided archings => 14

13b Leaf blade with many pocks protruding on both sides, often pale green; with narrow opening on underside, occasionally also on upperside. C. laevigata, monogyna: Eriophyes crataegi

14a Leaf blade with many small bulging swellings, yellowish or often carmine-red. Froth-covered nymphs in grooves on underside. C. laevigata, monogyna, rhipidophylla: Cacopsylla melanoneura

14b Leaf blade browned by vagrant gall mites. C. macrocarpa, monogyna, rhipidophylla: Calepitrimerus armatus

14c In similar malformations on hawthorns during the same period also lives Cacopsylla peregrina

14d Leaf blade with small depressions on the underside, and corresponding tiny bulges, often coloured red, on the upper side. In each cavity is one flat froth-covered nymph. C. laevigata, monogyna: Cacopsylla affinis

= The psyllid Cacopsylla crataegi is only weakly cecidogenic, and often reported only as inquiline, or successorium (secondary inhabitant) in aphid galls.

14e Leaf blades usually bent downwards along the venation. Malformations without abnormal pubescence. C. laevigata, rhipidophylla: Aculops crataegumplicans

15a Leaves variously curled, leaf blades not discoloured or sometimes marbled yellow. Malformation usually with many leaves, loosely arranged on shoots or ± clustered on shoot tips => 17

15b Leaves swollen, bladder-like, and conspicuously discoloured yellowish or reddish. Galls caused by several Dysaphis species, all host alternating and difficult to separate => 16

16a Leaf blade usually keel-shaped, curved downwards; segments between the veins especially close to the midrib strongly inflated, bladder-like, discoloured yellowish, not red. Galls mainly on several leaves distributed over the plants. C. laevigata, monogyna: Dysaphis ranunculi

16b Galls usually strongly reddened, otherwise not different from previous species. Often on several neighbouring leaves occurring already during unfolding of leaves. Larvae usually greenish or pink. Aphids mainly distinguished by their different host alternation. Aphids interbreed on Crataegus. Exules on roots, at stem base or sheaths, rarely on leaf blades of basal leaves of various Apiaceae:

a Migrating to Daucus carota, sativus (Anthriscus, Aegopodium): Dysaphis crataegi

b Migrating to Aethusa cynapium: Dysaphis crataegi subsp. aethusae

c Migrating to Angelica: Dysaphis angelicae

d Migrating to Apium graveolens and Petroselinum crispum: Dysaphis apiifolia subsp. petroselini

e Migrating to Heracleum, Conium: Dysaphis lauberti

f Migrating to Laserpitium, Anthriscus: Dysaphis laserpitii

g Migrating to Petroselinum, (Levisticum officinale, Conium): Dysaphis apiifolia subsp. petroselini

h Migrating to Pastinaca sativa: Dysaphis crataegi subsp. kunzei

17a Leaves not conspicuously discoloured => 18

17b Several leaves at shoot tip loosely arched, marbled yellow, soon drying. C. laevigata, monogyna, rhipidophylla, sanguinea: Prociphilus pini

17c Cherry-red to crimson curled-leaf galls in spring. Crataegus laevigata, monogyna: Dysaphis apiifolia

17d Red curled-leaf galls on leaves. C. curvisepala: Dysaphis incognita

17e Pale green or red curled-leaf galls. C. orientalis: Dysaphis virgata

18a Aphids green => 19

18b Aphids black; rolling and curling of young leaves. Crataegus spp.: Aphis fabae

19a Leaves on the unshortened shoots normally distributed or sometimes loosely clustered at shoot tip. Midrib conspicuously bent, screw-like, leaf blade sometimes undulate, nested, loosely or more compactly bent downwards. Aphid with short, thick green siphunculi. C. coccinea, laevigata, monogyna: Rhopalosiphum oxyacanthae

19b Leaves at stunted ends of shoots bent downwards over tip and margins rolled. Aphid with rather long black siphunculi. Crataegus spp.: Aphis pomi

20a Leaves curled or swollen, bladder-like, also young stems partially ± thickened and curved, occupied by grey-white fungal fructifications => 22

20b Considerable yellowish, also reddened, pad- or bulge-shaped swellings on leaves, young stems and even fruits. Galls occupied by spermogonia and aecia => 21

21a Peridium cylindrical, 2–3 mm long, lacerated brush-like later on, divided from the tip into many long lobes. Lateral walls of peridium cells with many, irregularly shaped tubercles of different size. Crataegus spp.: Gymnosporangium clavariiforme

21b Aecia similar. Lateral walls of peridium cells with strong transversely and obliquely running tubercles and ridges. Crataegus spp.: Gymnosporangium confusum

22a Leaves with yellowish-green or reddened bladder-like swellings, at maturity appearing white-frosted because of presence of many asci. Sori occasionally slightly arched, usually on one side, and ± curved swellings on young shoots, flower peduncles and even floral parts; sporadically developing almost witches’ broom-like malformations. C. laevigata, monogyna, nigra, sanguinea: Taphrina crataegi

22b During development of infected young shoots, according to response ability, the internodes partially appearing shortened, slightly thickened, partially etiolated, elongated and in case of mainly one-sided infestation ± conspicuously curved and often ± reddened. Diseased organs covered with a loose white mycelium. Crataegus spp.: Podosphaera clandestina

23a Malformations caused by fungi on flower parts or young fruits => 21, 22

23b Malformations caused by animals => 24

24a Outer parts of flower buds, especially basally, slightly swollen, not opening. Between the inner parts occur larvae with inconspicuous head capsules => 25

24b Receptacle and ovaries sometimes facultatively slightly swollen. Flowers remain closed, corolla distinct between healthy flowers because of its premature browning. Inside is a single larva with distinct head capsule. C. laevigata, monogyna: Anthonomus pedicularius

25a Larvae ivory-coloured, jumping. C. laevigata, monogyna: Contarinia anthobia

25b Larvae red, non-jumping. C. crus-galli, laevigata, monogyna: Dasineura oxyacanthae

= Inquiline of Dasineura oxyacanthae, larvae orange-coloured, non-jumping: Dasineura fusca

gallers on Geranium

pub 8.xii.2019

Dichotomous table for gallers on Geranium

by Hans Roskam

1a Galls on root collar or on parts above ground => 2

1b Roots with swellings only a few mm long, nodular or spindle-shaped, which bear side roots. Geranium spp.: Meloidogyne hapla

2a Malformations on inflorescences or flowers => 25

2b Malformations on vegetative parts => 3

3a Malformations caused by fungi, developing on surface or fruiting there => 17

3b Malformations caused by animals => 4

4a Gall formation includes single groups of organs or their parts => 5

4b Complete plant disfigured; basal stem parts variously swollen, spongy, from there developing organs ± reduced and disfigured. G. dissectum, molle: Ditylenchus dipsaci

5a Malformations on plant parts above ground => 6

5b Adventitious buds on root collar transformed into cauliflower-like proliferations, up to 20 mm long. G. molle, pusillum: Cause unknown – ? gall mite

5c Repeatedly reported leafy proliferations, have been attributed to Rhodococcus fascians

5d Closed fleshy proliferations, tuberculate at surface. Geranium spp.: Agrobacterium tumefaciens

6a Malformation of several organs on shoot tips or only on leaves => 7

6b Axial parts of shoot, also petioles, with bulging swellings with rimmed depressions containing the causer. Geranium spp.: Planchonia arabidis

7a Leaves with narrow rolls of margin or with strong pubescence => 10

7b Leaves lacking conspicuous pubescence; leaf blades deflected or loosely rolled, ± curled => 8

8a Malformations induced by aphids or spittlebugs => 9

8b Leaf blade ± curled, without particular curving. G. palustre, pratense: Unidentified hemipteran

9a Leaf blade strongly deflected, often ± nest-like, variously curled, dark green close to infestation. Geranium spp.: Philaenus spumarius

9b Several terminal leaf blades of shoots ± wrinkled and disfigured; tips loosely deflected or rolled. Shoot axis shortened if strongly infected, as well as stalks of clustered leaves. Geranium spp.: Acyrthosiphon malvae

10a Malformations distinguished by strong pubescence => 13

10b Narrow roll of leaf margin lacking conspicuous pubescence => 11

11a Malformation of many terminal leaves on shoots => 12

11b Leaflets often in single basal leaves, rarely in stem leaves, sack-shaped, rolled upwards, lighter. Veins thickened, containing several white larvae. G. sylvaticum: Unidentified gall midge

12a Leaf blade more subdivided, partially narrowly rolled inwards at margin. G. robertianum: Unidentified gall mite

12b Leaves on shortened shoot tip accumulated, tuft-like, tips rolled upwards, appearing almost needle-like, ± thickened, often reddened. Geranium spp.: Aceria geranii

13a Leaf blades with conspicuous rolls of margin => 14

13b Leaf blades with mainly yellow- or red discoloured irregular hunchbacked archings, covered with a white-silk-like glossy, abnormal pubescence. Hairs cylindrical, frizzy. Erinea may also encroach onto petioles, shoot axis and even calyx leaves. Geranium spp.: Aceria geranii

= The gall mite Aceria dissecti has been described from G. dissectum causing deformations of petals and young leaves, and shrivelling of leaves

13c Leaf margins hardly rolled inwards, more densely haired on both sides soon ± brownish discoloured. Mites free-living on leaf underside. G. caeruleatum, robertianum, sanguineum, sylvaticum: Epitrimerus geranii

14a Malformation of many clustered terminal leaves => 15

14b Malformations on shoot tips, of which axial parts, as well as petioles, are elongated and thinner. Leaflets rolled inwards and upwards, white erineum on underside. Inflorescences transformed into whitish capitula. Complete plant ± discoloured. G. molle: Unidentified gall mite

15a Leaves additionally subdivided due to infestation => 16

15b Shoot axis shortened, leaves accumulated, tuft-like, their tips rolled inwards and upwards, ± thickened, reddened, on many hosts conspicuously strongly pubescent. Geranium spp.: Aceria geranii

16a Shoot tip stunted, leaves ± finely subdivided, their tips ± rolled inwards, curved, twisted. Flowers ± distorted, accumulated into capitula, abnormally pubescent. G. pyrenaicum: Aceria schlechtendali

16b Similar malformations on G. dissectum, lucidum, molle, palustre, phaeum, sanguineum, sylvaticum: Aceria dolichosoma

17a Malformations bearing aecia and telia of rust fungi => 19

17b Malformations caused by mildew fungi => 18

18a Minor swelling, up to 1.5 mm long, situated mainly below the leaf blade on petiole, covered by at first white, then ± brown mycelium containing many punctiform perithecia. Geranium spp.: Podosphaera fugax

18b Grey-white down of conidiophores on leaf underside. Leaves usually completely diseased; at first developing faster, longer stalked than healthy ones; leaf blades smaller, yellowish-green, the margins usually loosely rolled downwards. Geranium spp.: Peronospora conglomerata

= The mildew Plasmopara wilsonii causes sharply delimited upper surface leaf spots on G. molle, phaeum, initially some mm large, ultimately often filling the entire leaf; pale yellowish at first, in the end violaceous brown

= Other Plasmopara species on G. palustre, pratense, sylvaticum and relatives occurring in similar down, are much more frequent, but are never cecidogenic

19a Malformations bearing spermogonia and aecia => 22

19b Swellings with only telia => 20

20a Teliospores 2-celled => 21

20b Teliospores 1-celled; on leaf underside in small, dark-brown dusty sori. G. phaeum, ? palustre: Uromyces carpathicus

21a Sori remaining covered by epidermis for a long period. Spores with compact stalks. Pads on leaf underside small, on yellowish to reddish discoloured spots, or sori on spindle-shaped variously distorted bulges on stems, petioles or main veins, up to 20 mm long, usually red to crimson margined. G. albiflorum, macrorrhizum, pratense, sylvaticum: Puccinia morthieri

21b Pads soon naked and powdery; spores easily falling, with warty surface. Sori in densely arranged groups on ± distinct, small or elongated, up to even 80 or more mm long, often variously distorted bulges. Geranium spp.: Puccinia geranii-silvatici

21c On similar malformations on G. macrorrhizum develops Puccinia flahaulti

22a Mature aecia often arched and wide open => 23

22b Mature aecia appearing depressed, with narrow ostiole, margin star-shaped, lacerate, soon falling. Sori on leaf underside on large, rotund, slightly swollen, tuberculate, reddened spots. G. sanguineum: Puccinia oerteliana

23a Aecia on conspicuously thickened pads. Fungi monoecious. Peridium cells only loosely connected. Often conspicuous swellings, often associated with strong distortion, yellowish, sometimes ± reddish margined, on main veins encroaching into the leaf blade, or bulges of variable length on petioles and stems. Geranium spp.: Uromyces geranii

23b Aecia on not thickened leaf sites, surrounded by distinctly discoloured areas. Minor swellings may develop facultatively if sori encroach onto main venation. Fungi host alternating => 24

24a Sori mainly on intensively blood-red or crimson discoloured spots, sometimes additionally surrounded by a yellowish-green area. Peridium cup-shaped with rigidly connected wall cells; after opening the margin finely frayed and bent inwards. Geranium spp.: Puccinia polygoni-amphibii

24b Similarly without intensive marginal discolouration spots develop on G. columbinum, dissectum, molle, pusillum, rotundifolium: Puccinia polygoni

25a On flowers or fruits => 27

25b Expanded parts of inflorescence disfigured => 26

26a Malformation by aphids; the distorted and abnormal pubescent flowers are clustered. Geranium spp.: Acyrthosiphon malvae

26b Flower head-like clustering of disfigured, ± abnormally pubescent flower buds or calyx leaves, caused by gall mites => 14

27a Flowers ± swollen, unopened. Geranium spp. Several unidentified gall midges

27b Fruit basally ± strongly swollen. Containing several orange-yellow midge larvae. G. sanguineum, sylvaticum: Dasineura geranii

gallers on Silene

pub 7.xii.2019

Dichotomous table for gallers on Silene

by Hans Roskam

1a On parts above ground => 3

1b On subterranean parts => 2

2a Roots with 2–5 mm long, cylindrical galls, sporadically bearing side roots. S. atropurpurea, coeli-rosa, gallica, vulgaris: Meloidogyne hapla

2b Subterranean buds swollen, up to 4 mm across. Leaves clustered, tuft-like, succulent, whitish. Containing a single white larva. S. cucubalus, nutans, vulgaris: Dasineura subterranea

3a On inflorescences or flowers => 30

3b On stems, shoot tips, axillary buds or leaves => 4

4a Malformations on leaves, shoot tips, axillary buds or upper stem parts => 8

4b Basal rosettes or basal shoot organs largely disfigured, or leaf blades of rosette leaves with small yellowish warts => 5

5a Malformations caused by animals => 6

5b Leaf blades of rosette leaves with many warts, less than 1 mm long, multicellular, yellowish, occasionally coalescing; also on basal stem parts. Silene flos-cuculi: Synchytrium aureum

6a Malformations of basal leaves or leaf blades => 7

6b Young plants severely stunted. Stems stunted, spongy, swollen, inserted leaves variously disfigured. Silene spp.: Ditylenchus dipsaci

7a Basal leaves stunted. Leaves with their base spindle-shaped, converging; containing a green caterpillar, distinguished by its dark red first segment. It feeds on bast and cortex of young stems, which appear slightly thickened because of callus formation. S. nutans: Caryocolum sp.

7b Leaf blades of basal leaves in longitudinal direction knee-like bent, almost at right-angles, at any point. Breaking point close to midrib succulent, swollen, usually yellow-green, sometimes reddish. S. viscaria: Planchonia arabidis

8a On shoot tips, side shoots, and -buds or on leaves => 14

8b On axial parts of shoot => 9

9a Malformation caused by larvae with a distinct head capsule => 10

9b Swellings spongy; very variable in shape and expansion; with undulate or wrinkled surface. Silene spp.: Ditylenchus dipsaci

10a Malformations caused by a pith-tunneling caterpillar => 11

10b Stem with conspicuous ± spindle-shaped or cylindrical, tough-walled, glabrous swellings; caused by beetle larvae. Galls about 10 mm long and 5 mm thick, spindle-shaped or cylindrical; single or with a few together. Containing a single larva. Silene spp.: Sibinia femoralis

11a Galls very conspicuous on all sides, more than 15 mm long => 12

11b Stem stunted, ± swollen and curved. S. nutans, otites, viscaria: Caryocolum amaurella

12a Up to 30 (40) mm long and 8 (10) mm thick spindle-shaped-cylindrical gall, situated in the shortened internodes. A long tunnel in pith containing a dirty-grey, brown-headed caterpillar => 13

12b Swellings in axial parts of shoot tips. S. hayekiana, saxifraga: Caryocolum saginella

13a On S. dichotoma, gallica, italica, nutans,otitis, parviflora: Caryocolum cauligenella

13b On S. vulgaris: Caryocolum inflativorella

14a Galls on tips or buds of main- or side shoots => 25

14b Malformations mainly on leaves, sometimes encroaching into stem parts => 15

15a Malformations only minor, bearing sori of fungi => 22

15b Malformations caused by animals => 16

16a The causers are external on the galled tissue => 17

16b Spongy, swollen on both sides, ± wrinkled or undulate swelling on petiole or leaf blade; on narrow leaves also proliferating beyond the margin. Sometimes all parts of a rosette or of young plants are disfigured. Containing many eelworms. Silene spp.: Ditylenchus dipsaci

17a Leaves folded upwards over the midrib, ± discoloured. Malformations often on many plant parts. Caused by aphids => 18

17b Shoot axis locally stunted and ± curved. Leaves deflected over their tip, undulately curled; often clustered, nest-like, on the ± stunted stem parts. S. armeria, flos-cuculi, gallica, vulgaris: Philaenus spumarius

= As causer of similar malformations of shoot and leaves Taeniothrips atratus has been sporadically indicated.

18a Aphids pale green or yellowish => 21

18a Aphids red to dark-brown or black => 19

19a Aphids black => 20

19b Aphids red to dark brown. Leaves rolled downwards. S. alba, flos-cuculi: Myzus certus

20a Young leaf blades curled or rolled slightly downwards, caused by glossy black aphid with very short, rounded cauda. Silene spp.: Brachycaudus lychnidis

20b Flat, not discoloured bulges. S. alba, dioica. Wingless aphids with dull black body and tongue-shaped cauda: Aphis fabae

21a Apterae are whitish yellow to pale green, strongly wax-powdered; body length 1.4‒2.2 mm. Antennae half the body length. Siphunculi much shorter than the oblong, black cauda. S. vulgaris and varieties: cf. Brachycolus cucubali

21b Aphid yellowish or pale green, glossy, body length 1.4‒1.8 mm. Antennae about two-thirds of body length. Siphunculi weakly clavate, pale yellowish, only slightly longer than the yellow cauda. S. alpina, atropurpurea, flos-cuculi, nutans, otites, pendula, suecica, viscaria: Volutaphis centaureae

22a Malformations bearing yellowish to yellowish-white sori => 23

22b Minor rotund or oblong dense sori, sometimes bulging on venation, bearing dark-brown, 2-celled teliospores. Silene spp.: Puccinia arenariae

23a Aecia on several Silene species, S. nutans excepted => 24

23b Aecia mainly on S. nutans. Peridium short cylindrical, with white, deflected margin, subdivided into long narrow lobes. Uromyces inaequialtus

24a Malformations and aecia similar to those of preceding fungus. Spots on upperside often reddened. Aecia disc-shaped with strongly lacerate, deflected margin. Fungus lacking uredinia, with repeated development of aecia. S. cucubalis, alpina, densiflora, dichotoma, dioica, elisabethae, maritima, noctiflora, nutans, otites, rupestris, uniflora incl. subsp. thorei, vulgaris incl. subsp. prostrata: Uromyces behenis

= Witches’ broom-like malformations after infestation on S. uniflora may also be caused by this rust fungus.

= On S. otites the aecia of a host-alternating fungus (Aecidium otitis) have been recorded repeatedly with unknown life-cycle

24b Occasionally on cultivated plants of S. coeli-rosa, etiolated shoots with narrowed, paler leaves have been observed bearing on the undersides expanded, scattered yellow sori of Melampsorella caryophyllacearum

24c Aecia arranged in circular groups on hypertrophied sori on various organs, often crowded, more rarely extending over complete leaf; accompanied by spermogonia and often uredinia, less by 2-celled teliospores. Peridium very small, short cylindrical, with lacerate white margin. S. vulgaris, more rarely S. armeria, nutans, pendula, etc.: Puccinia behenis

25a Galls not excessively pubescent => 27

25b Malformations with abnormal whitish pubescence => 26

26a Leaves on shoot densely clustered. Leaf blades rolled and ± curved, almost linear; strongly white pubescent. In case of severe infestation the whole plant is atrophied. S. nutans: Unidentified gall mite

26b Almost bud-like accumulation of severely stunted, disfigured and abnormally haired leaves on shoot tips or in axillary buds. Containing several white larvae. S. alba, densiflora, dichotoma, dioica, latifolia,noctiflora, nutans, otites: Neomikiella lychnidis

26c Similar malformations of shoot tip, lateral buds, inserted unfolding leaves with loose, fleshy thickened marginal upward roll, exceptionally also downwards. Containing several white larvae. S. nutans: Unidentified gall midge

27a Malformations ± bud-like; caused by midge larvae => 29

27b Galls elongated, not of compact bud-like appearance, caused by midge larvae as well as other inducers => 28

28a Apical parts of plant distorted and discoloured. Silene alpina: Volutaphis alpinae

28b Leaves accumulated at the shoot tip over its length loosely upwardly rolled and ± thickened, bearing aphids or thrips. S. vulgaris, nutans: cf. Brachycolus cucubali

28c Several leaves of stunted shoots distorted, variously rolled and curved. S. latifolia, vulgaris: Taeniothrips atratus

28d The upper leaf pair of shoot tip erect, slightly thickened at base; the margins folded together or rolled. Containing several white to pale orange larvae. S. vulgaris: Macrolabis sp.

28e Similar galls containing white, jumping larvae. S. vulgaris: Contarinia cucubali

28f Leaves of shoot tip bushy clustered. S. nutans, vulgaris: Unidentified gall midge

29a Up to 10 mm long, ± onion-like, glabrous galls on the axillary buds or tips of lateral shoots. Containing several white larvae. S. vulgaris: Macrolabis sp.

29b Leaves bud-like accumulated on vegetative shoots, stunted, at base broadened, thickened and ± discoloured. Larvae pink-red. S. acaulis: Jaapiella alpina

29c The youngest one- or two pairs of leaves at the tip offside shoots are narrowly rolled into one another, swollen at base and discoloured. Containing several red larvae. S. viscaria: Jaapiella viscariae

29d Several rolled glabrous leaves form a spindle-shaped bud gall at the vegetative tip, contain many cream-coloured gall midge larvae. S. behen: Macrolabis behen

30a Malformation of flowers and of flower parts caused by fungi => 40

30b Malformations of inflorescences or single flowers caused by animals => 31

30c Fruits swollen. S. alba, dioica, fruticosa: Sibinia pellucens

31a Flowers unopened, swollen. Containing midge larvae => 34

31b Flowers ± stunted, their parts variously greened or leafy => 32

32a Malformations associated with a strong stunting of inflorescence => 33

32b Malformations usually restricted only to the sometimes shortened axial parts of stem. All flower parts leafy inside the hardly changed calyx. Inflorescence axis sometimes ± developing further. S. nutans, otites, rupestris: Aceria silenes

32c Malformations on S. “parviflora”: Eriophyes parviflorae

32d Flowers greened, transformed into small shoots bearing strongly pubescent little leaves. Also the vegetative buds may develop similarly disfigured, ± elongated, dense bunches. S. alba, dioica, latifolia vulgaris: Unidentified ? gall mite

32e Inflorescence stunted, disfigured, flowers clustered. Conspicuous pubescence absent, calyx widened, enclosing greened organs. Unidentified gall mite

33a Complete host stunted, flowers greened. S. dichotoma: Inducer unknown, ? virus

33b Flowers on usually severely stunted plants transformed into a widely protruding rosette of variously disfigured little leaves; stamens hardly disfigured but greened. S. alba: Inducer unknown – ? virus

33c Axial parts of inflorescence ± compact. Flowers ± clustered; calyx swollen. Organs inside variously disfigured and greened. S. vulgaris: cf. Brachycolus cucubali

33d Similar malformations on inflorescence. S. alba, vulgaris, occasionally S. baccifera, borysthenica, coronaria, dioica, italica, latifolia, uniflora, viscaria: Brachycaudus lychnidis

33e On S. dioica. Between strongly inflated calyx and stunted corolla: cf. Brachycaudus lychnidis or B. klugkisti

34a Galls usually with dense abnormal pubescence => 39

34b Galls not, or only slightly more pubescent than the normal organs => 35

35a On Silene species, but not S. alba, dioica, latifolia => 36

35b On S. alba, dioica, latifolia. Flower buds swollen, stunted, mostly unopened, on usually inconspicuously shortened axial parts of inflorescence. Containing several midge larvae, at first white, soon yellow, jumping: Contarinia steini

36a On Silene species, S. italica, vulgaris excepted => 37

36b On S. italica, vulgaris & subsp. glareosa: Calyx conspicuously swollen, largely unopened. Also the other flower parts enlarged and exceptionally ± leafy. Larvae yellowish to pale red: Jaapiella floriperda

36c Also described for similar galls on same hosts. Larvae white: Jaapiella cucubali or J. inflatae

37a On Silene species, but not S. atropurpurea, flos-cuculi, viscaria => 38

37b On S. flos-cuculi, viscaria, similar galls contain many red larvae: Dasineura praticola

37c On S. viscaria, similar galls contain only 4–8 red-yellow larvae: Jaapiella moraviae

38a On Silene species, but not S. nutans => 00

38b On S. nutans. Flowers stunted; ± globular, unopened, hardly swollen. Sometimes on the ± shortened axial parts clustered into rotund, sometimes weak whitish pubescent balls. Containing midge larvae. Unidentified gall midge

38c On S. nutans. Swollen flower buds, abnormally pubescent. Calyx strongly thickened. Larvae yellowish to pale red: Dasineura bergrothiana

39a On S. bupleuroides. Flower buds swollen, pale, unopened. Calyx thickened; corolla greened. Containing several yellow larvae. Unidentified gall midge

39b On S. otites. Flowers transformed into a rotund gall, up to 4 mm. Calyx abnormally pubescent. Corolla greened. Stamens ± normal. Containing red, non-jumping larvae. Dasineura sp.

39c Similar galls on S. parviflora, pseudotites: Unidentified gall midge

= In C-Eu occasionally galls on S. nutans, otites consisting of several, densely clustered, severely stunted and whitish pubescent buds; between the buds live white larvae of a gall midge assigned to Neomikiella lychnidis. Galls on these hosts often simultaneously occurring in vegetative shoot tips or lateral buds

40a Fungus fructifies in the ± distinctly swollen anthers. Spores separated, not arranged in easily decomposing balls; ± violet tinged. Other flower parts not galled => 43

40b Flower buds stunted, unopened, transformed into globular to broad egg-shaped galls. Inner part soon destroyed and displaced by a yellow- to tobacco-brown spore mass, consisting of many easily decomposing balls => 41

40c lowers leafy or partially greened. Organs variously disfigured, transformed into sometimes ± clustered, ± reddish tufts. S. viscaria: Cause unknown

41a On several Silene species, S. otites excepted => 42

41b On. Silene otites. Diseased flowers distorted; often distinctly swollen, for a long period unopened, corolla usually atrophied. Sori rupturing later on and with dusting: Microbotryum majus

42a On Silene alba, alpestris, dioica, nutans, rupestris, vulgaris. Flowers outwardly hardly changed. Infestation caused by this fungus results in an early opening of the flower accompanied by a shortening and swelling of the stamens, and in the female flowers a transformation into similarly disfigured anthers: Microbotryum violaceum

= Microbotryum heliospermae is an anther smut fungus occurring on alpine S. pusilla; M. silenes-saxifragae is an anther smut fungus on S. saxifraga

42b On many other Silene species. Flowers outwardly hardly changed. Spore mass usually pale grey-violet: Microbotryum silenes-inflatae

= The smut fungus Microbotryum silenes-dioicae transforms the content of the anthers of S. dioica into a brown vinaceous mass of spore

= Note: because the fungus leaves the ovary intact, the negative impact on the reproductive capacity of the flower is very limited. The real damage is caused by the gall midge Contarinia steini, see lead 35b.

= Microbotryum silenes-acaulis has been reported on S. acaulis, uniflora

43a On S. alba, dioica, latifolia, mollissima, nutans, repens, thymifolia, uniflora, velutina, vulgaris: Thecaphora melandrii

43b On S. flos-cuculi, viscaria: Thecaphora saponariae

gallers on Brassica

pub 6.xii.2019

Dichotomous table for gallers on Braasica

by Hans Roskam

1a On inflorescences, flowers or fruits => 23

1b On vegetative parts => 2

2a On parts above ground => 6

2b On root collar or on roots => 3

3a On roots => 4

3b Root collar with ± rotund, succulent swellings, about 8–10 mm long, containing a single larva. Galls, especially on perennial species, often many per plant and largely coalesced into ± lumpy gall complexes; sometimes also on the basal stem parts or close to surface on main root, especially on cabbage. B. napus, oleracea: Ceutorhynchus assimilis

= The snout beetles Aulacobaris coerulescens and Melanobaris laticollis have erroneously been reported as inducers of root collar-, root- and stem galls. The larvae develop by boring into ungalled roots or above ground stem parts and occasionally arrive in galls already produced by other inducers

4a Nodule-shaped swellings, only a few mm long, on the finer side roots, not noticeably swollen, transiently bearing cysts => 5

4b Main- or side roots often with very conspicuous, often clustered, spindle- or ± finger- to nodule-shaped, thick succulent, massive swellings; inside many cells with dense masses of minute spores. B. oleracea: Plasmodiophora brassicae

= Occasionally conspicuous nodular proliferations occur on main roots, or more frequently on above-ground parts, especially on forms of B. rapa. The tissue is, in contrast to that caused by Plasmodiophora brassicae, uniform coloured and without development of spores. Cause unknown, but some authors attributed these malformations to Agrobacterium tumefaciens

5a Roots with spindle-shaped or rotund, smaller, sometimes about pea- to exceptionally nut-size swellings caused by eelworms living inside. B. napus, oleracea, rapa, incl. subspecies and forms. Meloidogyne hapla

5b Inconspicuous, some side roots bearing root galls. B. napus, oleracea: Meloidogyne artiellia

5c Roots externally not swollen; inside with giant cells. Occasionally stronger development of side roots. Temporarily at surface with about poppy-seed sized, lemon-shaped, at first milk white, then browned cysts. Brassica spp.: Heterodera schachtii

5d On many cabbage species occur also the very similar, but slightly smaller, on average up to 0.6 mm, and more rotund cysts of Heterodera cruciferae

6a Malformations with white sori on surface => 22

6b Malformations caused by animal parasites => 7

7a Terminally on main- and side shoots => 18

7b On stems or leaves => 8

8a On stalks or leaf blades of leaves => 10

8b Stem with short spindle-shaped or elongate expanded swellings => 9

9a Thin stems with all-sided, thicker stems with one-sided, spindle-shaped swellings, 10–15 mm long, glabrous, also green inside. Contains a single larva. B. napus, nigra, oleracea, rapa: Ceutorhynchus chalybaeus

= Aulacobaris coerulescens, A. cuprirostris, A. lepidii, A. chlorizans have been reported as causers of stem galls. The larvae tunnel in the stem and the thicker roots; pupation in the gallery

9b Development of stem, especially of winter oil seed, stunted in spring, swollen over variable length, often ± s-shaped curved, often erupting over large expansion. In the strongly enlarged pith many, up to 7 mm long, yellowish-white apodous larvae with brownish, relatively large head capsule. B. napus, oleracea, rapa: Ceutorhynchus napi

= Occasionally has, especially for Brassica, been recorded Ceutorhynchus pallidactylus. Oviposition is not followed by gall formation. For B. rapa thickened leaf parenchyma has been reported caused by Ceutorhynchus leprieuri

10a Malformations mainly of leaf blades => 12

10b Galls on petioles or main venation => 11

11a Galls 10–15 mm long, compact, spindle-shaped, with glabrous surface, also green inside. B. napus, nigra, oleracea, rapa: Ceutorhynchus chalybaeus

11b Stems of germinating, also older plants or petioles, usually also the basal part of midrib shortened, spongy, swollen, yellowish green; at infestation sites brittle and necrotic, at surface ± undulately-wrinkled, variously on leaf blades, also encroaching on parts of rape. B. napus: Ditylenchus dipsaci

12a Leaf blade ± curled, loosely rolled inwards or folded => 14

12b Leaf blade with very narrow marginal roll or with lenticular galls => 13

13a Galls occurring from autumn to early spring; lenticular, up to 5 mm across, succulent, on both sides flat protruding, also green inside, especially conspicuous on yellowing parts, often many per leaf, often including main veins. Containing a single larva. B. rapa, rarely B. napus, oleracea: Ceutorhynchus leprieuri

13b Leaf blade with narrow marginal roll upwards. B. nigra: Inducer unknown

14a Malformations caused by aphids or spittlebugs => 15

14b Leaf blades to varied extent swollen and stunted, bent upwards along midrib; pale green; several whitish to pale yellow, jumping midge larvae on upper side between folds. B. napus, oleracea, rapa, souliei subsp. amplexicaulis: Contarinia nasturtii

15a Malformations caused by aphids => 16

15b Leaf blades of larger leaves deflected into mainly oblique rolls or distortions; usually curled and deep green close to froth covered froth-covered nymph. Brassica spp.: Philaenus spumarius

16a Aphid green => 17

16b Aphid black. Leaf blade at margin ± deflected, curled, infestation mainly on terminal stem leaves. Brassica spp.: ? Unidentified aphid

= Black aphids of Aphis fabae s.l. do not cause galls on Brassica. However, they may occur as inquilines in galls caused by other inducers

17a Leaf blade with expanded, conspicuously bulge- or bladder-like, pale green, on many species sometimes reddish or violet marbled folds or swellings; large colonies of densely grey-powdered aphids often on underside. B. napus, oleracea, rapa: Brevicoryne brassicae

17b Aphid not mealy powdered. Leaf blades of stem leaves often rolled downwards at margin, ± curled. B. napus, oleracea: Myzus persicae

18a Galls on tips of rosette leaves => 19

18b Tips of flowering main- and side shoots severely stunted; leaves as well as flower buds densely clustered, variously swollen at base. Similar malformations also on axillary, often hardly developed shoots. Between the galled parts are several whitish- to pale yellow, jumping larvae. B. napus, oleracea, rapa, souliei subsp. amplexicaulis: Contarinia nasturtii

19a Inducers live inside malformations => 20

19b Central leaves disfigured. Lower parts of petiole, vegetative point, especially at infected area, strongly swollen and bent sidewards. Between galled parts are several whitish- to pale yellow, jumping larvae. B. napus, oleracea, rapa, souliei subsp. amplexicaulis: Contarinia nasturtii

20a Shoot thickened over variable length, stunted. Leaves ± clustered, the inner ones often severely stunted or dead. Pith often contains several beetle larvae => 21

20b Stem of young plants completely or partially spongy, pale green; infestation similarly encroaching into petioles and leaf veins, mainly on underside. Galls contain many eelworms. B. napus: Ditylenchus dipsaci

21a Shoots, occasionally also leaf base of non-shooting forms, distinctly thickened; pith greatly increased. Vegetative point often largely stunted or necrotic. Several beetle larvae in heavily infected pith. B. napus, oleracea, rapa: Ceutorhynchus napi

21b Similar, usually weaker swellings inhabited by only 1 to 3 larvae. B. oleracea and forms. Ceutorrhynchus rapae

22a Loose down of branched conidiophores in ± expanded sori on the underside of only pale leaves. Rarely on leaf veins or young stems causing occasionally minor swellings, usually containing oospores. B. napus, nigra, oleracea, rapa: Hyaloperonospora brassicae

22b Sori on leaf underside rotund, on stem parts oblong-oval to spindle-shaped, compact, at first closed, glossy, porcelain-like, with mealy dusting after rupturing. Often many per plant; hardly cecidogenic on the leaf blades, on young stems often developing distinct pads. B. juncea, napus, nigra, oleracea, rapa: Albugo candida

22c Leaf with small hard, solid, gregarious pustules caused by fungus, less than 0.5 mm across. Brassica spp.: Synchytrium aureum

23a Malformations on single or many flowers or fruits; stem parts hardly disfigured => 26

23b Inflorescence disfigured => 24

24a Malformations caused by aphids or spittlebugs => 25

24b Racemes greatly shortened terminally; flower buds densely clustered, severely stunted, occasionally swollen at base. Between buds are several whitish- to pale yellow, jumping larvae. B. oleracea, rapa, souliei subsp. amplexicaulis: Contarinia nasturtii

25a Midrib locally swollen and severely stunted, usually bent to one side; flowers clustered, variously disfigured. Leaves distorted and curled. Containing a froth-covered nymph. Brassica spp.: Philaenus spumarius

25b Inflorescence broom-like disfigured and bent, longitudinal growth stunted. Flowers often mostly necrotic; occasionally also several largely disfigured shoots. Stems at first bearing ± densely grey powdered aphids. B. napus, oleracea, rapa: Brevicoryne brassicae

26a Malformations of ovaries or fruits => 29

26b Malformations of flowers => 27

27a Single or several buds of inflorescence swollen, unopened => 28

27b Usually consecutive flowers of large parts of inflorescence, often terminally of raceme variously disfigured; especially the ovaries prematurely elongated and increasing towards the top, swollen like enlarged, slender Capsella siliques; stamens and corolla disfigured, greened and often, like calyx necrotic. B. napus, oleracea and forms. Cause unknown – ? virus disease

28a Gall ± globular; calyx enlarged; corolla shortened; stamens disfigured, their filaments swollen and bent; anthers aborted; ovaries stunted, swollen; style and stigma necrotic. Containing several white, later on pale yellow, jumping larvae. B. oleracea, rapa, souliei subsp. amplexicaulis: Contarinia nasturtii

28b Similar flower galls with several, but non-jumping, larvae which are also white when mature. B. barrelieri, napus, oleracea, rapa: Gephyraulus raphanistri

29a Young or often well-developed shoots ± shortened and slightly swollen over their complete length, or with ± expanded often pale green swellings causing conspicuous curving. Galled siliques sterile or ± early bursting => 30

29b Ovaries, sometimes also calyx leaves and stamens, conspicuously disfigured, enlarged, with white at first closed, soon dusty sori. B. juncea, napus, nigra, oleracea, rapa: Albugo candida

30a Larvae white, only rarely pale yellow later on, non-jumping, usually many per silique. B. napus, oleracea, rapa: Dasineura napi

= Fruit galls, occasionally recorded from literature for Ceutorhynchus assimilis or for larvae of unidentified snout beetle, might also be attributed to this midge

30b Silique swollen, contains a single orange midge larva. B. nigra: Asphondylia stefanii

gallers on Euphorbia

pub 5.xii.2019

Dichotomous table for gallers on Euphorbia

by Hans Roskam

1a On parts above ground => 4

1b On subterranean buds, shoots or roots => 2

2a On buds or stems => 3

2b Roots with small nodular or slender spindle-shaped swellings, up to 6 mm long. E. peplus, cyparissias, helioscopia: Meloidogyne hapla

3a Underground part of usually severely stunted shoot axis often with already on rhizome with an up to about 10 (12) mm long and 4 (6) mm broad, acorn- to spindle-shaped, rough-walled swelling. The terminally situated shoot is severely stunted and soon shrivelling. Containing in the widened pith a compact, cylindrical maggot with black pharyngeal skeleton; puparium later on dark brown. E. cyparissias, amygdaloides: Pegomya euphorbiae

3b Underground stem with large swelling that incorporates leaf buds; cavity inside with a maggot or puparium. E. cyparissias, esula, amygdaloides: Pegomya argyrocephala

4a Expanded malformations on shoots, soon bearing fruiting bodies of fungi => 15

4b Malformations caused by animals => 5

5a Galls on flowers or inflorescences => 13

5b Malformations on vegetative parts => 6

6a Galls only terminally on main- or side shoots, or on axillary buds => 9

6b Malformations on leaves or on expanded shoot parts => 7

7a On several organs of shoot => 8

7b Margin of leaf blade rolled inwards. E. nicaeensis: Unidentified gall midge

8a All terminal leaves of a shoot, also entire plants ± twisted spirally, loosely rolled upwards and inwards, discoloured yellowish or reddish; terminally sometimes clustered into loose tufts. E. amygdaloides, cyparissias, epithymoides, esula, peplus, palustris: Eriophyes euphorbiae

= The gall mite Phyllocoptes euphorbiae causes malformation of apical shoots of E. cyparissias, salicifolia

= The gall mite Aculops euphorbiae on E. spinosa causes drying of apical plant parts, buds and flowers

= The gall mite Eriophyes septemlineatus causes drying and malformation of terminal growth points and inflorescences on E. dendroides

= On E. glabriflora, amygdaloides, capitulate, serpentini the gall mite Aculops glabriflorae causes shortening and drying of vegetative growths and deformation of the inflorescence, and on E. myrsinites the gall mite Aculops montenegrinus causes similar malformations

8b Malformations caused by thrips on leaves of E. cyparissias, esula subsp. tomassiniana, myrsinites: Anaphothrips euphorbiae

8c Plants often severely stunted, infected stems, and other parts swollen, spongy ± distorted. E. helioscopia: Ditylenchus dipsaci

8d Minor swelling of twigs. E. characias: Thamnurgus characiae

8e Similar gall. E. amygdaloides, characias: Thamnurgus varipes

9a Leaves not connate, terminally clustered into a globular or elongated, ± bud-like tuft => 10

9b Upper 2–7 leaves connate forming a capsule-like gall; up to 15 mm long and 10 mm thick, sometimes rotund, usually oblong, pear- or bottle-shaped. Wall striate and hard. In smaller forms also on axillary buds as well as in inflorescences. Larvae orange-coloured to vivid red. Euphorbia spp.: Dasineura capsulae

10a Many leaves strongly broadened; curved over their complete length, tips converging towards gall, making a rotund, ± compact gall => 12

10b Tuft of leaves more loose and oblong, composed of several to many leaves; these with erect or sometimes ± deflected terminal part => 11

11a Tuft up to 30 mm long and 7 mm thick, consisting of 4–5, almost pod-like converging leaves. Sometimes also the following 2–3, ± spreading leaves similarly curved. Containing a single pale orange-red larva. Euphorbia spp.: Dasineura schulzei

11b Similar loose tuft gall; mainly known from Italy; very rare. E. esula: Spurgia esulae

12a Galls compact and ± globular, up to 10 mm across, yellowish-green, often conspicuously reddened; usually containing many orange-red larvae. Euphorbia spp.: Spurgia euphorbiae

= Similar galls on E. cyparissias may contain inquilinous white midge larvae: Macrolabis lutea

12b Terminal gall consisting of short leaves, thickened, leather-like, enveloping one another at base and making a rosette in their terminal half. Containing several yolk-coloured larvae. E. characias: Janetiella euphorbiae

13a Galls bud- or capsule-like => 14

13b Development of inflorescence ± stunted. Flowers disfigured, unopened or ± greened and leafy (phyllanthy). E. amygdaloides, cyparissias, epithymoides, esula, peplus, palustris: Eriophyes euphorbiae

13c Generative shoots stunted. Flower peduncles are partially shortened; variously clustered. Euphorbia spp.: Philaenus spumarius

13d Malformations of the flowers and the shoot tips. E. characias subsp. wulfenii: Aceria dalmatina

14a Gall capsule-like, up to 7 mm long and 5 mm broad, spindle-shaped or ± globular; laterally closed, often curved, with ± beak-shaped tip. Contains orange to vivid red larvae. Euphorbia spp.: Dasineura capsulae

14b The fruit is disfigured, ovoid, pea-size. E. boissieriana, cyparissias:
Dasineura euphorbiarum

14c Both bracts enlarged, inflated, compactly adpressed against each other, enclosing the aborted or disfigured flowers. Gall globular, similar to flower bud, up to 6 mm long. E. aleppica, esula & subsp. tommasiniana, falcata, nicaeensis, seguieriana: Euphorbomyia loewii

15a Malformation with brown to black sori, often together with spermogonia. Species complex of Uromyces scutellatus => 19

15b Malformations bearing yellowish sori of aecia and spermogonia; many species also subsequently develop the brown to blackish other spore forms => 16

16a Single or several shoots of the non-flowering plants are disfigured => 17

16b Malformation restricted to ± extensive parts of terminal shoot. Diseased shoot parts usually conspicuously elongated, lankier than normal ones and non-flowering. Leaves shortened, thickened, slightly broadened, pale-green; at first bearing pleasant smelling, later on stinking spermogonia; after a longer period the scattered aecidia-like sori develop on the underside. E. amygdaloides, carniolica: Endophyllum euphorbiae-silvaticae

17a Apart from the aecia and spermogonia bearing mycelium, other spore forms are also developed. Fungus monoecious => 18

17b Only aecia and spermogonia. Shoots, at first ± growing ahead, rigidly erect, abnormally elongated; exceptionally severely stunted; sometimes producing branched inflorescences with disfigured flowers. Leaves usually shortened, broadened, thickened and ± pale-green; with scattered aecia on the underside and spermogonia partially also on upper side. Fungi host alternating. Euphorbia spp.: Uromyces tuberculatus species complex

18a On E. exigua, nicaeensis subsp. glareosa: Uromyces tuberculatus

18b On many other Euphorbia spp.: Uromyces proëminens

19a On species of the subgenus Esulae => 22

19b On species of the subgenus Helioscopia => 20

20a On E. angulata, dulcis: => 21

20b On E. exigua, nicaeensis subsp. glareosa: Teliospores with minute, hardly visible warts. Uromyces tuberculatus

21a On E. angulata. Wall of teliospores densely reticulate: Uromyces bresadolae

21b On other Euphorbia spp.: Wall of teliospores delicately reticulate: Uromyces scutellatus

22a On Euphorbia species with glabrous seed coat => 23

22b Mainly on E. nicaeensis & subsp. glareosa, also on E. agraria, macroclada, petrophila. Teliospores with densely arranged very delicate warts. Uromyces sublevis

22c Mainly on E. falcata, also on E. dracunculoides subsp. glebulosa. Teliospores with coarse warts: Uromyces winteri

23a Infected leaves distinctly disfigured => 24

23b Diseased shoots hardly differ from healthy shoots. Infected leaves usually distinctly longer than normal ones. Telia bearing small warts, only visible under high magnification. E. cyparissias: Uromyces alpestris

24a Leaves on diseased shoots usually shorter and sometimes distinctly broader than those on healthy plants => 26

24b Leaves on diseased, usually elongated shoots, usually hardly disfigured. On E. seguieriana and close relatives => 25

25a Teliospores completely glabrous. E. nicaeensis, seguieriana: Uromyces laevis

25b Teliospores bearing loosely arranged small warts. E. barrelieri subsp. thessala, hyberna, macroclada, nicaeensis incl. subspp. glareosa & stepposa, seguieriana: Uromyces tinctoriicola

25c Teliospores with coarse, often coalescing warts. E. petrophila, seguieriana: Uromyces cristulatus

26a Wall of teliospores with ridges of varying length; apically provided with a distinct papilla. E. boissieriana, cyparissias: Uromyces striolatus

26b Teliospores bearing large, coarse, irregularly margined warts; apically lacking papilla. E. agraria, cheiradenia, cyparissias, esula incl. subsp. tommasiniana, exigua, lucida, nicaeensis incl. subspp. glareosa & stepposa, peplus, salicifolia, seguieriana, verrucose: Uromyces scutellatus

26c Wall of teliospores provided with small but distinct warts; apically bearing a papilla. E. cyparissias, esula: Uromyces kalmusii

gallers on Vicia

pub 3.xii.2019

Dichotomous table for gallers on Vicia

by Hans Roskam

1a On parts above ground => 5

1b On roots or root collar => 2

2a On roots => 3

2b Conspicuous proliferations on root collar or stems. V. faba, villosa, etc.: Agrobacterium tumefaciens

= The bacterium Rhodococcus fascians may cause “leafy galls” on V. faba

3a Roots with nodular swellings or laterally inserted nodules => 4

3b Roots on the outside not distinctly changed; temporarily bearing poppy-seed sized, lemon-shaped, white, soon brown cysts. Giant cells develop inside. Vicia spp.: Heterodera goettingiana and/ or Heterodera trifolii

4a Roots with nodular- or slender spindle-shaped to cylindrical swellings, up to about 6 mm long, bearing some lateral roots. Vicia spp.: Meloidogyne hapla

4b Rotund or cylindrical, about 2–7 mm long or compact, apically broadened, also forked or comb-like to coralloid subdivided nodules, which are inserted with narrowed base into main- and adventitious roots. Vicia spp.: Rhizobium leguminosarum

5a On inflorescences, flowers or fruits => 38

5b On vegetative parts => 6

6a Stem with localised swellings, spindle- to bulge-like or young plants at base conspicuously stunted and spongy, thickened => 32

6b Malformation of many organs terminally on shoots, or galls on leaves => 7

7a Expanded parts of shoots etiolated; internodes elongated; leaves ± reduced in size, usually paler, or internodes and leaf axis ± shortened, slightly thickened; leaf blades reduced. Malformations soon bearing fruiting sori at surface => 27

7b Malformations on single or many, normally inserted or ± clustered leaves; caused by animals => 8

8a Galls on separate leaves or on ± largely unfolded leaf blades => 9

8b Leaf completely disfigured; midrib hypertrophied; leaflets folded, pod-like Containing several orange-coloured larvae. V. angustifolia: Dasineura vicicola

8c Shoot tip distinctly stunted; the very young, hardly developed vegetative or generative organs largely stunted, swollen. Marginal leaves sessile, all basal parts strongly swollen, the peripheral leaflets increasingly developing, leaf blades rolled over their complete length or with unfolded tips only. Larvae white, non-jumping. V. sepium: cf. Dasineura viciae

8d Folded hypertrophied discoloured leaflets; contain yellow, 3 mm long midge larva. Vicia lutea: Anabremia trotteri

9a On petioles, midrib or on midrib of unfolded leaflets => 26

9b On leaflet leaf blades => 10

10a Galled leaflets conspicuously fleshly thickened. In early infestations usually all leaflets of several, clustered leaves disfigured. On older leaves only a few leaflets are galled => 23

10b Leaves not fleshly swollen; curled, curved, folded or rolled inwards => 11

11a Leaf curls or -rolls caused by aphids or spittlebugs => 19

11b Leaf folds, -rolls, curvings caused by midge larvae, thrips or mites => 12

12a Folds or rolls caused by midge larvae => 16

12b Malformations caused by gall mites or thrips => 13

13a Mite galls => 14

13b Plant largely atrophied and distorted; leaflets smaller, irregularly constricted and curved, locally discoloured or browned; ± upwardly folded or -rolled. Plant largely atrophied and distorted; leaflets smaller, irregularly constricted and curved, locally discoloured or browned; ± upwardly folded or -rolled. V. cracca, hirsuta, pannonica, sativa, sparsiflora, tenuifolia, tetrasperma, etc.: Firmothrips firmus

= Stunting of various parts is occasionally caused by the black-brown “pea thrips”: Kakothrips robustus

14a Malformations on species with tendrils => 15

14b On V. cassubica, sepium. Leaflets upwardly folded, bent, petiole ± twisted. Unidentified gall mite

15a Leaf blade of leaflet, mainly of apical leaves, rolled upwards from margin up to midrib, ± curved and deflected. V. angustifolia, cracca, sylvatica, tenuifolia, villosa: Aculus retiolatus

15b Similar malformations on V. hirsuta, tetrasperma: Aceria trifolii

16a Leaf blades of single or all leaflets folded, pod-like, over the midrib or occasionally rolled inwards; not conspicuously thickened. On glabrous Euvicia species => 18

16b Similar galls on ± pubescent species. V. villosa, cracca, hirsuta => 17

17a On V. cracca, villosa, incl. subsp. varia. Fold only slightly thickened. Larva pale flesh-coloured: Anabremia massalongoi

17b Single leaflets of mostly unfolded leaves rolled upwards over the midrib on both sides. Leaf blades not shortened. Gall wall hardly thickened, at first usually not discoloured-, later on often yellowish to brownish. Larvae pale yellow to pale orange-yellow. V. cracca: Tricholaba viciarum and/ or Tricholaba similis

17c On V. hirsuta. Leaf blade folded together upwards with only its midrib thickened. Unidentified gall midge

18a Single to several leaflets per leaf loosely bent upwards. Leaf blades almost normally developed, hardly thickened and discoloured. Larvae white to dull yellow. V. sylvatica: Lathyromyza sp.

18b On V. cassubica, dumetorum, pisiformis. Single or several leaflets of younger leaves folded upwards, only the midrib thicker and discoloured. Galled parts drying after departure of the larvae, causing the unaffected leaf blade parts to be distorted ± sickle-shaped. Unidentified gall midge

19a Malformations caused by aphids => 20

19b Leaf blades usually with several deflected, ± clustered nest-like on the stunted, also curved axis; locally strongly curled and discoloured deep-green. Vicia spp.: Philaenus spumarius

20a Aphid black => 21

20b Aphid dark-green; of considerable size; siphunculi club-like, black, like cauda and legs. V. sativa, sepium, etc., occasionally on V. faba: Megoura viciae

21a On narrow-leafed Vicia species => 22

21b On V. faba; especially at shoot tips, often occurring in large colonies; causing only stunting, no gall-like malformations. Aphid up to about 2.5 mm long, dull-, rarely brown-black: Aphis fabae

= Bulging of leaves may also be caused by Vicia-virus 1.

22a Aphid up to about 2.75 mm long, black, appearing bluish translucent through white powdering; antennae longer than half the body length; siphunculi and the about equally long oblong cauda black. V. cassubica, cracca, Paederota lutea, Vicia pannonica, tenuifolia, tetrasperma, villosa: Aphis craccae

22b Aphid variating in size; black. Froth-covered nymphs only slightly frosted. Apterous adults with glossy back. Siphunculi longer than cauda, black. V. cracca, faba, sepium, etc.: Aphis craccivora

23a Galls on V. sylvatia, cassubica => 25

23b Galls on other vetches => 24

24a Leaflets folded upwards, pod-like. Wall succulent thickened, ± discoloured, also reddened. Often on severely stunted, terminal- or lateral shoot tips already the youngest leaves become galled and clustered into conspicuous balls, up to even 30 and more mm long; in other cases unfolding leaves have been attacked and several to all, usually distinctly shortened, leaflets have sometimes been transformed into clustered, thick-walled pod-like galls. Containing several white, later on proximally ± pink-coloured larvae. Mainly on V. sativa, sepium and other related Euvicia species: Dasineura viciae

= Also Anabremia bellevoyei has been reported as causer of disfigured leaflets, but this species is inquilinous like all other Anabremia species

24b Galls similar. Larvae pale-red. V. cracca, hirsuta, tenuifolia, tetrasperma, villosa, etc.: Dasineura loewiana

24c Similar galls on various Vicia species; containing whitish-yellow larvae: Dasineura spadicea

= Inquiline of D. viciae, loewiana and spadicea: Macrolabis vicicola

25a On V. sylvatica. Unfolding young to almost full grown leaves all or only several leaflets are transformed into strongly cartilage-like thickened, pod-like galls, in cross section almost rotund, usually pale-green. Containing a single or several larvae white to yellow at maturity: Tricholaba viciobia

= Inquiline gall midge: unidentified Macrolabis sp.

25b On V. cassubica. All leaflets of one or more youngest, already isolated or unfolding leaves folded upwards, pod-like. Complete gall wall conspicuously thickened, ± discoloured or reddened. Containing several milk-white, non-jumping larvae. Unidentified gall midge

26a Up to 10 (15) mm long, spindle-shaped, thin-walled swelling with oblong larval chamber on petioles or midrib. Containing a single larva. V. cracca, ? villosa, incl. subsp. varia, dumetorum, sylvatica: Cyanapion gyllenhalii

26b Midrib weakly swollen. V. sepium: Apion sp. s. lat.

27a Infected parts, especially on leaf underside, with expanded, ± grey-white patches of branched conidiophores. Malformations almost only caused by systemic infection, partially etiolated, partially associated with shortening of diseased organs => 29

27b Malformations caused by rust fungi => 28

28a Aecia and spermogonia loosely distributed over underside of leaf; mycelium often completely pervading the ± disfigured plant; leaves conspicuously smaller and shorter, pale-green. V. onobrychioides: Uromyces valesiacus

28b Fungus repeatedly developing aecia. Spermogonia only occurring together with primary aecia. Secondary aecia cup-shaped with slightly bent margin; in small groups with 2–5 on sometimes weakly galled pads on stems or scattered on expanded, usually not disfigured parts on undersides of leaves. V. hirsuta, more rarely V. tetrasperma: Uromyces ervi

29a On several Euvicia species => 30

29b On V. hirsuta, lathyroides, tetrasperma: Peronospora ervi

30a On V. cracca and forms, resp., on V. sepium => 31

30b On V. angustifolia, sativa, villosa: Peronospora viciae

31a On V. cracca: Peronospora mayorii

31b On V. sepium: Peronospora viciae

32a Stem with tough-walled or spongy swellings, containing gall causers => 33

32b Stem on any area, mainly close to ground, with broad spindle-shaped to bulging swellings, which bear single, or several rimmed depressions on the surface, containing froth-covered nymphs. Vicia spp.: Planchonia arabidis

33a Stem, also inflorescence stalks and -midrib, sometimes also leaf axis, with slender spindle-shaped, thin-walled, often at first pale-green coloured, large-chambered swellings; containing beetle larvae => 34

33b Seedlings severely stunted. Internodes stunted, sometimes twisted, often distinctly swollen. Gall tissue spongy, necrotic. Similar infestation ± encroaching into petioles and midrib; leaflets disfigured. Swellings often one-sided, curved, wrinkled, bulging, yellowish or reddish, irregularly arranged over the internodes. V. cracca, faba, hirsuta, pannonica, sativa, tetrasperma, villosa: Ditylenchus dipsaci

34a Swellings elongate spindle-shaped, usually slightly protruding => 36

34b Galls distinct, middle parts about twice as thick as the normal organ; elongate at the internodes, more compact on nodes; about 7–10 mm long. Containing a larva with a small head capsule => 35

34c Internodes with expanded, slender swellings, about 15–25 (35) mm long, reaching twice the organ diameter. The pith, which is excavated over a length, containing a compact white maggot with black gullet: cf. Agromyza erythrocephala

35a On V. cracca, dumetorum, hirsuta, sepium, sylvatica, tenuifolia, tetrasperma, etc.: Cyanapion gyllenhalii

35b Similar galls on V. cracca: Catapion seniculus

36a Galls usually differing from the previous ones by their small size, however, not positively distinguishable without rearing of adults. V. pyrenaica, sativa subsp. nigra => 37

36b V. angustifolia, lathyroides, sativa, sepium, tenuifolia, parviflora, villosa: Apion sp. s. lat.

37a V. sativa subsp. nigra: Holotrichapion pullum subsp. aestimatum

37b V. pyrenaica, ? V. sativa, sepium. Swelling of node, about 2 mm broad, 7 mm long; inconspicuous: Holotrichapion aethiops

38a On fruits => 44

38b On inflorescences or flowers => 39

39a Malformation of the complete inflorescence or localised galls on its stem parts only => 40

39b Unopened flowers contain several white, eventually orange-coloured jumping midge larvae. V. cracca, cassubica, tenuifolia, villosa, incl. subsp. varia, etc.: Contarinia craccae

= White larvae of Ametrodiplosis viciae, living on V. cracca, belong to an inquiline of Contarinia craccae

= White larvae of Jaapiella sp. are developing together with Contarinia craccae in flower heads of V. cracca

= Orange-yellow larvae of Anabremia viciae, recorded from flower buds, are inquilines of an unidentified gall midge

40a Malformations extending over inflorescence => 41

40b Spindle-shaped, up to 15 mm long, usually yellowish-green swelling on inflorescence stalks or rachis. Containing a single larva. V. cracca, hirsuta, sylvatica: Cyanapion gyllenhalii

41a Inflorescence and flowers stunted, ± clustered, ball-like => 42

41b ll flowers of a raceme ± greened and leafy. V. hirsuta, tetrasperma: Aceria trifolii

= On V. cracca and especially V. villosa inflorescences occasionally with all flowers, usually on many racemes, variously disfigured and partially greened by viruses

42a Gall midge larvae occur between organs on stunted shoot tips => 43

42b Inflorescences and shoot tips clustered into balls of flowers, or leaves. Aphids almost black, appearing bluish because of the white powdering; also encroaching onto stems. V. cracca: Aphis craccae

43a hoot tips distinctly shortened. All inserted organs clustered into conspicuous, ± dense balls. Flower primordia, situated between young leaves with pod-like disfigured leaflets, largely stunted, variously swollen and unopened. Only exceptionally normally coloured. Within and between organs are many white larvae. V. angustifolia, sativa, sepium: Dasineura viciae

43b Axial parts of inflorescence distinctly stunted. Buds clustered into rotund, more pubescent balls; unopened or only slightly opened. Yellow larvae present between buds and rachis. V. sepium: Unidentified gall midge

44a Pods disfigured by midge larvae => 45

44b Locally variously distinctly swollen pods containing a larva with narrow head capsule. V. cracca: Apion sp. s. lat.

46a Galls on Vicia species developing tendrils => 47

46b Galls on erect Vicia species => 46

46a Pods often completely or slightly disfigured, at their surface bumpy to sometimes undulately, curved. Containing several jumping, white larvae. V faba, ? angustifolia, ? sativa: Contarinia sp.

46b Pods disfigured; locally more swollen and with mycelium inside. Containing a larva at first pale-yellow, later on orange-coloured. V. sepium: Asphondylia lathyri

47a Pod of V. hirsuta, sylvatica etc. locally distinctly swollen. Inner wall of gall with mycelium. Containing a pale- to yolk-yellow larva: Asphondylia ervi

47b Ditto on V. cracca. Containing white larvae: Asphondylia sp.

gallers on Ribes

pub 2.xii.2019

Dichotomous table for gallers on Ribes

by Hans Roskam

1a On inflorescences, flowers or fruits => 28

1b On vegetative parts => 2

2a On parts above ground => 3

2b Roots with spindle-shaped to nodular swellings, usually bearing some side roots. R. rubrum: Meloidogyne hapla

3a On buds or leaves => 11

3b On shoot axis => 4

4a On higher parts => 6

4b On root collar => 5

5a Nodular to walnut-, sporadically chicken egg-sized proliferations on root collar, tuberculate on surface, at first white, succulent, later on browned and woody; galls sometimes also on larger roots close to surface and on higher situated stem parts. R. rubrum, uva-crispa: Agrobacterium tumefaciens

5b Excessive branching at stem base; shoots only a few cm long, strongly succulent, variously striate, with disfigured stump-like branchings. R. uva-crispa: Rhodococcus fascians

6a Causer not occurring on gall surface => 8

6b Younger axial parts usually with many rotund- to oblong-oval pock-shaped swellings, which contain a flat causer in a rimmed depression => 7

7a Scale ± rotund; 1.2–1.6 (1.8) mm wide, dirty to brownish-grey, flat arched, with dark yellow central area. Froth-covered nymph red, mainly harmful on R. nigrum: Epidiaspis leperii

7b Scale pear-shaped, white to grey-white, up to about 2.5 (3.0) mm wide. Female wine-red. Ribes spp.: Chionaspis salicis

7c Sporadically recorded on R. alpinum, R. rubrum, R. uva-crispa: Viscum album

8a Swellings on thin axial parts, elongate, ± spindle-shaped, often inconspicuous. Caused by insect larvae boring inwards => 10

8b Conspicuous, nodular or bulging or almost witches’ broom-like malformations => 9

9a Branches, more rarely stems, with warty-nodular, usually several burr tubers. R. uva-crispa, less frequently on R. alpinum, aureum, rubrum and other Ribes species: Inducer unidentified – ? bacterium, fungus; may partially be caused by: Agrobacterium tumefaciens

9b Cauliflower-like proliferations, occurring mainly on root collar. R. uva-crispa: Rhodococcus fascians

= Sporadically witches’ broom-like malformations have been associated with the rust fungus Cronartium ribicola; aecia develop on Pinus strobus, non-cecidogenic, Uredinia and telia developing mycelium in protruding cylinders clustered on leaf underside of several Ribes species

10a Inconspicuous oblong swellings of bark, mainly visible in autumn, on young axial parts. Older larvae boring in spirals in inner bark. Rare on R. nigrum: Agrilus cuprescens

10b Similar swellings on young woody shoots; older larvae feeding in pith; whitish with dark dorsal band and brown head. Ribes spp.: Synanthedon tipuliformis

10c Midge larvae live gregariously under bark. The bark is peeling off, sometimes accompanied by a dying back of the top shoots. R. nigrum: Resseliella ribis

11a On leaves => 12

11b Young side-, also apical buds distinctly swollen, producing ‘big buds’. Infestations especially conspicuous in spring, because diseased buds only partially open, and do not unfold. R. alpinum, nigrum, rubrum, rarely on R. uva-crispa: Cecidophyopsis ribis

11c Similar terminal or lateral big buds on R. rubrum: Cecidophyopsis selachodon

= The gall mite Colomerus riberini causes silvery white erineum on the underside of the leaf of R. nigrum, and the gall mite Cecidophyopsis grossulariae causes foliar injury, cavities at vein bases, enations on leaf disk, discoloration. R. nigrum, rubrum, uva-crispa

= Leaf buds of R. alpinum swollen to almost one cm in diameter, do not unfold; caused by the gall mite Cecidophyopsis alpina. Similar swollen leaf buds of R. aureum are caused by the gall mite Cecidophyopsis aurea

12a Curls, archings or bladder -shaped swellings caused by aphids => 19

12b Expanded folds, rolls, curls, or abnormal pubescence or localised warts and bulges caused by other parasites => 13

13a Localised swellings by rust fungi => 17

13b Malformations caused by animals => 14

14a Expanded malformations => 15

14b Leaf margin with several egg capsules, soon necrotic after emergence of larvae (procecidia, oviposition scars, not true galls). R. rubrum, uva-crispa: Pristiphora appendiculata

= The yellow gooseberry sawfly Nematus ribesii lays her eggs like pearls on a string along the veins without development of procecidia.

15a Leaf folds or rolls caused by midge larvae; galls lacking additional pubescence => 16

15b Leaf blade often severely disfigured, curved, folded, irregularly hunchbacked, rolled at margins, ± abnormally haired. R. alpinum, aureum: Aceria scaber

15c Less protruding, slight bladder-like archings on leaves of R. uva-crispa: Cecidophyopsis ribis

16a On R. nigrum. Margins of still unfolded leaves ± funnel-shaped to rolled, screw-like; margins of older leaves rolled over upwards to varied extent, also folded. Leaf blade curled. Spaces in between with several, at first whitish, then yellowish or yellow larvae: Dasineura tetensi

16b Similar malformations on other Ribes species. Rolls, especially on younger, developing leaves; on many hosts more densely covered with elongate, ± hair-like structures. Assignment of causer insufficiently known. Unidentified gall midges:

a On R. alpinum: Causer questionably assigned to Dasineura tetensi.

b On R. petraeum; Folds ± thickened and reddened. Abnormal grey to brown pubescence. Containing several white midge larvae.

c On R. rubrum: several white midge larvae. Asphondylia ribesii. Furthermore Stroblophila aberrans which does not induce galls

d On R. uva-crispa: Leaf blades partially abnormally pubescent, containing several midge larvae, at first milky-white, eventually pale yellow are attributed to Dasineura tetensi

17a Pads or bulges bearing yellow to orange-coloured aecia => 18

17b Rotund, sometimes joined, chestnut-brown, yellowish margined weak pads, usually protruding on upper side of leaves, with 2-celled, wart-like teliospores. Frequently also on fruits. R. alpinum, nigrum, petraeum, rubrum, uva-crispa, etc.: Puccinia ribis

18a Swellings minor, almost only on main veins, with joined sori. Aecia lacking peridium, dusty, belonging to the species complex of Melampsora ribesii-viminalis

18b Similar on many Ribes species: Melampsora epitea

18c On several Ribes species also develops: Melampsora epitea var. epitea

18d Swellings always distinct, protruding on leaf underside, usually rotund, up to 10 mm across, yellowish, on upper side often red margined; developing on petioles, young stems and midrib of racemes, oblong, sometimes much larger bulges; young fruits sometimes largely covered. Aecia with cup-shaped opening peridium; often ± circularly arranged on the galls. Ribes spp.: Puccinia ribesii-caricis

19a Leaves ± rolled, curled or weakly arched; often clustered, nest-like, on shoot tips => 21

19b Leaf blades often with several, conspicuous, larger or smaller, yellowish, often deep-red speckled, strongly to broad bladder-like swollen, open, upward archings => 20

20a On R. alpinum: Cryptomyzus korschelti

20b Galls mainly on R. rubrum, rarer on R. nigrum, petraeum, spicatum, uva-crispa and others, also on many cultivated foreign species: Cryptomyzus ribis

21a Disfigured leaves densely clustered, nest-like, on severely stunted shoot tip. Wingless aphids dull on surface, antennae about half the body length => 27

21b Disfigured leaves on often only slightly shortened shoots clustered in nests, or situated distally. Body of wingless aphids glossy, antennae always longer than half the body length, often even longer than the whole body => 22

22a Aphids with club-shaped siphunculi => 23

22b Aphids with cylindrical siphunculi. 2–3 mm, pale-green to green. Siphunculi pale with darker tip, about twice as long as cauda. Antennae of fundatrixes shorter, of fundatrigenia slightly longer than body. Leaves only weakly arched and not discoloured. R. alpinum, nigrum, rubrum, uva-crispa, etc.: Nasonovia ribisnigri

23a Aphid differing from all other aphids on Ribes by its dark brown body. Leaf blades of basal leaves narrower, woody, shaded shoots disfigured, discoloured, soon dropping. R. nigrum, rubrum: Rhopalosiphoninus ribesinus

23b Aphids of different colour => 24

24a Adults with expanded brown to black dorsal pattern. Mainly on seedlings, rolling the brittle leaves but not discoloured, often developing dense nests of leaves. Aphid 2.7–3.1 mm; basic colour green. Tibiae, siphunculi and cauda black. R. rubrum: Hyperomyzus rhinanthi

24b Dorsal body part of apterous aphids lacking pigmentation, or with only minor pigmentation. Siphunculi of apterous aphids pale coloured => 25

25a Aphids pale yellowish-green, difficult to distinguish and only by microscopical examination => 26

25b Aphid green. Leaves ± rolled over their length, also arched; sometimes in loose nests. Venation yellowed or leaf blades yellowing, mosaic-like. Ribes spp., especially on R. nigrum: Hyperomyzus lactucae

= Similar malformations are caused by viruses.

26a Leaves arched, in loose nests. Aphid 2.5 mm long, glossy, pale yellowish-green, siphunculi pale, sometimes darker in the middle and at their tip, rather strongly swollen. Antennae about as long as body. R. alpinum: Hyperomyzus picridis

26b Leaves weakly arched, yellowed at veins. Occasionally in loose nests. R. uva-crispa: Hyperomyzus pallidus

26c Disfigured shoot apices, petioles and curled leaves. Ribes spp.: Hyperomyzus zirnitsi

27a Leaves accumulated at tip, in dense nests. On all wild and cultivated forms of R. uva-crispa: Aphis grossulariae

27b Similar malformations and dense leaf nests on R. rubrum, also on R. alpinum, aureum, nigrum, sanguineum, etc.: Aphis schneideri

= Sometimes the polyphagous, never gall inducing, mite Bryobia praetiosa s. lat., appear as successoria (secondary inhabitants) in early vacated galls of various aphids. From spring onwards in many food plants, especially fruit, partially as important pest, because of suction damage on unfolding, early withering leaves.

28a On fruits => 32

28b On flowers or on inflorescences => 29

29a Flower galls => 30

29b Complete inflorescence disfigured. R. alpinum: Unidentified gall midge

= Various malformations associated with greening, on several flowers of a raceme of R. nigrum, are caused by virus

30a Flowers enlarged, unopened. R. alpinum, rubrum, uva-crispa => 31

30b Flowers transformed into globular- or pear-shaped, whitish or reddish galls. Corolla strongly swollen. Containing one or more yellowish or orange-red midge larvae. R. nigrum: Dasineura ribis

31a Base of calyx succulent, pale yellow to red; corolla and stamens hard. Larvae often gregarious, at first white, then yellow to orange-coloured. Galled flowers dropping after larvae complete development. R. uva-crispa: Contarinia ribis

= The N-Am gall midge Rhopalomyia grossulariae has been recorded on Ribes grossularia

31b On R. alpinum, rubrum. Flowers enlarged, unopened. Unidentified gall midge(s)

32a Galls caused by fungi => 34

32b Galls caused by insects => 33

33a Immature fruits variously disfigured, up to twice the normal size. Containing a single to five orange-coloured larvae. R. uva-crispa: Unidentified gall midge

33b Fruit strongly swollen or elongated and narrowed. R. nigrum: Pachynematus pumilio

34a Fruit wall often with several wart-like pads, a few mm long, on which the telia develop. Ribes spp.: Puccinia ribis

34b Infected fruits often bulging on expanded areas. Many aecia on pads. Sori occasionally also on fruit stalks and stalks of fruiting racemes. Ribes spp.: Puccinia ribesii-caricis

gallers on Pyrus

pub 1.xii.2019

Dichotomous table for gallers on Pyrus

by Hans Roskam

(Pyrus communis s. lat.; including cultivated pear, P. domestica, as well as P. communis subsp. achra and pyraster)

1a On above-ground parts => 4

1b On root, root collar or basal stem parts => 2

2a Malformation larger than 10 mm => 3

2b Root with nodular swellings. P. communis: Meloidogyne hapla

3a Roots, including the older ones, with cancer-like, and. buckled enlargements or rotund swellings. P. communis, nivalis: Eriosoma lanigerum

3b Root, root collar or also basal stem parts with hazelnut- to egg-size or even larger, tuberculate proliferations, which occasionally coalesce into voluminous complexes. P. communis: Agrobacterium tumefaciens

4a On flowers or fruits => 28

4b On vegetative organs => 5

5a On leaves or buds => 10

5b On lignified parts => 6

6a Predominantly on stem parts, occasionally on thicker branches => 7

6b On thicker branches, less frequent on stems, variously slightly spindle-shaped, swollen. From the galls develop: Viscum album

7a More or less open, rimmed cancer wounds on thicker branches => 9

7b Mainly closed cancers on shoot axis, especially on younger trees, or irregular depressions on bark of younger shoots => 8

7c Midge larvae cause woody, plurilocular galls on twigs. P. communis: Apiomyia bergenstammi

8a Bark of younger stems with irregular rimmed depressions, containing causer beneath a 1.2–1.6 (1.8) mm long, dirty-grey, rotund scale. P. amygdaliformis, communis and forms: Epidiaspis leperii

8b Occasionally also on Pyrus species in similar galls beneath a pear-shaped scale up to about 2.5 mm long: Chionaspis salicis

8c Local, according to the organ’s development, usually closed cancer-like proliferations, especially on stems of younger trees or on thinner branches. P. communis: Eriosoma lanigerum

9a Irregular, eventually open cancer wounds, developing from proliferations and thickenings of bark; sometimes containing several lepidopteran caterpillars eating bark and sapwood. P. communis: Enarmonia formosana

= The clear-wing moth Synanthedon myopaeformis, which lives mainly on apple is an occasional inhabitant of cancers, but do not cause them.

9b Expanded open cancer wounds caused by fungi: Neonectria ditissima

10a On leaves => 11

10b Buds transformed into a globular to conical, yellowish, multi-chambered, woody gall. If strongly infected, stunting of shoot and accumulation of galls into a larger, irregular clustering. Each chamber containing a single larva. P. communis, salicifolia, syraica: Apiomyia bergenstammi

11a Galls of indefinite shape. Leaf blade extended and variously disfigured; folded, ± irregular and without particular thickening, only loosely rolled inwards, variously bulging swollen or ± curled => 19

11b Gall constant, locally ± defined; narrow or tough marginal roll; callosity, pock, pustule, abnormal pubescence or local, strictly defined bulges => 12

12a Narrow, restricted to edge roll of margin or thick-walled upward roll of the complete leaf blade => 18

12b Gall formation on the leaf blade => 13

13a Bladder-like enlargement, bulges, pocks or pustules => 14

13b Felt-like, initially yellowish or reddish, later on brownish pubescence, mainly of leaf underside. Hairs long, cylindrical, blunt, bent. P. communis: Unidentified gall mite

14a Callosities, pucks or pustules => 15

14b Up to 10 mm broad, pale-, later on yellowish-green, soon blackening, upward arched bladders, single or in groups. At maturity of fungus densely covered with pink-coloured asci. Exceptionally also on floral parts. P. communis, especially cultivated-, less abundant on wild forms, also on P. amygdaliformis: Taphrina bullata

= Various archings of leaf might be caused by viruses.

15a Rotund to elongate spindle-shaped, yellowish to orange-red bulges, predominantly partially including the main venation. Rust fungi => 16

15b Initially yellowish, ± red tarnished, later on brownish to 5 mm broad, per leaf blade usually many, irregular pocks, protruding on both sides. Exit underside. The mites live in enlarged intercellular spaces of the swollen leaf parenchyma. Pyrus spp.: Eriophyes pyri

= Warts on the leaves, hollow on the underside are caused by the gall mite Eriophyes pseudoinsidiosus. They are the result of sucking damage to the leaf while still in the bud stage. P. communis

15c Translucent usually solitary pustules on the leaf blade or midrib, visible on both sides, vacated by eclosing larvae (procecidia: oviposition scars, not true galls): Pristiphora abbreviata

16a Swelling slightly arched. The cylindrical peridium of aecia developing from the bulge opens at apex and frays out. Telia on Juniperus communis etc. => 17

16b Swellings very distinct. Peridium of aecia egg- to cone-shaped. Unopened at apex, opening with longitudinal slits. Pyrus spp.: Gymnosporangium sabinae

17a Minor swellings. Aecia often hardly developed. Spores 19–26 x 19–22 μm. Gymnosporangium confusum

17b Swellings and aecia usually distinct. Spores 22–30 x 18–26 μm. Pyrus spp.: Gymnosporangium clavariiforme

18a Usually both leaf halves, tip excepted, from margin often to midrib rolled upwards. The rolled part arched, thickened, ± yellowed or reddened, soon browned. Galls predominantly on terminal leaves of suckers or young trees. Larvae often many, white or reddish. Pyrus spp.: Dasineura pyri

18b Similar galls on Pyrus salicifolia. Only one cream coloured larva develops in a gall. It is not clear if it is a gall causer or inquiline in galls caused by Dasineura pyri: Macrolabis pyricola

18c Leaf blades of extending leaves remain unrolled up to midrib. Containing a yellow black-headed larva. Pyrus spp.: Anthonomus spilotus

18d Upward roll narrow, compact, hardly thickened. Leaf blade sometimes darker discoloured. Pyrus spp.: Epitrimerus marginemtorquens

19a Malformations caused by aphids => 20

19b Malformations caused by psyllids or gall mites => 21

20a Leaf blade more or less stunted and browned, weakly rolled. Usually many leaves are infected on the ± stunted shoot tips. Pyrus spp.: Epitrimerus pyri

= Similar malformations are caused by thrips. Taeniothrips inconsequens lives on Pyrus and also in a similar way on other hardwoods

20b Leaves variously slightly to spirally deflected, curled and discoloured. Pyrus spp.:

a Cacopsylla pyrisuga ‒ The only psyllid harmful on pears.

b Cacopsylla pyricola – Galls similar, but facultative.

c Cacopsylla pyri – Gall-like malformations exceptional, only on young plant parts; infestation of older leaf blades results in spotting and browning of prematurely dropping leaves.

21a The disfigured leaves are ± uniformly distributed on the stunted shoot tip => 25

21b Infected leaves usually ± clustered at the shoot tip => 22

22a Aphids pale to dark-green or reddish-brown to brown. Apterous aphids powdered or dull; dorsal side at most with some pigmented spots => 23

22b Aphid black-brown with pale legs; apterous adults with dark pigmented glossy backs, grey powdered as froth-covered nymphs. Leaf roll very variable, in spring; midrib often circular-, spirally- or screw-like rolled. Leaf blades variously stunted, ± yellow marbled or discoloured. P. communis: Melanaphis pyraria

23a Aphids reddish-brown to brown, covered with wax powder => 24

23b Aphid leaf-green, lacking wax powder, with rather long dark siphunculi; on leaf underside and on shoots. P. communis: Aphis pomi

23c Occasionally observed as causer is: Rhopalosiphum oxyacanthae

24a Leaves loosely or strongly deflected; midrib contorted in loose spiral. Leaf- cluster loose; at latest vacated by end 5. Aphid yellowish-green, with dark-green, segmentally striated pattern on back, weakly grey-powdered. Producing red juice when crushed. Pyrus spp.: Dysaphis pyri

24b A very close aphid lives in similar ± triangular bag-like rolled malformations. Galls still inhabited in 7, 8; locally serious pest: Dysaphis reaumuri

25a Aphids green or brown. Leaves yellow; along the midrib almost bag-shaped, more rarely rolled-folded, ± marbled => 26

25b Aphids black. Leaves on the usually slightly stunted shoot tip spoon-shaped deflected and more strongly rolled at margin. On the shoot tips of seedlings or coppice. Aphis fabae

26a Immature alates produced by brown fundatrices => 27

26b Immature alates produced by green fundatrices, with a double row of dark green spots: Anuraphis farfarae

27a Galls indistinguishable from previous species: Anuraphis subterranea

27b In galls indistinguishable from previous species lives the presumably inquiline Anuraphis catonii

28a On fruits => 29

28b Flowers severely stunted. Corolla unopened covering the eaten inner parts. Containing a single larva. P. communis, amygdaliformis: Anthonomus pomorum

= Anthonomus piri deposits its eggs already in late autumn in flower bud primordia, larvae develop in early spring, destroying many flower primordia, however, without causing galls.

29a Infected fruits swollen calabash-like; initially significantly faster growing than normal ones; up to hazelnut size; hence distinguishable from the only half as large healthy ones. Often ± buckled, soon black-spotted, inside spongy, later hollow, then dropping. Containing gregarious larvae, white to pale yellow, jumping. P. communis, salicifolia: Contarinia pyrivora

29b Younger or older immature fruits with wart-shaped soft swellings, usually less than 5 mm across, occasionally coalescing, pale-green. P. communis: Eriophyes pyri

= Conspicuous, bump-shaped, hard fleshy swellings on the ± deformed fruits are caused by punctures of the bug Closterotomus fulvomaculatus

gallers on Malus

pub 30.xi.2019

Dichotomous table for gallers on Malus

by Hans Roskam

1a On above-ground parts => 3

1b On roots => 2

2a Rotund, cancer-like proliferations on roots and root collar, several cm long, at first glabrous on surface then ± bumpy, soon lignifying, laterally inserted, often many and variously coalescing. Especially on young plants. Malus spp.: Agrobacterium tumefaciens

2b Roots with nodular, rotund or oval swellings, up to about 7 mm long ± cracked or bulging, eventually bursting; close to ground level, even on older roots groups often coalescing, stimulated new tissue developing into voluminous cancer-like growths. Occupied by white woolly aphids. Malus spp.: Eriosoma lanigerum

2c Nodular, usually smaller, glabrous swellings. Malus spp.: Meloidogyne hapla

= The red bud borer Resseliella oculiperda damages rootstocks of cultivated roses and apples when these are grafted with scion buds by “shield budding”.

3a On leaves, buds, flowers or fruits => 7

3b On stems, branches and twigs => 4

4a Galls on or in the bark => 5

4b Expanded spindle- or club-shaped swellings on branches or stems. Malus spp.: Viscum album

= Witches’ broom-like malformations at the end of shoots are partially caused by virus diseases. The early developing malformations are distinguished by their discoloured leaves, which are longer stalked and have larger stipules than the normal ones.

= Cancer-like structures usually develop as excessive callus proliferations in over-sensitive responses. Also many wound-calluses may develop into smaller, similar, but locally depressed nodules.

5a Younger plant parts with nodular, or older ones with cancer-like proliferations of irregular nature => 6

5b Up to 2 mm long, lenticular, bulging-rimmed depressions on bark of young shoots, in case of heavy infestation slightly swollen. Each depression containing a red insect, covered by a ± rotund scale, 1.3–1.6 mm wide: Epidiaspis leperii

5c In similar, but deeper depressions on the swollen bark: Chionaspis salicis

6a Nodular swellings of bark, up to walnut-size, later on erupting and cracking; often many coalescing and developing expanded cancer-like swellings. Especially on young trees. Containing white powdered aphids in cracks. Spring to autumn. Malus spp.: Eriosoma lanigerum

6b Buckled margined cancer wounds, increasing on older branches and of very varied shape. At first, on younger parts, because of the strong regenerative ability of host, usually transformed into variously delimited, bumpy, ± closed, nodular tumours; later on, the central tissue decays on older branches resulting in fissured cancer wounds, open, into the wood: Neonectria ditissima

= Caterpillars of clear-winged moth Synanthedon myopaeformis or Enarmonia formosana are occasional inhabitants of cancers, but do not cause them.

= Also the sac fungus Neofabraea perennans has occasionally been reported as inducer of Nectria-like cancers on apple and pear.

7a On buds, flowers or fruits => 29

7b On leaves => 8

8a Malformations associated with various curls, swellings, folds or loose rolls, which often involve the complete leaf blades sometimes of many terminal leaves => 15

8b Narrow, compact marginal rolls or leaf blades with locally defined galls => 9

9a Narrow roll of leaf margin => 13

9b Pock-like or slightly bladder- to bulge-shaped galls, with erinea => 10

10a Pocks, bulges, or minor bladder-like swellings => 11

10b Irregular, initially reddish white, then brownish erinea, mainly on leaf underside, usually along venation. Hairs long, cylindrical, blunt, spiral. Mainly on M. sylvestris, less so on M. pumila, etc.: Phyllocoptes malinus

11a Malformations caused by fungi => 12

11b Leaf blades with many ± oval pocks, usually 2–4 mm across, protruding from both sides. M. communis, sylvestris, etc.: Eriophyes mali

11c Vagrant mites on the underside of the leaves. At high densities rusting may occur. M. domestica, pumila, sylvestris: Calepitrimerus baileyi

11d Translucent pustules, visible on both sides, soon collapsing, in 5, 6, usually on the midrib, are procecidia of the black pear sawfly, occurring mainly on pear, occasionally on apple. Pristiphora abbreviata

12a Yellowish pads rotund on leaf blade, ± spindle-shaped on midrib, protruding on underside, later on with oblong-cylindrical, often curved aecia. Peridium thread-like rupturing onto base. Malus spp.: Gymnosporangium tremelloides

12b Rarer on apple are the cylindrical, tuft-like aecia of Gymnosporangium cornutum

12c Minor, usually several per leaf blade, covered with ± radiating, blackish mycelium, rotund, up to 7 mm long upward archings on young leaves of hawthorn shoots. Malus spp.: Venturia inaequalis

13a Rolls of leaf margin lacking conspicuous pubescence => 14

13b Expanded, border-like upward rolls with abnormal pubescence, occasionally encroaching well into the leaf blade. M. sylvestris, etc.: Phyllocoptes malinus

14a Similar, but not conspicuously pubescent roll of leaf border. M. pumila, sylvestris: Eriophyes malimarginem-torquens

14b Leaves of young shoots with cartilaginous thickening, often on both margins, usually discoloured yellowish or reddish, often running parallel to midrib, usually resulting in an upward roll. Inside the brittle tube are several, at first cream-white, then red midge larvae. Malus spp.: Dasineura mali

= Inquilinous cream-coloured midge larvae living in galls of Dasineura mali: Macrolabis mali

15a Malformations caused by aphids => 19

15b Malformations attributed to other causes => 16

16a Malformations caused by mites, psyllids or spittlebugs => 17

16b Several terminal leaves on shoots stunted, disfigured, their margins ± bent upwards, slightly thickened and often completely covered by a sometimes cotton wool-like, white mycelium. Malus spp.: Podosphaera leucotricha

17a Malformations caused by mites or spittlebugs => 18

17b Leaves variously curled and deflected; with many small spots, soon turning brown, caused by suction feeding of flattened, yellowish to greenish froth-covered nymphs, up to 1.5 mm long, exuding copious honeydew. Malus spp.: Cacopsylla mali

17c Very similar infestation: Cacopsylla picta

18a Leaf blade stunted and soon browned due to many suction spots; in cases of severe infestation both halves are strongly folded upwards and their margins may even come in contact. Infected shoots die off prematurely. Malus spp.: Aculus schlechtendali

= Predating gall midges: Arthrocnodax mali, wissmanni.

18b Stems of saplings shortened. Leaves ± clustered and converging, leaf blades crumpled, locally deep-green. Containing a froth-covered nymph. M. pumila: Philaenus spumarius

19a Leaves folded along their midrib or rolled, distinguished by yellowish to reddish discolouration => 23

19b Rolls of margin or folds without particular thickenings => 20

20a Variously disfigured leaves are loosely inserted often on only slightly stunted shoot ends => 22

20b Shoot tip conspicuously shortened => 21

21a Many leaves on the ± stunted, curved and etiolated shoot tip are strongly deflected and ± curled. Dark-green aphids, ± 2 mm long, with long, dark brown-black siphunculi feed on underside of leaves and move onto shoots. Malus spp.: Aphis pomi

21b Similar galls, only inhabited in spring. M. pumila: Allocotaphis quaestionis

22a Downward leaf roll and curling caused by black aphids. M. pumila: Aphis fabae

22b Midrib of leaves sometimes loosely contorted. Leaf blades deflected downwards, often strongly rolled, making loose clusters; aphid yellowish-green with segmental dark-green striping dorsally and with dark siphunculi that are pale only at the tips. Malus spp.: Rhopalosiphum oxyacanthae

23a Leaves often crookedly rolled downwards on only one side, usually up to midrib, coarsely undulate at tip; discoloured yellowish or mainly intensively red => 24

23b Young leaves at shoot tip strongly rolled, often on both sides, almost intestine-like or ± spirally bent, discoloured yellowish. Often many young shoots infected; in which case the plants look bushy. Malus spp.: Dysaphis plantaginea

24a Aphid galls are usually vacated by end of June; galled leaves already drop in July => 25

24b Galled leaves stay on tree; also inhabited during summer. Malus spp.: Dysaphis devecta

25a The roll galls occurring on cultivated apple and relatives of the next aphids do not differ morphologically; the closely related aphids are only microscopically distinct; main difference is their host alternation. Furcula (mid-thoracic fork) of the wingless aphids is always bifid. Summer hosts are Polygonaceae, Apiaceae or Plantaginaceae => 26

25b Furcula not bifid. Summer hosts are Valeriana species. Malus spp.: Dysaphis brancoi

26a Aphid alternating to Apiaceae or Plantago => 27

26b Exules living on roots of Rumex and Rheum: Dysaphis radicola

27a Aphids alternating to Apiaceae => 28

27b Aphids migrating to Plantago: Dysaphis plantaginea

28a Leaf-roll galls in spring. Exules develop on Anthriscus. Malus spp.: Dysaphis anthrisci

28b Leaf-roll galls in spring. Exules develop on Chaerophyllum. Malus spp.: Dysaphis chaerophylli

28c Rolling and reddening the edges of the leaves. M. domestica and M. orientalis: Dysaphis chaerophyllina

28d Aphids living without host alternation, rolling and blistering leaves. Malus spp.: Dysaphis affinis

28e Rolling and reddening the lateral edges of the leaves. M. domestica and M. orientalis: Dysaphis armeniaca

28f Rolling leaves in E-Eu (North Caucasus, Crimea, Armenia) in spring, but the galls are yellow rather than red. Malus spp: Dysaphis brachycyclica

28g Rolled lateral margins of leaves in spring. M. domestica: Dysaphis flava

28h Rolling and reddening leaves. M. domestica: Dysaphis physocaulis

= Haplorhynchites caeruleus is galling the shoots of Malus sylvestris

29a On flowers or fruits => 30

29b The young caterpillar inhabits buds from 7, 8 onwards, feeds on these and tunnels in shoot during spring. Occasionally the bark reacts at infestation site with further development of conspicuous, sometimes cancer-like swellings. M. pumila: Blastodacna atra

30a On flowers => 31

30b Mainly apical half of infected fruits disfigured, knobbly: Dysaphis plantaginea

30c Scale of young fruits sometimes with many flat, ± pock-like swellings, up to ± 2.5 mm across, usually lighter coloured than surrounding tissue. M. pumila: Eriophyes mali

= Thrips flavus may be causer of distorted apples; not a true gall causer.

31a The corolla of infected buds does not open, but is closed and hood-shaped, at first reddish but soon browning and drying. Containing a single larva. Malus spp.: Anthonomus pomorum

31b Flower peduncle shortened, conspicuously thickened; corolla parts narrowed, variously disfigured, discoloured yellowish to greenish-white. All leaves of the diseased young shoots stunted, often bent upwards, spoon-like and with mealy dusting on both sides. Malus spp.: Podosphaera leucotricha

= Various anomalies of flowers, partially associated with greening, might be attributed to virus diseases.

gallers on Hieracium

pub 29.xi.2019

Dichotomous table for gallers on Hieracium and Pilosella

by Hans Roskam

1a On inflorescences or in the capitula => 23

1b On vegetative parts => 2

1c Proliferations on the base of terminal rosettes on stolons. Pilosella spp.: Aulacidea subterminalis

2a On leaves => 8

2b On shoot axial parts or tips => 3

3a On shoot axial parts => 5

3b On shoot tips => 4

3c All parts of shoot with white crusty blisters, very variable in size; shoot often distorted. Hieracium and Pilosella: Pustula obtusata

4a Rosettes with many variously enlarged and thickened leaves at their centres, externally with abnormally felt-like pubescence, the leaf margins or leaf blade often ± cone-shaped converging. Several, initially white- to cream-coloured, later red larvae. Pilosella spp.: Macrolabis pilosellae

4b Terminal leaves of lateral and main shoots swollen, folded upwards, making a fleshy pouch, with outside often ± villous pubescent; mid- and basal veins, sometimes also the neighbouring stem parts, thickened and discoloured. Larvae yellow-white. Hieracium spp., exceptionally on Pilosella: Macrolabis hieracii

5a Inducers inside the galls => 6

5b The inducers are in bordered, hollowed depressions in small bulging swellings, solitary or many Hieracium spp., less on Pilosella: Planchonia arabidis

6a Tough, broadly protruding galls caused by gall wasp larvae => 7

6b Slim stem swellings caused by eelworms Spongy swellings in the stem, predominantly on species of Pilosella. Tissue fragile and necrotic, lacking larval cavities. Ditylenchus dipsaci

7a Shoot with rotund or barrel-shaped swelling, up to 40 mm long, multilocular, initially green, later brown, ± occupied with stiff-bristly white hairs. One yellowish-white larva per chamber. On many species of Hieracium; sporadically also on species of Pilosella: Aulacidea hieracii

7b Irregularly shaped, multilocular swellings of the stem, 2–2.5 x 1.5 cm in size; the galls are hardly lignified and can easily be opened. They ripen in autumn; adults emerge in the following spring. Hieracium sp.: Diastrophus hieracii

7c Similar, but smaller, 4–10 mm long, uni/bilocular swellings in the upper part of the shoot, also at the base of the flower head or below the leaf rosettes on stolons. Pilosella officinarum: Aulacidea sp.

8a Malformation predominantly situated on the leaf blade or leaf margin, usually without involving the midrib, sometimes with abnormal pubescence => 12

8b Galls in petioles or midribs, sometimes ± extending into the leaf blade => 9

9a Inconspicuous, usually yellow margined, 2–3 mm long, 1 mm wide swelling on the midrib; covered with brown fungus spores => 11

9b Tough walled or spongy, loose, galls with animal inducers inside => 10

10a Long-oval to spindle-shaped, woody swelling, with large central chamber, on the underside of petiole or midrib; up to 3.5 mm long and 1.5 mm wide, ± yellowish. Often several galls, in various ways connate. Containing a single yellowish-white larva. Pilosella cymosa, echioides, flagellaris, floribunda, officinarum, onegensis: Aulacidea pilosellae

= Larvae of Dasineura nervicola cause egg-shaped swellings on the mid-vein of Pilosella lactucella, officinarum. Very rare.

10b Irregular, spongy, pale green or red tinted massive swellings of various size extending from petiole or midrib to the leaf blade. Hieracium and Pilosella: Ditylenchus dipsaci

11a On Hieracium spp.: Puccinia hieracii

11b On Pilosella spp.: Puccinia hieracii var. piloselloidearum

12a Malformations of the leaf margin, curls or abnormal pubescence => 16

12b Pustules, grooves or warts on leaf blade, sometimes only slightly changed => 13

13a Rotund pustules, up to 6 mm long, often rimmed, bulging on the upper side; usually a few to many per leaf blade => 15

13b Warts or small grooves => 14

14a Less than 1 mm long, yellowish gleaming or coloured warts on the underside of the rosette leaves, usually many and variously coalescing into crusts or into stripes the stems. Pilosella officinarum: Synchytrium aureum

14b Leaf blade with small downward outgrowths. In case of heavy infestation both halves bent upward along the midrib. Hieracium racemosum; Pilosella officinarum, onegensis, piloselloides subsp. praealta: Trioza proxima

14c Similar malformations. Hieracium sp.: Craspedolepta flavipennis

15a Yellowish-green to intensively reddened pustules, many per leaf, occasionally coalescing, especially frequent on basal leaves on the underside between epidermis and parenchyma. Larvae reddish-yellow to dark orange-red, up to 2 mm long. Hieracium and Pilosella: Cystiphora sanguinea

15b Initially yellowish-white, later brown (never reddish) rotund, sometimes weakly swollen irregularly margined spots. Hieracium and Pilosella: Entyloma hieracii

16a Loose roll of the leaf margin or curls of the leaf blade => 19

16b Narrow leaf roll, often simultaneously developing with swellings, or only ± expanded erinea, of the leaf blade => 17

17a Expanded, compact upward rolling of the leaf margin => 18

17b Short, densely felt-like pubescent marginal bulge or –nodule, corresponding nodules also on the leaf blade; sometimes strong erinea on the upper side, also on the underside venation. Hieracium lachenalii, murorum: Eriophyes villificus

18a Only known from Pilosella officinarum: Aceria pilosellae

18b As well on Hieracium as Pilosella: Aceria longiseta

19a Malformation predominantly a marginal rolling of the leaf blade => 21

19b Malformation predominantly as a markedly curved, additionally curled leaf, or as a slight bulging of the same organ => 20

20a The shoot is stunted on one side and slightly thickened; in the affected area leaves are clustered, the leaf blades curved, variously twisted and curled, locally coloured intense green. Hieracium and Pilosella: Philaenus spumarius

20b Weak, merely facultative, not discoloured swellings of the leaf blade. Aphid straw yellow, green or reddish; apterous adults dorsally with dark spots. Hieracium and Pilosella: Nasonovia ribisnigri

21a Leaf margins rolled upwards => 22

21b Leaves rolled downwards or often curved and ± strongly curled. Usually several leaves on the shoot tip are conspicuously malformed. Hieracium spp.: Aphis hieracii

22a In spring on the upperside of the leaves which fold upwards to enclose the colonies, later feeding on stems and inflorescences. Hieracium and Pilosella: Nasonovia compositellae

22b In spring inside upwardly rolled leaves, later moving onto stems and flowers. Hieracium alpinum, lachenalii, murorum; Pilosella aurantiaca, officinarum, piloselloides: Nasonovia pilosellae

23a Receptacle of one- or several capitula deformed => 24

23b Stalks of complete inflorescences shortened, thickened and curved. In the axils of clustered leaves 2–3 pale orange-yellow larvae. The development of neighbouring capitula often markedly stunted. Hieracium umbellatum: Unidentified gall midge

24a Inducers develop in the receptacle => 27

24b Inducers develop between the involucral scales => 25

25a Malformations caused by gall midges => 26

25b Malformations caused by gall mites. Capitula ± semiglobular, flowers markedly stunted and greened, flowers occasionally variously developing further. Hieracium and Pilosella: Aceria longiseta

26a Capitula often extensively shortened, usually enlarged on all sides. Several yellow, jumping larvae. Hieracium lachenalii, prenanthoides, umbellatum; Pilosella caespitosa, flagellaris, officinarum; Tolpis staticifolia: Contarinia pilosellae

26b Similar malformations of capitula on Hieracium murorum; Pilosella officinarum caused by orange-red, non-jumping midge larvae: Jaapiella compositarum

27a Conspicuous larvae developing solitarily or gregariously in distinct cavities of the receptacle => 28

27b The turgid, usually unilaterally malformed receptacle consists of a spongy, uniform parenchyma containing many eelworms. Pilosella cymosa, officinarum: Ditylenchus dipsaci

28a Whitish or yellowish maggots, , lacking a distinct head capsule => 29

28b Larvae with thoracic legs and distinct head capsule occurring in clearly swollen capitula. Hieracium amplexicaule, lachenalii, murorum, prenanthoides, umbellatum: Hellinsia didactylites

29a Malformations caused by tephritid larvae with conspicuous mouthparts and eventually developing a puparium => 30

29b Malformations caused by cynipid larvae, white. Hieracium lachenali: Aulacidea nibletti

30a Flower heads distinctly swollen at base, not opening, not conspicuously hardened; clearly curved if infected on one side; usually all capitula of a panicle infected. On many Hieracium and Pilosella species. Noeeta pupillata

30b Larvae in hardly disfigured flower heads. Pilosella lactucella, officinarum: Tephritis ruralis

30c Ditto. Hieracium murorum, sabaudum: Trupanea stellata

gallers on Elymus

pub 29.xi.2019

Dichotomous table for gallers on Elymus

(incl. Agropyron, Elytrigia, Hordelymus, Leymus, Roegneria, Sitanion, Thinopyrum)

by Hans Roskam

1a On shoots or shoot axis => 2

1b Roots with small slender, crooked or screw-like bent swellings. Elytrigia repens: Subanguina radicicola

= Furthermore, there are records of the cereal root-knot eelworm Meloidogyne naasi

2a On inflorescences or other generative parts => 27

2b On vegetative parts => 3

3a Malformations on culms or leaves caused by smuts => 25

3b Malformations caused by other fungi or by animals => 4

4a Malformations by animals => 6

4b Malformations by fungi => 5

5a Plants with systemic infections, growing rigidly erect, sterile; internodes shortened. Early infected leaves thickened irregularly, ± curved and disfigured; if infected later on the leaf blades are clearly widened; diseased leaf blades often with pale yellow stripes. Elytrigia repens: Physoderma graminis

5b Diseased leaves rolled and twisted, usually thickened conspicuously, pale, later brown and breaking up, exposing chestnut brown, globular naked oospores, 26–33 µm across. Spikes usually stunted, with disfigured, ± succulent, partially blue-green spikelets. Elymus caninus: Sclerospora graminicola

6a Malformation on shoot tips, and terminal shoots or on undeveloped shoots => 19

6b Malformations of culms, leaf sheaths or leaf blades => 7

7a Culm variously disfigured => 14

7b Malformations of leaves => 8

8a On leaf blades => 10

8b On leaf sheaths => 9

9a Leaf sheaths swollen, inhabited by aphids. Elytrigia repens: Laingia psammae

= Grain aphid, Sitobion avenae and/ or Blackberry cereal aphid, S. fragariae, known from many grasses, especially in inflorescences, cause also similar malformations on couch grass.

9b Leaf sheaths thickened above the nodes, usually open on one side. Several spindle-shaped galls inside. Larvae yellow. Elymus s.l.: Tetramesa hordei

10a Malformations of leaf blades caused by aphids => 12

10b Malformations of leaf blades caused by other parasites => 11

11a Leaf blade usually at base with tough, narrow, bulging, usually dark red coloured swellings. Elytrigia repens: Unidentified eelworm

11b Leaves remain unfolded or do not develop completely; discoloured. Elytrigia repens: Abacarus hystrix

= DNA-analysis has demonstrated that “A. hystrix” actually is a complex of a number of species.

12a Leaves rolled inwards by green aphids => 13

12b Leaves ± rolled upwards, often withering early. Aphid about 2 mm long, elongate, narrow, brownish-yellow with pale median stripe. Elytrigia repens: Sipha elegans

13a Leaves rolled upwards, twisted. Aphid 2–2.75 mm long, olive-green, reddish-brown between siphunculi. Elytrigia repens, Elymus caninus: Rhopalosiphum padi

13b Shoot stunted, leaves shortened, tuft-like accumulations. Leaf blades rolled, ± twisted. Agropyron cristatum; Elymus caninus; Elytrigia intermedia, repens: Diuraphis frequens

14a Culm swollen locally, galls contain larvae => 18

14b Inducers are outside galls => 15

15a Larvae in depressions on culm => 17

15b Causers not in distinct depressions => 16

16a Small, blister-shaped protuberances in long brown stripes or as crust-like cover. Elytrigia repens, Elymus caninus: Steneotarsonemus canestrinii

= Steneotarsonemus culmicolus occurs sometimes in the leaf sheaths of couch grass and other grasses and causes facultatively discoloured white spikes. Similar symptoms are also caused by Siteroptes cerealium, occurring on many grasses.

16b Shoot severely stunted. Inflorescence often remains largely hidden in the sheath. Culm at the base of the inflorescence ± swollen. Contains a single larva. Elytrigia repens: Oscinella frit and/ or the closely related O. pusilla

= Oscinella agropyri develops on couch grass without causing malformations.

17a Culm below leaf sheath usually above the upper node and the penultimate node with an expanded weak, usually blackened depression, containing a single orange-yellow to brick-red larva. Elytrigia repens, Elymus caninus: Hybolasioptera fasciata

17b Culm predominantly above the upper and penultimate nodes below the slightly swollen leaf sheath usually with oblong, saddle-shaped depressions, strongly inflated at the ends. Containing single 3–5 mm long bright red larvae. Elytrygia intermedia subsp. trichophora, repens: Haplodiplosis marginata

17c Recorded as inducer of further unspecified slight swelling of stems of Elytrigia repens: Lasioptera calamagrostidis

18a Culm at various places, often above a node or also close to the ground, with spindle-shaped, tough-walled, later on often yellowish-brown galls up to 7 mm long. Occasionally many per plant and fused in variable numbers and in various shapes, forming larger galls bulging from the sheaths as erupting swellings. Each chamber contains a yellow larva. Elymus s.l.: Tetramesa hordei

18b Culm below the often atrophied spikes which remain largely hidden in the sheaths often with several, ± fused, broad spindle-shaped to elongate-oval, very hard swellings, occasionally erupting from the sheaths. Each chamber contains a single larva. Elymus s.l.: Tetramesa hordei

18c Inside a culm or a hardened leaf sheath several ± oval, size of grain of rice size, galls. Culm at outside with irregular swellings, leaf sheath strongly swollen and ripped open. Containing a single pupa or white larva. Elytrigia repens, juncea: Tetramesa linearis

19a Shoot severely stunted already early in development, inflorescence usually not developing => 22

19b Terminal malformation on developed shoots => 20

20a Galls caused by chalcidoid larvae, with tuft of 3 or 4 conspicuously enlarged, increasingly shortened unfolding leaf blades => 21

20b Tip of shoot markedly shortened, swollen. Leaves clustered tuft-like, their sheaths shortened and broadened. The ± reduced leaf blades are usually not broadened and are appressed with their bases against the gall. Gall containing a single maggot. Elymus caninus; Elytrigia atherica, juncea, repens: Chlorops pumilionis

= Chlorops strigulus, C. interruptus, C. marchali and C. speciosus are all non-cecidogenous parasites of Elytrigia repens. – Concerning affiliation of the inducer of malformations on couch grass examination of larvae and rearing of adults is necessary.

21a Malformations, usually distinguished from fly galls by larger size length and width. Larval chamber in pith, oblong, thick-walled, usually extending over 3–4 internodes. Elymus caninus; Elytrigia intermedia, repens: Tetramesa hyalipennis

21b Similar, usually broader galls, up to 40 mm long, on Elytrigia juncea: Tetramesa maritima

22a Leaf blades mostly developed, but plants remain sterile => 23

22b Shoot tips etiolated, elongated, bent, spindle-shaped, enlarged. Elytrigia repens: ? Dasiops latifrons

23a Malformations caused by maggots => 24

23b Young shoots severely stunted; close to the ground ± conspicuously sponge-like swollen to large extent. Leaf blades shortened and disfigured to a varied extent. Elymus s.l.: Ditylenchus dipsaci

23c Short, compact onion-like galls arising from the basal part of young shoots, containing many eelworms: Elymus s.l.: Anguina agropyri

24a Young shoots sometimes, if many larvae or puparia present, slightly swollen. Leaves initially more erect, darker green and more compact than those of healthy plants. Central leaves often withering later on or dying; shoots with sessile, etiolated spikes; culms sometimes slightly swollen and often cracked above the basal nodes. Contain several white larvae and flax seeds-like puparia. Elytrigia repens, etc.: Mayetiola destructor

= Larvae, whitish ± 3 mm long, or puparia of Mayetiola baudysi live within a leaf sheath just above a node, causing a light, often brownish swelling on Elytrigia repens

24b Infected rudiments of shoots severely stunted, sometimes slightly swollen at base. Central leaves soon yellowing and withering. Shoots occasionally developing additional tillers. Elymus s.l.: Delia coarctata

25a Narrow stripes on leaf blades and -sheaths caused by smuts, rarely on culms => 26

25b Patches with smut predominantly on sterile remaining culms which initially grow faster. A number of internodes often noticeably enlarged. Elymus s.l.: Tranzscheliella hypodytes

26a Plants often severely stunted. Stripes long, narrow, ± coalescing, almost black; lacerating the leaf blade if ripped open. Spores slightly dusty, separated, spherical to rotund-oval, about 11–18 µm across. Membrane with blunt, sometimes coalescing warts. Elytrigia repens, more rarely on Elytrigia juncea, Elymus caninus: Ustilago serpens

26b Infected stems at first developing quickly, later on stunted, often remaining sterile, extensively covered with brown-black patches with spores. Elymus caninus, Elytrigia juncea, repens: Tranzscheliella hypodytes

26c Similar infestation. Spores blackish, solitary or aggregated in pairs, however, more rarely with 3–4 together and enveloped by several accessory cells which have a pale yellow membrane. Elymus s.l.: Urocystis agropyri

26d Ditto on Elytrigia atherica, campestris, pungens: Urocystis agropyri-campestris

27a Malformations caused by parasitic fungi => 29

27b Malformations caused by animals => 28

28a Inflorescence usually disfigured over extensive patches. Spikelets according to degree of infestation ± disfigured and greened or discoloured, stunted. Elytrigia repens, Leymus arenarius: Aceria tenuis

= Occasionally this mite is associated with Aceria cornuta.

= Proliferations of flowers of Elytrigia repens are teratological malformations.

28b Flowers greened. Elymus caninus: Inducer not clarified – ? Eelworm

29a Patches with smuts extending to other flowering parts. Elymus caninus, trachycaulus: Ustilago bullata

29b Patches with smuts restricted to ovaries. Smut grains foul-smelling, oblong, grey- to blackish brown, enclosed by slightly spreading glumes. Spores globular, 18–22 µm across; membrane reticulate. Elymus s.l.: Tilletia controversa

= Conspicuously protruding, rough, often bent bodies, black on outside and white on inside, are not true galls, but are sclerotia of ergot Claviceps purpurea, frequent on couch grass. The identity of ergot on Elytrigia juncea has not been clarified

gallers on Crepis

pub 28.xi.2019

Dichotomous table for gallers on Crepis

(incl. Aetheorhiza)

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodule- to spindle-shaped swellings. Crepis spp.: Meloidogyne hapla

1c Rounded root galls 4–5 mm long on Aetheorhiza bulbosa: Entyloma crepidicola

2a Malformations of capitula => 28

2b Galls on vegetative parts => 3

3a Malformations with fruiting bodies of fungi on the outside => 21

3b Malformations caused by animals or by fungi whose fruiting bodies develop inside the galls => 4

4a Galls exclusively or predominantly on the stems => 18

4b Galls only or mainly on leaves => 5

5a Galls especially on midrib and main veins, only secondarily on leaf blades => 13

5b Galls largely extended over the leaf blades-, or local, induced by psyllids, gall midges or gall mites and fungi => 6

6a Malformations of undefined shape, extending over the whole leaf blade => 12

6b Galls of ± defined shape and size => 7

7a Malformations with abnormal pubescence => 11

7b Galls glabrous or without supplementary pubescence => 8

8a Galls only about 1–3 mm long, wart- or callus-shaped => 9

8b Leaf blade usually with several rotund, up to 4 mm wide, pale green, often yellowish or reddish bordered pock-shaped upward bulges. Galls only closed by the epidermis beneath, a red-yellow larva showing through. C. biennis, conyzifolia, praemorsa, Aetheorhiza bulbosa, etc.: Cystiphora sp.

9a Galls pearl-like, often very many on the underside, sometimes also on upper side of the rosette leaves, hardly 1 mm long, red- to golden yellow translucent. Occasionally also occurring on leaf veins and petioles and below on the stem; sometimes forming crusts or bars resulting in further malformation of the plant parts => 10

9b Leaves with rotund, 1–3 mm wide, slightly protruding yellow-grey bulges. C. biennis, rubra: Entyloma crepidis-rubrae

10a On C. biennis. Leaf blades with pearl-like, compound galls, often aggregating into extended, orange-yellow, or blood-red crusts: Synchytrium taraxaci

10b On C. alpestris, biennis. Orange- to golden yellow multicellular warts: Synchytrium aureum

11a Protrusions of the leaf underside with erineum. C. paludosa: Unidentified gall mite

11b Similar malformation, in connection with narrow, abnormal pubescent marginal rolling, usually only short upwards stripe. C. praemorsa: Unidentified gall mite

12a Leaf blades of basal leaves sometimes with several dimple-shaped depressions on the underside, each dimple with one larva. Leaf blades, which are occupied by many older larvae, are deformed and have deflected, often ± twisted, margins. C. biennis: Craspedolepta flavipennis

12b Malformation of the leaf blades by aphids: Nasonovia ribisnigri

12c Leaf blade apex and margins nest-like downwardly curved, especially close to the site of attack strongly curled and dark green. Infestation of stem is accompanied by localised stunting and curving of the stem, which bears 2–3 closely situated bent and curled leaves. C. biennis, pyrenaica, paludosa: Philaenus spumarius

13a Extensive galls on the midrib, often already emerging from leaf base => 16

13b Galls on other sites, not connected with the leaf base => 14

14a Nodule- or bulge-like, massive galls on the veins, without a central chamber, the inside with fungus spores => 15

14b Midrib with pale spindle-shaped swelling; one larva inside. C. biennis: Unidentified gall midge

15a Galls predominantly on leaf tips. Infected parts initially yellowish, brown-red later on; often bladder-like swelling on upper side; veins also swollen, especially protruding on underside, often conspicuously reddened. Spores in vascular tissue. C. biennis: Protomyces crepidicola

15b Nodule-like, chocolate-brown swellings on the main- and midribs of the leaves, as well as more bulged swellings of the basal stem parts. Spores in and next to the vascular bundles. C. paludosa: Protomyces crepidis-paludosae

15c Leaf galls on C. froehlichiana subsp. dinarica. Bulges about 0.5–0.75 mm wide, ± grey-yellow, protruding hemispherically on the underside, often many per leaf blade: Protomycopsis crepidis

16a Midrib at its base up to three times its normal size, swollen. Gall gradually narrowed to mid-leaf, or further, swelling not extending to the sometimes nested leaf blade parts. Contains a maggot inside => 17

16b Midrib of several, often severely stunted rosette leaves, including adjacent leaf blade parts usually spongy, swollen, pale green, sometimes, ± reddened. Many eelworms inside. C. biennis, capillaris, paludosa, tectorum: Ditylenchus dipsaci

17a Rosette leaves, more rarely stem leaves, mined. C. biennis: Phytomyza robustella

17b Similar galls, mainly in basal leaves of C. paludosa: Phytomyza araciocecis

18a Galls glabrous, tough-walled. Contain larvae => 19

18b Galls spongy, pale green, with ± rugose surface. Very differently extending, even many cm long. Stem swollen on all sides, or more one-sided; internodes often strongly shortened, spirally twisted, curled or bent. Infestation especially on the basal leaf parts; occasionally also to a different degree in the swollen, ± nodding and closed capitula. C. biennis, capillaris, foetida subsp. rhoeadifolia, taraxacifolia, etc.: Ditylenchus dipsaci

19a wellings close to the stem base => 20

19b Stem with ± spindle-shaped swellings, about 10–40 mm long and 6–15 mm broad, sometimes multiple hunchbacked, also bent. Galls on main stems of C. biennis often united to 15 and more cm long, ± large chambered swellings. Inside the greatly enlarged pith are many, lateral- or central compact-shelled larval chambers. One larva per chamber. C. biennis, capillaris, tectorum: Aulacidea sp.

19c Similar galls are also described from C. paludosa, taraxifolia: Phanacis lusitanica

19d Corresponding galls on C. pulchra: Phanacis rufipes

20a Stem bases of young plants stunted, swollen to a different extent, with ± reduced and mutually close leaves. In the swollen pith is a boring maggot. C. capillaris: Napomyza lateralis

20b Basal part of stem, including root collar severely shortened and swollen; occasionally bent, partially bushy (phyllanthy). Several white larvae inside. C. setosa: Unidentified beetle

21a Malformations with spores of rust fungi => 23

21b Malformations caused by other fungi => 22

22a Internodes shortened, plant very bushy; development of flowers stunted in strong infestations; stem and leaves irregularly curved, with small spore-bearing pock-like depressions. C. biennis, capillaris: Didymaria matricariae

22b Leaf blade initially with dark green, later on yellowish, ± vesicular swellings, showing grey-white layers of asci after ripening. C. conyzifolia, mollis, pygmaea, pyrenaica: Volkartia rhaetica

23a Fungus host alternating, on Crepis only producing aecia and pycnidia. Sori sometimes slightly blistered, swollen => 27

23b Fungus host-specific, all spore types developing on Crepis; gall-like malformations only by the aecidial stage with thickened inner wall of the peridium => 24

24a Aecia-producing mycelium locally, sori facultatively blistered, swollen => 26

24b Aecia-producing mycelium extending over large areas within the usually sterile host; cups scattered, usually occurring on all leaves of the host => 25

25a Whole plant changed. Diseased leaves upright, often narrowed, thickened, abnormally pale; on the underside and partially also upperside, with many aecia and pycnidia. Infected stem ± swollen, initially taller than the healthy ones, pale green, often remaining sterile. C. capillaris, tectorum, etc.: Puccinia crepidis

25b Pycnia and aecia on C. aurea: Uredo breventiaca

25c Pycnia and aecia on C. foetida incl. subsp. rhoeadifolia: Puccinia barkhausiae-rhoeadifoliae

26a The closely situated aecia in yellowish, sometimes red margined bulge-like swellings. These are rotund on the leaf underside and oblong on the veins and stems. Intensity of gall formation depends upon interaction of host and parasite. Basic differences between the malformations caused by the following species are absent. Wall cells of the pseudo-peridium in irregular rows, the inside thickened. Uredinia and telia not cecidogenic, in small sori, widely distributed on leaves and stem. Fungi differ in microscopic characters, especially if telia are present and largely according to the host. Stages with pycnia and aecia are facultatively cecidogenic:

a On C. biennis: Puccinia praecox

b On C. paludosa: Puccinia major

c On C. alpestris: Puccinia alpestris

d On C. aurea: Puccinia crepidis-aureae

e On C. pyrenaica, also on alpestris, capillaris, tectorum: Puccinia crepidis-blattarioidis

f On C. conyzifolia: Puccinia crepidis-grandiflorae

g On C. foetida, taraxifolia, etc.: Puccinia crepidicola

h On C. jacquini: Puccinia krupae

i On C. mollis: Puccinia crucheti

j On C. [Intybus] praemorsa: Puccinia intybi

k On C. pygmaea: Puccinia crepidis-pygmaeae

l On C. sibirica: Puccinia crepidis-sibiricae

27a Sori often bright yellow, sometimes red margined, not- or only slightly thickened. Usually freely situated on the leaf blade, rotund, on the underside slightly bulging, on the upper side slightly depressed and occupied with spots of brownish pycnidia; the aecia on the underside with well-developed pseudoperidia, which open cup-shaped, their cells in regular rows and thickened on the outside. C. biennis, more rarely C. capillaris, taraxacifolia, vesicaria: Puccinia opizii

27b Cushions on the leaf blade more distinctly bulged; pycnia and aecia mainly on the venation, possibly on petioles and even on stems. C. biennis: Puccinia silvatica

28a Capitula greened and leafy, with a multiplication of flower peduncles supporting small malformed capitula (phyllanthy => 31

28b Capitula stunted, weakly thickened, remaining closed => 29

29a Malformations by gall midge larvae => 30

29b Malformations by fly maggots. C. biennis: Noeeta crepidis

29c Capitula swollen, peduncles swollen just below the flower head; stems also swollen if attacked in rare cases. C. taraxacifolia: Ditylenchus dipsaci

30a Several yellow, jumping larvae occur in the basally weakly thickened and twisted capitula. C. biennis, etc.: Contarinia hypochoeridis

30b Malformed capitula with pale, non-jumping larvae. C. paludosa: Unidentified gall midge

31a Capitula, often in large numbers per plant, completely deformed, sometimes partially developing into further, similarly deformed reduced capitula. Involucre often not changed, corollas severely stunted and ± greened; anthers and ovaries changed into green, ± leafy structures. C. biennis, capillaris, tectorum: Aceria rechingeri

= The gall mite Phyllocoptes oligostictus is inquiline in enlarged flower heads of C. biennis caused by Aceria rechingeri

31b Capitula almost witches’ broom-like, sometimes even repeatedly developing into stalked smaller capitula; flowers often hardly, sometimes unrecognisably deformed though with ± lanceolate, leafy structures instead. Usually all capitula of a host are similarly deformed. C. biennis, tectorum: Inducer unknown

gallers on Chrysanthemum

pub 26.xi.2019

Dichotomous table for gallers on Chrysanthemum

(incl. Argyranthemum, Coleostephus, Dendranthema, Leucanthemum, Leucanthemopsis, Parthenium, Pyrethrum, Tanacetum pp.)

by Hans Roskam

1a On above-ground upper plant parts => 6

1b On roots, rhizomes or root collars => 2

2a On root collar, rhizome or subterranean buds => 3

2b Roots with small nodule-shaped swellings. Chrysanthemum spp.: Meloidogyne hapla

3a Considerable proliferations on the root collar => 5

3b On rhizome buds or rhizomes => 4

4a Rhizomes with rotund swellings, up to 5 mm long, succulent, containing one or several chambers. A white larva develops in each chamber. Leucanthemum vulgare, Tanacetum corymbosum: Oxyna nebulosa

4b Stem of the upper root part, especially the basal buds, thickened; rosette stunted; leaves swollen to a uniform fleshy gall, remaining closed; ± covered by stunted leaf parts. Larva reddish. Leucanthemum atratum, L. vulgare: Rhopalomyia hypogaea

5a Crop-like proliferations, globular, usually uniformly, with compact rough surface. Chrysanthemum spp.: Agrobacterium tumefaciens

5b Ramification of root collar. Shoots only stub-shaped, irregular, partially even leaf-like broadened, fleshy thickened; forming ± dense witches’ broom-like clusters composed of markedly degenerate leaves. Chrysanthemum spp.: Rhodococcus fascians

6a Galls on capitula, flowers or fruits => 28

6b Malformations of vegetative plant parts, occasionally also protruding parts of, or complete inflorescences => 7

7a Malformations exclusively, or predominantly, on leaves or apical shoots => 12

7b Malformations mainly on stems, sometimes additionally also on the petioles and leaf veins => 8

8a The inducers are inside the galls => 9

8b Stem over various lengths ± bulged, swollen, occasionally curled. On the rind some to many, wall-like framed depressions containing a flat scale insect. Leucanthemum vulgare: Planchonia arabidis

9a Malformations ± expanded, however with locally distinct solitary galls => 11

9b Malformations of different dimensions, without distinct solitary galls => 10

10a Stem slightly swollen close to the inflorescence, somewhat stunted and more pubescent. In the hollowed pith is a caterpillar, which often also ± infests the receptacle. Leucanthemum vulgare: Unidentified lepidopteran

10b Stem mainly underneath the flower head differently malformed, often over extended length, spongy, swollen, partially screw-like curled or curved. Neighbouring capitula stunted and deformed to a different extent. Leucanthemum: Ditylenchus dipsaci

11a Stem internodes ± stunted and swollen, occupied often with many, 2–3 mm long, acute-conical, ± obliquely protruding, ± pubescent galls. Corresponding galls often simultaneously also on leaves and sometimes axillary buds and even galling parts of the inflorescence. Hosts in case of severe infestation often largely deformed. Larvae initially milk-white, yellowish to red-orange later on. C. indicum, rubellum, incl. various forms: Rhopalomyia chrysanthemi

11b Similar malformations of stem and buds with usually less many fleshy galls. One reddish larva per gall chamber. Leucanthemum vulgare etc.: Rhopalomyia hypogaea

12a Wart-shaped, distinctly defined swelling caused by fungi, hardly 1 mm long or ± flat callous, which fruit either in the inside or on the surface of the galls => 24

12b Leaves with strongly protruding swellings, flat, ± irregularly bordered or with expanded marginal rolls and curls, usually caused by animals => 13

13a Leaf blades with malformations of various shape and growth, usually on several terminal leaves; caused by aphids, cercopids, leaf-hoppers or erineum-like fruiting fungi => 20

13b Leaves with locally restricted malformations, often many or with narrow rolls => 14

14a Conspicuous malformations of the leaf margin => 18

14b Malformations of the leaf blade => 15

15a Leaf blade with succulent, conical, or nodule- to bulge-like galls => 16

15b Leaf blades predominantly of the rosette leaves, with many dimple-shaped swellings, protruding on the upper side. Leucanthemum vulgare: Trioza chrysanthemi

15c Similar dimples on the basal leaves containing froth-covered nymphs. Leucanthemum vulgare: Craspedolepta flavipennis

15d Slightly locally suberose leaf swellings. Thrips nigropilosus

16a Galls up to 3 mm long, conical or nodule-shaped => 17

16b Petioles, usually of several rosette leaves, shortened, markedly spongy, swollen, pale green. Swellings variously extending into the leaf blade; sometimes ± isolated on the leaf blade and fading from a rugose vein into the leaf blade, again conspicuously pale green. Leucanthemum maximum: Ditylenchus dipsaci

17a Leaf blade with nodular swellings, Tanacetum corymbosum: Unidentified eelworm

17b Leaves often with many conical galls, on the upper side or also beneath, obliquely protruding, 2–2.5 mm long. Corresponding lumps often simultaneously on other plant parts. Larvae initially milk white, later red-orange. C. indicum: Rhopalomyia chrysanthemi

18a Leaf blade margin lacerate => 19

18b Leaves with downward rolls. Tanacetum corymbosum: Unidentified psyllid

19a Leaf blade lacerate, with small protrusions on the upper side. Leucanthemum vulgare: Unidentified gall mite

19b Leaf blade deeply and irregularly striped, long white pubescent. Tanacetum corymbosum: Cause unknown – ? gall mite

20a Leaf blade bent and curled by animal parasites => 21

20b Leaves usually with several shoot tips locally or completely bleached, swollen, ± curved or deformed in other ways; the underside soon covered by a coherent dirty violet fungus. Capitula, if present, severely stunted, sometimes with hardly spreading, shortened and greened ligules and likewise ± greened tubular florets. C. segetum: Peronospora danica

21a Malformations by aphids => 22

21b Leaves nest-like contracted, close to the site of attack curled, dark green. Infestation of stem leaves or stems often leads to curved, one-sided thickened stems with converged, ± rolled leaves. Infestation of stem parts close to the capitula results in diverse malformations on inflorescences and flowers. Chrysanthemum spp.: Philaenus spumarius

22a On Leucanthemum vulgare, Tanacetum corymbosum => 23

22b On Chrysanthemum indicum, Argyranthemum frutescens. Leaves and also flower parts deflected. Aphids dark browns to black. 1.5–2.5 mm long, antennae as long as body, siphunculi thick, conical, slightly shorter than the long cauda: Macrosiphoniella sanborni

22c Superior internodes strongly shortened, with dense tufts of leaves and stunted capitula. Argyranthemum frutescens: Macrosiphoniella artemisiae

= Various malformations of shoot- and inflorescences may be virus-associated.

23a Leaf blade of Leucanthemum vulgare deformed by green aphids, curved. Attack on terminal shoots results in considerable stunting and curling of plant parts, incl. capitula and flowers. Aphid about 2–2.3 mm long and with almost black siphunculi: Brachycaudus cardui

23b In similar malformations on several Chrysanthemum species occurs another aphid, which is only 1.5–2 mm long with green to olive-brown siphunculi: Brachycaudus helichrysi

23c Basal leaves of Tanacetum corymbosum curved, soon yellowing: Macrosiphoniella miestingeri

24a Sori cushion- or bulge-shaped; fruiting bodies at the surface, on Leucanthemum vulgare => 27

24b Galls wart- or pock-like with spores inside => 25

25a Galls nodule-shaped, over 1 mm wide => 26

25b Underside of the rosette leaves often with many, hardly 1 mm long hemispherical, pearl-like warts, with a yellowish translucent fungal body. in the middle. Leucanthemum vulgare: Synchytrium aureum

26a Usually distinct, rotund, flat pocks up to about 2 mm long, initially grey-white, later browned, predominantly solitary; mostly with several on the underside of basal- as well as stem leaves; more rarely on petioles or stems. Spores of various size, thick-walled; terminally produced on the mycelium ramifications, outside the vascular bundle. Leucanthemum vulgare: Protomycopsis leucanthemi

26b Similar, mostly less conspicuous flat, initially whitish-yellow pocks on the leaf underside, sometimes also on the stems of the inflorescences. Leucanthemopsis alpina: Protomycopsis leucanthemi

27a Underside of the rosette leaves mostly with many, small, rotund, brown telia; if produced on petioles of young leaves in especially early spring sometimes slightly swollen, mostly yellow-margined, oblong-oval cushions. No host alternation: Puccinia leucanthemi

27b Leaf underside with rotund, 3–10 mm wide yellowish, often purple-margined aecia. Sori on main veins sometimes slightly bulge-like swellings. Species alternating on Carex montana: Puccinia aecidii-leucanthemi

27c Similar aecia, on the same host but alternating on Carex caryophyllea, ericetorum: Puccinia leucanthemi-vernae

28a Galls mainly locally in capitula, on the receptacle, involucre, bracts or fruits => 35

28b Malformations over ± extensive parts of the inflorescence => 29

28c Slight swelling of main stem below flower head, causing distortion of head, with side shoots growing past it; larva tunnels inside stem and often into flower head from which frass may exude, in stem or head (or in ground). Leucanthemum vulgare: Dichrorampha consortana

29a Malformations of approximately well-defined shape, involving the receptacle => 33

29b Malformations of varying extensions on parts or complete capitula => 30

30a Malformations of ± open capitula => 32

30b Capitula stunted, remaining closed => 31

31a Capitula slightly swollen; several yellow to pink jumping larvae between the achenes. Leucanthemum vulgare, maximum: Contarinia chrysanthemi

= The gall midge Dasineura chrysanthemi has been recorded from flower heads of Leucanthemum vulgare; as well midge larvae assigned to Jaapiella sp.

31b Complete flower head deformed, flowers aborted. Leucanthemum vulgare: Paraphytoptus chrysanthemi

= For the ornamentally cultivated C. carinatum, indicum, conspicuous damage caused by viruses has been recorded. Malformations consisting of greening of the flowers in connection with malformations of the capitula

32a Malformations caused by aphids or cercopids => 21

32b Inflorescence variously stunted or deformed; infected organs partially covered with an area of loosely, dichotomous, grey-violet conidiophores. Tubuliform flowers often soon withered, infected ligules elongated, often variously curved, usually with abundant oospores, lacking conidiophores. Leucanthemum vulgare: Peronospora radii

33a Receptacle swollen, without involvement of the often strongly atrophied flowers => 34

33b Receptacle locally, including one or several flowers, initially swollen to a succulent, conical, apically almost closed gall, surmounting the later ± deformed disc. One reddish larva. Leucanthemum vulgare: Rhopalomyia hypogaea

= Similar galls but with terminally spreading lobes later on Leucanthemum vulgare are caused by the gall midge Rhopalomyia tanaceticola which lives usually on Tanacetum.

34a Receptacle deformed, ± swollen, hardened. Leucanthemum vulgare: cf. Eurasimona stigma

= According to Smit (2010) the capitula of Leucanthemum vulgare are also infested by the tephritid fly Tephritis neesii; widely distributed in Eu, no records from E-Eu.

34b Receptacle almost only enlarged in combination with corresponding swellings on the neighbouring parts of the stem and accordingly curved. Leucanthemum vulgare, maximum: Ditylenchus dipsaci

35a Up to 2 mm long, obliquely protruding, conical galls on leaves of the involucre and solitarily scattered even on the ligules. C. indicum: Rhopalomyia chrysanthemi

35b Ovary or fruit swollen without or together with the lower flower parts. Also the bract may be involved in the gall formation. One yellow larva. Chrysanthemum argenteum (Tripleurospermum inodorum and Anthemis bornmuelleri are main hosts; furthermore Leucanthemum vulgare: Ozirhincus longicollis

35c Similar galls; Chrysanthemum coronarium, segetum: Ozirhincus anthemidis

= O. longicollis and O. anthemidis differ by the length of the adult proboscis: in O. longicollis proboscis long, from base of labrum to tip of labella longer than height of eye; in O. anthemidis proboscis shorter than height of eye.

gallers on Alnus

pub 26.xi.2019

Dichotomous table for gallers on Alnus

by Hans Roskam

1a On parts above ground => 2

1b Lateral roots initially with small, nodule-like, later on with rotund, hazelnut- to fist-size gall masses (rhizothamnia), composed of thick, coral-like branches, usually densely clustered. Alnus spp.: Frankia alni

1c The disease usually starts at the roots and root collar, and extends from there in a few years up into the crown; it manifests itself by large brown bleeding bark lesions, later in a reduction of the foliage and branch die-back. A. cordata, glutinosa, incana: Phytophthora alni

2a On shoots or leaves => 4

2b On flowers or inflorescences => 3

3a Cone scales broadly band-like proliferating, succulent, often temporarily ± reddened, eventually browned. Alnus spp.: Taphrina alni

3b Male catkins distorted, sometimes knobby or appearing thickened over their whole length. Containing a single larva. Alnus spp.: Unidentified lepidopteran

3c s occasional inhabitants of gall-like malformations the following species have been recorded: Epinotia immundana and/ or E. tenerana

4a On leaves => 11

4b On shoots => 5

5a Malformations witches’ broom-like or occupied by mistletoe => 10

5b Malformations different => 6

6a The inducers develop inside the malformations; or have their fruiting bodies on the surface => 7

6b The inducers are to be found in ± lenticular rimmed depressions, up to about 2 mm long, on the bark of young, already woody twigs. A. glutinosa, incana: Chionaspis salicis

= The “alder spittlebug” Aphrophora alni causes distinctive calloused rings on shoots

7a Localised malformations on young woody twigs with tunnels bored inside => 9

7b Malformations caused by fungi, which at least temporarily have their fruiting bodies developing on the surface => 8

8a Bark of older shoots with ± fissured, initially closed, later on centrally open, ridge-like bordered cancer wounds. “Nectria cancer”. A. incana: Neonectria major

= The polyphagous Agrobacterium tumefaciens is also reported from alder as inducer of closed cancers

8b Axial parts of young shoots conspicuously swollen usually over their whole length. Leaves often remarkably swollen, bladder-like and curled. A. glutinosa, glutinosa x incana, rubra (cult.): Taphrina tosquinetii

9a One year old shoots with swelling, up to 10 mm long and about 5 mm broad, downwardly gradually narrowed. The pith contains a yellowish or pale green caterpillar with brown-yellowish head and often a darker neck shield. Alnus spp.: Epinotia tetraquetrana

9b Elongated, weak, eventually usually dehiscing swelling in terminal part of twig. Contains a single larva. A. glutinosa, incana, viridis, etc.: Heliozela resplendella

= The larvae of the snout beetle Cryptorhynchus lapathi tunnel in older stems, as well as in many other woody hosts, which results in conspicuous deformations. However, these results of regeneration are not true galls.

10a Heavier stems with ± distinct spindle- or barrel-like swellings, from which sprout Viscum album

10b Loose to densely bushy, often conspicuous witches’ broom. Shoots elongated, rigidly erect, considerably thickened, especially at base, with many lenticels. Brooms 2–3 (–4) years overlaying, often many per tree. Leaves often slightly thickened, paler, more curled than healthy ones. A. glutinosa x incana, incana: Taphrina epiphylla

10c A fungus with similar symptoms has been described as Taphrina tosquinetii

11a Malformations only on petioles or main veins, not or only secondarily extending to the leaf blade, without accessory pubescence => 27

11b Malformations on leaf blades close to the major veins or including them => 12

12a Galls mostly on expanded, fully developed leaves => 15

12b Malformations on young leaves or leaf blades over the midrib ± folded upwards => 13

13a Leaf blade, according to the extent of development at infection time, ± completely upwardly folded. Midrib and basal parts of the side veins ± spongy, thickened. Gall midge larvae present between the folds => 14

13b Young leaves curled together. Veins undulate. A. glutinosa: Aceria longirostris

14a Larvae gregarious, initially white, later red. A. glutinosa, incana, glutinosa x incana; also on cultivated alders: Dasineura tortilis

14b In similar galls live gregarious yellow larvae with terminal red parts: Jaapiella clethrophila

= Furthermore reddish-yellow larvae of the gall midge Macrolabis alnicola, also an inquiline of D. tortilis

15a Malformations with conspicuous abnormal pubescence which is visible from the outside => 22

15b Pubescence of gall surface normal => 16

16a Leaf blades with ± expanded bladder-shaped swellings => 18

16b Galls globular, 1–2 mm across, constricted at base, often many on the upper side of the leaves, yellowish-green or sometimes reddened. Opening on underside, surrounded by a glabrous rim; only the inside pubescent => 17

17a On A. glutinosa: Eriophyes laevis

17b On A. incana: Eriophyes alniincanae

18a Galls caused by fungi, whose fruiting bodies develop at maturity as loose, ash-grey coverings of upwardly bent leaf undersides => 19

18b Leaf blade with flat, ± extended, not acutely delimited, initially pale, later on brownish swellings with many mites on the underside. Alnus spp.: Tegonotus heptacanthus

18c Similar malformations of mites which are known as inquilines in other mite galls on alder have occasionally been reported: Tegonotus trouessarti and/ or Acaricalus trinotus

19a Swellings only flat, ± pale green, slightly extended; usually with several present on the slightly enlarged leaf blades => 20

19b Leaf blade considerably enlarged, completely or the major part heavily bladder-like swollen, pale green. Alnus spp.: Taphrina tosquinetii

20a On A. incana, viridis => 21

20b On A. glutinosa, glutinosa x incana, incana and cultivated species: Taphrina sadebeckii

21a On A. viridis: Taphrina viridis

21b On A. incana: Taphrina epiphylla

22a Erinea not noticeably encroaching on the venation, or mostly restricted to the vein axils => 23

22b The often expanded areas with abnormal pubescence predominantly along the midrib and lateral veins, secondarily also on the leaf blade and petiole. Pubescence dense, hair longer than normal. Erinea initially white, brown later on. A. glutinosa, incana: Unidentified gall mite

23a Erinea distributed over the leaf blade without particular pattern => 24

23b Galls mostly in the vein axils along the midrib, often on both leaf halves; over a length of 2–3 mm, protruding upwards, initially yellowish, brownish later. In the cavity on the underside initially white, later on ± browned, hairs. On the central part of the erineum slim club-shaped hairs, with acuminate rigid hairs on the margin. Alnus spp.: Eriophyes inangulis

24a Hairs in erinea club-shaped or cylindrical, only slightly different from the normal ones => 25

24b Hairs on top distinctly broadened, irregular bumpy or lobed, head- or toadstool-shaped. Erinea on the underside, more rarely also on the upper side, forming initially yellowish-white, later on rust-brown, oval spots or more extensive coverings. Alnus spp.: Acalitus brevitarsus

25a Hairs cylindrical or slightly club-shaped, irregularly bent and intricate => 26

25b Hairs slightly different from normal ones. Erinea on the underside in weak archings of the leaf blade. A. glutinosa, incana: Unidentified gall mite

26a On A. glutinosa, incana, glutinosa x incana. Erinea on underside, more rarely upper side, mostly rotund-ovate, initially white, reddened later on: Acalitus phyllereus and/ or Aceria bistriata

26b On A. viridis. Erinea usually on upper side and peach red, later like the previous species: Eriophyes euryporus and/ or Aceria bistriata

= The eriophyoid mite Aceria alniviridis has been recorded as inquiline in galls of Eriophyes euryporus

27a The malformations result from oviposition and are already vacated by the departed larvae. “Procecidia”: oviposition scars, not true galls => 28

27b Petioles ± distinctly swollen and sometimes appearing shortened, usually bursting open later. Caterpillar often only occurring in the ± swollen petioles, eventually appearing with a short, full depth corridor into the leaf blade, cutting an oblong-ovate case, and dropping to the ground in that housing. Alnus spp.: Heliozela resplendella

28a Procecidia (oviposition scars) on petiole, sometimes extending to midrib => 30

28b Procecidia on the veins only => 29

29a Midrib with up to 8 punctures made on the leaf upper side; procecidia arranged longitudinally, contacting one another. Batches bursting downwards, recognizable for a longer time. Alnus spp.: Eriocampa ovata and/ or E. umbratica

29b Midrib on the leaf underside usually with up to 15 procecidia, inconspicuous and hardly permanent, which are arranged in one row. Alnus spp.: Craesus septentrionalis

30a Egg capsules usually on both-sides of petiole or in the midrib; now left, now right, alternating or opposite. Alnus spp.: Hemichroa crocea

30b Egg batches on petiole solitary. Alnus spp.: Hemichroa australis

gallers on Veronica

pub 24.xi.2019

Dichotomous table for gallers on Veronica

by Hans Roskam

(incl. Paederota bonarota, lutea; Pseudolysimachion longifolium, spicatum, spurium)

1a On parts above ground => 2

1b Roots with small nodular to spindle-shaped swellings. Veronica spp.: Meloidogyne hapla

2a On inflorescences, flowers or fruits => 36

2b On stems, shoot tips or leaves => 3

3a On stem parts below shoot tip => 9

3b On tips of main- and side shoots => 4

4a Galls irregular, tuft- or ball-like => 7

4b Galls almost regular, bud-like or pouch-shaped => 5

5a Terminal leaf pair folded upwards together, narrowed, thickened, especially basally discoloured or reddened. V. scutellata, serpyllifolia, anagallis-aquatica, beccabunga => 6

5b Terminal leaf pair folded together, pouch-like, swollen, thickened. Transformed into a uniform, usually broad conical, sometimes laterally flattened, 2-valved, 5–10 mm long gall. On glabrous Veronica species glabrous and inconspicuous, sometimes reddened basally; on pubescent hosts ± strongly to even white-woolly haired and often of conspicuous size. Containing orange-red larvae. Veronica spp.: Jaapiella veronicae

= Inquilines: Whitish-yellow midge larvae of Macrolabis incolens

6a On V. scutellata, etc. Terminal pair of leaves folded together in an erect, reddened, spindle-shaped gall. Containing several orange-red larvae: Dasineura similis

6b Similar, however much smaller, glabrous malformations on V. serpyllifolia: Jaapiella veronicae

7a Malformations caused by gall mites on clustered terminal vegetative, or generative parts => 8

7b Shoot tip stunted, disfigured; flowers greened. Containing red larvae. V. fruticans: Dasineura jaapi

8a Tip of generative or vegetative shoots severely stunted, organs densely clustered, variously disfigured; all green parts abnormally pubescent. V. alpina (incl. subsp. pumila), chamaedrys, fruticulosa, officinalis: Aceria anceps

8b Similar, ± strongly pubescent malformations on V. aphylla, fruticans require further analysis. Unidentified gall mite(s)

8c Vagrant mites on the underside of the leaves. At high densities the underside of the leaves may turn violet. V. chamaedrys, longifolia: Aculus latus

= This species is also reported as an inquiline of Aceria anceps

9a Galls locally, of more or less same shape, only rarely longer than 10 mm; on stems and leaves => 24

9b Malformations of largely indefinite shape, depending on organ; malformations of leaves and partially simultaneously on stems => 10

10a Malformations distinguished by excessive pubescence or down caused by branched conidiophores => 20

10b Malformations made conspicuous by rolling or curling of leaves, or spongy swellings on young plants => 11

11a Malformations of leaves, with or without involvement of stem => 12

11b Young plants severely stunted. Stem stunted, swollen, spongy. Surface of gall ± undulate, wrinkled, pale. Tissue brittle, necrotic. Swellings to various extent in closed or loose form on petiole, on the ± disfigured leaf blades as well as encroaching onto further developing stem parts. V. agrestis, arvensis, hederifolia, opaca, peregrina, persica, serpyllifolia, Pseudolysimachion spicatum, etc.: Ditylenchus dipsaci

= Also locally defined galls on stems and leaf veins of V. chamaedrys, persica might be attributed to this eelworm, causing minor damage – isolated galls on shoot parts – on young plants.

12a Various malformations caused by aphids, usually of several terminal leaves => 14

12b Malformations caused by spittlebugs, mites or thrips => 13

13a Upward rolls of leaf margin, containing single or several froth-covered nymphs. V. austriaca: Unidentified thrips

= Haplothrips aculeatus is reported as causer of such gall-like malformations

13b Leaves arched, with deflected margins, leaf blades curled and deep green close to infestation. Depending on leaf size, several to many, similarly disfigured leaves accumulated, almost nest-like, on ± stunted and distorted stems. Veronica spp.: Philaenus spumarius

14a Often minor, facultative malformations on various Veronica species are caused by various non-specific, differently coloured aphids, green, more rarely yellowish or reddish => 15

14b Similar malformations caused by black aphids. Veronica spp.: Aphis fabae

15a Antennae shorter than body, apterous aphids more or less dull coloured. Aphid 1–2 mm long => 18

15b Antennae of aphid as long as or distinctly longer than the very glossy body. Aphid often longer than 2 mm => 16

16a Siphunculi cylindrical or slightly conical, without swelling, 1/5–1/4 as long as body. Winged aphids with black head and thorax as well as with dorsal dark transverse stripes on abdomen, or only weakly pigmented => 17

16b Siphunculi in distal 2/3 distinctly swollen, 1/7–1/6 of body length. 1.6–2.0 mm, pale olive-coloured to greenish. Froth-covered milky coloured nymphs. Alates dark pigmented and with large, black central spot on abdomen. Veronica spp.: Myzus ascalonicus

17a Aphid pale straw-yellow, green or reddish; adult apterous often with dark spotted pattern. Siphunculi either completely or only terminally dark. Aphid about 1.9–3.1 mm long, alternating with Ribes species. Veronica spp.: Nasonovia ribisnigri

17b Light yellowish-green, base of siphunculi darker green. Siphunculi pale with blackish tip. Length 2–3 mm. Body pear-shaped, broadest distally. Veronica spp.: Aulacorthum solani

18a Siphunculi of apterous aphids black => 19

18b Siphunculi of apterous aphids yellowish-green with brown tip. Apterae rotund-oval, alternating with Rhamnus species. Veronica spp.: Aphis nasturtii

19a Siphunculi as long as cauda, body yellowish-green. Primary host Frangula dodonei. Veronica spp.: Aphis frangulae subsp. beccabungae

19b Siphunculi distinctly longer than cauda. All gradations from dark green to dirty-yellow are found in varying amounts. Veronica spp.: Aphis gossypii

20a Malformations covered with branched conidiophores => 22

20b The ± dense erinea consist of unbranched hairs of host plant => 21

21a Plant abnormally pubescent over extensive areas on leaves, stems and other green parts, sometimes additionally disfigured. V. alpina, chamaedrys, fruticulosa, officinalis, serpyllifolia: Aceria anceps

21b Similar, felt-like pubescence mainly on leaf blades. Paederota bonarota: Aceria bonarotae

22a Malformation of many leaves often over extensive areas ± etiolated shoots => 23

22b Malformations mainly on single or several terminal leaves, localised or expanded, bladder-like pale-green swellings. V. beccabunga, etc.: Peronospora grisea

23a On V. anagallis-aquatica: Peronospora aquatica

23b On other Veronica species. Depending on response ability of host, results in minor to ± distinct malformations. Conspicuous malformations only on early systemically infected organs, which show distinct etiolations:

a On V. agrestis, arvensis, chamaedrys, persica, polita, teucrium, verna:
Peronospora agrestis

b On V. hederifolia, triphyllos: Peronospora arvensis

24a Malformations bearing sori on their surface => 34

24b Galls without sori on their surface => 25

25a Single galls up to 3 mm long => 31

25b Galls usually longer => 26

26a Stem galls below the inflorescence or at least on the nodes of upper stem parts => 30

26b Galls predominantly on basal stem, exceptionally also on middle stem parts => 27

27a Causers are inside the galls => 28

27b Irregular spindle-shaped, sometimes curved swellings of variable length, with single or several rimmed depressions on their surface containing the causer. V. officinalis, chamaedrys: Planchonia arabidis

28a Galls with glabrous surface, containing larvae in chambers; V. serpyllifolia, Pseudolysimachion spicatum Galls with glabrous surface, containing larvae in chambers; V. serpyllifolia, Pseudolysimachion spicatum => 29

28b Stem with internodes or nodes with spindle-shaped, often ± curved and reddened swellings of variable length; surface of swellings undulately wrinkled. Causers inside galls. Similar, smaller galls sometimes on leaf veins. V. chamaedrys, etc.: Ditylenchus dipsaci

29a Shoots conspicuously stunted, in basal or middle parts with very irregularly shaped, about 3–7 mm long, nodular, one- to two-chambered galls. Each chamber containing a single larva. Mainly V. serpyllifolia: Gymnetron melanarium

29b Stem base, sometimes also root collar and upper root part, with conspicuous, rotund, up to about 12 mm long, one-chambered gall. Containing a single larva. Pseudolysimachion spicatum: Gymnetron erinaceum

29c Beetle larvae in locally strongly swollen stems. V. anagallis-aquatica: Gymnetron vittipenne

= Gymnetron aper has been reported as causing swelling of stem of V. officinalis

30a Shoot axis with spindle-shaped or acuminated, barrel-shaped to oblong cylindrical swellings, often distorted, up to 3 (4) mm thick. Smaller galls also on leaf- and flower peduncles, as well as on leaf veins; cells contain cinnamon-brown spore masses. Mainly on V. arvensis, hederifolia, triphyllos, also recorded from V. chamaedrys, filiformis, fruticans: Sorosphaerula veronicae

30b Shoot axis swollen below inflorescence. Pseudolysimachion spicatum: Jaapiella veronicae

= On Pseudolysimachion spicatum swollen leaf buds on stem (first midge generation) and flower buds (second generation) are caused by Dasineura spicatae

= Similar stem swelling, but associated with malformation of shoots or clustered flower buds, especially on higher growing species. Very variable galls of Jaapiella veronicae

31a Galls distinctly protruding at upper-, as well as on underside => 32

31b Leaf blade with rotund, up to 2 mm long spots, ± slightly swollen, at first dirty white, then brownish containing spores. V. serpyllifolia: Entyloma veronicae

32a Galls less than 1 mm across, wart-shaped; usually in large numbers on underside of basal leaves; sometimes on petioles and stems; solitary or joined, crust-like => 33

32b Leaf blade with reddish swellings on upperside. V. chamaedrys: Unidentified thrips

33a Multi-cellular warts, hemispherical, with depressed top. Nutritive cell with colourless content. V. anagallis-aquatica, beccabunga, chamaedrys, scutellata: Synchytrium globosum

33b Warts minute, coalescing into small brown-red spots. Galls simple, often hardly protruding; adjacent cells often not enlarged. V. scutellata: Synchytrium johansonii

34a Sori mainly on leaves, usually developing gregariously, protruding on underside, pad-shaped non facultatively – conspicuously swollen socket, covered with brown telia. Pads on leaf blade rotund, on upperside usually ± depressed; on venation oblong-oval to spindle-shaped on distinctly protruding bulges => 35

34b Sori usually ± elongate, chestnut-brown, mainly on variously distorted basal stem parts and on midribs on underside of more basal leaves. Spores glabrous or wall of upper cell with small warts. The mycelium developing telia usually expanded. V. alpina, aphylla, bellidioides: Puccinia albulensis

35a On V. montana, Pseudolysimachion spicatum, spurium. Sori pale brown, usually arranged in circles on sometimes weakly arched pads slightly sunken on upperside. Stalks of telia not brittle: Puccinia veronicae

35b Infestation similar. Sori developing in spring compact, pad-like arched on underside, depressed on upperside Teliospores thin-walled, with compact stalk. Sori with dark, thick-walled teliospores on brittle stalks develop in circles during summer. V. austriaca, ponae, Pseudolysimachion longifolium, spicatum, etc.: Puccinia albulensis

= The rare rust fungus Puccinia veronicae-longifoliae has also been recorded from Pseudolysimachion spicatum

36a On inflorescences or flowers => 39

36b Malformations on ovaries or fruits => 37

37a Ovaries unchanged outwardly. Malformation confined to ovula => 38

37b Ovaries strongly swollen, rotund-oval, sometimes with laterally ± shifted, arched, more rarely depressed apical part; galls ± globular, up to 6 mm across, wall succulent. Corolla and stamens dropping early. Containing a greenish tinged, dirty-yellow, black-brown headed larva, actively moving if disturbed. V. anagallis-aquatica, anagalloides, scutellata: Gymnetron villosulum

38a Stalk of ovary temporarily strongly swollen; other flower parts poorly developed. Tissue of entire ovary soon destroyed and filled with black, slightly brown-tinged spores. V. hederifolia, campylopoda: Schroeteria decaisneana

38b Ovaries temporarily swollen. Tissue inside soon replaced by a blue-grey to black-grey spore mass. V. acinifolia, agrestis, arvensis, persica, triloba, triphyllos, verna: Schroeteria delastrina

39a Flowers ± greened, leafy, also double or poorly developed, disfigured. Malformations often over ± extensive areas of inflorescence, sometimes abnormally pubescent. Caused by aphids or gall mites => 43

39b Flowers unopened, swollen => 40

40a Malformations caused by larvae which lack obvious, large head capsule => 42

40b Malformation mainly of the ovary caused by larvae with distinct head capsule => 41

41a In slightly swollen ovaries lives a seed-eating larva. Perianth of early infected flowers sometimes enlarged and unopened. V. beccabunga, scutellata, etc.: Gymnetron beccabungae

41b Also on V. anagallis-aquatica has been reported as causer of succulent ovary galls: Gymnetron veronicae

41c lowers unopened, swollen. V. arvensis, etc.: Gymnetron sp.

42a Flowers unopened, inflated, globular; each containing a single larva. When inflorescences are infected early, the largely undeveloped buds remain clustered, tuft-like; containing the orange-red coloured larvae. Veronica spp.: Jaapiella veronicae

42b Flowers swollen. Corolla slightly larger than calyx. Containing a single orange-yellow larva. V. anagallis-aquatica, beccabunga, scutellata, Pseudolysimachion spicatum, etc.: Dasineura similis

43a Malformations bearing aphids => 48

43b Malformations caused by gall mites => 44

44a Axis of inflorescence ± stunted; flowers variously disfigured => 47

44b Inflorescence not stunted or ± excessively branching; flowers disfigured => 45

45a Malformations without excessive branching => 46

45b Inflorescence ± excessively branched. Flowers ± greened or leafy, sometimes unopened, joined to almost cauliflower-like balls. Axial parts and calyx ± abnormally pubescent. V. chamaedrys, officinalis, prostrata, serpyllifolia, etc.: Aceria anceps

= Almost witches’ broom-like malformations with severely disfigured greened and leafy flowers on Pseudolysimachion longifolium could not be attributed to a particular cause

= Greening of flowers on V. persica is caused by viruses

46a Flowers double by multiplication of corolla leaves. In axils of corolla leaves sometimes short-stalked buds or similarly disfigured flowers. Stamens and ovaries aborted. V. officinalis: Unidentified gall mite

46b Flowers greened, calyx lobes ± enlarged and thickened. Paederota lutea:
Unidentified gall mite

47a Upper part of inflorescence with shortened midrib. Flowers ± greened. Bracts reduced. Pseudolysimachion longifolium: cf. Aceria anceps

47b Rachis of inflorescence and flower peduncles shortened, flowers clustered; calyx ± abnormally pubescent; other flower parts normal. V. alpina, bellidioides: Aceria anceps

48a Axis of inflorescence stunted and ± distorted. Flowers clustered, ± unopened, disfigured. Pseudolysimachion longifolium, spicatum: Aphis pseudolysimachiae

48b Stalk of inflorescence stunted. Flowers poorly developed; clustered, ball-like. V. anagallis-aquatica: Aphis frangulae subsp. beccabungae

gallers on Trifolium

pub 22.xi.2019

Dichotomous table for gallers on Trifolium

by Hans Roskam

1a On above ground organs => 4

1b On roots => 2

2a Roots with lateral nodules, or swellings situated on all sides in the root body => 3

2b Roots externally hardly changed, temporarily bearing about poppy-seed sized egg capsules (cysts), at first white, soon brown, which drop at maturity. Giant cells develop at the infestation site. Plant atrophied, with “starvation roots”. Trifolium spp.: Heterodera trifolii

3a Roots with nodular or slender spindle-shaped swellings on all sides, up to 6 mm long, bearing several lateral roots. T. alexandrinum, hybridum, incarnatum, pannonicum, pratense, repens, etc.: Meloidogyne hapla

3b Rotund-oval to slender cylindrical or forked nodules, also coralloid branched, up to 5 mm long, laterally inserted on main- or adventitious roots. Trifolium spp.: Rhizobium trifolii

4a On inflorescences, flowers or fruits => 25

4b On vegetative organs => 5

5a Localised malformations on stems, buds, leaves or more expanded malformations on single shoots => 6

5b Complete plant stunted, often excessively leafy. Shoots, also leaf- and inflorescence stalk stunted, usually spongy thickened at base; organs clustered, often distorted. Leaf blades reduced, swollen, sometimes extensively twisted, undulate or brittle. T. arvense, campestre, dubium, hybridum, incarnatum, medium, pratense, repens: Ditylenchus dipsaci

= Witches’ broom-like malformations lacking spongy thickenings on T. repens have been described as virus disease

6a Malformations on stems or leaves, caused by fungi, which develop their distinctive fruiting bodies at the surface of the host organs => 17

6b Galls caused by animals or by fungi, which fruit inside the host tissue => 7

7a Galls on leaf blades or -stalks, sometimes additionally also on stems => 12

7b Pronounced stem galls or malformations on buds => 8

8a Bud galls => 11

8b Stem galls => 9

9a Galls always on higher situated stem parts => 10

9b Stem with spindle-shaped swellings, up to 6 x 2.5 mm, on root collar or on higher situated parts. Containing a single larva. T. arvense, aureum, campestre, dubium, hybridum, pratense, spadiceum: Catapion pubescens

= Catapion curtisii has been recorded from oval swellings (6 x 3 mm) in root collar or root. T. fragiferum, repens

= Conspicuous proliferations on root collar by the polyphagous wood cancer Agrobacterium tumefaciens have also been reported for Trifolium

10a Galls spindle-shaped to ± cylindrical; sometimes developing to twice the stem diameter. T. hybridum, medium, pratense, etc.: Catapion seniculus

10b Stem often with several one-sided, almost hemispherical galls, sometimes clustered or coalescing. Each containing a single larva. T. arvense, pratense: Protapion varipes

11a End- or lateral buds transformed into a usually flattened egg-shaped gall, up to 8 mm long and 5 mm thick, succulent, one-chambered, yellowish-green, sometimes reddish at tip and ± enveloped by the associated enlarged stipules. Containing a rugose yellow larva with distinct brown head capsule. T. alpestre, arvense, aureum, campestre, medium, pratense, striatum, subterraneum, etc.:
Tychius polylineatus

11b Similar galls in lateral buds of T. medium and also T. fragiferum, purpureum, scabrum. Containing a single red midge larva. Dasineura axillaris

12a Single galls about 1 mm across, golden-yellow translucent, sometimes coalescing into crusts or ridges or hyaline to brown, 0.5–3 mm long. Caused by fungus => 16

12b Malformations larger => 13

13a Leaves ± folded and simultaneously variously twisted or curled => 15

13b Leaflets without particular curling, folded upwards over the midrib. Galls especially at midrib; their wall conspicuously or hardly thickened => 14

14a Galls bilge-like swollen; their wall conspicuously ± succulent to cartilaginous thickened, glabrous or slightly rugose, pale-green or reddened. Gall body on many hosts with ± broad, not thickened margin. Larvae at first white, later on orange- to reddish-yellow. Trifolium spp.: Dasineura trifolii

14b Galls restricted to the central part of the leaf blade, always surrounded by a broad margin of not thickened leaf blade tissue. Wall only slightly thickened, sometimes pale-green, also red discoloured, browned if mature. Containing 1–2 (3) pale yellow to pale orange-red larvae. T. pratense: Tricholaba trifolii

15a Leaf blade of leaflet folded together upwards or loosely rolled inwards; not or slightly thickened, twisted and ± undulately curled. Trifolium spp.: Aceria trifolii

= he gall mite Aculops eximius causes rust on mediterranean T. ochroleucon, pratense

15b Malformations of clustered leaves on locally stunted shoots caused by a froth-covered nymph. T. pratense: Philaenus spumarius

15c Leaves stunted; leaf blades of leaflets constricted, upwards ± folded together. T. dubium: Unidentified thrips

16a Galls consist of several cells, hemispherical, greenish-yellow, ± golden-yellow translucent, the depressed nutritive cell containing an overwintering sporangium about 160 (‒180) μm large; usually in large numbers mainly on the leaf blades of basal leaves, on their ± distorted stalks and sometimes on their lower stem parts. T. dubium. pratense, repens: Synchytrium aureum

16b Warts hyaline, 0.5–1 mm across, with sporangia and perennial spores. Galls unopened for a long period; later on rupturing in the middle; usually many on leaves as well as on the additionally disfigured stems, leaf- and inflorescence stalks. T. hybridum, incarnatum, montanum, repens: Physoderma trifolii

16c In similar galls on ± distorted leaves, leaf- and inflorescence stalks. T. hybridum, montanum, repens: Olpidium trifolii

16d Petioles and leaf veins, also inflorescence stalks, with several, usually elongate-oval, 2–3 mm long, soon discoloured black-brown, occasionally coalescing swellings; the bearing organs ± arched, bulging. T. fragiferum: Physoderma vagans

= Enatia on leaf undersides on T. incarnatum and other Trifolium species are caused by the Pisum-Virus I

17a The usually bulging galls bear yellowish aecia or dark coloured sori. Galls caused by rust fungi => 18

17b Leaf blades of developing leaves with inconspicuous weak archings, usually expanded, pale-green, bearing a down of branched conidiophores on leaf undersides. “False mildew”. The fungi which are ± frequent on several clover species are very specialised and may be assigned according to biometrical characters to the following micro-species:

a On T. alpestre: Peronospora trifolii-alpestris. – Minor swellings have sporadically been recorded

b On T. arvense: Peronospora trifoliorum. – Galls not observed

c On T. campestre, dubium, spadiceum: Peronospora trifolii-minoris. – Galls not observed.

d On T. hybridum, strictum: Peronospora trifoliorum. – This fungus exceptionally causes minor bulgings; especially on T. hybridum

e On T. medium, incarnatum: Peronospora trifoliorum. – Gall-like arching of leaf only rarely observed. Fungus especially distributed on the often conspicuously etiolated T. medium

f On T. pratense: Peronospora trifoliorum. – Fungus usually only in small pale-green spots on undersides of leaves that are not disfigured.

g On T. repens: Peronospora trifoliorum. – Occasionally the mycelium causes minor archings

18a Malformations bearing aecia, usually also other spore forms present => 22

18b Malformations bearing uredinia, or telia, no spermogonia or aecia => 19

19a Sori contain uredinia as well as telia => 20

19b Oblong swellings, sometimes associated with conspicuous distortions on underside of leaf veins or on petioles; bearing only telia. Mainly occurring on T. fragiferum, repens; also recorded from T. alpestre, arvense, aureum, dubium, etc.: Uromyces trifolii

19c Similar malformations are sometimes caused on T. repens: Uromyces trifolii-repentis

20a In addition to aecia, fungi also develop on sometimes distinctly different malformations, in some species also facultatively cecidogenic, spore forms on Trifolium species. Parasites not positively distinguished according to the malformations => 22

20b Fungi host alternating; develops only on the veins or stems on Trifolium, sometimes facultatively weakly cecidogenic uredinia and telia => 21

21a Sori usually mainly on leaf underside, scattered over the leaf blade, only causing minor swellings and sometimes distinct archings if developing on the venation. T. arvense, aureum, campestre, dubium, micranthum, striatum and close relatives: Uromyces striatus

21b Similar, minor malformations, facultatively on venation T. campestre, dubium, scabrum: Uromyces jaapianus

22a Fungi; all spore forms develop on Trifolium species. Telia only with warts, solitary or arranged loosely in rows => 24

22b Fungi do not develop uredinia => 23

23a Fungus mainly on T. montanum. Aecia often densely arranged in slightly swollen pads, especially on venation, up to 10 mm long. Also recorded from T. angustifolium: Uromyces minor

23b Fungus living on T. repens. Aecia on leaf veins and -stalks usually on distinct longitudinal swellings and malformations, occurring on leaf blades in small, circularly arranged groups: Uromyces trifolii

= Stems and leaflets bearing aecia, telia and uredinia on T. pratense, medium, incarnatum have been assigned to Uromyces fallens

24a Aecia only in spring, usually rare. Aecia mainly in elongated groups on underside of ± swollen and curved leaf veins, more rarely on bulges on petioles and stems; spermogonia usually on leaf upperside. Cups with whitish lacerate margin. Trifolium spp.: Uromyces trifolii

24b Aecia from spring to late autumn. Spermogonia occurring between aecia, often on same petiole. Cups circularly arranged in small dense groups; oblong on veins, leaf- and inflorescence stalks, often causing yellowish discoloured bulges and distortions. Peridium cup-shaped, with narrow, finely lacerate margin. T. repens, fragiferum, etc.: Uromyces trifolii-repentis

25a Localised malformations caused by fungi, gall midge larvae or snout beetles => 26

25b Extended malformation usually of many inflorescences. Flowers ± twisted; calyx teeth strongly developed; corolla stunted, disfigured, ± greened or also sometimes largely leafy, like the stamens and ovaries. T. arvense, aureum, campestre, dubium, hybridum incl. subsp. elegans, medium, montanum, pratense, repens, spadiceum, striatum: Aceria trifolii

= The flower thrips Frankliniella intonsa has also recorded from Trifolium.

= On several Trifolium species, especially T. repens, more rarely T. hybridum, incarnatum, pratense, occur conspicuously disfigured, greened, leafy inflorescences. These are caused by viruses, transmitted by cicadellids

26a Malformations contain larvae with distinct head capsule => 29

26b Malformations caused by midge larvae or fungi => 27

27a Galls inhabited by midge larvae => 28

27b Flowers unaltered externally. Ovary slightly stunted and swollen, sometimes covered with conidia. T. pratense: Thecaphora deformans

28a Flower buds in capitula where oviposition has been early are severely stunted. Corolla unopened and usually shorter than calyx teeth; like the calyx, distinctly swollen, especially at base. Sex organs atrophied. Inside at first white- to yellowish, at maturity pink-coloured larvae. T. pratense, medium, less frequently on T. hybridum and some other related species: Dasineura leguminicola

= In flowers of T. repens, more rarely T. hybridum, pratense lives the white clover midge Dasineura gentneri. Because this midge deposits eggs in already developed flowers, galls are not induced.

28b Similar malformation. The infected flowers are less swollen. Also these remain unopened, but the corolla surmounts the calyx teeth. Larvae orange- to ochre-yellow, jumping. T. pratense, occasionally also T. medium, hybridum, repens: Tricholaba trifolii

28c Yellow larvae in swollen flower buds. T. medium: Hadrobremia longiventris

29a Often only minor malformations mainly to parts of flowers; only secondarily sometimes also the midrib of the inflorescence => 32

29b Gall formation primarily affects the inflorescence axis => 30

29c Flowers greened, larvae living inside the stalk in a long corridor. T. repens, pratense: Hylastinus obscurus

30a Malformations of T. arvense, hybridum, ochroleucon, pratense, repens => 31

30b Inflorescence stalk terminally swollen to a small, asymmetrical gall. Containing a single larva. T. dubium: Protapion filirostre

31a Axis of inflorescence swollen. Calyx of affected flowers at first turgid. Containing single or several larvae. T. arvense, pratense, repens: Protapion dissimile

31b Similarly living on T. ochroleucum, pratense, more rarely on T. hybridum, repens, etc. are the larvae of Protapion dissimile

31c Infected inflorescences about a half times broader than normal ones; terminally truncated, otherwise looking normal, apart from the discoloured calyx which is often entirely pale-green. Containing 1 (2–3) larvae. T. arvense: Tychius pusillus

32a Inflorescences largely disfigured => 33

32b In often conspicuously damaged capitula, usually only single parts are galled. Gall-like malformations usually involving flowers on which eggs are deposited by snout beetles. Calyx often swollen, belly-like, on one side, the axis of inflorescence usually remains normal. Usually several larvae per inflorescence. Trifolium spp.: Apion div. species:

a Flower galls in disfigured inflorescences. Mainly on T. repens, also on T. aureum, hybridum, medium, pratense: Protapion fulvipes

b Flower malformations on T. repens, also on T. alpestre, medium, ochroleucon, pratense, rubens: Protapion trifolii

c In hardly disfigured flowers of T. repens, etc.: Protapion nigritarse

d In disfigured capitula with densely clustered flowers on T. medium, montanum, pratense might develop: Protapion varipes

e As inducer of bud galls on several Trifolium species has also been recorded: Holotrichapion pisi

= Larvae of the curculionid beetle Hypera nigrirostris may cause galls on clover

33a Young inflorescences, usually developing from axils or several flowers variously transformed into a uniform succulent gall. Infestation of larger, older flower buds results only in strong stunting of corolla and ± distinct bladder-like swelling of calyx. Containing a single yellow larva. Galls variable, depending on condition of host. On T. arvense mainly as bud gall; similarly also on T. subterraneum. Larvae also known from T. alpestre, aureum, campestre, medium, pratense, strictum. Tychius polylineatus

33b Inflorescence compact. The infected flowers soon transformed into a hardening, ± knobby mass. Containing several larvae. T. medium, montanum, pratense: Protapion apricans

gallers on Rumex

pub 22.xi.2019

Dichotomous table for gallers on Rumex

by Hans Roskam

1 On parts above ground => 9

1b On roots, rhizomes or root collar => 2

2a Rotund to spindle-shaped swellings containing causers in well-defined chamber or tunnel => 5

2b Galls compact, lacking chambers or feeding tunnels => 3

3a On roots => 4

3b Conspicuous, at first whitish, later on browned, succulent proliferations on root collar, eventually decaying. R. acetosella: Agrobacterium tumefaciens

4a Roots with slender spindle-shaped swellings, up to 7 mm long, sometimes bearing side roots. R. acetosella, crispus: Meloidogyne hapla

= Among the cyst developing Heterodera species, which cause development of giant cells inside roots, H. schachtii has been recorded

4b Expanded, globular, tuberous or ± barrel-shaped proliferations on roots, up to 20 mm thick and 30 mm long, which originate from enlarged and multiplied host cells. In cavities, together with many thick- and brown-walled, globular perennial spores, up to 46 µm large. R. scutatus: Physoderma ruebsaamenii

5a Swellings oblong or rotund, with single to several larval chambers => 6

5b Oblong, irregular expanded swelling on root, up to 15 mm long or more. Feeding tunnel elongate; containing a slender, dirty-white caterpillar with dark dorsal stripe and black-brown head. R. acetosella: Pyropteron triannuliformis

6a Galls more than 10 mm long, usually multi-chambered => 8

6b Galls only rarely up to 10 mm long, usually one-chambered => 7

7a Rotund, one-chambered or composite, multi-chambered galls on rhizomes, roots, rarely on root collar oblong, up to 10 mm long. Containing a single white larva. R. acetosella: Apion frumentarium

7b Oblong, rotund swelling on roots. Rumex spp.: Apion frumentarium

8a Galls on upper part of roots or root collar, very irregularly shaped, usually variously coalesced into tuberose, ± gnarled complexes, rotund- to oblong-oval, 10–30 mm long with several, irregular, crossing feeding tunnels. R. acetosella: Perapion marchicum

8b Swelling containing one or two chambers. R. acetosella: Apion rubiginosum

8c Irregularly rounded, succulent swellings on upper root part or on root collar, about 15 mm long and 10 mm thick, one- to multi-chambered. R. acetosa: Apion sp.

9a Galls restricted to single plant parts; on leaves, stems, inflorescences or fruits => 16

9b Gall development localised or diffuse, usually on several plant parts => 10

10a Galls caused by smut fungi, their pale- to dark violet spores translucent and dusty later on => 13

10b Galls induced by other causes => 11

= (Regarding malformations caused by animals living on host surface, see lead 29)

11a Causers develop inside galls => 12

11b Mycelium overwintering in rhizome, grows together with above ground plant parts and develops very dense, violet-grey down of branched conidiophores on completely covered leaf undersides, stem of inflorescence and flower parts. Diseased leaves are erect and rigid, leaf blades reduced, pale-green or reddened, slightly thickened, at margin usually distinctly rolled downwards. Inflorescences and flowers reduced, variously disfigured. R. acetosa, acetosella, alpestris, scutatus, thyrsiflorus, rarely crispus: Peronospora rumicis

12a Scattered swellings on basal-, more rarely on stem leaves, up to about 1 mm broad, flat, rotund, red-brown; coalescing on stems, often developing long knobby bulges. Rumex spp.: Physoderma majus

12b Young plants severely stunted, petioles and midribs, basal leaf blade parts, as well as stem primordia, including inserted organs, disfigured, pale green and thickened, spongy. Gall surface ± wrinkled. Later infestation results in development of ± localised galls on leaves and stems. R. acetosa, acetosella, crispus: Ditylenchus dipsaci

13a On several R. acetosa, acetosella, alpestris, thyrsiflorus, etc => 14

13b On R. longifolius, obtusifolius. Conspicuous, usually contiguous pustules, often on leaf margins; galls also on stems and especially on stems of inflorescences and flowers. Infected inflorescences usually completely diseased. Perigone, filaments and ovaries thickened and ± enlarged: Microbotryum warmingii

14a Malformations are inconspicuous swellings => 15

14b Infected plants largely diseased, often crippled, curved, usually sterile. Stem, inflorescence, petioles often distinctly shortened, ± distorted, conspicuously swollen to bloated, with many sori of dark brown-violet spore masses. Leaf blades often hardly unfolded, curved, main veins swollen, distinctly protruding on underside. R. alpinus, maritimus, obtusifolius, palustris: Microbotryum parlatorei

15a Weak swellings on leaves, stems, inflorescence stalks and flowers: Microbotryum kuehneanum

15b Sori inconspicuous, grey-reddish, in pale, thickened leaf blades and -stalks, only rarely in stems and flowers: Microbotryum goeppertianum

16a On inflorescences, flowers or fruits => 33

16b On vegetative parts => 17

17a On leaves => 20

17b On stems and stalks of inflorescences => 18

18a Galls ± spindle-shaped, 10–30 mm long, glabrous, tough-walled with central larval chamber => 19

18b Stem- or inflorescence axis at any point, and occasionally on all sides, weakly thickened; often many feeding tunnels in pith. Larvae whitish. R. acetosa, also on R. conglomeratus, crispus, nemorosus, obtusifolius, patientia, pulcher, etc.: Perapion violaceum

18c Rotund to irregular spindle-shaped swellings mainly of internodes, also on nodes and inflorescence axis, on all sides or sometimes on one side, 5–20 (30) mm long. R. acetosa, etc.: Perapion affine

18d In similar stem galls, e.g., on R. acetosella, hydrolapathum: Apion frumentarium

19a Short to extensive bulging swellings containing pale to dark-violet spore masses 13

19b Stem over variable length stunted on one or all sides and swollen, spongy. Surface ± wrinkled. If infected on one side then ± distorted. Side organs at infestation site clustered and variously galled as well. R. acetosa, crispus, obtusifolius: Ditylenchus dipsaci

20a Extensive malformations, even on large parts of whole leaf blades => 27

20b Gall formation at least of leaf veins, and -stalks or consists of locally restricted, ± rotund or oval galls on leaf blades => 21

21a Galls on leaf blade, often rotund, caused by fungi => 24

21b Spindle-shaped swellings on midrib, rarely on petioles, caused by animals => 22

22a Galls rather constant in size, spindle-shaped, surface glabrous. Containing causers in distinct cavities => 23

22b Midrib over variable length spongy, swollen, malformation ± encroaching onto neighbouring leaf blade areas, often pale-green, with wrinkled surface, Occasionally on petioles. Gall chamber absent. R. acetosa, crispus: Ditylenchus dipsaci

23a Midrib or petiole with spindle-shaped, yellow or red swelling, up to 10 mm long and 5 mm thick, often surrounded by a similar discoloured area. Containing an orange-coloured larva. R. acetosa, acetosella, crispus, ? hydrolapathum, patientia, thyrsoides: Apion frumentarium

23b Swelling in midrib or petiole; containing weevil larva or pupa. R. acetosella: Apion rubens

23c From similar galls on:

a R. acetosa, acetosella, etc.: Perapion curtirostre

b R. conglomeratus, sanguineus, etc.: Apion frumentarium

24a Rotund, more than 3 mm long, usually made conspicuous by red colouration, often hardly gall-like thickened pad caused by the aecia developing mycelium of rust fungi => 25

24b Less than 1 mm long, on the underside of leaf blade usually many flat, colourless, usually 1-celled small warts; also on leaf veins, -stalks. R. acetosa: Synchytrium anomalum

25a Aecidiospores 15‒21 x 12‒18 μm, orange-red when fresh, membrane uniformly with fine warts. Cells of peridium with narrow curved lumen; outer wall reaching far downwards => 26

25b Aecidiospores, diam.16‒26 μm, white. Membrane with fine and also scattered coarse warts. Aecidiosori on leaf underside on up to 10 mm broad, crimson-red, often yellow or pale red bordered spots, wide cup-shaped with white, deflected margin. Cells of peridium in longitudinal section with almost orthogonal lumen; outer wall with only short continuation downwards. Spermogonia whitish to pale-yellow, mainly on leaf upperside. On R. acetosa, etc.: Puccinia phragmitis

26a On R. acetosa, acetosella. Aecia on leaf blades on rotund, 2–5 mm broad, often crimson-red, hardly gall-like thickened spots, often arranged in a circle, mainly on leaf underside. Peridium whitish-yellow, with irregularly lacerate, hardly deflected margin. Sori on main veins and petioles, however, oblong-oval, on often distinctly swollen pads: Uromyces acetosae

26b On R. alpinus. Aecia like those of previous fungus. Spermogonia undescribed: Uromyces acetosae

27a Curling of leaf or –rolls caused by aphids => 31

27b Malformations of leaf blade by other inducers => 28

28a Caused by animals => 29

28b Caused by fungi. Leaves rigidly erect, leaf blades reduced, pale-green, margin ± narrowly rolled inwards, densely covered by grey-violet down of branched conidiophores on underside. R. acetosa, acetosella etc.: Peronospora rumicis

28a Leaf blade variously disfigured or rolled, caused by psyllids => 30

29b Leaf blade usually deflected over tip or laterally loosely rolled, strongly curled and deep green, especially at infestation site. Containing one or more froth-covered nymphs. Rumex spp.: Philaenus spumarius

29c Leaves wrinkled with erinea on underside. R. acetosella: Aculops macrotuberculatus

30a Restricted or extensive downward roll of leaf margin, ± thickened and leather-like. R. acetosella, acetosa, alpinus, scutatus: Trioza rumicis

30b Sorrels of Section Acetosa, Acetosella. Leaves variously disfigured, distorted, reddened, often with deflected margins. R. acetosa, acetosella, scutatus, etc.: Aphalara exilis

30b On Section Rumex, leaf curled downwards, discoloured; with small depressions each containing a froth-covered nymph. R. obtusifolius: Aphalara ulicis

= Furthermore the psyllid Aphalara purpurascens causing enclosed galls on disfigured leaves has been recorded. On R. aquaticus, conglomeratus, crispus, longifolius, obtusifolius

31a Leaf blade curled, also ± rolled or twisted => 32

31b Leaf blades rolled downwards over their length, tube-shaped. Rumex spp.: Aphis rumicis

32a Leaf blade parts strongly curled, irregularly rolled downwards at margin, leaf blade insignificantly thickened and swollen. Aphids black. Rumex spp.: Aphis fabae and/ or Aphis fabae subsp. solanella

= Bulging of leaf blades may primarily be caused by virus

32b Aphid green, leaves twisted, plant stunted, sometimes excessive leafiness. R. acetosella: Brachycaudus helichrysi

33a Galls restricted to flowers or their parts; axial parts only secondarily involved => 39

33b Malformation of ± large parts of inflorescence, flowers included => 34

34a Animal causers => 36

34b Malformations caused by fungi => 35

35a Inflorescence with all parts ± stunted. Buds clustered into dense groups, soon, like also the axial parts, covered with violet-grey down of branched conidiophores. R. acetosa, acetosella and relatives: Peronospora rumicis

35b Usually all flower buds of a plant swollen, variously disfigured. Inner organs soon destroyed by a black-violet, later on slightly dusty spore mass. R. acetosa, alpinus, thyrsiflorus: Microbotryum stygium

36a Caused by psyllids, larvae of beetles or gall midges => 37

36b Internodes stunted, side shoots and flowers ± densely clustered. R. thyrsiflorus, rugosus, etc.: Aphis acetosae

36c Inflorescences stunted; organs clustered like the neighbouring, disfigured stem leaves, bearing many reddish aphids. R. acetosella: Brachycaudus rumexicolens

36d Similar malformation on R acetosella: Unidentified aphid

36e Similar, but often much more extensive malformation. Rumex spp.: Philaenus spumarius

37a Causers live between or in stunted flowers => 38

37b Axis of inflorescence ± shortened and thickened. Flowers clustered, ± stunted and sterile. Containing beetle larvae. R. obtusifolius etc.: Apion sp.

38a Axis shortened; flowers densely clustered, little disfigured; bracts sometimes excessively developed. Between the flowers lives a psyllid. R. acetosella: Unidentified psyllid

38b Axis severely stunted; ± thickened, curved. Flowers clustered in dense balls, disfigured. Larvae reddish. R. acetosa, acetosella, etc.: Jaapiella rubicundula

38c Male flower buds contain midge larvae. R. acetosella: Contarinia rumicina

39a Galls mainly or exclusively on ovaries or fruits => 41

39b Ovaries distorted, gall consists of perigone => 40

40a Flower buds shortly stalked as result of infestation; therefore ± clustered, twice as large as healthy ones; oblong, irregularly bulging, yellowish to reddish. Stamens and ovaries distorted. R. acetosella, pulcher, maritimus: Contarinia rumicis

40b Galls similar. Larvae yellowish-white to orange-coloured. R. acetosa, acetosella: Contarinia acetosellae

41a Galls caused by animals => 42

41b Ovaries transformed into a conspicuous cylindrical or club-shaped gall, up to 3 mm long, 1 mm broad. Containing in nutritive cell 1–3 perennial spores with brown content. R. acetosella: Physoderma acetosellae

42a Malformations in outline ± oval, caused by gall midge larvae => 43

42b Ovaries usually greatly elongated, up to 25 mm long, transformed into a closed tube, or more rarely, with all transitions, into a ± stalked open funnel or cup. Often with 3 lobes at top. Perigone slightly enlarged. Stamens ± aborted. R. alpinus, scutatus: Trioza rumicis

43a Fruit or ovary, including flower, disfigured. Larvae between ovary and ± outwardly bent perigone, sometimes living in fruits. R. acetosella, obtusifolius, scutatus: Contarinia scutati

43b In similar malformations: Contarinia variabilis

gallers on Cirsium

pub 21.xi.2019

Dichotomous table for gallers on Cirsium

by Hans Roskam

1a On above-ground organs => 3

1b On roots => 2

2a Lateral roots with nodule-shaped, 2–3 mm across. C. arvense, oleraceum: Meloidogyne hapla

2b Main root or basal stem part with spindle-shaped swelling, up to 50 mm long and 10 mm thick. Contains a single larva. C. arvense, oleraceum, vulgare, etc.: Cleonis pigra

= The slightly cecidogenic caterpillar of Epiblema scutulana in stems and roots of various Asteraceae might also be responsible for root galls on Cirsium

3a On capitula or florets => 30

3b On stems or leaves => 4

3c Stems and leaves with white blisters, sometimes crust-like. C. oleraceum:
Pustula obtusata

4a Malformations restricted to single plant parts or to parts of shoots => 6

4b Malformations of expanded shoot parts of entire plants => 5

5a Plant completely stunted, ± disfigured; with expanded, or merely local, pale green, spongy swellings on all parts. C. arvense, oleraceum, tataricum: Ditylenchus dipsaci

5b Complete plant etiolated; development initially proceeding, later on stunted. Rosette leaves distinctly erect, lanky, usually non-flowering. Leaf blades narrowed, pale green, less spiny, occupied on both sides by many, sweet smelling widely distributed honey-yellow pycnidia, which are followed by initially reddish-brown uredinia and later on by black brown telia; only on C. arvense:
Puccinia punctiformis

6a Malformations exclusively or mainly on leaves => 10

6b Malformations predominantly on stems => 7

7a Swellings ± slender spindle-shaped => 8

7b Main- or side shoots with large, rotund or oblong multi-chambered swellings, about 10–50 mm long and 5–20 mm thick, initially green and succulent, later browned and woody. Each chamber contains a single larva. C. arvense, scattered on C. oleraceum: Urophora cardui

7c Facultative malformation of stem. Cirsium spp.: Ceratapion carduorum

8a Stem with extensive malformations => 9

8b Knob-like thickenings on root collar or on higher situated branchings. C. vulgare: Acanthiophilus helianthi

= All-sided, 10 cm long, inconspicuous stem swelling above the ground. Containing many amber-coloured puparia of an unidentified dipteran. Presumably a gall-like stunting caused by the larvae of a leafminer belonging to Melanagromyza

9a Stem terminally ± stunted and slightly thickened; tip of shoot stunted, closed. The pith contains a greenish, black-headed caterpillar. C. arvense, vulgare: Unidentified lepidopteran

9b On C. palustre. Swelling just below a clustered group of stunted capitula, containing a dirty red caterpillar: Epiblema scutulana

9c Stem over extensive parts usually spongy and swollen on one side, and sometimes distinctly curved. Galls with ± rugose surface, pale green; predominantly either close to the ground or close to the inflorescences. Cirsium spp.: Ditylenchus dipsaci

= The weevil Ceutorhynchus litura causes a malformation of 30–40 mm long on stem which becomes hardened and inflated, containing up to 12 larvae

10a Malformations with fungi fruiting on the outside => 28

10b Malformations caused by fungi fruiting on the inside of the galls, or caused by animal inducers => 11

11a Malformations of leaf margins or of leaf blades => 15

11b Malformations of the venation, sometimes ± widely extending into the unrolled leaf blade => 12

12a Galls restricted to the venation => 13

12b Main- or lateral veins to varied extents spongy, swollen and discoloured pale green together with their additionally sometimes ± clustered, also curled, surroundings. Cirsium spp.: Ditylenchus dipsaci

13a Main venation with ± extensive spindle-shaped swellings, situated predominantly on the leaf blade => 14

13b Midrib of the basal half of the rosette leaves slightly swollen. One to several larvae inside, tunnelling, more rarely mining. C. palustre, vulgare: Phytomyza continua

14a Galls spindle-shaped, usually brighter rimmed, with a single larva inside; gall rapidly collapsing and browning after the larvae have departed. C. arvense, tataricum, oleraceum, palustre, vulgare: Unidentified gall midge

14b Spindle-shaped bulges, about 2–12 mm long, yellowish to bright green, compact, glabrous, ± vitreous, sometimes in rows situated on the underside of the leaves; occasionally many small bulges on the basal stem parts. Sporulating close to the vascular bundle. C. oleraceum: Protomyces cirsii-oleracei

15a Leaves with either many, sometimes coalescing, hardly 1 mm long warts, or with very narrow rolls of the leaf margin => 24

15b Leaf blades with different malformations => 16

16a Extended malformations caused by aphids or cercopids => 20

16b Galls caused by other inducers => 17

17a Leaf blade with many small depressions or with pustule-shaped galls => 19

17b Leaf blades with irregular curls or folds => 18

18a Leaf margin ± folded or rolled, on the underside with several groove-like depressions, at first with a flat froth-covered nymph; leaf tip also folded, curled, or rolled. C. arvense, helenioides, oleraceum, etc.: Trioza viridula

18b Similar galls, on C. arvense, erisithales, heterophyllum, oleraceum, palustre: Trioza cirsii

18c Downward leaf roll, loosely undulate curled and tuberculate on the upper side. Leaf blade uneven, sometimes additionally with hairs. C. arvense, oleraceum: Trioza agrophila

19a Leaf blade with small depressions on the underside, with corresponding elevations on the upper side. C. helenioides: Trioza viridula

19b Leaf blade with green pustules. Containing a single midge larva. C. helenioides: Unidentified gall midge

20a Malformations caused by aphids => 21

20b Leaf blade, according to size, partially or completely and variously contracted; locally strongly curled and dark green. Infestation of young stems results in stunting, bending and clustering of neighbouring ± curled leaves. Cirsium spp.: Philaenus spumarius

21a Malformations caused by brown-black to dull black aphids => 23

21b Aphids yellow or dark red-brown => 22

22a Malformation of leaves caused by yellow aphids living on the underside. C. tataricum, oleraceum: Capitophorus horni

22b Aphid large, about 4 mm long, dark red brown, with transverse rows of black dots. Leaf blade curled, rolled, sometimes more densely haired. Heavier infestation may result in conspicuous stunting of young shoots. C. arvense, oleraceum, palustre, rivulare, vulgare: Uroleucon cirsii

23a Aphids about 1.5 mm long, brown-black, slightly powdered. Antennae half the body length. Siphunculi short, conical, slightly longer than cauda. Leaves rolled upward. C. oleraceum. pannonicum, ? canum: Aphis cirsiioleracei

23b Aphid about 2.5 mm long, dull black, rarely brown-black; antennae half the body length; siphunculi longer than the cauda. Affected leaves ± curled and bent downward. Strongly infected shoots variously stunted. Malformations not specific for the inducer. Following species host alternating, only distinguished by microscopical characters. Cirsium spp.:

a Aphis fabae s.s.

b Aphis fabae subsp. cirsiiacanthoidis

c Aphis fabae subsp. evonymi

24a Galls wart-shaped, consisting of several cells => 26

24b Roll of leaf margin => 25

25a Leaf margin narrowly rolled upwards and inwards. Larvae yellowish. C. oleraceum: Unidentified gall midge

25b Leaf margin narrowly rolled downwards and inwards. C. oleraceum:
Unidentified gall mite

26a Warts of conspicuous colour; content of nutritive cell yellow to red => 27

26b Content of nutritive cell colourless. Warts compact, vitreous green, pearl-like, often in large numbers on the underside of the leaves; sometimes coalescing into crystalline crusts. C. oleraceum: Synchytrium globosum

27a Galls compact, golden-yellow translucent; many on the underside of the basal leaves, scattered or ± coalescing. C. helenioides, oleraceum: Synchytrium aureum

27b Galls compact, reddish; on the underside of the rosette leaves, often coalescing into expanded yellowish- to blood red crusts. C. palustre: Synchytrium sanguineum

28a Sori with brown spores => 29

28b Sori with aecia, often several on the leaf underside, ± yellow or reddish margined; sometimes with oblong-oval shape on the major veins and only here facultatively inducing minor swellings. Cirsium spp.: Puccinia dioicae

29a Leaf blade on the underside with many small uredinia and telia. Fungus with two kinds of uredinia. The primary uredinia, accompanied by pycnidia, develop on the venation, sometimes on slight, bulge-like swellings. Cirsium spp.: Puccinia calcitrapae

29b Leaf blade with conspicuous sori, up to 5 mm wide, rotund, compact, initially yellowish-white, on the underside often clearly arched, soon coalescing bearing telia. Galls facultative. Cirsium spp.: Puccinia cnici-oleracei

30a Malformation primarily of receptacle. The gall causers are inside the host tissue => 34

30b Malformations of capitula or florets => 31

31a Capitula or florets hardly transformed => 32

31b Capitula usually enlarged, more rarely stunted, hardened, receptacle fleshy thickened. Florets greened or leafy. C. arvense. ? vulgare: Aceria anthocoptes

= Symptoms on capitula were also attributed to phytoplasma

32a Flower parts stunted or only slightly changed; malformations merely the results of inhibition rather than of gall induction => 33

32b Florets disfigured and discoloured; pistil thickened and lengthened, extending well above the florets. Containing red larvae. C. vulgare: Jaapiella compositarum

33a Florets stunted predominantly on one side of the ± twisted flower head. C. acaule, arvense, vulgare: Jaapiella cirsiicola

33b Capitula slightly stunted; florets hardly disfigured. Contain red larvae. C. arvense: Macrolabis cirsii

= Larvae of several gall midge species live between the aborted achenes on the receptacles of ± disfigured capitula of several Cirsium– and Carduus species. They hibernate in the decaying receptacles

33c Capitula with up to about 30 unilocular galls, 3 mm in across, with hard, lignified walls. C. ukranicum, also on Onopordum sp.: Isocolus cirsi

34a Larvae in or on the receptacle => 35

34b Capitula in the beginning ± spherically swollen, soon stunted and initially dark-violet, later brown, filled with dusting of spore balls. C. arvense, dissectum, helenioides, oleraceum, palustre, vulgare, etc.: Thecaphora trailii

35a Malformations caused by larvae without conspicuous head capsule => 36

35b Capitula almost normally developed. Receptacle somewhat thickened and hardened, contains one to several white larvae of snout beetles with brown heads, eventually also attacking the ovaries. C. arvense, dissectum, oleraceum, palustre, etc.: Larinus planus

36a Larvae cylindrical, with hook-shaped black mandibles; tephritid maggots => 38

36b Larvae slender, ± flattened, without conspicuous mandibles but with sternal spatula; gall midge larvae => 37

37a Receptacle swollen, hard, several chambers, containing red-yellow larvae. C. palustre, ? acaule: Unidentified gall midge

37b Capitula poorly developed, often oblique and twisted; stalks bent and buckled; flowers partially remaining closed; receptacle slightly swollen; several orange-red larvae. C. dissectum: Jaapiella cirsiicola

= Receptacles of many Asteraceae, especially in ± disfigured and stunted capitula of Cirsium- and Centaurea-species contain orange-red larvae of the saprophagous gall midge Clinodiplosis cilicrus. They invade hibernating and decaying receptacles which are earlier infected by other gall causers.

38a Receptacle completely or partially swollen => 39

38b Receptacle together with ± expanded parts or bearing stalks transformed into a slender, barrel-shaped, multi-chambered tough gall; florets completely withered. C. arvense: Urophora cardui

39a On C. eriophorum, erisithales, helenioides, etc. => 41

39b On C. vulgare, etc. => 40

40a Receptacle distinctly swollen, hardened, with several perpendicular oblong-oval chambers. Each chamber contains a single larva. Cirsium spp.: Urophora solstitialis

40b Receptacle thickened, hardened; containing several larvae. Urophora stylata

40c Furthermore in flower head galls of C. vulgare: Chaetorellia jaceae

40d Occasionally reported malformation of receptacles of Cirsium species. Larvae white with brown head capsule; black unsegmented pupal cocoons: Rhinocyllus conicus

41a On C. erisithales, helenioides, oleraceum => 21

41b On C. eriophorum. Receptacles often with several tough galls of different size, sometimes ± laterally coalesced and may expand over the whole receptacle. Many, usually perpendicular oblong-oval chambers, each containing a single larva: Urophora eriolepidis

41c In flower heads of C. eriophorum, spinossimum, vulgare: Urophora terebrans

42a Receptacle distinctly swollen, hardened. Containing several larvae: Tephritis conura

42b Receptacle conspicuously swollen, hardened, with several upright larval chambers. C. erisithales: Urophora congrua

42b Five more tephritid flies have been recorded from flower heads, viz., (1) Tephritis acanthiophilopsis from C. canum; (2) T. cometa from C. arvense, palustre, vulgare; (3) Terellia ruficauda from C. arvense; (4) Terellia longicauda from C. rivulare; (5) Terellia serratulae from C. vulgare, also on Carduus; all not true gall causers.

gallers on Centaurea

pub 20.xi.2019

Dichotomous table for gallers on Centaurea

(incl. Amberoa, Cheirolophus, Leuzea, Mantisalca, Rhaponticum)

by Hans Roskam

1a On above-ground parts => 4

1b On roots and root collars => 2

2a On main- and lateral roots => 3

2b Root collar with an often plurilocular fleshy swelling, up to 15 mm long. One larva per chamber. C. scabiosa, jacea, etc.: Isocolus scabiosae

3a Main root with spindle- or pear-shaped enlargement on all sides, up to 30 mm long, Containing one larva. C. jacea, stoebe, nigra: ? Pseudocleonus grammicus

3b Root nodule galls. Centaurea spp.: Ceratapion onopordi

3c Rarely developing oblong root galls which may contain a reddish-brown caterpillar with dark brown head capsule. C. jacea, nemoralis, etc.: Epiblema scutulana

3d Adventitious roots with small nodule-shaped swellings. Centaurea spp.:
Meloidogyne hapla

4a On capitula and fruits => 28

4b On vegetative parts => 5

4c Infested plants stunted, showing reduced growth, very bushy, with the apical parts of the stems and capitula still green and fresh during the hot and dry season, less spiny than usual, and producing less seed. C. solstitialis:

a Aceria solcentaureae

b Aceria solstitialis

c Aceria squarrosae

5a Plant parts with localised malformations caused by fungi or animals and with extensive malformations caused by animal parasites => 8

5b Complete plants or major plant parts etiolated; internodes ± elongated and lanky; leaves ± narrowed and paler; large areas of the underside occupied by fungal fruiting bodies => 6

6a Sori yellowish or brown => 7

6b Completely diseased shoots ± etiolated; also curved on one side. Especially the leaf undersides with expanded whitish areas of branched conidiophores. C. montana: Bremia centaureae

7a Shoot usually completely diseased; normally remaining sterile. The pycnidia and primary rugose uredinia soon also partially produce darker telia bearing mycelium which pervades the whole plant whilst deforming it. Secondary uredinia and later telia in dot-like sori are widely dispersed over normally shaped plant parts. C. montana, nervosa, nigra, phrygia, triumfetti, uniflora, etc.: Puccinia montana

7b Corresponding malformations with similar mycelium, completely pervading the plant; uredinia and telia confluent C. cyanus: Puccinia cyani

8a On leaves => 17

8b In buds, shoots or stems => 9

9a On stems => 11

9b In buds or shoots => 10

10a Leaves of the shoot tip of different length ± tuft-like stunted; leaf blades narrow, ± rolled, curled and often strongly pubescent. C. jacea, scabiosa, vinyalsii: Unidentified gall mite

= Extensive malformation of shoots of C. montana are caused by the aphid Uroleucon montanivorum

10b Shoot tip or lateral buds stunted, densely white-felt-like pubescent, somewhat thickened at base. Leaf blades of further developing leaves with irregularly distributed covers on both sides. One or several yellow-red larvae. C. jacea, montana, triumfetti: Dasineura centaureae

11a Malformations predominantly of the stems => 12

11b Younger stems locally stunted and sometimes curled; leaves stacked, nest-like converged; leaf blades curled and locally dark green. Shoots sometimes deformed over larger parts. C. cyanus, jacea, montana, nigra, etc.: Philaenus spumarius

12a The gall causers live inside the stem => 13

12b Stems with bulging swellings over various lengths. Galls ± strongly bent, solitary or with several ridges framed by depressions, which contain the gall causer. C. scabiosa: Planchonia arabidis

13a Galls caused by insect larvae => 14

13b Stem, also neighbouring leaf stems, of young plants with pale green, spongy, sometimes curved swellings which may differ in their respective lengths. C. cyanus, Amberoa moschata, etc.: Ditylenchus dipsaci

14a Swellings inconspicuous or absent => 15

14b Stem with conspicuous swellings => 16

15a Outside of stem hardly changed. Galls only visible after dissection; inside of stem usually with several oval, tough-walled larval chambers, up to 5 mm long and 1 mm wide, each with one larva protruding into the pith. C. aspera, diffusa, jacea, micranthos, nigra, phrygia, stoebe, scabiosa: Phanacis centaureae

15b Galls in stems in a form of rounded or elliptical cells in the parenchyma; the stem sometimes slightly malformed. C. adpressa: Isocolus volgensis

15c Similar gall. C. adpressa, orientalis: Phanacis crassinervis

15d Similar gall. C. adpressa, orientalis: Phanacis varians

15e Upper part of the young stem especially stunted in longitudinal direction; basal part slightly spindle-shaped swollen over a length of 3–4 cm. A long, narrow larval chamber in the pith, contains a single caterpillar. C. stoebe, scabiosa: Unidentified ? lepidopteran

= The caterpillar of the leafroller Epiblema scutulana lives in the capitula of several Asteraceae but without causing galls. However, those of the next generation infest the stems and roots of C. jacea and is reported as a gall causer of stems for C. nemoralis

16a Stem in different extensions, sometimes over a length of 10–15 cm, irregularly crookedly swollen. The inside with many solitary or gregariously situated oval, tough-walled larval chambers each containing one larva. C. scabiosa incl. subsp. sadleriana, etc.: Isocolus scabiosae

16b Conspicuous more or less globular one-sided swelling, multi-chambered. C. aspera: Isocolus latreillei

16c Similar usually smooth swelling. 20–25 x 15–18 mm. C. aspera, melitensis, Mantisalca salmantica: Isocolus lichtensteini

16d One-chambered swelling on stem base. C. aspera: Isocolus fitchi

16e Stem strongly swollen and buckled some distance below the flower head. Containing several orange-coloured larvae. C. decipiens: Unidentified gall midge

17a Rotund to oval, only slightly cushion- or callus-like swellings, which are soon occupied by the yellow or brown sori of rust fungi => 25

17b Malformations caused by other gall causers => 18

18a Malformations predominantly of the leaf blades => 21

18b Galls on the midrib or on veins of main- or lesser order => 29

19a Galls not extending onto the leaf blades => 20

19b Veins of different order, more rarely also the midrib or petiole, regularly with solitary rotund-oval or spindle-shaped galls, but also in rows situated gregariously, in the leaf blade extending and visible on both sides. Wall fleshy to cartilaginous, ± pale green. Area around the galls often yellowish or purple coloured. Containing a single yellow larva. Centaurea spp.: Loewiola centaureae

20a Midrib or petiole with rotund, tough-walled, unilocular swelling, up to 8 mm long, visible on both sides. Containing a single larva. C. scabiosa: Isocolus fitchi

20b Midrib in the middle of the leaf blade with lemon-shaped, tough-walled swelling containing a large chamber; terminal part of the spindle recurved. Containing a single larva. C. stoebe: Unidentified gall wasp

21a Malformations by aphids or cercopids => 23

21b Galls small, usually many, wart- or pock-like => 22

22a Leaf blades, especially of basal leaves, with ± rotund-oval lenticular pocks, 1.5 to 2.5 mm long, visible on both sides, often bright green, also reddish to black violet with a fine opening on the upper side. Centaurea spp.: Aceria centaureae

22b Basal leaves on the underside with many semi-globular, golden yellow gleaming, pearl-like warts, hardly 1 mm long. C. jacea: Synchytrium aureum

= The chytrid Synchytrium solstitiale occurs with many orange red warts, up to 0.2 mm across, on the leaves of C. solstitialis. that often are more or less distorted. In a later resting stage the warts are grey

23a Leaf rolls caused by aphids => 24

23b Leaf blades, according to leaf size, completely or partially nest-like deflected; curled mainly close to the site of attack and dark green. Centaurea spp.: Philaenus spumarius

24a Leaves of several shoot tips often rolled over their length. Aphid bright yellowish to yellow-green. C. cyanus, paniculata: Brachycaudus helichrysi

24b Similar malformations caused by black aphids. C. calcitrapa, stoebe, etc.: Aphis fabae

25a Callosities or cushions with brown sori => 26

25b Swellings or hardly thickened areas on the leaf blades bearing aecia and usually also pycnidia. Galls facultatively; on the same host often developed to a different extent, ± reddish coloured. Aecia on underside of leaf, in rotund yellow- to crimson red bordered sori. Peridium broadly deflected, with irregularly incised border. C. nigra: Puccinia arenariicola

26a Minor swellings of leaf veins or petioles, ± rotund-oval, facultative gall causer; only in spring and ± solitary. Only produced by the primary mycelium bearing uredinia and partially also pycnidia. The far more frequent much darker secondary uredinia and telia, produced in little sori, are not cecidogenic. Fungus with various biological forms => 27

6b Leaf blade with rotund compact red brown cushions about 2–5 mm long, often many and usually protruding on the leaf underside, often yellow-bordered. Sori, when on the veins ± oblong-oval; exclusively with densely set, glabrous, 2-celled, dark brown telia. C. scabiosa, also jacea, kotschyana, maculosa, montana, phrygia, etc.: Puccinia verruca

27a Leaf blade on underside develop sori with aecia, often several on the, ± yellow or reddish margined; sometimes with oblong-oval shape on the major veins and only here facultatively inducing minor swellings. Centaurea spp.: Puccinia dioicae

27b Leaf blade on the underside with many small uredinia and telia. Fungus with two kinds of uredinia. The primary uredinia, accompanied by pycnidia, develop on the venation, sometimes on slight, bulge-like swellings. Centaurea spp.: Puccinia calcitrapae

27c Uredinia with two terminal germ pores, warts not developed over the spore surface On C. jacea, etc.: Puccinia hieracii

27d Close to this species is the fungus on Rhaponticum scariosum, occasionally on the veins on the upper side with primary large sori, up to 15 mm long, which are slightly swollen and curved, sometimes accompanied by pycnidia: Puccinia centaureae-rhapontici

27e Uredinia with three equatorially situated germ pores, also with loosely placed fine warts here, as well as on the remaining surface of the spore. Especially on C. scabiosa, but also on many other Centaurea species: Puccinia carthami

28a Galls in ovaries or fruits, capitula externally hardly or not markedly changed => 38

28b Malformations in other parts of the capitula => 29

29a Gall causers are found in the receptacle => 36

29b Malformations in flowers or in the scales of the involucre => 30

30a Substantial parts of the capitula malformed => 31

30b Scales of the involucre of the otherwise not markedly malformed capitula at the base with an oblong-oval, up to 7 mm long and 4.5 mm wide, single-chambered, tough-walled, glossy bulge. Containing a single larva. C. scabiosa: Isocolus rogenhoferi

30c On C. adpressa, solstitialis. Gall at the base of the flower head and/ or on the stem below it. In many cases no deformation of the flower head base and stem was observed and only single galls were found in each infected flower: Isocolus ponticus

30d Same hosts. A large number of galls are developing in one flower head, and these strongly deforming and enlarging the flower head and the stem below. The galls are merging together and forming a hard, lignified conglomerate at the base of the flower head: Isocolus tauricus

30e On C. ruthenica. Galls are formed at the base of flower heads. Usually 8‒10 galls form a conglomerate, up to 30‒35 mm in diameter and, thus the base of a galled flower head is usually enlarged, swollen. Mature galls are lignified, thick-walled, brown: Isocolus ruthenicae

30f On C. (Phaeopappus) trinervia. The usual gall wasp induces galls at the base of flower heads: Isocolus phaeopapucii

30g On Leuzea conifera. Galls inside flower heads. Isocolus leuzeae

30h On C. diffusa, pseudomaculosa, virgata subsp. squarrosa. The galls lie between the involucral bracts and eventually fall off. They are unilocular, 2 mm long, elliptic; the wall is thin, lignified and slightly rough: Isocolus centaureae

30i On C. orientalis. Galls in the capitula, between the achenes: Isocolus flavus

31a Capitula malformed, ± stunted and remaining closed => 33

31b Capitula enlarged, ± wide, gaping. Flowers not developed, malformed, succulent, thickened => 32

32a Ditto on C. bracteata, decipiens, micrantha, scabiosa subsp. sadleriana stoebe: Aceria grandis

32b Ditto on C. jacea: Unidentified gall mite

32c Ditto on C. aspera: Aceria brevisetosa

32d Capitula swollen, malformed, spines reduced. C. aspera: Aceria calathidis

32e Inconspicuous swelling of capitula. C. aspera: Larinus longirostris

33a Malformations caused by gall mites => 34

33b Development of capitula together with their organs remarkably stunted, containing several, usually orange-yellow larvae. C. scabiosa: Dasineura miki

34a Capitula severely stunted, only about 5 mm long and ± disc-shaped, abnormally haired together with the neighbouring parts of the shoot. C. scabiosa: Unidentified gall mite

34b Capitula stunted, remaining ± closed. Flowers ± greened and haired. C. decipiens: Unidenified gall mite

34c Similar, ± greened, but hardly haired, pea-sized malformations of capitula. C. phrygia: Aceria centaureae

35a Extensive parts of receptacle swollen, hardened, with several oblong-oval, perpendicular to the surface, rarely ± inclined larval chambers. Infected capitula often more globular than normal ones. One maggot per chamber with abruptly humped back: various tephritid flies

35b Ditto, with distinct head capsule => 36

36a Beetle larvae feed on flower head; these only malformed on one side, development stunted, ± distorted or skewed. C. jacea, scabiosa, etc.: Larinus planus

= Beetle larvae of Larinus minutus feed on the developing achenes, and pupate in the partly eaten receptacle. Not a true gall. C. diffusa, stoebe.

36b Similar malformation by caterpillars. C. nigra, scabiosa, etc.: Unidentified lepidopteran

= The larvae of the gelechiid moth Metzneria metzneriella are frequently found in the capitula of many Centaurea species, but do not cause galls

37a Fruits ± swollen or elongated, caused by larvae of cynipids which are narrowed at both ends => 38

37b Fruits inconspicuously swollen, slightly elongated. The gall includes occasionally, in the case of young flowers, the under part of the lightly greened corolla tube. Containing a plump, conical, terminally blunt white larva with black mouth parts. C. jacea: Urophora jaceana

38a Fruits oval, up to 8 mm long, swollen, tough-walled, woody; one larva. C. scabiosa: Isocolus scabiosae

38b Fruit weakly swollen, up to 4.5 mm long. Gall tough-walled, ± connate to the receptacle. Containing a single larva. Adult with indistinct carinae on anterior part of mesonotum (comp. next lead). C. jacea, montana, paniculata, stoebe, scabiosa, etc.: Isocolus jaceae

gallers on Rubus

pub 19.xi.2019

Dichotomous table for gallers on Rubus

by Hans Roskam

1a On above-ground parts => 3

1b On roots, on root collar or on basal stem parts => 2

2a Roots, root collar or basal stem parts with irregular proliferations, up to 20 mm long, at first succulent, later on lignifying, ± globular, rough on the surface, without gall chamber. Rubus spp.: Agrobacterium tumefaciens

2b Young roots of R. idaeus with several swellings, 1–2 mm long, approximately urn-shaped, with fungus mycelium interspersed: Mimeuria ulmiphila

2c Small solid swellings, often curved and twisted, at the tips of lateral roots; other parts of roots sometimes thickened; adult eelworms slender and transparent, 1.5–12 mm long; feed on outside of root (so, often are not seen): Longidorus sp. and/ or Xiphidinema sp.

2d Stem base, also roots, with elongated swellings, up to15 mm long, brownish. Pith containing a whitish, black-headed caterpillar. Rubus spp.: Pennisetia hylaeiformis

3a On flowers and fruits => 32

3b On vegetative plant parts => 4

4a On shoot tips or leaves => 8

4b On stem parts => 5

5a Younger or older axis with conspicuous strong swellings => 6

5b Younger, and even lignified shoots with elongate spindle-shaped swelling, which displays a screw-like tunnel around the shoot. R. idaeus, fruticosus: Agrilus cuprescens

5c Salmon pink larvae live under rind. Attacked stem may die back. R. idaeus: Resseliella theobaldi

6a More or less globular, one-sided proliferations or spindle-shaped nodular swellings on the branches => 7

6b Oblong, about 30–80 mm long, and up to 10 mm broad, multi-chambered, with bumpy -tubular swellings, enclosed by glabrous bark. Each chamber containing a single white larva. Rubus spp.: Diastrophus rubi

6c Similar gall. R. idaeus: Aulacidea rubi

7a One-sided protrusions, more or less globular up to 30 mm long, at first succulent, white, later on browned and lignified compact proliferations with tubular surface, usually originating from bud primordia of young lignified stems. Galls sometimes coalescing ridge-like. Rubus spp.: Agrobacterium tumefaciens

= Irregular proliferations, at first short, later on usually extending over several internodes, erupting from bark, pale-green, free from parasites, mainly on two-years old, often additionally swollen shoots of R. idaeus, occasionally also on bramble. Often teratological malformations, predominantly on branches weakened by parasites

7b Rotund to constricted barrel-shaped swelling, mainly one-sided, about 10–20 (50) x 5–7 (20) mm; later woody with rough fissured bark. Inside are many larvae, at first white, later on orange-red. Rubus spp.: Lasioptera rubi

7c Inconspicuous localised swelling. R. fruticosus, idaeus: Agrilus cuprescens

8a Malformations on shoot tips or expanded parts of leaf blade disfigure => 20

8b Localised galls on leaf blades, of ± defined shape => 9

9a Galls almost exclusively on leaf blade parenchyma => 14

9b Galls almost exclusively or mainly on leaf veins, -midrib, -stalk; sometimes only conspicuous by discolouration of leaf blade => 10

10a Venation or axis with bulge-like thickening of various size, soon covered with fungus fructifications => 11

10b Main- or lateral veins of leaflets with swellings 5–7 mm long, 2–3 mm broad, stronger on underside, less protruding on upperside, almost completely filled with larvae and collapsing after their departure. Neighbouring leaf blade parts at first hardly discoloured, after vacation usually yellowish, rarely reddish tinged, occasionally interspersed by a violet-black discoloured venation over a length of 20–30 mm and width of about 12 mm. Larvae conspicuous large, white, sulphur-yellow later on, often greenish translucent. R. idaeus: Buhriella rubicola

11a More or less distinct, facultative yellowish bulges on main venation, on leaflet- and petioles, occasionally also on young shoot stems. In the leaf blades are small rotund patches with spores developing on underside, and sometimes on upper side. Possible gall formation in spring by caeoma-sori of monoecious rust fungi. On. R. arcticus, idaeus, saxatilis => 13

11b Analogous malformations on other Rubus species => 12

12a Aecia with large disc-like warts; mainly developing in often red-margined sori on underside; uredinia rather densely-spiny, teliospores mainly 6-celled, with awl-like tip at apex. Rubus spp.: Phragmidium bulbosum

12b Aecia and uredinia with distantly spiny-warts; telia usually 4-celled, with blunt papilla at apex; developing on often violet-red margined sori. Rubus spp.: Phragmidium violaceum

13a On R. saxatilis: Phragmidium acuminatum

13b On R. arcticus, arcticus x saxatilis, with similar biology, Phragmidium arcticum

14a Galls 2 mm long or less => 16

14b Leaf blade either with expanded rotund pads caused by fungi or with expanded erinea caused by mites on underside => 15

15a Leaf blade with weak, ± yellow, sometimes red-margined, pad-like swellings. Sori either on upper- or underside => 11

15b On underside often with many, locally, slightly expanded rotund depressions with white erinea; on upperside not or only slightly protruding. Hairs ± curved, spirally; erinea sometimes coalescing, but not extending into other organs. Rubus spp.: Eriophyes rubicolens

16a Galls nodule or pustule-shaped, visible on both sides of leaf, caused by animals => 18

16b Galls wart-shaped, one-sided, caused by fungi => 17

17a Warts golden-yellow, many-celled. R. caesius, dumetorum: Synchytrium aureum

17b Warts almost colourless. Galls 1-celled. R. arcticus: Synchytrium myosotidis var. potentillae

18a Galls pustule-shaped, conspicuously shrunken. “Procecidia”, oviposition scars, not true galls => 19

18b Rotund nodules, protruding on both sides, 2 mm across. Exit small, usually on underside, rarely on upperside and then cup-like. With club-shaped or cylindrical hairs inside proliferations, R. arcticus, saxatilis: Aceria silvicola

19a Pustule-shaped egg capsules between leaf dentition. R. fruticosus, idaeus: Arge gracilicornis

19b Egg-shaped “procecidia”, oviposition scars, not true galls, 1.5 mm long, yellow swellings, visible on both sides, often with several together, in the axils of ± curved veins. The emerging larva leaves the gall and lives free on the leaf surface. R. corchorifolius: Unidentified sawfly

20a Malformations mainly of several terminal leaves, caused by aphids => 26

20b Various malformations of single or several terminal leaves by other causers (for witches’ broom-like malformations => 21

21a Malformations sometimes expanded, ± pubescent or glabrous => 22

21b Expanded parts of leaf, shoot- and inflorescence axis, flower peduncle, possibly flower buds, and the green parts of ± opening flowers and even the almost mature, already black-violet coloured mericarps with velvet-like greyish pubescence. Early infected leaves stunted, with curved venation. Hairs cylindrical, acuminate, rigid and longer than the normal ones. Rubus spp.: Epitrimerus gibbosus

22a Galls caused by animals => 24

22b Galls caused by parasitic fungi => 23

23a Leaf blade with yellow, slightly thickened spots, which bear on the upperside spermogonia and on both sides, golden-yellow, primary uredinia arranged in rings. R. caesius, fruticosus, hirtus, nemorosus, plicatus, etc.: Kuehneola uredinis

23b Infected leaves ± disfigured, usually smaller and paler than the healthy ones. In autumn and spring on underside, accompanied by spermogonia, caeoma-sori. R. arcticus, saxatilis: Gymnoconia nitens

23c Similar malformation. R. arcticus, canadensis, chloocladus, leptadenes, saxatilis: Arthuriomyces peckianus

24a Leaflets variously folded upwards and additionally further disfigured => 25

24b Leaflet ± abruptly bent, deflected over the top, close to the infestation site strongly crumpled, dark-green. Rubus spp.: Philaenus spumarius

24c Localised malformation of leaf blade. R. fruticosus: Trioza tripunctata

25a Leaflets folded upwards along ± thickened main veins, undulately curled and often ± discoloured; stunted and sometimes more densely pubescent; several white larvae briefly between folds. Rubus spp.: Dasineura plicatrix

25b Midrib and side veins of first and second order bent in and out. Leaf blade folded, folds scantily pubescent, usually discoloured on underside. Malformations only exceptionally conspicuous, leaf blades ± arched. R. idaeus and many other brambles: Phyllocoptes gracilis

25c Similar, only exceptionally gall-like damage on R. caesius, candicans subsp. thyrsoideus and cultivated relatives: Anthocoptes rubi

25d Vagrant mites on the underside of the leaves. At high densities some discolouration may occur. R. laciniatus: Anthocoptes rubicolens

26a Aphid greenish => 27

26b Populations of green and brownish-red aphids usually present. Siphunculi thin and long, about a third of body length. R. caesius and other brambles: Macrosiphum funestum

27a On raspberry (R. idaeus) and various brambles, R. caesius, fruticosus, etc. => 28

27b On R. saxatilis: Aulacorthum cylactis

28a On brambles => 30

28b On raspberries => 29

29a Leaves weakly arched: Amphorophora idaei

29b Leaves variously crumpled, with several bunched together in relatively compact clusters. Aphis idaei

30a Leaves relatively loosely arched and weakly rolled. Minor stunting of shoot. Malformations only facultative. Aphid yellowish-green to green. Adults larger than 2.5 mm => 31

30b Leaves strongly rolled inwards in spring; aphid also living on green shoots in dense colonies. Aphis ruborum

31a Siphunculi cylindrical and often dark-brown. Antennae slightly shorter than or almost as long as body: Sitobion fragariae

31b Siphunculi slightly swollen, colourless, with thin tip. Antennae longer than body: Amphorophora rubi

= Virus diseases occur widely on Rubus species, especially raspberries, causing mosaic-like discoloured malformations of leaves, as well as curling of many leaves on ± severely stunted shoots

32a On inflorescences or flowers => 33

32b Receptacle thickened. R. idaeus: Unidentified ? tephritid fly

33a Malformations of flowers only => 34

33b All parts of inflorescence with abnormal silvery pubescence. Rubus spp.: Epitrimerus gibbosus

34a Flowers conspicuously greened, leafy or developed further => 36

34b Flowers unopened, variously disfigured => 35

35a Flowers unopened. The calyx, sometimes appearing enlarged, encloses the other, usually smaller, ± disfigured inner flower organs. Many ivory-white to yellowish jumping larvae per bud. Infected flowers soon dropping. Rubus spp.: Contarinia rubicola

35b Corolla stunted, abnormally developed, ± greened. Sex organs reduced; at first greened, later on browned. R. fruticosus: Unidentified thrips

35c Bud swollen, unopened, containing beetle larva. R. ulmifolius incl. vars: Anthonomus rubi

36a Flower organs mostly greened, transformed into small green structures. R. fruticosus: Acalitus essigi

36b Flowers conspicuously and variously disfigured, greened, leafy, sometimes developed further. Rubus spp.: Virus disease

= Cause of the malformations associated with enlargement of calyx in raspberries and brambles is the well-known “Rubus-branching virus”, which may also induce a witches’ broom-like dwarf growth

gallers on Rosa

pub 18.xi.2019

Dichotomous table for gallers on Rosa

by Hans Roskam

1a On above-ground parts => 3

1b On roots or root collar => 2

2a Roots with spindle-shaped swellings. R. canina, multiflora: Meloidogyne sp.

2b On roots or on root collar, expanded, at first succulent, then lignifying proliferations with tuberculate surface. Rosa spp.: Agrobacterium tumefaciens

2c Small solid swellings, often curved and twisted, at tips of lateral roots; other parts of root sometimes thickened; eelworms live externally in soil, not often seen. On Rosa cultivars: Xiphinema diversicaudatum

= The red bud borer Resseliella oculiperda damages rootstocks of cultivated roses and apples when these are grafted with scion buds by “shield budding”

3a Fruit variously disfigured, often ± etiolated. Rosa spp.: Rhagoletis alternata

3b On vegetative plant parts => 4

4a Malformations of various extent caused by fungi, which produce brownish or whitish sori on the gall surface, soon yellowish to orange => 29

4b Malformations induced by other causers => 5

5a Galls on various plant parts, distinguished by moss-like proliferations or swelling of stem bearing bushes of mistletoe => 28

5b Malformations different => 6

6a Galls never closed on all sides, only on leaves; leaf blades folded, rolled, curled, with erinea, or with egg capsules on petioles, leaf blades or between leaf teeth => 19

6b Malformations different; on stems or leaves => 7

7a Malformations closed on all sides, with single or several tough-walled chambers => 13

7b Galls without chambers; only on shoot axis => 8

8a Minor, soon fragile swellings on young shoots caused by egg batches of sawflies (procecidia, oviposition scars, not true galls) => 12

8b Malformations exist for a longer period => 9

9a Causer not recognisable from the outside => 10

9b Bark with small, bulging rimmed depressions, containing causer below a flat, 2.3–3 mm long scale. R. canina, eglanteria, pomifera, villosa, etc.: Chionaspis salicis

9c More expanded malformations bearing Viscum album

10a compact or cancer-like malformations => 11

10b Young lignified shoots slightly swollen over a length of 30–50 mm. The swelling contains a tunnel in the inner bark running in relative narrow turns around the axis. R. x damascena, rubiginosa, x rugosa. spinosissima, etc.: Agrilus cuprescens

11a Axis of older shoots or young stems often with many walnut-size, at first succulent, then lignifying proliferations, mainly close to a node. Rosa spp.: Agrobacterium tumefaciens

11b Infestation sites depressed to varied extent, on reactive young twigs rimmed by flat to almost cauliflower cancer-like proliferations. Proliferations at first dirty-white to yellowish, then browned. “Bark spot disease”. Rosa spp.: Coniothyrium wernsdorffiae

= Similar damage may be caused by the widely distributed, also known from other hosts, equally hardly cecidogenic sac fungus Leptosphaeria coniothyrium

12a Egg capsules arranged in two rows. bark often ripping open and sometimes more or less rimmed later on. Rosa spp.: Arge pagana

12b About 16–18 egg capsules, arranged in one row, just below shoot tip, soon bending, occasionally browning and withering. Rosa spp.: Arge ochropus

13a Galls smaller than 10 mm => 14

13b Galls often larger, usually irregular, bulbous and bumpy, up to 25 (40) mm long. Wall not very tough, yellowish-brown or ± reddened, dark-brown later on. With many long spines, up to 3 (5) mm. Galls on shoots, especially conspicuous at the ends and multi-chambered; with smaller sized galls also on all leaf parts, flowers and hips. Containing a single larva per chamber. Rosa spp.: Diplolepis mayri

13c Galls similar to those of D. mayri, but only in their external morphology, especially when the galls of the last species develop on hips. However, D. fructuum galls are produced by the hypertrophy of seeds inside the fruit, the development of which can finally split the external envelope of the hip. In this case, each seed is modified into an egg-shaped multilocular gall, containing up to 10 larval cells and reaching a size of 15 x 12 mm; one hip can be modified into a large multilocular gall. Galls of D. mayri do not split the external envelope of the fruit. R. canina: Diplolepis fructuum

13d Rounded or elongate swelling in stem, smooth when young, later becoming fissured; containing several orange or orange-yellow larvae in irregular cavities. 6–7; gall splits in 7–8 releasing larvae which pupate in soil. R. spinosissima: Janetiella frankumi

13e Oblong swelling on stem, 80–120 x 20–30 mm, surface slightly fissured. R. gallica: Unidentified microlepidopteran

14a Galls almost exclusively on leaves > 15

14b Shoot axis with acuminate- to oval or elongate spindle-shaped swellings, up to 10 mm long, one- to more-chambered. R. majalis, spinosissima , tomentosa: Diplolepis sp.

15a Galls ± globular, with strongly constricted attachment, only protruding on a single side of leaf => 16

15b Galls on both leaf sides, sometimes coalesced into bumpy groups, surrounded by a ± wide, unchanged leaf margin, variously shaped, rotund or oblong, glabrous or rarely provided with small spines; single galls usually 3–5 mm long, yellow-green, sometimes reddish, one-chambered; on leaf midrib and stalk, ± uneven, more- to one-side, sometimes with several united into larger, almost homogenous gall bodies. On all leaf parts, also on flowers, even on corolla. Containing a single larva. Rosa spp. Diplolepis spinosissimae

16a Outside gall wall glabrous, in some cases tuberculate or provided with short papillae, also with only a few, almost normal spines => 18

16b Galls with many thin or with only a few conspicuous strong and rough spines => 17

17a Galls rotund, 4–6 mm, ± red tinged or spotted, with several strong, sometimes slightly bent, tough spines, star-like; robin’s pincushion. One-chambered, containing a single larva. Aberrant gall form indicates presence of parasites or inquilines. Rosa spp.: Diplolepis nervosa

17b Galls rotund, with many often unequal large slender spines, up to 3 mm long. On leaf-blades or calyx mainly one-chambered; on larger organs often several are united into larger many-chambered, bumpy aggregations. Rosa spp.: Diplolepis mayri

18a Galls glabrous, rarely somewhat tuberculate, up to 8 mm across; one-chambered; thin-walled, mainly on leaf underside, occasionally on upper side and then conspicuously reddened, also on flower peduncles, even on stamens or the tips of calyx leaves or even on attachments of spines, as well as on protuberances of D. rosae galls. Galls containing parasites or inquilines are often variously disfigured and sometimes enlarged and many-chambered. A single larva per chamber. Rosa spp.: Diplolepis eglanteriae

= Periclistus species may be inhabitants of irregularly shaped, also enlarged globular galls of several Diplolepis species. These are commensals developing outside the gall chamber in separate cavities of the gall wall

18b On R. arvensis develops in inconspicuous galls: Diplolepis nervosa

18c Galls similar, but usually provided with short, acute, simple, stiff ± reddened spikes or papillae. Containing a single larva. R. canina, caesia, centifolia, pomifera, etc.: Diplolepis nervosa

19a Leaf blade curled over extensive parts or ± loosely rolled => 23

19b Leaf folded pouch-like, or with pustule-shaped egg capsules or with hair felts => 20

20a Pustule-shaped procecidia (oviposition scars, not true galls) up to 2 mm across => 22

20b Folds or erinea => 21

21a Halves of leaflets narrow pod-like, folded upwards, up to a narrow marginal border strongly swollen, pouch-like; galls sometimes arched, sickle-like. Wall succulent, thickened, brittle, sometimes conspicuously reddened. Containing several orange-yellow larvae. Rosa spp.: Dasineura rosae

21b White to reddish erinea at undefined places. Strongly infected leaflets roll in ± longitudinally upwards. R. rubiginosa: Unidentified gall mite

22a Often with several egg capsules between leaf teeth at leaf margin. Rosa spp.: Arge gracilicornis

= On various occasions also Arge enodis has been reported as producing egg capsules on roses, arranged like strings of pearls. This sawfly normally lives on Salix

22b Pustules, on both sides of leaf, 2–3 mm long, protruding further on upper side, pale yellow to -brown, usually single, usually in petioles, more rarely in basal leaf blade parts, also in stipules. R. canina: Cladardis elongatula

= The female of the sawfly Ardis pallipes deposits her eggs in hardly conspicuous egg capsules in the tips of developing shoots. The thick, yellowish larva up to 10 (12) mm long, eats into pith a 30–40 mm long downwardly directed tunnel, pushing the shoot downwards while it withers.

= Also the sawfly Cladius pectinicornis deposits its eggs in rapidly shrunken procecidia on the petiole surface. Larvae gregarious on leaves, at first eating the parenchyma in between the veins, then producing holes.

23a Leaf blade ± tube-shaped rolled or bent upwards and browned => 25

23b Leaf blades conspicuously curled, variously bent => 24

24a Single or several leaves at stem deflected; their leaflets crumpled, almost nest-like downward converged; at infestation site usually dark green. Containing a single or several froth-covered nymphs. Philaenus spumarius

24b Leaf blades of the terminal leaves curled and ± strongly deflected; usually with several bunched together in loose nests. Rosa spp.: Aphis pomi

25a Leaf blade bent upwards, not thickened; ± discoloured, spotted or browned => 27

25b Rolls of leaf margin => 26

26a Both leaf blade halves tube-shaped rolled downwards to midrib, additionally often twisted. On many wild roses and cultivated forms: Blennocampa phyllocolpa

26b Leaves loosely rolled upwards, hardly thickened, not or slightly discoloured. R. canina: Callyntrotus granulatus

27a On R. alpina, spinosissima: Eriophyes rhodites

27b On R. canina, ? alpina: Callyntrotus schlechtendali

28a Up to 50 (80) mm long, rotund masses with thread-like, ± branched appendages. “Bedeguar”, “Robins pin cushion gall”. Usually many-chambered, very tough, ± reddened. Rosa spp., not on cultivated roses: Diplolepis rosae

28b Stems of R. canina with strong nodular swellings bearing: Viscum album

29a Sori orange-coloured or brownish => 30

29b Shoot tips and expanded parts of ± curved leaf blades covered with a dense, white, or grey mycelium. Rosa spp.: Podosphaera pannosa

30a Young shoot axis, leaf blade, -midrib, stipules, petioles, calyx leaves or young fruits with buckled swellings, their surface eventually covered with orange spore masses. Galls according to response ability of infected substrate. Fungus with all spore forms monoecious => 31

30b Leaves often completely infected, on underside with rotund, often coalescing, dusty, brownish sori of (1) 2 (3) celled teliospores. Leaf blades stay smaller and remarkably thickened. R. acicularis, macrophylla, majalis and relatives: Phragmidium kamtschatkae

31a Aeciospores with loosely arranged spines; wall thickenings of germ pores not substantially protruding inwards => 32

31b Aeciospores with densely arranged, coarse spiny warts; provided with 6–8 germ pores, with wall thickenings protruding hemispherically inwards. Rosa spp.: Phragmidium tuberculatum

32a On R. alpina, majalis and spinosissima. Fungi differ from next species insignificantly and mainly biologically => 33

32b On many other Rosa species as well as on cultivated forms. Teliospores 5–9 celled, often upper half broadened; slightly narrowed at apex, with short papilla. Galls like those of previous species. Rosa spp.: Phragmidium mucronatum

= Mycetophagous gall midge: Mycodiplosis coniophaga

= Almost witches’ broom-like malformations are initiated by unknown causes

33a On R. alpina, acicularis, caesia var. glauca, majalis, pomifera: Phragmidium fusiforme

33b On R. caesia, rubiginosa and many cultivated spp.: Phragmidium tuberculatum

33c On R. majalis, spinosissima, rubrifolia. Teliospores not deep dark-brown as in all previous species, but chestnut-brown: Phragmidium rosae-pimpinellifoliae

gallers on Lathyrus

pub 17.xi.2019

Dichotomous table for gallers on Lathyrus

by Hans Roskam

1a On shoot parts => 4

1b On roots => 2

2a Conspicuous galls => 3

2b Outside of roots not conspicuously changed, giant cells developing inside; at surface temporarily with poppy seed sized egg capsules. Lathyrus spp.: Heterodera sp.

3a Nodular swelling in root body. L. odoratus: Meloidogyne sp.

3b Slender oval to cylindrical galls which grow on roots of very different thickness, apically often branched or hand- to coral-shaped, subdivided, on many hosts, up to 8 mm long and 1.5 mm broad, sometimes united into larger complexes. Lathyrus spp.: Rhizobium leguminosarum

4a On inflorescences, flowers or fruits => 36

4b On vegetative parts => 5

5a Galling confined to leaf blades or buds => 16

5b Galling on other vegetative parts including malformations of terminal shoot => 6

6a Malformations mainly or exclusively confined on stem or axial parts => 13

6b Extensive malformation of complete shoot systems => 7

7a Usually expanded malformations of shoot tips => 9

7b Galls on basal parts => 8

8a At stem base are several close shoots, severely stunted, succulent, thickened, ± curved and bearing minute, crippled small leaves. L. odoratus: Rhodococcus fascians

8b Stem bases of young plants stunted in development, severely stunted and over about 40 mm long, spongy, swollen; petioles and basal veins of infected leaves similarly swollen. L. odoratus: Ditylenchus dipsaci

9a Malformations by animal causers => 11

9b Systemic diseased shoot tips show a stunting of internodes and bear slightly clustered, stunted, pale, at margin ± deflected and relatively thickened leaves, which on their underside, as on the young shoot axis, are covered with a whitish-grey down of conidia => 10

10a On L. palustris, heterophyllus, sylvestris: Peronospora lathyri-palustris

10b On different Lathyrus species:

a On L. linifolius: Peronospora orobi

b On L. niger: Peronospora senneniana

c On L. pratensis, nissolia: Peronospora trifoliorum

= These cecidogenic fungi develop systemic infections, and may induce different responses in different host plants. Any additional assignations of Peronospora forms on different Lathyrus species require further study; additional micro-species have also been described from southern areas

= Furthermore Peronospora viciae, frequent on several Lathyrus species, also on Pisum and Vicia, causes proliferating leaves and buds forming a rosette

11a The margins of ± stunted leaflets of many leaves are rolled => 12

11b Few to several leaves are usually at the one-sided bent axis ± deflected, locally deep green and are nest-like converging. Lathyrus spp.: Philaenus spumarius

12a Leaflets mainly of the terminal leaves with narrow, hardly discoloured upward rolled margins. L. pratensis, sylvestris: Aculops lathyri

12b The stunted leaflets usually of all leaves on the strongly necrotic plant are loosely rolled upwards, yellow-green, not thickened. L. pratensis: Odontothrips loti and/ or O. phaleratus

= Stunting of various parts are occasionally caused by the black-brown “pea thrips” Kakothrips robustus

13a Shoot axis with localised spindle-shaped or semi-globular galls => 14

13b Wart-shaped, green galls on stems, usually coalescing into broadened crusts. L. niger: Synchytrium viride

14a Bulges caused by fungi with distinct fruiting bodies on the outsides => 15

14b Stem with swelling on all sides, spindle-shaped, up to 10 mm long with central chamber. L. annuus, cicera, etc.: Holotrichapion gracilicolle

= The larva of Cyanapion columbinum lives in elongated one-sided stem galls and pod-like galls on leaves of L. heterophyllus

15a More or less semiglobular or oval galls, 3 x 10 mm long, many occurring on upper stem parts, inflorescence stalk as well as in petioles. L. linifolius, pratensis: Physoderma lathyri

15b The aecia bearing mycelium may develop facultatively spindle-shaped, slightly swollen sori on responsive stem parts or petioles. Aecia small, depressed, with yellowish, broadly deflected, with lacerate margins usually in loose groups on leaf spots. Lathyrus spp.: Uromyces viciae-fabae

16a Galls induced on single leaves or their parts => 19

16b Several leaves involved in the development of a ± bud-like or onion-like swollen single gall => 17

17a Malformations of shoot tip => 18

17b Rough swelling of bud in leaf axil. Containing a single larva. L. pratensis: Cyanapion alcyoneum

18a The stipules enclose a mass of disfigured leaves or inflorescence buds, resulting in a ± globular gall at the shoot tip; internodes of terminal shoot partly shortened. Larvae gregarious, yellowish-white. L. pratensis: Contarinia jaapi

18b Inflorescence transformed into a rotund structure bearing many, ± largely stunted buds; these completely reduced and ± greened. Gregarious white larvae. L. pratensis, ? clymenum: Dasineura pratensis

18c Two terminal stipules slightly swollen at base and ± discoloured and enveloping a mass of dying tissues. Terminal shoot stops further growth and dies. Usually complete plant ± dwindling and non-flowering. Larvae gregarious, from white to pale red. L. pratensis, ? sylvestris, ? tuberosus, ? vernus: Dasineura lathyricola

= Yellow larvae of Dasineura lathyrina develop as inquilines in galls caused by D. lathyricola

= Several unidentified gall midges have been recorded on tips of side- and terminal ± onion-like swollen shoots. Leaflets ± strongly enlarged, fleshy thickened, brittle, ± leather-like folded upwards. Larva whitish or also orange-coloured. Because of the different colour of larvae several midge species are probably involved.

19a Malformation of leaves and buds caused by a false mildew, forming a rosette and causing further distortions => 10

19b Malformations of leaf blade or petiole => 20

20a Malformations of leaf blade => 21

20b Petiole with weak spindle-shaped swelling. L. vernus: Apion sp.

21a Marginal roll or pod-like fold of leaf => 23

21b Curling of leaf or locally defined galls on unfolded leaf blade => 22

22a More or less rotund to oval galls on leaf blade. L. linifolius: Physoderma lathyri

= Enations on leaves of Lathyrus species are often caused by viruses.

22b Leaf curls associated with other malformations. Unidentified aphid

23a Loose to compact, even cartilaginous marginal rolls or also folds caused by midge larvae => 24

23b Leaf margin over variable length irregularly rolled, occasionally up to midrib. The gall wall is variously thickened and appears to be ± hard, sometimes brittle and yellowish spotted. L. sylvestris, also L. cicera, heterophyllus, latifolius, pratensis, tuberosus: Cyanapion columbinum

23c Leaflets mainly of the terminal leaves with narrow, hardly discoloured upward rolled margins. L. pratensis, sylvestris: Aculops lathyri

24a Galls on different Lathyrus species => 28

24b Galls on L. pratensis (records on different Lathyrus species are marked with ‘?’ need verification) => 25

25a Leaflets or stipules with rolled margins => 26

25b Leaflet or stipule swollen and folded over midrib, forming a soft discoloured pod ± mussle-shaped. L. pratensis: Dasineura lathyri

26a Marginal roll usually on one side, not involving the whole margin => 27

26b Marginal roll often enlarged, violet discoloured, rolled upwards over midrib on both sides. Originally described as looking like a cowry shell. Reddish larvae. On L. ? pratensis, sylvestris: Anabremia bellevoyei

27a The not thickened, soft and hardly discoloured leaflets are ± tightly rolled upwards. Larvae yellowish white at first, later pale red: Jaapiella volvens

27b Marginal roll hardly thickened and not discoloured, one or both margins rolled inwards. Usually in the topmost parts of the plant ± dwindling and non-flowering. Larvae gregarious, from white to pale red. L. pratensis, ? sylvestris, ? tuberosus, ? vernus: Dasineura lathyricola

28a Galls on different species of Lathyrus (not on L. linifolius) => 29

28b On L. linifolius, ? sylvestris. Tube-shaped to cylindrical, not thickened and discoloured, sometimes ± reddened roll containing white to pink coloured larvae: Lathyromyza schlechtendali

29a Galls on L. vernus => 30

29b Galls on L. palustris and L. sylvestris group, including L. heterophyllus, latifolius, odoratus, tuberosus => 31

30a Cartilaginous roll on leaflets and stipules. Larvae yellowish. Macrolabis orobi

30b On leaflets and also stipules the roll, often of only a part of the margin and usually apically situated, does not reach the basal part of median vein: Unidentified gall midge

31a The upwardly bent parts are fleshy to cartilaginously thickened => 33

31b Leaflets or also stipules weakly enlarged, softly rolled upwards => 32

32a The not thickened, soft and hardly discoloured leaflets rolled upwards on L. sylvestris. Larvae whitish: Unidentified gall midge

32b On leaflets and also stipules the roll, often of only a part of the margin and usually apically situated, does not reach the basal part of median vein, contain whitish larvae. L. tuberosus: Unidentified gall midge

32c Roll on leaflets, often of only a part of the margin, does not reach the basal part of median vein. Containing pale orange larvae. L. palustris, vernus: Macrolabis orobi

33a Galls on L. pannonicus and L. tuberosus => 34

33b Galls on L. heterophyllus and L. sylvestris => 35

34a Tube-shaped, strongly enlarged, especially at base, pale green rolling together of ± shortened appearing leaflets. Containing white larvae. L. pannonicus, tuberosus: Various unidentified gall midges

34b More or less unexpanded leaflets are folded upwards. Gall wall strongly thickened, cartilaginous brittle, pale green, sometimes margined by narrow normal leaf blade parts. Containing several larvae. Unidentified gall midge

35a Leaflets or stipules often enlarged, violet discoloured, rolled upwards over midrib on both sides. Reddish larvae. L. sylvestris, ? pratensis: Anabremia bellevoyei

35b Similar gall with fleshy leaf rolls. Reddish larvae, pupation in galls. L. heterophyllus, sylvestris: Geocrypta heterophylli

36a On fruits => 43

36b On inflorescences or flower buds => 37

37a Galls on single flower buds => 39

37b Malformation of inflorescence => 38

38a Inflorescence transformed into a rotund structure bearing many, ± largely stunted buds; these completely reduced and ± greened. Larvae white. L. pratensis, ? clymenum: Dasineura pratensis

38b Already the young inflorescence is severely stunted. Several larvae between flowers. L. tuberosus: Unidentified gall midge

= From L. tuberosus malformations have been assigned to a Contarinia sp.

39a Flower buds swollen, unopened, on several Lathyrus species, but not on those mentioned in lead 39b. Various unidentified gall midges

= Similar galls occur on L. niger with yellow, jumping larvae, as well as on L. vernus with such jumping but cream-coloured larva

39b Flower buds swollen, unopened on L. linifolius, pratensis, tuberosus, odoratus, sylvestris => 40

40a Galls on L. odoratus, sylvestris, tuberosus => 42

40b Galls on L. pratensis and linifolius => 41

41a Flower buds swollen, unopened. Larvae white to lemon-yellow, jumping. L. pratensis: Contarinia lathyri

41b On L. linifolius. Flower buds slightly swollen, unopened. Containing a single white to pink-coloured or reddish larva. Also on L.? sylvestris, ? pratensis,? tuberosus, ? odoratus: Lathyromyza florum

41c Same host, flower galls with yellowish-white, jumping larvae. Unidentified gall midge

42a lower buds slightly swollen, unopened. Larvae vitreous to milk-white, or reddish (after description) non-jumping. L. sylvestris: Dasineura silvestris

42b Similar galls contain a single white to pink-coloured or reddish larva. On L. linifolius, also on L. ? sylvestris,? pratensis, ? tuberosus, ? odoratus: Lathyromyza florum

42c Similar galls contain red, non-jumping larvae. L. sylvestris: Dasineura fairmairei

43a Malformations on fruits caused by insect larvae => 44

43b Malformations on fruits caused by fungi. Fruits by early infestation stunted in further development, only occasionally slightly disfigured. Later on with dusting of dirty brown-violet spores; mycelium destroys only in case of early, externally usually indistinct infestation of all seeds of a pod. Lathyrus (Orobus) species: Thecaphora lathyri

44a Malformations caused by gall midge larvae => 45

44b Beetle larvae feed within the pod on the developing seeds; this may cause some galling of the pods. L. linifolius, pratensis, sylvestris, vernus: Tychius quinquepunctatus

45a Pod bulging. swollen, discoloured. Malformations without fungus inside. Many white to lemon-yellow larvae inside, able to jump. L. sylvester, tuberosus: Contarinia silvestris

45b Local, oval or ± spindle-shaped swellings, inside covered with a dense mycelium. Containing a yellow to orange-yellow midge larva: Asphondylia lathyri

gallers on Carex

pub 16.xi.2019

Dichotomous table for gallers on Carex

by Hans Roskam

1a On above-ground parts => 2

1b Roots with terminal swellings, 5–8 mm long, club-shaped; with almost colourless elliptical spores inside. C. limosa: Entorrhiza caricicola

2a In flowers or fruits => 17

2b On vegetative parts => 3

3a Leaves or stems with malformations caused by rusts or smuts => 14

3b Malformations caused by animals => 4

4a On leaves => 12

4b On buds, shoot tips or stems => 5

5a On stems or rhizomes => 7

5b On buds or shoots => 6

6a Lower parts of side shoots swollen, bud-like. C. praecox, ? echinata, ? flacca: Planetella sp.

6b Buds stunted, thickened; galls corniculate. C. elata, flacca, montana, pallescens, nigra, praecox, sylvatica. Planetella cornifex

7a Stem with various kinds of swellings => 9

7b Stem with lateral tufts of leaves or with depressions => 8

8a The stem with a laterally protruding severely stunted shoot with a tuft of severely disfigured, yellowish leaves, the covering sheaths are especially well developed and broadened. Carex sp., muricata, etc.: Livia crefeldensis

8b Stem and leaf sheath with weak depressions. Larvae often many per culm. Each depression contains a single orange-red larva. C. appropinquata, ericetorum, echinata, muricata, remota: Thurauia aquatica

8c With similar biology, may be conspecific with the previous midge. Thurauia uliginosa

= Also other gall midge larvae develop underneath the leaf sheaths of sedges without causing distinct galls:

a Antichiridium caricis, larvae red, on C. echinata

b Antichiridium striatum, larvae yellow, on C. pseudocyperus and Molinia caerulea

c Brachydiplosis caricum, on Carex spp.

d Sterrhaulus corneolus, larvae yellow-red, on Carex spp. According to Jaap (1918) this species also develops as an inquiline in galls of Planetella gallarum

9a Galls egg-shaped, rotund- to oblong-oval => 10

9b Axis of shoot thickened at base, onion-like. Sometimes the complete axis is transformed into a horn-like gall. C. ? bigelowii, flacca, montana, nigra, praecox: cf. Planetella cornifex

10a Galls one-chambered, usually not in dense clusters => 11

10b Shoot axis on rhizome already seriously stunted; often with only etiolated leaves above the ground. Stems or leaf sheaths with ± egg-shaped galls, which usually consist of several oblong-oval, flattened one-chambered parts. C. acuta, acutiformis, arenaria, davalliana, hirta, muricata, nigra, ? praecox: Planetella arenariae

10c Similar galls on C. flacca, nigra, praecox: Unidentified gall midge

11a Stem of shoot in ground, close to surface, with one-chambered, egg-shaped brown swelling, up to 2.5 mm long and 1.5 mm wide, grain-like. C. divulsa, echinata, nigra, praecox, pallescens, ? elata, filiformis: Planetella granifex

11b Similar, often acuminate galls, which are often only attached to the leaf at the tip and are ± distant from the further part of the leaf that bears them. Containing single larvae. Carex spp.: Planetella caricis

11c Similar galls, about 5 mm long. C. praecox: Planetella sp.

11d From C-Eu has been described from C. praecox: Planetella caricis var. baudysi

11e Acuminate galls on culms close to the ground; egg-shaped, about 2 mm long and 1.2 mm wide, one-chambered. C. echinata: Planetella kneuckeri

11f Stem of shoot, also leaves, usually close to the ground, with oblong, glabrous, ± glossy brown, terminally rounded galls, only connected with their middle part to the basal leaf part, narrowed at both ends. Containing a single white larva. Carex spp.: Planetella gallarum

11g Similar galls on C. vesicaria. Larvae white: Planetella tarda

11h Similar galls on C. pseudocyperus: Unidentified gall midge

12a Galls usually less than 5 mm, one-chambered => 13

12b At base where leaves come close to one another, are complexes of several whitish or brownish galls, 5–8 mm long and 2–3 mm thick, acuminate, with thin leathery walls. Containing a single larva. C. ? hirta, pilosa, rostrata, vesicaria, and probably other sedges. Planetella fischeri

12c Similar galls at base of a leaf at lowest node. C. acuta, nigra, praecox:
Planetella rosenhaueri

12d Similar galls on C. davalliana, filiformis, vesicaria: Planetella sp.

= On C. davalliana: Planetella billoti

12e Single- or multi-chambered gall, up to 10 mm long and 5 mm broad. C. appropinquata, acutiformis: Planetella sp.

12f Oblong swellings at leaf base. C. nigra, praecox, pallescens, elata, ? filiformis: Planetella sp.

12g Similar galls on C. divulsa, pallescens: Planetella frireni

13a Subterranean leaf sheaths with oblong-oval single-chambered swellings, up to 4 mm long, about 1 mm broad, thick-walled, dark-brown. Containing a single orange-yellow larva. C. flacca: Planetella sp.

13b Small blister-like swellings of leaf base; often many on several shortened leaf blades. C. acuta, ? hostiana, elata, etc.: Planetella tuberifica

13c Leaves similarly swollen at base, containing many slender spindle-shaped single galls. Each chamber contains a single larva. C. acutiformis, pseudocyperus: Planetella tumorifica

13d Rotund-oval galls, about 3 x 2 mm on subterranean leaf parts. C. divulsa, praecox: Planetella subterranea

14a Expanded stripes on leaves, caused by smut fungi => 15

14b Patches in disfigured stalks of inflorescence; midrib and also culm of diseased plants ± shortened. Spores in balls, not enveloped by sterile cells. Carex spp.: Moreaua aterrima

15a Spores clustered in balls, enveloped by sterile cells => 16

15b Spores single. Smut sori in long, parallel stripes. C. brunnescens, canescens, glareosa, lachenalii, macloviana, etc.: Orphanomyces arcticus

16a Stripes of smut on leaves of various length. Spores 1–2 (4) often without gaps, enveloped by sterile auxiliary cells. Carex spp.: Urocystis fischeri

16b Stripes similar. Spores with 1–6, mainly 3, ± completely enveloped by sterile auxiliary cells. C. montana: Urocystis littoralis

17a Malformations on flowers or fruits, caused by fungi => 22

17b Galls on flower parts caused by gall mites or gall midges => 18

18a Malformations on ovaries or fruits caused by gall midge larvae => 19

18b Utricles transformed into very long, thickened galls. C. misera, nigra, praecox: Phytoptus caricis

19a Galls less than 5 mm long => 21

19b Galls about 5–9 (12) mm long => 20

20a Ovary transformed into an acuminated, cylindrical, usually pale green gall, 5–10 (12) mm long. Larva orange. Especially on sedges of the subgenus Vignea, such as C. brizoides, caryophyllea, disticha, divulsa, vulpina, pairaei, etc.: Wachtliella caricis

20b Galls similar, more club-shaped. Larvae pink-coloured. C. arenaria: Oligotrophus loewianus

20c Utricles strongly enlarged, containing a single lemon-yellow larva. C. cuprina: Dasineura inflata

= The galls cannot be differentiated externally form those of Wachtliella caricis. A difference is that the larvae of inflata are lemon yellow, while those of caricis are orange

21a Ovary, or fruit inflated into an egg-shaped gall, up to 3 mm long. Containing a single orange-coloured larva. C. elata: Unidentified gall midge

21b Similar gall, described in no more detail, on many other sedges. Unidentified gall midge

21c Utricles thickened, containing a single orange-red larva. C. acutiformis:
Dasineura koesterbecki

21d Utricles disfigured, containing a single orange-red larva. C. paniculata:
Dasineura minungula

22a On the first slightly enlarged ovaries, which are soon destroyed, develop considerable smut bodies, protruding conspicuously from the inflorescence; these are initially compact and enclosed by a white envelope, releasing their solitary, mutually ± firmly clotted spores rather late => 24

22b Malformations on various flower parts or on ovaries with lightly dusting of sori => 23

23a Ovaries swollen, soon filled with a dark olive-brown to blackish mass of single spores, pervaded by sterile hyphae. Spores lightly dusting or crumbling, leaving the sterile hyphae as characteristic, soon ± fraying bundle. C. riparia and many other Carex species: Farysia thuemenii

23b Black-brown spore balls in various disfigured flower parts; on more rarely infected female florets often in the abnormally elongated perigyne, often only in the ovary, on male florets predominantly in the anthers. Carex spp.: Moreaua aterrima

24a Spore wall glabrous or with small papillae => 27

24b Spore surface with distinct warts => 25

25a On C. canescens, nigra, rostrata => 26

25b On many sedges of the sect. vesicariae, hirtae and hybrids: Anthracoidea subinclusa

26a On C. rostrata, pilulifera, rotundata and close relatives: Anthracoidea inclusa

= On C. canescens, with glabrous spores, lives the closely related Anthracoidea karii

26b On Carex sect. Acutae: Anthracoidea echinospora

26c On C. canescens and relatives: Cintractia fischeri

= On C. pilulifera, the ovary smut Cintractia caricis-oederi has been described.

27a On many sedges species complexes of ovary smuts occur. Spores irregular, ± edged, 15–26 x 12–22 µm. Wall dark brown, with very many fine warts. Nominate form on C. pilulifera: Anthracoidea caricis

27b Many fungi are ± host-specific and partially morphologically distinct:

a On C. alba. Spores ± angular, with many fine papillae, 19–27 x 12–21 µm. Also recorded from C. digitata, ornithopoda, sempervirens: Anthracoidea caricis-albae

b On C. arenaria. Spores dispersing early, rotund to elliptical, ± flattened, 13–18 x 12–16 µm.: Anthracoidea arenariae

c On C. brizoides, cespitosa, divulsa, echinata, muricata, leersii, pairae and relatives Spores irregular rotund, appearing almost glabrous at maturity, 13–20 x 12–17 µm.: Cintractia leioderma

d On C. brunnescens and hybrids. Spores 15–22 x 10–16 µm, ± irregular rotund-elliptical, with yellowish-brown glabrous or minutely punctated membrane; therefore clearly different from Anthracoidea fischeri: Anthracoidea karii

e On C. chordorrhiza. Spores rotund to elliptical, 15–22 x 11–19 µm; wall dark-brown, with, only slightly protruding, about equal warts; forms transition to warty-spored species. Usually all spikes with many or all ovaries diseased: Anthracoidea aspera

f On C. digitata and relatives. Spores ± elliptical, very polymorphic, 18–27 x 13–22 µm. Wall brown, with many densely positioned, not protruding, rotund or ± elongate small warts. Smut grains rotund, 2–5 mm across; usually solitary to several in the fruiting spikes, sometimes dropping as a whole: Anthracoidea irregularis

g On C. dioica and hybrids. Spores rotund-elliptical, ± angular, 18–26 x 16–22 µm. Wall dark brown, with densely arranged inclusions, making the membrane almost non-transparent. Close to nominate form: Anthracoidea turfosa

= Also found on C. dioica, distinguished by its smaller spores is Anthracoidea caricis-dioicae

h On C. ferruginea: Anthracoidea caricis

i On C. flacca, buxbaumii. Smut grains relatively soft and soon dusty; spores rotund or elliptical, sometimes slightly angular, 16–26 x 14–22 µm.: Anthracoidea pratensis

k On C. glareosa. Spores 15–21 x 13–19 µm; membrane very thick, up to 2.6 µm, with densely arranged ± coalescing, minute papillae: Cintractia glareosa

l On C. hirta. Spores rotund- to oblong-oval, usually strongly flattened and irregular angular, 16–26 x 13–21 µm; wall dark-brown, up to 2 µm thick, almost glabrous: Cintractia angulata

m On C. limosa and relatives. Spores rotund to elliptical, often flattened, 17–26 x 14–24 µm; wall almost glabrous. Smut grains 2–5 mm across; envelope soon rupturing; spores crumbling: Anthracoidea limosa

o On C. panicea and relatives. Spores rotund- to oblong-oval, very irregularly shaped and rimmed, densely finely punctate, 18–20 x 13–17 µm. Other hosts are C. echinata, nigra, praecox, pilulifera: Cintractia baccata

gallers on Prunus

pub 16.xi.2019

Dichotomous table for gallers on Prunus

by Hans Roskam

1a On above-ground parts => 3

1b On roots or root collar => 2

2a Roots with small elongated or nodule-shaped swellings. P. domestica, persica: cf. Meloidogyne hapla

2b Pea-, walnut- up to even fist-size proliferations on root collar, also on basal root- or stem parts. P. amygdalus, armeniaca, avium, cerasifera, domestica, insititia, mahaleb, persica: Agrobacterium tumefaciens

3a On flowers or fruits => 52

3b On vegetative parts => 4

4a Malformations not bush- or broom-like => 7

4b Conspicuous witches’ brooms or mistletoe gall => 5

5a Witches’ brooms => 6

5b Upper stem parts or older branches with spindle-, club-, or nodule-shaped swellings bearing: Viscum album

6a Conspicuous, occasionally even up to 3 m large, perennial witches’ brooms. Basal part of twigs distinctly swollen, deflected downwards and then growing steeply erect. Leaves variously swollen, bladder-like, leaf blades hardly thickened; on underside usually covered with a grey-white pubescence of asci when the fungus has matured. On P. avium, less frequent on P. cerasus, fruticosa, and some close foreign cherries: Taphrina wiesneri

6b Similar, usually less substantial, only exceptionally up to 1 m large, perennial witches’ brooms on P. cerasifera, domestica, insititia, spinosa, ussuriensis: Taphrina pruni

= Witches’ brooms also occur occasionally on species belonging to the subgen. Euprunus, especially on P. spinosa, without verified causers

6c On P. armeniaca: Taphrina armeniacae

= Taphrina insititiae is also able to cause witches’ brooms on Prunus species. The mycelium develops intercellularly in the branches and leaves

7a On shoot ends, buds or on leaves => 16

7b On younger or older shoot axis => 8

8a On green shoots or thin twigs => 10

8b On stronger stem parts => 9

9a Bark with localised thickenings, cancer-like proliferations and exuding gum. Prunus spp.: Enarmonia formosana

= From similar cancer-like bark necrosis has also been described the sac fungus Phomopsis prunorum

= Cancers on P. avium are also caused by viruses.

9b Closed, or later on opening, variously shaped Nectria cancers, which often result in stronger bending of younger stems, sometimes occurring on older stems in large numbers. P. serotina: Neonectria ditissima

9c Smooth bark of variously aged stems with small irregular rimmed depressions, which contain a scale, up to 1.6 mm long. P. avium, domestica, dulcis, persica: Epidiaspis leperii

9d Woolly apple aphid on cancers of stem and branches. P. domestica: Eriosoma lanigerum

10a On annual, still green shoots => 12

10b On thin, wooden, two- to a few years old twigs => 11

11a Rotund galls, up to about 2 mm long, at first green, then often dark-red, eventually ± browned, single or usually clustered on veins of bud scales or leaves of 2 years old shoots. P. amygdalus, domestica, insititia, armeniaca: Acalitus phloeocoptes

11b Similar galls on P. spinosa: Acalitus prunispinosae

11c Single or several globular to irregular oblong proliferations, mainly one-sided with cracked or rugose, often gum covered surface; on two- to a few years old twigs. P. armeniaca, persica: Stigmina carpophila

11d Rotund to spindle-shaped swelling often at base of side stems. Inside is a yellow lepidopteran caterpillar with contrasting head. P. padus: Argyresthia semifusca

12a Stem with cup-shaped, nodular or bulge-like malformations > 13

12b Shoot tip covered by dense, white mycelium, variously extending to leaves. P. persica: Podosphaera pannosa

13a Malformations smaller than 5 mm => 14

13b Malformations larger than 5 mm, elongate spindle-shaped swellings => 15

14a Green axis with small, almost cup-shaped protuberances. P. padus, avium, communis, domestica, dulcis, mahaleb, spinosa: Phyllocoptes eupadi

14b Small nodular protuberances, often with several along the axis. Prunus spp.: Stephanitis pyri

15a Extensive swellings, up to 35 mm long and 7 mm wide, yellow-green, mainly one-sided, ± curved bulge-like on P. padus: Taphrina padi

15b On P. domestica, spinosa. Similar but smaller swellings of axial parts: Taphrina pruni

15c Similar malformations on twigs of P. persica: Taphrina deformans

16a On shoot tips or leaves => 18

16b On buds of woody or almost woody young shoots => 17

17a Bud transformed into a 4–5 mm long, acute, rotund or egg-shaped, thin-walled greenish, eventually browned gall, surrounded at base by several scales. Inner wall lined with mycelium. Containing a whitish, later on yellow-red larva. P. cerasifera, domestica, fruticosa, insititia, spinosa and relatives: Asphondylia pruniperda

17b Abnormal multiplication of buds; flowers and fruits do not develop. Attacks result in the death of trees. P. dulcis, persica: Odinadiplosis amygdali

17c Discoloured swellings of stunted shoot buds up to 15 mm long. P. padus: “Anthonomus bicinctus”

17d Bud, with involvement of neighbouring stem parts, strongly swollen; galls inside fleshy. P. padus: Taphrina padi

17e Similar malformations of buds. P. spinosa: Taphrina pruni

17f Similar malformations of buds. P. fruticosa: Taphrina wiesneri

17g Malformation of buds and leaves, caused by gall mites. P. armeniaca, cerasifera, persica: Eriophyes armeniacus

18a Local; or extensive malformations on single leaves or also on many, mainly terminal leaves => 21

18b Galls on shoot tips => 19

19a Axis shortened, leaves bunched together, rolled, uneven, ± rugose and cartilaginous => 20

19b Young leaves folded as in the buds, weakly swollen and pale-green. Galls at base sometimes partially bent outwards. Containing several white larvae. P. spinosa: Unidentified gall midge

20a On P. armeniaca, avium, cerasifera, domestica, fruticosa, insititia, spinosa: Dasineura tortrix

20b White larvae develop as inquilines in same galls. P. domestica, insititia, spinosa: Dasineura sodalis

21a Various malformations caused by aphids => 39

21b Different malformations caused by other causers => 22

22a Leaf blade ± browned or curled and curved inwards, caused by mites, spittlebugs or fungi => 36

22b Leaf blade with expanded marginal rolls, folded over, pouch-like, formation of hairs or small localised protuberances => 23

23a Leaf blade with pouch-like folds or with abnormal pubescence, or localised protuberances => 26

23b Leaf margin rolled or folded over => 24

24a More or less rugose and discoloured upward roll of leaf margin => 25

24b Leaf margin largely deflected downwards. Malformation ± sickle-shaped, at first green, then discoloured yellowish. P. domestica, spinosa: Pristiphora monogyniae

25a On P. armeniaca, avium, cerasifera, domestica, fruticosa, insititia, spinosa: Dasineura tortrix

25b In similar roll of leaf margin on same host larvae of the probably inquilinous: Dasineura sodalis

26a Leaf blade with abnormal pubescence or localised protuberances => 27

26b Border of leaf blade, or leaf blade at midrib or side vein with pouch-like, downward fold. Folds (10) 20–30 (50) mm long, thickened, cartilaginous, often reddened. Eventually with narrow, opening longitudinal slit on upper side. Usually containing several orange-yellow or -red larvae. P. domestica, fruticosa, insititia, spinosa, etc.: Putoniella pruni

27a Pouch-, horn-shaped or nodular galls, or small protuberances or warts => 32

27b Leaf blade with abnormal pubescence caused by gall mites => 28

28a Erinea situated along venation or in vein axils => 30

28b Felt pubescence mainly situated freely on the leaf blade => 29

29a On P. padus, mainly on underside of leaf blade, irregular, at first grey-white, then rust-brown, erinea. Hairs short, thick, club-shaped or irregular: Eriophyes distinguendus

29b Abnormal pubescence on underside of leaves of P. amygdalus, persica: Unidentified gall mite

= Whitish erinea on underside of leaf blade base are caused by Eriophyes similis, normally living in marginal pouch galls

30a Erinea mostly in vein axils, variously extending onto the leaf blade => 31

30b Felt-like pubescence along the veins. Hairs resembling the normal ones. P. insititia, spinosa: Unidentified gall mite

31a Vein axil with upward protuberances; abnormal pubescence on underside. P. spinosa: Unidentified gall mite

31b Small pustules on leaf blade. P. spinosa: Unidentified gall mite

31c Brown tufts of hairs in the vein axils on underside. P. padus: Unidentified gall mite

= The polyphagous thrips Taeniothrips inconsequens, especially frequent on fruit trees, causes small, yellowish, glabrous archings in the vein axils of P. padus

32a Galls pouch-, horn-shaped or globular, caused by gall mites => 34

32b Leaf blade with small upward protuberances or with warts on underside => 33

33a Leaf blade with small protuberances on upper side, with corresponding small depressions on underside, containing flat froth-covered nymphs. P. padus: Psylla sp.

33b Leaf blades on underside with multicellular warts, up to 1 mm across, golden-yellow; also occurring on basal petioles or stems of saplings. P. spinosa: Synchytrium aureum

34a Galls mainly situated in the middle part of the leaf blade or in the vein axils, normally protruding from upperside => 35

34b Elongated oval galls up to 2 mm across, pouch-shaped mainly at margin of leaf blade, protruding strongly on underside and closed, with a weakly pubescent, bulging rimmed slit on upperside. Galls sometimes inversely situated. Of various shape, depending on the substrate, exceptionally also occurring on petioles, on young stems and even on young fruits. P. armeniaca, domestica, fruticosa, insititia: Eriophyes similis

34c Similar galls in P. spinosa: Acalitus prunispinosae

34d Hairy galls on upperside of leaf along the midrib and the veins, on the underside a small opening. P. cerasus, domestica, mahaleb, padus, spinosa: Eriophyes homophyllus

35a Gall horn-shaped on upperside, up to about 4 mm long, with exit hole on underside. Exceptionally also occurring on underside, on petiole or on young stems. P. padus: Phyllocoptes eupadi

35b Rotund or club-shaped pouch galls, up to 2 mm long and 3 mm high with exit hole on underside. Occasionally in vein axils. Exceptionally also on petioles or on young stems. P. domestica, fruticosa, insititia, spinosa: Eriophyes prunianus

= The eriophyoid mite Eriophyes similisprunianus causes protruding pouch- or finger-like galls with a pilose opening on the lower surface of the leaf blade of P. domestica, cerasifera

= Leaves of P. avium, cerasus may have tubercular- to leaf-like proliferations “enations” between the veins. Leaves often rosette-like bunched together or developing as terminal leaf tufts. Leaf blades narrowed, reduced, ± thickened, chequered mosaic-like or mottled, disfigured at margins. Recorded as virus diseases, partly also on cherry and related Prunus species

= Also a “pock disease” is induced by a virus on P. domestica.

36a Leaf blade conspicuously undulately curled or swollen, bladder-like sometimes strongly curved => 37

36b Leaf blades ± converging upwards, markedly stunted, initially mottled yellow, then browned. Mites free-living mainly on the upperside. P. armeniaca, avium, cerasifera, cerasus, domestica, mahaleb, padus, persica, triloba, etc.: Aculus fockeui

37a Conspicuous curls or ± accentuated bladder-like swellings caused by fungi => 38

37b Terminal leaves of young shoots loosely rolled inwards or strongly deflected and twisted over their tops, densely crumpled at infestation site and often deep-green. Containing a froth-covered nymph. P. avium, cerasus, domestica, padus, etc.: Philaenus spumarius

38a Usually expanded parts of leaf blades swollen, bladder-like, curled, curved or ± twisted. Swellings pale green or often intense red, with fleshy thickened, brittle tissue. Stem sometimes stunted resulting in bushy aggregations of leaves. At maturity covered mainly on underside with whitish asci. P. persica: Taphrina deformans

38b Mainly in southern areas, also in GB, occur less conspicuous fleshy curls also on almond, P. amygdalus: Taphrina deformans

38c Conspicuous bladder-like galls on leaves of P. serotina; also the inflorescences may be heavily infested. Introduced from the Nearctic together with its host plant: Taphrina farlowii

38d Several leaves of developing buds are soon completely or partially ± swollen, bladder-like. Diseased leaf parts are hardly thickened, often lighter green than the healthy ones, occasionally reddened at margins. Characteristic symptoms, especially on partially infected leaves. Often on young long shoots all leaves are diseased; stems are ± elongated and thickened. At maturity of fungus the asci develop mainly on underside as an ash-grey covering. P. avium, cerasus, fruticosa: Taphrina wiesneri

38e Similar malformations lacking a reddening of diseased leaf blades. P. domestica, insititia, spinosa: Taphrina pruni

= Red midge larvae developing inside dry fruits of P. domestica containing the fungus Polystigma rubrum belong to the gall midge Dichodiplosis langeni

39a Malformation of single to several leaves on young shoots, which are not conspicuously stunted in development => 44

39b Malformation of many terminal leaves on shoots which are stunted in longitudinal growth => 40

40a Loose clusters at shoot tips => 41

40b Leaves on shoot tip often bunched together in large clusters. Leaf blades strongly curled, ± narrowly rolled inwards. P. avium, sometimes on P. serratula, yedoensis: Myzus cerasi subsp. pruniavium

41a On P. cerasus, spinosa, mahaleb => 42

41b On P. persica strong roll of the not discoloured, curled, sometimes bulging leaves, which are ± densely clustered, nest-like, on the shortened, partially swollen shoot tipL Brachycaudus schwartzi

41c Curled narrow leaf rolls of P. amygdalus, occasionally also of P. persica: Brachycaudus amygdalinus

42a On P. cerasus, spinosa => 43

42b On P. mahaleb. Several, ± stunted and disfigured leaves bunched together in loose clusters at shoot tips: Myzus lythri

43a On P. cerasus. Shoots slightly stunted, leaves weakly deflected, arched: Myzus cerasi

43b On P. spinosa. Leaves strongly curled and shoot tips densely bunched together. Aphids often occurring in masses: Brachycaudus prunicola

= Blackman (2010) furthermore distinguished the aphid Brachycaudus prunifex. Apterae are shiny dark green to black; body length 1.5‒2.4 mm. Colonies occur all-year-round on Prunus spinosa, in spring causing severe leaf curl and discoloration to new growth. There is also a record from P. cerasifera var. atropurpurea. Suggestions of a facultative host alternation to Tragopogon do not appear to be substantiated. Alate males have been collected in 9, but oviparae are not yet recorded. In GB (England, Wales), IRL, and northern F. This species has been synonymised previously with B. prunicola, which occurs on the same host throughout the rest of Eu and in C-As, but it can be distinguished from that species (and from B. schwartzi) by the longer hairs on the antennae and anterior abdominal tergite

44a Leaves with pronounced rolls and curls at margin => 50

44b Leaves only weakly rolled, swollen, bladder-like or slightly curled => 45

45a Aphids not- or only slightly powdered => 47

45b Aphids strongly to densely mealy powdered => 46

46a On P. armeniaca, domestica, insititia, spinosa. Aphid covered with dense mealy layer of wax. Leaves stunted, otherwise only weakly disfigured, slightly deflected, not curled, sometimes discoloured pale-green, occasionally marbled, later on strongly powdered by the exuded aphid wax: Hyalopterus pruni

46b On P. persica, amygdalus. Malformations and aphids similar to those of previous species: Hyalopterus amygdali

46c Aphids on the underside of the leaves, 2‒3 mm long, probably strongly resembling those of Hyalopterus amygdali. P. persica: Hyalopterus persikonus

47a Leaves only weakly swollen or arched, without conspicuous discolouration => 49

47b Leaf blade slightly to conspicuously rolled or arched, ± conspicuously discoloured or yellow spotted => 48

48a On P. padus. Fundatrices pale green; fundatrigeniae dark grey-green: Rhopalosiphum padi

48b Similar malformations causing yellow and red spots on the deflected bladder-like inflated leaves. P. padus: Myzus padellus

48c On P. persica, nana, serotina; variously shaped minor leaf archings or -rolls, which are ± brightened: Myzus persicae

48d Leaves of P. persica are tightly rolled longitudinally: Myzus varians

49a Aphid shining dark red to dark-brown or black. On P. domestica. Leaves slightly deflected, not rolled. Brachycaudus persicae subsp. semisubterraneus

49b Aphid pale green to yellowish green, rather shiny, with three darker green dorsal longitudinal stripes. On P. domestica, fruticosa, insititia, spinosa, mahaleb, ? padus, serotina, etc. Leaves only weakly arched. The apterous aphids inhabit the leaf underside, also the complete shoot: Phorodon humuli

50a On. P. domestica, spinosa and close cherries => 51

50b On P. mahaleb. Leaves in spring with yellowish discoloured, bladder-like-rugose rolls, with walls clearly thickened and ± brittle: Roepkea marchali

51a Aphid 0.9–2.0 mm long, usually pale-green; siphunculi pale, very short, 1/11 to 1/15 times body length. Tip of rostrum not reaching the metacoxae. Leaves narrowly rolled and strongly curled, shoots often ± leaning: Brachycaudus helichrysi

51b Aphid about 2.2 mm long, pale-green with dorsal cuticle sclerotic and often brownish, fundatrices brownish-red. Adults usually with dark pigmented back. Siphunculi mainly brown, 1/6 to 1/8 times body length in fundatrigeniae [viviparous parthenogenetic wingless female aphid produced by a fundatrix and giving rise to further wingless forms or to migrants]. Leaves in spring narrow and curled or rolled, converging, bleaching after departure of aphids. Shoots sometimes ± stunted. P. domestica, spinosa; sometimes P. avium. armeniaca: Brachycaudus cardui

51c Very closely related, and often mixed with foregoing: Brachycaudus cardui subsp. lateralis

52a Malformations on ovaries and fruits => 54

52b Malformations of flowers => 53

52c Abnormal multiplication of buds; flowers and fruits do not develop. Attacks result in the death of trees. P. dulcis, persica: Odinadiplosis amygdali

53a The slightly enlarged corolla remains in bud condition. Receptacle, ovary and base of stamens ± clearly swollen. Larvae jumping, single or several. P. domestica, mahaleb, spinosa: Contarinia pruniflorum

53b Flowers disfigured, unopened. The corolla, which soon dies, arches roof-like over generative parts and receptacle and sometimes regenerating tissue is eaten by yellowish, brown-headed, larvae. P. padus, also mahaleb, avium, etc.: Anthonomus humeralis

53c Flowers disfigured, unopened. P. spinosa: Anthonomus rufus</