Plant Parasites of Europe

leafminers, galls and fungi

gallers on Stellaria

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 Betula

Last modified 14.viii.2020

Dichotomous table for gallers on Betula

by Hans Roskam

1a On parts above ground => 2

1b Roots, especially close to stem, with conspicuous, irregular, ± nodule-shaped, massive proliferations. B. pendula, pubescens: Agrobacterium tumefaciens

2a On catkins or fruits => 51

2b On vegetative plant parts => 3

3a On leaves => 18

3b On shoots or buds => 4

4a On shoots => 6

4b Bud galls => 5

5a Buds greatly enlarged; scales loosely adpressed, with outward tips, brownish, grey-silky pubescent. Gall often persistent, sometimes already developing early into small, compact witches’ brooms. Betula spp.: Acalitus calycophthirus

5b Leaf buds swollen, disfigured to a variable extent. B. pendula: Eriophyes leionotus

5c On buds of B. pendula is also reported: Unidentified gall midge

6a On thinner twigs => 12

6b On older stems or branches => 7

7a Bushy malformations in or on the branches => 8

7b Bark of thicker stems or branches with nodule-shaped or open, rim-like margined cancers. Neonectria ditissima

= Globular, several cm large wood balls or the giant wood cancers, observed occasionally have unknown causes and are not true galls.

8a Complete shoot systems are disfigured into conspicuous witches’ brooms, or young twigs with ± pronounced malformations. Usually only the leaves are covered by a short lanuginose grey-white layer of asci => 9

=Regarding compact small witches’ brooms => 5

8b Branches with nodular swellings which give rise to Viscum album

9a Fungi only exceptionally cause witches’ brooms. Northern species => 11

9b Fungi usually cause pronounced witches’ brooms => 10

10a Fungus scattered on many birches. Witches’ broom persistent. Leaves usually lighter coloured than the normal ones, occasionally enlarged but hardly thickened. Betula spp., incl. cultivated foreign species. Taphrina betulina

10b ngus frequently causes pronounced witches’ brooms, but may also develop on many disfigured, ± yellowing leaves without conspicuous malformations of the branches. Taphrina nana

11a Asci with stalk cells. Witches’ brooms only caused exceptionally; the fungus is merely located on darker green areas, on the underside sometimes ± rust-brown discoloured, usually on undisfigured leaves. Taphrina splendens

11b Asci without stalk cells. The fungus is located on often many, sometimes slightly enlarged, soon yellowing leaves of the infected plant, only exceptionally do witches’ brooms disfigure shoots. B. glandulosa, nana, pubescens, x alpestris. Taphrina bacteriosperma

12a Inducer inside the malformations => 14

12b The flat inducers are located in rim-surrounded depressions in the bark and, in case of heavy infestation, sometimes additionally on swollen or disfigured twig => 13

= Minute elevations on twigs of B. pendula, caused by the damselfly Chalcolestes viridis, are not true galls

13a Scale ± pear-shaped, 2.5–3 mm long, white to grey-white, females wine-red. Betula spp.: Chionaspis salicis

13b Scale ± rotund, 1.2–1.6 mm across, whitish to brownish-grey, with dark-yellow median spot. Insect red. Betula spp.: Epidiaspis leperii

14a Shoots with elongated spindle-shaped or ± distinctly separated, nodule-shaped swellings, up to 1 cm wide => 15

14b Young shoots with various proliferations of walls of wounds. Betula spp.: Cryptorhynchus lapathi

= Large nodular outgrowths up to several cm, like those found laterally on young shoots, cannot be attributed to a particular cause and could be considered as teratologies.

15a Inducers inhabit only galls on first-year twigs; galls on woody twigs vacated or occupied by successoria (secondary inhabitants) => 16

15b Older shoots with spindle-shaped thick swelling, up to 50 mm long and 15 mm wide. Gall extending over several internodes, broadest in the upper part caused by a swelling of the woody part; bark only slightly swollen. Inside a long tunnel. B. pendula, pubescens: Unidentified lepidopteran

16a Axis swollen at the top of the shoot => 17

16b Swelling situated below a node, rotund or more or less spindle-shaped, 5–10 mm long; broadest at the node. In a long tunnel inside the pith is a pale-green to greenish-yellow caterpillar with a pale brown head capsule. Exit hole in the leaf axil. Betula spp.: Epinotia tetraquetrana

17a Axis swollen at the top of the shoot. B. pendula, pubescens: Acleris notana

17b Young shoot with a slender swelling on all sides which usually starts below the top and expands downwards over several internodes. Internodes sometimes ± shortened. A tunnel in the pith contains a single caterpillar. B. pendula, pubescens and related species. Heliozela hammoniella

18a Galls on the leaf blades => 23

18b Malformations only on petioles and leaf veins => 19

19a Swellings hardly 2 mm across or smaller => 21

19b Galls several mm long => 20

20a Petiole shortened, over its whole length thickened; at the base of the leaf blade an oblong-elliptical excision. Betula spp.: Heliozela hammoniella

20b Main-, or more rarely lateral veins, occasionally also the petiole, with spindle-shaped, glabrous, hard, pale-green or often also ± purple-red swellings especially visible on the undersides. Each gall contains one single larva; in largely coalesced galls several white, later on pale red larvae. B. pendula, pubescens, x intermedia: Massalongia rubra

20c Much weaker, only up to about 3 mm long, pale green, thin-walled swellings, developing usually solitary per leaf blade on first or second order lateral veins. Containing a single white larva. B. pendula: Unidentified gall midge

21a Each swelling contains a single egg; the emerging larva leaves the rapidly collapsing egg capsule. “Procecidium” (oviposition scars, not true galls ) => 22

21b Up to 2 mm long, corn-like or more wart-like galls, up to 1 mm high, on petioles and veins. Cavity with some short, 1-celled hairs. B. pendula, pubescens: Cecidophyopsis betulae

22a Petiole, more rarely also the midrib, with two rows of egg capsules. B. pendula, pubescens: Hemichroa crocea

22b Egg capsules arranged in one row on the midrib or also on the side veins. B. pendula, pubescens: Craesus septentrionalis

22c In similar way develops on birches Craesus latipes

23a Leaf blade with weak to strong spoon- or bladder-like swellings caused by mites, aphids or fungi, whose asci develop on the galls => 40

23b Malformations different => 24

24a Galls mainly on unfolded leaf blades => 27

24b Leaves folded or rolled upwards => 25

25a Malformations without abnormal pubescence => 26

25b Leaf margin rolled upwards; on older leaves often only at the leaf base; early infected leaf blades may be completely taken up in a leaf roll with densely pubescent surface. Unidentified gall mite

26a The leaf blades of young leaves do not develop completely and remain mostly folded upwards. Midrib and basal part of the side veins thickened, pale green or ± reddened. Several yellowish-white larvae. B. pendula: Resseliella betulicola

= The white larvae of the gall midge Dasineura betuleti live, probably as inquilines, in similar galls which may be caused by the previous specie

26b Leaves close together at the tips of young shoots, severely stunted, rolled, curled and yellow-green. Unidentified thrips

= Stunting of leaves are occasionally caused by the thrips Mycterothrips consociatus

27a Galls situated in the leaf blades => 28

27b Teeth of the leaves with rapidly collapsing egg capsules after the larvae have emerged. “Procecidia” (oviposition scars, not true galls). B. pendula, pubescens: Pristiphora testacea and/or Arge pullata

27cPredominantly on Salix, occasionally on Betula: Pristiphora melanocarpa

28a Leaf blade with ± expanded felt-like cover => 34

28b Leaf galls of roughly defined shape, usually not excessively pubescent => 29

29a Galls wart-, nodule- or ± pouch-like, under 2 mm wide => 31

29b Parenchyma galls; rotund, weakly protruding on both leaf surfaces, about 3–4 mm wide; yellowish, usually red-rimmed. Often several per leaf => 30

30a On B. pendula, pubescens. Each gall contains an initially white, eventually sulfur-yellow larva. Galls usually several per young leaf. Anisostephus betulinus

30b On B. pendula, pubescens. Older leaf blades with solitary or only a few, very flat, concolorous, hardly protruding parenchyma galls. Containing a single pale to lemon-yellow larva. Massalongia betulifolia

30c On B. nana. Similar thick-walled parenchyma galls, strongly arched on the underside. Each gall contains a single orange-reddish larva. Massalongia bachmaieri

31a Galls larger than 1 mm => 32

31b Galls wart-shaped, smaller than 1 mm, golden-yellow translucent, often many on the basal leaves or stems. B. nana, pendula, pubescens: Synchytrium aureum

32a Galls persistent, tough-walled => 33

32b Leaf tips with irregularly distributed egg capsules on the underside which rapidly collapse after the larvae have hatched. “Procecidium” (oviposition scars, not true galls). Betula spp.: Nematus cadderensis

33a Leaf blade with, scattered glabrous nodules, about 1–1.5 mm long, ± reddish, later on browned, protruding strongly on the underside and with an exit hole closed by a rim of rigid hairs; wall of the cavity glabrous. B. pendula, pubescens: Eriophyes leionotus

33b otund, up to 3 mm high, ± pubescent pouch-like protrusions on the leaf upper side, predominantly close to the margin, rarer in the vein axils; wall of the cavity provided with yellowish-white, ± cylindrical, rigid hairs. B. pendula, pubescens: Acalitus longisetosus

34a Hairs cylindrical => 36

34b Hairs club- to toadstool-shaped => 35

35a Erinea dense, ± irregularly margined, initially often intensely red, eventually ± browned, predominantly on upper side, occasionally also on the underside. Hairs irregular head-shaped or ± toadstool-like. Betula spp.: Acalitus longisetosus

35b Dense wine-red coloured erinea with irregular head-shaped hairs; predominantly at the leaf base or along the veins. B. nana: Aceria vinosa

35c Erinea usually on leaf underside, sometimes on both sides, rarely on upper side; initially whitish, later on yellowish, eventually rust-coloured or brownish. Hairs head-shaped, usually longer stalked than those of the previous species. B. humilis, nana, pendula, pubescens, etc.: Acalitus rudis

36a Erinea on the leaf underside, in arched protrusions, predominantly in vein axils => 39

36 Erinea on the leaf underside, also in arched protrusions, but free in the leaf blade or near the margin, or erinea predominantly on petioles or leaf veins => 37

37a Erinea mainly in areas on the leaf blade => 38

37b White, also reddened erinea predominantly on the petioles and on the venation of the leaf base or extending from the stalks into the leaf base venation. B. pendula, pubescens, pubescens var. glabrata, etc.: Eriophyes leionotus

38a Leaf blades of B. nana predominantly close to the margin with ± discoloured archings on the upper side, which contain purple-red to almost whitish felt masses with cylindrical hairs. Aceria fennica

38b Leaves of B. pubescens with upward archings predominantly on the leaf blade, more rarely in the vein axils, which display on the underside ± dense, cylindrical, rigid, whitish-yellow hairs. Acalitus notolius

39a On the upper side arched, glabrous or more rarely weakly pubescent protrusions in the vein axils containing on the underside cylindrical, soon browned, densely packed, not spiralling hairs. B. pendula, pubescens: Acalitus longisetosus

39b Erinea relatively loose, with cylindrical, pointed contorted hairs; usually on the underside in rotund to oval, ± heavily pubescent pale green bladders, situated predominantly in the vein axils at the base of the midrib, more rarely close to the margin or on the leaf blade. B. pubescens & var. pumila, x intermedia: Eriophyes lissonotus

39c In similar galls, but containing beads or short finger-shaped blunt hairs. B. pubescens & var. pumila, x intermedia: Eriophyes leionotus

40a Galls caused by aphids or mites => 44

40b Malformations caused by fungi which fruit on the gall surface => 41

41a Malformations often only locally; on single or several leaves of a shoot => 43

41b Leaves on the infected, systemically attacked shoots often hardly disfigured, although completely or substantially attacked. Leaf blades usually paler, ± slightly enlarged and slightly arched upwards, without conspicuous thickening => 42

42a Fungus frequent or with only boreal-alpine distribution. Initially infections of fungi which occur on the same plant or in the same host population in conspicuous witches’ brooms. Asci with stalk cells

a Leaf blades of young shoots pale green, sometimes slightly enlarged. Axial parts ranging from not disfigured to witches’ broom-like malformations. Betula spp.: Taphrina betulina

b Similar malformations. Betula spp.: Taphrina nana

42b Usually witches’ broom-like malformations develop without simultaneous malformations of shoots and leaves

a Asci with stalk cells. Malformations rarely on axial parts, usually minor on leaves. Betula spp.: Taphrina splendens

b Asci lacking stalk cells. Leaves of the infected shoots often yellowing, sometimes with slightly enlarged leaf blades. Betula spp.: Taphrina bacteriosperma

43a eaves often with conspicuous yellowish or reddish discoloured, thickened, bladder-like swellings. Asci lacking stalk cells. Betula spp.: Taphrina carnea

43b Minor swellings, sometimes several per leaf on early infected young leaves. Infection sites about 2–10 (15) mm across, rotund, ± discoloured. Asci with stalk cells. Betula spp.: Taphrina betulae

43c On leaves, probably non-cecidogenic. Betula spp.: Melampsoridium betulinum

44a Malformations caused by aphids => 45

44b Leaves ± spoon-shaped bent downwards. Leaf blades soon yellowish to brownish discoloured; on the underside with free-living mites. Betula spp.: Epitrimerus subacromius

45a Leaves to various extents folded or curled => 46

45b Leaves with irregular, conspicuous bladder-like swellings, up to 10 mm high, upwardly directed, which occupy a major part of the leaf blade. Aphid egg-shaped, dark purple-red, covered with wax. B. x alpestris, pendula, pubescens: Hamamelistes betulinus

46a Aphids in various shades of yellow or green, or (because of its banded pattern) almost black => 47

46b Aphid dull brown, 2.5–3.5 mm long with brownish transverse stripes; on the underside of irregular undulate leaves. B. pendula, pubescens: Symydobius oblongus

47a Antennae shorter than body => 48

47b Antennae longer than body. Aphid about 2.5 mm long, pale yellowish or –greenish, with yellowish or greenish spots. Younger leaves curled, in cases of heavy infestation upwardly arched. B. pendula, pubescens: Calaphis betulicola and/or Calaphis flava

48a Aphids with dark coloured or margined short siphunculi => 49

48b Aphid about 1.3–2 mm long, greenish-white to pale yellowish-green. Siphunculi very short, yellowish-white, like the also equally short wart-shaped cauda. Antennae reaching beyond the middle of the body. Infected leaves ± distinctly upwardly arched, often withering prematurely; on the underside with considerable colonies. B. humilis, pendula, pubescens: Betulaphis quadrituberculata

49a Aphids more than 2 mm long; siphunculi black or black-green; antennae half the body length => 59

49b phid 1.5–2 mm long, almost egg-shaped, pale or yellowish-green, with broad, dark-green to brown, medially interrupted transverse bands. Antennae often shorter than half the body length. Internodes of young shoots ± stunted. Leaves curled or, in case of heavy infestation, upwardly arched. B. pendula, pubescens: Glyphina betulae

50a Aphid about 2.5 mm long, usually yellowish or greenish, deep to almost black-grey coloured by lighter or darker blackish transverse bands. Siphunculi very short, black; cauda only wart-shaped, green. Leaf margins ± downwardly bent and folded. B. pendula: Callipterinella calliptera

50b Similar malformations. Aphid about 2 mm long, pale yellow, abdomen near thorax with a wide brown-red transverse band, a large greenish-black spot behind, caudal margin brown-red. Siphunculi black-green, cauda pale yellow. B. pendula: Callipterinella tuberculata

51a Malformations visible on outside of catkins => 54

51b Malformations only visible after crumbling the female catkins => 52

52a Gall restricted to fruits, which are enlarged and paler than the healthy ones => 53

52b Galls restricted to the somewhat thickened base of the fruit scales, which are firmly connected to the spindle of the catkin. Containing a single bright orange-red larva. Betula spp.: Semudobia skuhravae

53a Fruit more or less egg-shaped, swollen, dull, more or less pubescent, wings smaller than those of healthy fruits, but distinctly developed. Exit circular, distinct. Contains a single bright orange larva. Betula spp.: Semudobia betulae

53b Fruit almost globular, swollen, glossy, glabrous, wings almost completely reduced, exit indistinctly translucent. Contains a single bright orange-red larva. Betula spp.: Semudobia tarda

= A frequent inquiline is the gall midge Dasineura interbracta, whose pink larvae adhere to the outside of the galls and feed on these galls at the expense of Semudobia betulae as well as S. tarda, larvae of which eventually die

= A less frequent inquiline gall midge: Dasineura fastidiosa, whose pale yellowish larvae adhere to the outside of the galls and feed on these galls at the expense of mainly Semudobia betulae, larvae of which eventually die

54a Caterpillars with distinct thoracic legs => 55

54b Larvae with distinct head capsules, lacking distinct thoracic legs; inside the variously stunted fruit catkins. They tunnel along the spindle of the catkin and feed both on plant tissues and on midge larvae and their galls. B. pendula, pubescens: Betulapion simile

54c Catkin enlarged, caused by gall midges. B. pendula: Unidentified gall midge

= Furthermore the aphid Callipterinella minutissima has been recorded from birch catkins.

55a Catkins shortened, appearing ± thickened, often twisted screw-like and not reaching maturity. B. pendula, pubescens: Cochylis nana

55b atkins similarly stunted. B. pendula, pubescens: Epinotia bilunana

55c Further facultative deformations are occasionally caused by the caterpillar of Epinotia tenerana

gallers on Filago

Last modified 10.vii.2020

Dichotomous table for gallers on Filago

(incl. Logfia, Phagnalon)

by Hans Roskam

1a Leaves at the shoot tip thickened, coalesced to a gall. F. gallica, germanica, minima. Acentrotypus brunnipes

1b Tips of flowering and vegetative shoots distorted, available leaves twisted with inrolled margins, stems shortened; infected with green or yellowish aphids covered with white wax. F. arvensis, germanica, lutescens: Pemphigus populinigrae

1b Terminal swellings of shoots. Phagnalon saxatile, rupestre: Spathulina sicula

gallers on Ficus

Last modified 10.vii.2020

Dichotomous table for gallers on Ficus

by Hans Roskam

1a On parts above ground => 2

1b Nodular swellings on roots. F. carica: Meloidogyne hapla

2a Malformations of leaf blade => 4

2b Small glossy galls inside fig fruit => 3

2c ranch cankers. F. carica: Phomopsis cinerascens

3a On F. carica, cordata subsp. salicifolia, palmata, sycomorus: Blastophaga psenes

3b On F. sur: Blastophaga occultiventris

3c Terminal part of young shoots stunted; leaves folded upwards and transformed into irregular pods the margins of which touch at several places; both of the leaf blade halves may be rolled completely up to the midrib and form a succulent, brittle cylinder. External surface reddish with many reddish spots, ± coalescing if severely infected. F. elastica, benjamina, microcarpa: Gynaikothrips ficorum

3d Female florets within the fig, develop into a small, globular shining gall. F. ? benjamina, microcarpa: Eupristina verticillata

= Three more fig wasp species have been recorded in florets of syconia, viz., Blastophaga psenes, Odontofroggatia galili and Pleistodontes sp.

4a Half-globular swellings, protruding on upperside of leaf, with corresponding depression on underside, 1–2 mm across. F. sycomorus: Aleyrodes sp.

4b Leaf blade rolled upwards, along midrib, with small reddish elevations scattered on underside, and corresponding depressions on the other side. F. benjamina: Unidentified gall mite

= On F. carica the gall mite Aceria ficus causes injuries of fig buds and rolls of leaf margin and cause leaf chlorosis, rusting, bronzing and distortion, causing in premature leaf drop. The mite is involved in vectoring the ficus mosaic disease agent

4c Conspicuous leaf galls caused by thrips. F. elastica, benjamina, microcarpa: Gynaikothrips ficorum

4d Irregular, hairless swelling of the leaf, about equally protruding at both faces, ± a cm in diameter, often several coalesced in blister galls, usually considerably extended over leaf surface. Caused by fig wasps. F. microcarpa: Josephiella microcarpae

4e Small discoloured leaf galls, mature galls become thick and brown. F. benjamina, microcarpa: Horidiplosis ficifolii

gallers on Ferulago

Last modified 10.vii.2020

Dichotomous table for gallers on Ferulago

by Hans Roskam

1a On part of umbel or fruits => 4

1b On vegetative parts => 2

2a Galls caused by animals => 3

2b Oblong bulges on leaf veins, -stalks and stems, bearing aecia. F. campestris, communis, sadleriana: Puccinia ferulae

= Also known from Mediterranean, SE-Eu, Ferulago hosts is the rust Uromyces ferulae, with cecidogenic aecia.

3a Yellowish, wrinkled thickenings on midrib and tips of leaflets. F. campestris: cf. Ditylenchus dipsaci

3b lmost nest-like deflected larger parts of leaves, associated with curling of inserted leaflets on stunted midrib. F. campestris: Philaenus spumarius

4a Centre of stalk of (partial) umbel with one- or several-chambered tough-walled, ± club-shaped swellings. Each chamber containing a single larva. F. campestris, setifoliae: Lasioptera carophila

4b Fruits inflated, bladder-like globular, distinctly protruding above the umbel, containing a red larva. F. campestris: Kiefferia pericarpiicola

gallers on Ferula

Last modified 9.vii.2020

Dichotomous table for gallers on Ferula

by Hans Roskam

1a Galls in umbels and fruits => 2

1b Oblong swellings of variable gradation on leaf veins, -stalks, densely covered with aecia. F. communis, sadleriana: Puccinia ferulae

= Also known from Mediterranean, SE-Eu, Ferula hosts are the rusts Uromyces ferulae and Uromyces graminis, with cecidogenic aecia

1c Leaf sheath especially close to umbel inflated, bulging and swollen, succulent, often lacking leaf blade. F. communis: Jaapiella hedickei

2a Fruit swollen, rotund or pear-shaped, conspicuously bent if only one half galled. F. heuffelii: Asphondylia ruebsaameni

2b Galls in umbellules and fruits, inside wall lined with mycelium. F. communis:
Lasioptera carophila

gallers on Fagopyrum

Last modified 9.vii.2020

Dichotomous table for gallers on Fagopyrum

by Hans Roskam

1a On parts above ground => 2

1b Nodular swellings on main-roots, occasionally on thicker side roots. F. esculentum, tataricum: Meloidogyne hapla

2a Malformations caused by animals => 3

2b Leaf blades with conspicuously arched, pale spots, covered on underside by a down of branched conidiophores. F. esculentum, tataricum: Peronospora ducometi

3a Malformation usually of several terminal leaves, caused by aphids or spittlebugs => 4

3b Complete plant stunted, often excessively branched. Single shoots shortened at base, thickened, ± curved. Axial parts of leaves swollen. Leaf blades partially variously thickened and disfigured. Galls ± wrinkled, necrotic. Containing many eelworms. F. esculentum, tataricum: Ditylenchus dipsaci

4a Black aphids. Leaves singly or on shoot tip with several bulges, margin ± deflected. F. esculentum: Aphis fabae subsp. solanella

4b Stunting, one-sided distortion and clustering of variously disfigured leaves by infestation of stem. Infected leaf blades deflected, curled and often intense green. F. esculentum, tataricum: Philaenus spumarius

gallers on Laser

Last modified 9.vii.2020

Dichotomous table for gallers on Laser trilobum

by Hans Roskam

1a On leaves => 2

1b Centre of (partial) umbel or stalk of umbel ± swollen, globular to club-shaped. Gall one-to multi-chambered, inner wall covered with mycelium. Each chamber containing a red larva. Lasioptera carophila

2a Bulge-shaped pads bearing yellowish spermogonia and aecia on petioles, -midrib and main veins. Puccinia sileris

2b Leaf tip undulately curved. Trioza sp.

gallers on Lappula

Last modified 8.vii.2020

Dichotomous table for gallers on Lappula

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. L. squarrosa, myosotis: Meloidogyne hapla

2a Large parts of plant disfigured. Excessive leafiness, abnormal pubescence or inflorescence stunted, ± densely pubescent, flowers stunted or partially leafy. L. squarrosa, myosotis: Aceria eutricha

2b Yellow, also reddish to brown nodules developing from a single cell, occasionally coalescing and sometimes with additional swelling on stems and leaf veins arranged in ridges or crusts. L. squarrosa, myosotis: Synchytrium myosotidis

gallers on Koenigia

Last modified 8.vii.2020

Dichotomous table for gallers on Koenigia islandica

by Hans Roskam

1a Stem with about 1–5 mm long bulges, 1–2.5 mm thick, irregular tuber- to barrel-like, sometimes distorted, at first lead-grey translucent, with black dusting after rupturing. Microbotryum koenigiae

= The rare ovary smut Microbotryum picaceum with irregular globular to elliptic spores attacks fruits, which are soon destroyed. Wall densely covered with minute punctated warts

gallers on Kickxia

Last modified 8.vii.2020

Dichotomous table for gallers on Kickxia spuria

by Hans Roskam

(comp. Linaria)

1a Galls on roots, sometimes encroaching onto basal stem part => 2

1b Spongy, pale green swelling on basal shoot parts; galls occasionally also encroaching onto leaf midrib. Ditylenchus dipsaci

2a Galls conspicuous, more or less globular to tuberous => 3

2b Side roots with slender spindle-shaped swellings on all sides, bearing side roots. Meloidogyne hapla

3a Roots with rotund swellings, containing a single, curved beetle larva in chamber. Rhinusa collina

3b Similar, irregular tuberose, compact swellings on upper part of main root, sometimes on basal stem part or terminally on side roots. Galls contain many black spores. Melanotaenium hypogaeum

gallers on Jurinea

Last modified 7.vii.2020

Dichotomous table for gallers on Jurinea

by Hans Roskam

1a Leaf blade on the upperside with many pouch-shaped galls, ± 2.5 mm across, at the base somewhat constricted, usually rather strongly pubescent ± reddish. Opening on the underside, densely white tomentose. J. consanguinea, mollis: Aceria brevicincta

1b Receptacle hardened, sometimes disfigured, slightly swollen. J. mollis.
cf. Tephritis frauenfeldi

gallers on Jasione

Last modified 10.viii.2020

Dichotomous table for gallers on Jasione montana

by Hans Roskam

1a Malformations of shoot tips, stems or capitula => 2

1b Complete plant ± disfigured and sometimes measuring only several cm. Axial parts of non-flowering shoots stunted, causing leaves rosette- or tuft-like clustered, broadened and abnormally pubescent. Leaves of flowering shoots, as well as bracts of capitula ± broadened and strongly abnormally pubescent. Flowers aborted, sterile, ± greened or leafy, pubescent, sometimes excessively branching. Aceria enantha

2a Spindle-shaped swelling of stem or malformation of flower head => 3

2b Shoot tip stunted, leaves accumulated, clustered at tip, rosette-like. In pith an about 8 mm long cavity containing a single larva. Napomyza lateralis

3a Stalk below flower head irregularly thickened, spongy, with wrinkled surface, ± bent. Unidentified eelworm

3b Flower head distorted and etiolated. Thrips major

gallers on Isopyrum

Last modified 7.vii.2020

Dichotomous table for gallers on Isopyrum thalictroides

(incl. Leptopyrum fumarioides.)

by Hans Roskam

1a Expanded galls caused by rust fungi which fruit on the outside => 2

1b Wart-shaped, pearl-like gall consisting of only a few cells on leaves and stems. Sporangia colourless, with a nutritive cell inside. Synchytrium anomalum

2a Swellings bearing yellow aecia => 3

2b Swellings and malformations, up to 1 cm long, on stems, petioles and leaf veins with fungus developing only black, normally 3-celled teliospores, with dusty sori. Triphragmiopsis isopyri

3a Aecia on Leptopyrum fumarioides:

a Aecia golden-yellow, usually on distinct bulges on underside of veins, midrib or stalk of leaves. Puccinia actaeae-elymi

b Galls similar. Aeciospores narrow fine-warty. Outer wall of peridium 6–7 μm thick, transversely striate; inner wall coarse warty, 2–3 μm thick. Fungus alternating to wheat and related grasses. Puccinia recondita

3b Thickened bulges on the leaf axis and leaf blade. Puccinia milii-effusi

gallers on Iris

Last modified 16.vii.2020

Dichotomous table for gallers on Iris

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodular galls on Iris sp., up to 1 mm long or slightly larger. Iris spp.: Meloidogyne hapla

2a Leaves curled close to the ground, with slight irregular, spongy, pale green swellings. Iris sp., cultivated. Ditylenchus dipsaci

2b Fruit ± irregularly swollen, stunted and curved. Usually containing several white larvae. I. aphylla, foetidissima, x germanica, pseudacorus, sibirica and some cultivated forms: Mononychus punctumalbum

gallers on Hyoscyamus

Last modified 6.vii.2020

Dichotomous table for gallers on Hyoscyamus

by Hans Roskam

1a Leaves rolled inwards and ± curled. H. aureus, niger: Aphis fabae

1b On roots and stems => 2

2a Galls only on roots, primarily on adventitious roots; caused by eelworms => 4

2b Galls on main roots, sometimes encroaching onto stem base or only on stems => 3

3a Many proliferations, 1–3 mm long, rotund or irregularly shaped, which develop from side-, or higher located adventitious roots. H. niger: Synchytrium endobioticum

3b Young plants stunted; the basal stem parts and leaves, occasionally also the veins of leaves inserted there are ± sponge-like swollen H. aureus, niger: Ditylenchus dipsaci

4a Roots, especially side roots, with ± distinctly separated, nodular or spindle-shaped swellings with many side roots. H. aureus, niger: Meloidogyne hapla

4b Roots with slightly protruding, elongated, irregular tuberculate swellings; the parts situated beyond infestation usually disfigured. The developing ♀ ruptures the root rind with its body, producing the at first white, then yellow, eventually brown cysts attached to the outside of the gall body. H. aureus, niger: Globodera rostochiensis

gallers on Hydrocotyle

Last modified 6.vii.2020

Dichotomous table for gallers on Hydrocotyle vulgaris

by Hans Roskam

1a Leaf blade curled and distorted => 2

1b Leaves with multicellular warts, depressed at the tip ± golden-yellow, later on browned, hardly 1 mm long. Often many on leaf underside, also coalescing into long ridges or crusts, also on petioles and tillers. Synchytrium aureum

2a Weak wrinkling or curling of leaf blade caused by aphids on underside. Aulacorthum solani

2b Leaf blade strongly deflected downwards, curled and dark-green close to the froth-covered nymph. Philaenus spumarius

2c More or less conspicuous, sometimes distorted locally bulge-like swellings on stems or slight archings on leaves, with loosely arranged aecia and spermogonia. Uromyces lineolatus

gallers on Hottonia

Last modified 5.vii.2020

Dichotomous table for gallers on Hottonia palustris

by Hans Roskam

1a Weak swellings, several per leaf, small, distinguished by their lighter to red-brown colouration at infestation sites. Tissue containing spores. Heterodoassansia hottoniae

gallers on Honckenya

Last modified 5.vii.2020

Dichotomous table for gallers on Honckenya

by Hans Roskam

1a Brown, pad-shaped swollen telia, rotund on leaf underside, sometimes slightly countersunk on upper side, oblong-oval on axial parts, often resulting in distortions. Puccinia arenariae

gallers on Hornungia

Last modified 5.vii.2020

Dichotomous table for gallers on Hornungia

by Hans Roskam

1a On green plant parts => 2

1b On root collar, a one-sided rotund one-chambered swelling, up to 5 mm long. Containing a single white larva. H. alpina: cf. Ceutorhynchus assimilis

2a On leaves or stems => 3

2b lowers greened. H. alpina: Aceria drabae

3a More or less spindle-shaped galls on shoot axis => 4

3b Wart-shaped, multi-cellular, often variously coalesced galls on stems and flowers. H. alpina: Synchytrium infestans

3c Occasional infestation. H. petraea: Peronospora hornungiae

4a Vegetative part of stem spindle-shaped swollen. H. alpina: Unidentified snout beetle

4b Stem predominately swollen over variable length in inflorescence region and bearing white, later on vitreous, dusting of sori. H. alpina & subsp. auerswaldii, petraea: Albugo candida

4b 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. H. alpina & subsp. auerswaldii, petraea: Hyaloperonospora parasitica

gallers on Holosteum

Last modified 4.vii.2020

Dichotomous table for gallers on Holosteum umbellatum

by Hans Roskam

1a Malformations on shoot axis or leaves => 2

1b Malformations of capsules or exceptionally on stems, containing black-violet spores; seed capsule not- or slightly disfigured; ovaries temporarily swollen, soon transformed into a black-violet spore mass. Microbotryum holostei

2a Malformations at the surface, with fruiting bodies of fungi => 3

2b Shoot axis thickened because of short- to oblong-oval swellings; a rimmed depression containing the causer. Planchonia arabidis

3a Brown, pad-shaped swollen telia; rotund on leaf underside, sometimes slightly countersunk on upper side, oblong-oval on axial parts, often resulting in distortions. Puccinia arenariae

3b More strongly infected plants are occasionally ± stunted and excessively leafy. Weaker systemic infestation results in development acceleration, associated with etiolation. On leaf underside of similarly disfigured shoots whitish-grey down of conidiophores develop. Peronospora holostei

gallers on Convallaria

Last modified 4.vii.2020

Dichotomous table for gallers on Convallaria majalis

by Hans Roskam

1a On flowers or leaves => 2

1b Roots with nodular- to spindle-shaped swellings of a few mm long. Meloidogyne hapla

2a Flower buds slightly swollen, not opening. Containing several ivory-coloured jumping larvae. Contarinia convallariae and/or C. polygonati

2b Leaf blade with many small galls, about 5–7 mm long, up to 4 mm broad, which only protrude when occupied. After departure of the larvae the at first pale green infestation sites show conspicuous green-margined spots on prematurely yellowing leaf blades. Unidentified gall midge

2c Aphids on underside of leaves. The leaves develop large yellow spots and become desiccated. Aulacorthum speyeri

gallers on Conringia

Last modified 4.vii.2020

Dichotomous table for gallers on Conringia orientalis

by Hans Roskam

1a On above-ground parts => 3

1b On roots or on root collar => 2

2a Main- or side roots with conspicuous, spindle-shaped to acuminated, cylindrical, succulent, compact swellings. Plasmodiophora brassicae

2b Up to 5 mm long, ± globular, one-chambered swelling on root collar. Containing a single larva. Ceutorhynchus assimilis

3a Malformation with white felt-like down of branched conidiophores on surface. Diseased leaf blade parts yellow-green, ± slightly bulging; completely infected leaves conspicuously deflected, spoon-like; leaf blade ± reduced and thickened. Stem occasionally stunted in the area developing the inflorescence, curved in case of one-sided infestation. Peronospora conringiae

3b At first closed glossy, porcelain-like, later on rupturing and with mealy dusting, rotund to oblong-oval pads. Leaf blades with ± many, locally rounded swellings on underside. Leaves, often stunted shoots and young fruits with conspicuous, ± expanded, often curved bulges. Many parts of more severely diseased flowers, especially calyx and ovaries, conspicuously enlarged and distorted. Albugo candida

gallers on Conopodium

Last modified 3.vii.2020

Dichotomous table for gallers on Conopodium majus

by Hans Roskam

1a Bulging galls, bearing fungal sori on vegetative plant parts => 2

1b Centre of (partial) umbel stalk swollen, globular to club-shaped. Gall wall rigid, covered inside with mycelium. Containing a red larva. Lasioptera carophila

2a Yellowish to brownish, ± distinct swellings on leaf veins; stronger, sometimes distorted bulges on leaf midrib and -stalk, also on young stems; pads bearing densely positioned telia. Puccinia tumida

2b Less conspicuous, bulging yellowish swellings on leaf axis bearing aecia.
Puccinia bistortae

gallers on Conioselinum

Last modified 16.vii.2020

Dichotomous table for gallers on Conioselinum vaginatum

by Hans Roskam

1a Distinctly protruding smaller or up to about 20 mm long, ± distorted coalesced bulging swellings, bearing blackish, 3-celled, loosely long-spined telia. Nyssopsora echinata

1b Similar, usually less protruding bulges on leaf midrib, bearing, however, spermogonia and aecia. Puccinia altensis

gallers on Comarum

Last modified 3.vii.2020

Dichotomous table for gallers on Comarum palustre

by Hans Roskam

1a Galls on vegetative plant parts => 2

1b Flowers stunted, not opening, transformed into ± globular galls. Containing several orange larvae. Unidentified gall midge

2a Leaves strongly curled or with additional pubescence => 3

2b Many spots on both sides of leaf, up to 1 mm across, rotund to angular, usually slightly swollen dark-violet; on petiole developing sori appear as oblong-oval bulges. Nutritive cells distinctly enlarged, with solitary or several (2–4) resting spores. Physoderma comari

2c Leaves are hardly disfigured, but a slight change of colour is discernable.
Bactericera acutipennis

3a Leaves at infestation sites, mainly on underside of leaf, densely silk-like pubescent; grey on corresponding upper side, almost brownish on underside. Phyllocoptes roivaineni

3b Leaf midrib at infestation deflected, severely stunted. Leaflets clustered, nest-like bent downwards, locally strongly crumpled and dark green. Philaenus spumarius

gallers on Colutea

Last modified 2.vii.2020

Dichotomous table for gallers on Colutea

by Hans Roskam

1a Galls on parts above ground => 2

1b Roots with many elongate-cylindrical or also fork-shaped to coralloid branched nodules. Colutea spp.: Rhizobium leguminosarum

2a Younger, already woody twigs irregularly swollen on one or all sides, with several rimmed depressions, containing a broad pear-shaped, white scale of a scale insect. Colutea spp.: Chionaspis salicis

2b Both halves of a leaflet folded upwards and slightly hypertrophied. Containing several flesh-coloured larvae. C. arborescens: Dasineura sp.

gallers on Colchicum

Last modified 2.vii.2020

Dichotomous table for gallers on Colchicum

by Hans Roskam

1a Linear, 1–3 mm broad, up to 10 (20) mm long, spindle-shaped tapering bulges of the veins predominantly the terminal, but also other above-ground and subterranean leaf parts; at first closed, lead-grey translucent; later on irregularly splitting open, with black-brown dusting of spore balls. Often many per leaf, sometimes coalescing. Colchicum spp.: Urocystis colchici

1b Above-ground parts with local, pale-green, spongy swellings; containing many eelworms inside. C. autumnale: Ditylenchus dipsaci

gallers on Cicer

Last modified 2.vii.2020

(For a dichotomous table for galls on Cicer arietinum by Hans Roskam click here)

1a Roots with cylindrical or in apical part variously forked nodules. Rhizobium leguminosarum

1b Roots externally unchanged, inside with giant cells, temporarily bearing about poppy-seed sized, white to dark egg capsules. Heterodera goettingiana

gallers on Chrysosplenium

Last modified 2.vii.2020

Dichotomous table for gallers on Chrysosplenium

by Hans Roskam

1a Leaf blade with groove-like depressions, warts or flat pocks => 2

1b Small, rotund, often circularly arranged, pale brown sori on not- or sometimes weakly swollen, discoloured leaf spots. C. alternifolium, oppositifolium: Puccinia chrysosplenii

1c Leaves yellowish-green, larger than normal with longer petioles; often umbrella-like with downwardly turned margins. C. alternifolium, oppositifolium: Peronospora chrysosplenii

2a Leaf blade with groove-like depressions. C. alternifolium: Unidentified psyllid

2b Almost circular spots, 2–6 mm long, whitish, later on dirty yellow brown, especially visible on leaf underside, appearing exceptionally weakly thickened. Tissue contains spores, rarely tender conidia at surface. C. alternifolium, oppositifolium, tetrandrum: Entyloma chrysosplenii

2c Less than a mm wide, brown, semiglobular warts, mainly on the lower leaves. C. alternifolium, oppositifolium: Synchytrium chrysosplenii

gallers on Chelidonium

Last modified 1.vii.2020

Dichotomous table for gallers on Chelidonium majus

by Hans Roskam

1a On parts above ground => 2

1b Roots with spindle-shaped to nodular swellings. Meloidogyne hapla

2a Leaf blades weakly wrinkled, margins slightly bent. Acyrthosiphon chelidonii

2b Weakly wrinkled and ± discoloured leaves caused by aphids. Aphis fabae

2b Wrinkled leaves. Malformations caused by froth-covered nymphs of Philaenus spumarius

2b Flowers distinctly swollen, unopened; many yellow, non-jumping larvae inside. Jaapiella chelidonii

2b Pods irregularly swollen. Containing several yellowish, non-jumping larvae.
Unidentified gall midge

gallers on Chamaedaphne

Last modified 1.vii.2020

Dichotomous table for gallers on Chamaedaphne calyculata

by Hans Roskam

1a Malformations on leaves and shoots, caused by fungi => 2

1b Axial parts with rimmed depressions; causers under scales up to about 2.5 (3) mm long. Chionaspis salicis

2a Leaves with slightly swollen, sometimes reddened spots, covered with white spores when mature. Exobasidium cassandrae

2b Expanded part of terminal shoot with discoloured and ± deflected leaves, which are smaller or larger and weaker than the normal ones. Eventually with white sori on underside. Exobasidium myrtilli

gallers on Chamaecyparis

Last modified 1.vii.2020

Dichotomous table for gallers on Chamaecyparis lawsoniana

by Hans Roskam

1a Roots with nodular swellings. Meloidogyne hapla

1b Several twigs constricted, above the infection with expanded, strong swelling of the axis, and exudation of resin. Pestalotiopsis funerea

1c Pycnidia occur on dead twigs; whether the fungus is the cause of death is probable, but not certain. Pestalotiopsis monochaetioides

1d eveloping cones are slightly discoloured and distorted. Inside, seeds are distorted and concave; in each hollow lies a pale yellow, later orange larva, which pupates in a white cocoon in early spring; a cone may contain more than 20 larvae. Cupressatia siskiyou

gallers on Cephalaria

Last modified 30.vi.2020

Dichotomous table for gallers on Cephalaria

by Hans Roskam

1a Capitula short stalked, bloated apically and usually spirally rolled below the flower. C. leucantha: Diceratura roseofasciana leucanthana

= The gall midge Cephalaromyia capituli causes galls in flower heads of C. microcephala

gallers on Centranthus

Last modified 30.vi.2020

Dichotomous table for gallers on Centranthus

by Hans Roskam

1a Malformation of vegetative parts => 2

1b Flowers double, leaves disfigured. C. calcitrapa, macrosiphon, ruber:
Unidentified gall mite

2a Malformations caused by animals => 3

2b Upper side of the leaf with pale, eventually brown, spots. Underside with a greyish white down of erect conidiophores that are branching several times apically, each branch ending in a ± globular conidium. C. ruber: Peronospora centranthi

3a Axial parts of flowering and vegetative shoots ± stunted at tip; the variously disfigured organs clustered. Flower buds mostly stunted; leaves ± reduced, deflected and curled. Containing black aphids. C. calcitrapa, ruber: Aphis fabae

3b Leaves as well as bracts with pale green or reddened, ± fleshy thickened upward rolls of margin; smaller leaves completely disfigured. Infected flowers swollen, their parts variously disfigured and greened. C. angustifolius, calcitrapae, ruber: Trioza centranthi

gallers on Centaurium

Last modified 30.vi.2020

Dichotomous table for gallers on Centaurium

by Hans Roskam

1a Leaves on underside with many pearl-like small warts, hardly 1 mm long. C. pulchellum: Synchytrium globosum

1b Dull white spots, pustules, even crusts on underside of leaves, largely consisting of a mass of conidia. C. spicatum: Pustula centaurii

1c Plant ± disfigured; flowers greened. C. erythraea: Inducer unknown – ? gall mite

= Galls on Centaurium have been attributed to either the snout beetle Smicronyx reichi or S. funebris

gallers on Celtis

Last modified 29.vi.2020

Dichotomous table for gallers on Celtis

by Hans Roskam

1a Malformations of leaves => 2

1b Buds swollen on young twigs, about 8 mm long and 3–4 mm broad. C. australis: Aceria bezzii

2a Galls caused by aphids => 3

2b Galls caused by mites. Pale green, irregular and coalescing protrusions on upper side of leaf; corresponding depression on underside lined with whitish, 1-celled, simple, acuminate, thick-walled hairs with swollen base. The infected areas are twice as thick as the healthy ones. C. australis & subsp. caucasica: Reckella celtis

2c Galls caused by gall midges. Conspicuous blister gall on both sides of leaf; the blister is covered with short white hairs is on the underside, a concave depression covered with dense white fibers on the upper side. C. australis subsp. caucasica: Celticecis caucasicae

3a Pea-size protrusions on upper side with abnormally pubescent, bosselated surface. Often the complete leaf blade is covered with these galls; infected parts are fleshy and thickened. If several terminal leaves are infected, the twig is thickened and the leaves clustered. C. australis: Pemphigus sp.

3b Terminal leaves discoloured and curled. C. australis: Unidentified aphid

3b Irregular, discoloured protrusions on upper side leaf blade. C. crenata: Unidentified aphid

gallers on Castanea

Last modified 30.vi.2020

Dichotomous table for gallers on Castanea

by Hans Roskam

1a Malformations on parts above ground => 2

1b Considerable, ± rotund, broadly attached cancers close to the root collar. C. sativa: Agrobacterium tumefaciens

= Cancers observed on stems of young trees might, according to older references, be attributed to Diplodina castaneae

2a Galls caused by animals => 4

2b Stems with local, ± expanded swellings caused by mistletoes => 3

3a Evergreen mistletoe on spindle-shaped swelling. C. sativa: Viscum album

3b Deciduous mistletoe on slightly thickened branches, “woody roses”. C. sativa: Loranthus europaeus

4a Galls on young twigs, on leaf petioles or on the midrib of the leaves, unilocular or multilocular, 5–20 mm in diameter, green or rose-coloured, often including portions of developing leaves, stems and petioles. The gall dries, becomes wood-like, and remains attached to the tree for up to two years. C. crenata, dentata, mollissima, pumila, sativa, seguinii: Dryocosmus kuriphilus

4b Rotund pustule, about 1 mm across, slightly protruding on both leaf surfaces. Pustule paler than surrounding leaf blade. C. sativa: Unidentified gall midge

4c Bark of the two-year old and perennial twigs, usually on the underside with expanded, 2–3 mm thick, later with longitudinal fissures bursting proliferations of the cambium. C. sativa: Lachnus roboris

gallers on Carthamus

Last modified 29.vi.2020

Dichotomous table for gallers on Carthamus

by Hans Roskam

1a On above-ground parts => 2

1b Galls on roots, up to 7 cm deep in the ground, unilocular, sometimes more of them aggregated in groups, forming a root swelling. Carthamus sp.: Phanacis carthami

= Phanacis kiefferi induces galls on roots of C. lanatus.

2a On vegetative parts => 3

2b Capitula swollen, inhabited by tephritid larvae. C. tinctorius: Acanthiophilus helianthi

2c oluminous malformations, inhabited by tephritid larvae. C. lanatus, tinctorius: Unidentified tephritid, cf Urophora solstitialis

2d Capitula slightly swollen and disfigured, contain beetle larva. C. tinctorius: Larinus carinirostris

2e Gall in the involucral bracts, 1‒3 mm large. The wall is smooth, thick and very hard. C. lanatus: Isocolus carthami

3a Stems of young plants swollen at ground level, covered with pycnidia and brown areas of uredinia; developing malformed adventitious roots. C. glaucus, lanatus, oxyacantha, tenuis, tinctorius: Puccinia carthami

3b Leaf blade with round, compact cushions, weakly bulged on the lower side, sometimes weakly countersunk on the upper side. On the nerves round- to oval, usually slightly more swollen; at first yellow, later bearing 2-celled brown telia. C. lanatus, tinctorius: Puccinia verruca

3b Leaves on the underside with a dense white fungal down of erect conidiophores that apically bear a few short branches, each one ending in a conidium. C. tinctorius: Plasmopara carthami

gallers on Caragana

Last modified 28.vi.2020

Dichotomous table for gallers on Caragana arborescens

by Hans Roskam

1a On parts above ground => 2

1b Roots with laterally or terminally inserted branched nodules, oval, cylindrical or terminally fork-like, finger-shaped to coralloid. Rhizobium leguminosarum

2a Minor malformations of leaves. – Unidentified aphid

2b Main stems with ± spindle- or club-shaped swellings bearing mistletoe. Viscum album

= The gall mite Aceria arceosae, hidden in leaf axils, causes withering of buds.

= The mildew Erysiphe palczewskii has been reported from pea shrub

= The rare gall midge Dasineura sibirica may cause a pest

gallers on Calluna

Last modified 28.vi.2020

Dichotomous table for gallers on Calluna vulgaris

by Hans Roskam

1a Malformations ± witches’ broom-like => 2

1b Leaves clustered at shoot tip, imbricated covered, transformed into a bud-like, egg-shaped gall. Inducer unknown

2a Shoots may bear witches’ broom-like malformations. Many very small (0.1‒0.2 mm) orange uredinia on underside of leaves, which soon fall. Thekopsora fischeri

2b Thin twigs abnormal, twig slightly inflated at insertion. Mytilaspis pomorum

2c Plant with small witches’ broom-like malformations of shoot; leaves clustered, reduced, often ± abnormally pubescent, usually pale-green or reddish discoloured. Aceria exigua

= The rust fungus Thekopsora ericae causes witches’ brooms. Uredinia on underside of leaf, 0.1‒0.2 mm across

gallers on Buphthalmum

Last modified 28.vi.2020

Dichotomous table for gallers on Buphthalmum salicifolium

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodule-shaped swellings. Meloidogyne hapla

2a Leaf blades, veins, petioles, also stems of young plants with flat sori, on axial parts sometimes slightly swollen, occasionally bent. Uromyces junci

2b Leaf blade usually curved downwards obliquely over the top and margins ± nest- or roll-like. On the central part of the dark green area, strongly curled underside and with froth-covered nymph. Philaenus spumarius

gallers on Bunium

Last modified 27.vi.2020

Dichotomous table for gallers on Bunium

by Hans Roskam

1a Malformations of vegetative parts, mainly leaves => 2

1b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a single red larva. B. ferulaceum: Lasioptera carophila

2a Axis of leaves, also young stems, with expanded, sometimes severely distorted, ± yellowish swellings, bearing yellowish spermogonia and aecia. B. alpinum & subsp. corydalinum, atlanticum, bulbocastanum, cylindrium, ferulaceum, pachypodium: Puccinia bulbocastani

2b Leaf sheaths inflated, ± discoloured. B. bulbocastanum: Hyadaphis foeniculi

gallers on Buddleja

Last modified 27.vi.2020

Dichotomous table for gallers on Buddleja davidii

by Hans Roskam

1a Malformations of vegetative parts => 2

1b Aborted flower buds contain several midge larvae. Asphondylia buddleia

2a Smaller roots with nodular swellings. Meloidogyne hapla

2b eaf blade over tip and margins usually loosely and obliquely rolled downwards; curled close to the froth-covered nymph. Philaenus spumarius

gallers on Borago

Last modified 16.vii.2020

Dichotomous table for gallers on Borago officinalis

by Hans Roskam

1a Leaf blade with rotund yellowish swelling, more oblong-oval to spindle-shaped close to venation, protruding on underside, bearing aecia on underside, spermogonia on upper side. Puccinia recondita

1b Leaf blades curved downwards over margin, curled. Bearing colonies of black aphids on underside. Aphis fabae

gallers on Ballota

Last modified 26.vi.2020

Dichotomous table for gallers on Ballota nigra

by Hans Roskam

1a On leaves => 2

1b Shoot tips or lateral buds disfigured, leaves ± converging, discoloured, rolled upwards and inwards, also unopened and ± bud-like. Containing several white (yellow), jumping larvae. Contarinia ballotae

2a Upper leaves, including shortened petioles, swollen and succulent at base, sometimes additionally pubescent. Containing yellowish-white larvae. Unidentified gall midge

2b Leaf blades at shoot tips or in inflorescences slightly bent in at margin, ± arched and slightly curled. Brachycaudus ballotae

gallers on Capparis

Last modified 26.vi.2020

(For a dichotomous table for galls on Capparis by Hans Roskam click here)

1a Malformation of flowers or fruits => 2

1b Hard, nut-like swelling on twig, with irregular gall chamber. C. aegyptica: Unidentified lepidopteran

2a Flower swollen, disfigured, unopened. C. spinosa: Asphondylia capparis

2b Similar malformation caused by tephritid maggot. C. orientalis, spinosa: Capparimyia savastani

2c Slightly swollen fruit caused by gregarious gall midge larvae. Gall recognisable by exuviae of gall midge. C. spinosa: Unidentified gall midge

gallers on Cannabis

Last modified 26.vi.2020

Dichotomous table for gallers on Cannabis sativa

by Hans Roskam

1a On parts above ground => 2

1b Roots with small, nodular or spindle-shaped swellings. Meloidogyne hapla

1c Eelworm, making cysts on root surface. Heterodera humuli

2a Petioles and midribs, partially shortened, spongy, thickened; leaf blades stunted and distorted. Stem mainly at base, in case of later infestation also locally swollen and pale green higher up. Gall tissue brittle. Axial parts above bent or twisted galls ± severely stunted. In cases of early infestation additional side shoots develop. Ditylenchus dipsaci

2b Inflorescences, especially the female ones, disfigured and sometimes greened; development of fruits stunted. Phorodon cannabis

gallers on Callianthemum

Last modified 24.vi.2020

Dichotomous table for gallers on Callianthemum

by Hans Roskam

1a Leaves with bulging swellings on the surface of which develop ± yellowish or brown sori => 2

1b Bulges on leaves and stems, initially lead-grey translucent, later on rupturing and releasing a dusting of black spores. C. coriandrifolium: Urocystis callianthemi

2a Slightly thickened, above violet, below yellowish, brownish margined spots bearing dense aecia and spermogonia. Sori on midrib and petiole bulging. C. angustifolium, coriandrifolium: Puccinia sardonensis

2b ulges yellowish to brown-red, remaining closed for a long time, compact, often yellow- or red-margined; with dark telia. C. coriandrifolium:
Puccinia callianthemi
and/or P. kochiana

gallers on Calicotome

Last modified 24.vi.2020

Dichotomous table for gallers on Calicotome

by Hans Roskam

1a Galls contain midge larva inside => 2

1b Swelling of stem bearing rimmed depressions which contain causer. C. spinosa: Planchonia arabidis

1c Swelling of stem containing beetle larva. C. spinosa: Protopirapion kraatzii

2a Oblong to egg-shaped bud gall, green, succulent, covered with silk hairs. C. infesta subsp. intermedia, spinosa, villosa: Asphondylia calycotomae

2b Pods disfigured and shortened, up to 20 mm long, with a single spherical thick-walled swelling enclosing a large larval chamber. C. infesta subsp. intermedia, spinosa, villosa: Asphondylia calycotomae

gallers on Calepina

Last modified 24.vi.2020

Dichotomous table for gallers on Calepina irregularis

by Hans Roskam

1a On parts above ground => 3

1b On root collar or on roots => 2

2a Root collar with rotund galls, up to about 8 mm long, succulent, one-sided, one-chambered. Containing a single larva. Ceutorhynchus assimilis

2b Roots with conspicuous, spindle-shaped to cylindrical swellings, 3–12 mm long succulent, compact. Plasmodiophora brassicae

3a Midrib of leaves or young stems with 12–20 mm long spindle-shaped swellings. Containing a single larva. Ceutorhynchus chalybaeus

3b According to literature on this host also Brevicoryne brassicae as well as Albugo candida

2a On leaves => 3

2b Enlarged leaves and stems, with transformation of flowers into scaly structures on peduncles up to 20 mm long. Calendula sp.: Unidentified aphid

= The capitula of Calendula arvensis, maderensis are hardened by the tephritid fly Tephritis praecox.

3a Leaf blades of the larger leaves variously curved obliquely downwards or almost rolled; curled close to the dark green site of attack. One froth-covered nymph. Calendula spp.: Philaenus spumarius

3b Leaf blades often with many, rotund, up to 5 (7) mm wide, yellowish-white, later bright brownish spots, occasionally slightly curved over the surface. C. arvensis, officinalis, suffruticosa incl. subsp. fulgida: Entyloma calendulae

gallers on Bassia

Last modified 23.vi.2020

Dichotomous table for gallers on Bassia

(incl. Kochia)

by Hans Roskam

1a On parts above ground => 2

1b Side roots with nodular swellings, up to 3 mm long and 2 mm broad. B. scoparia: Meloidogyne hapla<

2a Malformation caused by animals => 3

2b Malformation caused by false mildews => 5

3a Shoot tip stunted => 4

3b Pod-shaped upwards folds on slightly thickened and discoloured, partially sickle-curved downwards curved halves of leaf blade. B. scoparia: Hayhurstia atriplicis

4a Gall consists of a rotund tuft of olive-coloured leaves, 10–15 mm across; leaves longer and more pubescent than normal ones, covered with abundant, long, whitish hairs. Leaves inserted on a shortened twig, succulent, one- or multi-chambered. Each chamber contains a single whitish larva. B. muricata: Stefaniola houardi

4b Terminal leaves and vegetative buds, which are transformed into small one-chambered galls, and inflorescence primordia, with long, dense pubescence; infected organs united into a tuft, about pea- to hazelnut-size, usually rotund, sometimes elongated. B. prostrata: Kochiomyia kochiae

5a Upper side of the leaf with lemon yellow spots. Underside with a brown down of erect conidiophores that apically are dichotomously branching several times, each branch ending in a conidium. B. prostrata: Peronospora kochiae-prostratae

5b Similar malformation, spots pale and down greyish purple. B. scoparia: Peronospora kochiae-scopariae

gallers on Bartsia

Last modified 23.vi.2020

Dichotomous table for gallers on Bartsia alpina

by Hans Roskam

1a On parts above ground => 2

1b Woody swelling of root, 20 mm long, 15–18 mm thick. Mirificarma mulinella

2a On leaves => 3

2b Shoot tip ± unopened. Leaves folded, slightly thickened, sometimes erect, enclosing tuft-like severely disfigured leaf- or flower primordia. Cause unknown – ? gall midge

3a Young leaves with slightly swollen folds at base. Cause unknown – ? gall midge

3b Leaf blades rolled downwards at margin, there discoloured yellowish or reddish, externally ± abnormally pubescent. Aceria bartschiae

gallers on Androsace

Last modified 22.vi.2020

Dichotomous table for gallers on Androsace

by Hans Roskam

1a Leaves with only small, wart- or spindle-shaped galls caused by fungi => 2

1b Shoots shortened at tip. Leaves shortened and broadened, spoon-like, tuft-like clustered, abnormally haired. A. chamaejasme: Unidentified gall mite

2a Galls bulge-shaped, bearing spores at surface => 3

2b Galls cylindrical, less than 1 mm long, usually many on the underside of leaves. A. chamaejasme: Synchytrium aureum

3a Pad-shaped sori bearing black-brown spores on rosette leaves, also on inflorescence stalks and even bracts. A. chamaejasme: Puccinia volkartiana

3b Rotund to oblong, dark-brown sori on both leaf sides, also on flower peduncles of A. alpina, carnea, helvetica, lactea, obtusifolia, pubescens: Puccinia dubyi

gallers on Andromeda

Last modified 22.vi.2020

Dichotomous table for gallers on Andromeda polifolia

by Hans Roskam

1a Malformations on expanded parts of shoot or on leaves => 2

1b Stem with rimmed depressions with causer under a 2.5 (3) mm long scale.
Chionaspis salicis

2a Single or several leaves with localised malformations => 3

2b Complete shoots infected, ± etiolated or ± disfigured witches’ broom-like. Leaves partially larger, partially smaller than healthy ones; hardly thickened; sometimes pale-green, often conspicuously reddened. At maturity of fungus the underside with white down of basidia. Exobasidium myrtilli

3a eaf blade ± keel-shaped curved, hardly thickened. Conspicuously rolled downwards at margin, ± reddish discoloured. Cecidophyopsis ruebsaameni

3b Leaf blades with expanded, strongly swollen, usually conspicuously reddened swellings. Twigs hypertrophied, leaves disfigured and discoloured reddish to violet. Exobasidium karstenii

3c Twigs not thickened, but leaves broadened and thickened, reddish. Exobasidium sundstroemii

gallers on Amaranthus

Last modified 22.vi.2020

Dichotomous table for gallers on Amaranthus

by Hans Roskam

1a On above ground organs, sometimes encroaching onto upper part of main root => 2

1b Side roots with nodular or spindle-shaped swellings. Amaranthus spp.: Meloidogyne hapla

= The cyst-developing eelworm Heterodera schachtii has been recorded on several Amaranthus species

2a On stems or leaves => 3

2b Flowers of single panicles ± enlarged, thickened and reddened. Bracts cylindrically thickened, rolled, inflated, wrinkled. A. retroflexus: Inducer unknown; possibly galls with oospores of Wilsoniana bliti.

3a Shoot tips ± stunted. Leaves ± clustered, margins deflected, sometimes contacting; leaf blades arched upwards, ± curled and partially discoloured. Amaranthus spp.: Aphis fabae

3b Axial parts, sometimes also flower parts, variously swollen, also ± distorted. Inside tissue is a mycelium which develops oospores. Mature oospores dark brown-red to blackish translucent. Amaranthus spp.: Wilsoniana bliti

gallers on Thesium

Last modified 21.vi.2020

Dichotomous table for gallers on Thesium

by Hans Roskam

1a Malformations of complete shoots or extended systems of shoots => 2

1b Stem, mainly close to ground, with sometimes bent, bulging swellings, on their surface with scale insects in single to several rimmed depressions. T. bavarum, humifusum: Planchonia arabidis

1c Yellow, rough nodular swellings, 2–8 mm across, clustered on root collar. T. humifusum: Unidentified weevi

2a Shoots completely pervaded and ± disfigured by perennial mycelium of a rust fungus. Aecia, unopened longer than wide, often ± red-brown coloured, occurring on both sides of leaf, on stems, occasionally also on bracts and flowers => 3

2b Inflorescence usually largely disfigured; excessive branching and leafiness; phyllanthy. T. alpinum, divaricatum, humifusum, linophyllon: Aceria anthonoma

3a The three monoecious rust fungi occurring on Thesium cannot be distinguished according to their aecia. Uredina easily detached, their sori later on ± with dusting. Aecia often rare or almost absent => 4

3b Teliospores glabrous, on compact stalks; sori compact. Aecia often present. Thesium spp.: Puccinia thesii

4a Fungus mainly on T. alpinum and T. linophyllon: Puccinia mougeotii

4b On several other Thesium species, mainly on T. ebracteatum: Puccinia passerinii

gallers on Thelypteris

Last modified 21.vi.2020

Dichotomous table for gallers on Thelypteris confluens

(incl. Lastrea)

by Hans Roskam

1a Leaf blade with slight swellings, up to 3 mm, yellowish, which bear asci later on the underside. Taphrina lutescens

1b ip of frond distinctly shortened, spirally rolled upwards, with the crowded leaflets making a dense nest. With a white larva on the midrib. Chirosia betuleti

gallers on Swertia

Last modified 21.vi.2020

Dichotomous table for gallers on Swertia perennis

by Hans Roskam

1a Aecia spaciously arranged, on underside of leaf blade on thickened, arched, rotund yellowish or brownish cushions or on oblong-oval, weak bulges on petioles and stems. Puccinia swertiae

1b Rotund-oval or flat spindle-shaped, one-chambered galls, up to 6 mm long; usually on petiole, also on leaf blade, on base of midrib as well as on stem base. Containing a single larva. Smicronyx swertiae

gallers on Succisa

Last modified 20.vi.2020

Dichotomous table for gallers on Succisa pratensis

by Hans Roskam

1a On parts above ground => 2

1b Roots usually with several to many nodular to spindle-shaped swellings, bearing several lateral roots. Meloidogyne hapla

2a In capitula or flowers => 4

2b On leaves => 3

3a Broad, many-celled warts, up to 1 mm high, pearl-like, yellowish-green. Usually many, solitary or variously coalesced later on into ± browned, flat ridges or crusts; after infestation on all green, not distinctly discoloured organs. Synchytrium succisae

3b Leaf blade with small grooves on underside. Mites free-living on underside of leaves, if strongly infected, conspicuously pale or brownish discoloured. Leipothrix succisae

4a Malformations caused by fungi => 5

4b Flowers compact, ± disfigured; unopened. Containing a whitish- to orange-yellow larva. Contarinia dipsacearum

5a Fungus develops on several flower parts or in ovary => 6

5b Fungus lives in externally unchanged flowers in originally shortened and bloated, soon completely aborted anthers; containing a whitish, to ochre coloured, later on dusty spore powder. Microbotryum succisae

5c The anthers are transformed into a purplish-brown powdery mass of spores.Microbotryum flosculorum

6a Diseased flowers sometimes strange-looking, ± discoloured. Several petals enlarged and ± disfigured. Generative parts greatly reduced. Loose down of branched conidiophores on emerging petals of usually completely diseased capitula. Peronospora violacea

6b Fungus develops in soon destroyed ovary, stigmas thickened and distorted; corolla unopened; anthers normal. Strongly infected capitula prematurely browned and dying. Covered with salmon-pink to orange slimy speckles when spores are mature. Gibberella fujikuroi

gallers on Smyrnium

Last modified 20.vi.2020

Dichotomous table for gallers on Smyrnium

by Hans Roskam

1a Galls caused by gall midges => 2

1b Malformations caused by fungi. Rotund, mainly protruding on underside, upperside ± depressed pads on leaf blades, or acuminate rotund- to oblong-oval aecia and spermogonia bearing bulges on leaf midrib, -stalk, stems and sporadically even on stalks of umbels and fruits. S. apiifolium, cordifolium, olusatrum, orphanidis, perfoliatum & subsp. rotundifolium: Puccinia smyrnii

2a Galls in umbellules and fruits, inside wall lined with mycelium. S. orphanidis, perfoliatum subsp. rotundifolium: Lasioptera carophila

2b Fruit conspicuously swollen, ± reddened, often protruding above the partial umbel. Containing a single orange-red larva. S. olusatrum: Kiefferia pericarpiicola

gallers on Sium

Last modified 20.vi.2020

Dichotomous table for gallers on Sium

by (incl. Berula)

by Hans Roskam

1a On stems or leaves => 2

1b Fruit disfigured into a ± globular swollen gall. Containing a single orange-red larva. Berula erecta: Kiefferia pericarpiicola

2a Wart-shaped or bulge-like galls caused by fungi => 3

2b Leaf midrib stunted and deflected. Leaflets ± clustered, ± curled and locally deep green. Berula erecta; Sium. latifolium, sisarum: Philaenus spumarius

3a Spores inside galls => 4

3b Veins on underside of leaf with weak, ± rotund-oval bulges; midrib and stalk with broad spindle-shaped, stronger protruding swellings, bearing yellowish spermogonia and aecia. Berula erecta; S. latifolium: Uromyces lineolatus

3c Leaves with discoloured spots. On the underside is a whitish fungal down, consisting of erect, terminally repeatedly branching conidiophores, each branchlet bearing a globular conidium. S. latifolium: Plasmopara sii

4a Galls elongate spindle-shaped, vitreous, pale green; often adjoining venation; depending on the plant part only a few to many mm long. On all green plant parts; sometimes even on calyx and fruits. Within the tissue close to vascular bundle are many, ± rotund, often 60–70 µm large perennial (‘dauer’) spores. Berula erecta; Sium latifolium: Protomyces macrosporus

4b Only a few mm long, wart-shaped, usually many, at first colourless-whitish, then dull brown galls, which cluster on leaf blade, -midrib, -stalk and stem may cause additional malformations. Inside nutritive cell several, about 20–35 x 15–30 µm large perennial (“dauer”) spores. Berula erecta; S. latifolium: Physoderma vagans

gallers on Sherardia

Last modified 17.vi.2020

Dichotomous table for gallers on Sherardia arvensis

by Hans Roskam

1a On parts above ground => 2

1b Roots with small nodular or spindle-shaped swellings. Meloidogyne hapla

2a Leaves broadened terminally on non-flowering shoots, ± arched or rolled, usually yellowish or reddish. Trioza velutina

2b Stem gall containing a single yellow midge larva. Dasineura sp.

2c Diseased young plants densely bushy. Internodes sometimes stunted, like adjacent reduced, pale-green leaves slightly thickened and lined by a down of branched conidiophores. Peronospora sherardiae

gallers on Setaria

Last modified 17.vi.2020

Dichotomous table for gallers on Setaria

by Hans Roskam

1a Malformations on inflorescences or florets => 3

1b Malformations on leaves, sometimes extending to inflorescence => 2

2a Leaf sheaths swollen; leaf blades variously disfigured. S. pumila: Rhopalosiphum padi

2b Diseased leaves remain rolled inwards, strongly thickened, brittle, at first pale, eventually fraying and releasing reddish-brown oospores. Inflorescence stunted, usually remaining in the leaves; peculiarly leaf-like and greened. S. adhaerens, italica, pumila, verticillata, viridis: Sclerospora graminicola

2c Leaves with long narrow stripes of smut. S. italica: Ustilago striiformis

3a Galls on ovaries caused by smut fungi => 4

3b Spikelets disfigured; sometimes ± greened and leaf-like. Glumes occasionally strongly elongated and rolled. Strong infestation results in bleaching. S. viridis, italica: Aceria tenuis

4a Ovaries swollen, soon filled with black-brown spore masses; spores glabrous, irregular rotund, 8–11 x 6–9 µm, dusty when mature. S. adhaerens, faberi, italica, parviflora, pumila, verticillata, viridis: Ustilago crameri

4b Ovaries strongly swollen. Diseased inflorescences often discoloured grey; appearing compact and thickened. Spores black, with spiny warts, globular to rotund-oval, usually 7–11 µm across. S. adhaerens, pumila, viridis: Macalpinomyces neglectus

4b Ovary hypertrophied by smut fungus. S. pumila: Sporisorium magnusianum

gallers on Scleranthus

Last modified 17.vi.2020

Dichotomous table for gallers on Scleranthus

by Hans Roskam

1a On parts above ground => 2

1b Roots with small, spindle-shaped swellings, bearing some side roots. S. annuus: Meloidogyne hapla

2a Malformations bearing fruiting bodies of fungi => 4

2b Malformations caused by animals => 3

3a Many leaves mainly distorted at shoot tips, thickened, sometimes bent S-shaped or rectangular, ± discoloured and showing suction feeding marks. S. annuus: Taeniothrips atratus

3b Whole plant atrophied. Basal parts with ± distinct, pale-green, spongy, soon necrotic, swellings. S. annuus: Ditylenchus dipsaci

4a Developing more on leaves if plants are infected early. Diseased shoots developing prematurely, growing rigidly erect. Internodes elongated, lanky; leaves smaller, slightly thickened, paler and often more deflected than healthy ones. Infected organs soon covered by a down of branched conidiophores. S. annuus, perennis: Peronospora scleranthi

4b Leaves and stems with rotund to oval powdery sori, sometimes slightly swollen and distorted on young organs, pale to red-brown. S. perennis: Uromyces scleranthi

gallers on Scirpus

Last modified 16.vi.2020

Dichotomous table for gallers on Scirpus

(incl. Blysmus, Bolboschoenus, Eleogiton, Isolepis, Schoenoplectus, Trichophorum. ‒ Comp. Eleocharis)

by Hans Roskam

1a Galls on above-ground parts => 3

1b Galls on roots => 2

2a Swellings on all sides, slender, elongate spindle-shaped, many on markedly shortened lateral roots. S. sylvaticus: Meloidogyne hapla

2b wellings on root tips almost club-shaped. Many oblong-oval to lemon-shaped, yellowish spores inside. Isolepis fluitans: Entorrhiza raunkiaeriana

3a Swelling in stem, about 15 mm long, at junction of leaf blade and sheath, probably on stunted shoots; containing a white larva or pupa. Bolboschoenus maritimus: Eurina lurida

3b Uredinia on underside leaf, cinnamon brown, pulverulent. Telia on both sides, long covered by the epidermis, brownish black; teliospores one-celled on a persistent pedicel. Blysmus compressus; Bolboschoenus maritimus; Schoenoplectus lacustris: Uromyces lineolatus

3b Ovaries at first ± swollen, egg-shaped then destroyed and transformed into a smut grain up to 2 mm long, almost globular, compact, black inside. Trichophorum cespitosum incl. subsp. germanicum, pumilum: Anthracoidea scirpi

gallers on Saussurea

Last modified 16.vi.2020

Dichotomous table for gallers on Saussurea alpina

by Hans Roskam

1a Galls localised or extending over leaves => 2

1b Development of flower head stunted, heads remaining closed, appearing ± globular turgid; soon filled with brown spore masses. Thecaphora trailii

1c Gall midge larvae in flower heads. Dasineura saussureae

2a Leaf blade with ± rotund pads bearing aecia, protruding on the underside, not or slightly swollen. Puccinia rupestris

2b Galls caused by animal parasite => 3

3a Malformations extensive, of various types => 4

3b Leaf blade with many small, pustule-like swellings. Aceria saussureae

4a Leaf blades or petioles with ± expanded, spongy, pale green, often rugose swellings. Ditylenchus dipsaci

4b Large parts of leaves curved downwards or rolled. Infected leaf blade parts ± crookedly curled and coloured dark green close to the froth-covered nymph. Philaenus spumarius

gallers on Robinia

Last modified 16.vi.2020

Dichotomous table for gallers on Robinia pseudoacacia

by Hans Roskam

1a On parts above ground => 2

1b Roots with laterally inserted nodules, rotund to oblong-oval or terminally broadened and hand-shaped to coralloid forked, up to 10 or more mm long, occasionally clustered. Rhizobium leguminosarum

2a On leaves => 3

2b Branches with ± distinct spindle- or club-shaped swellings, bearing. Viscum album

3a Malformations of leaflet caused by aphids => 5

3b Malformations of leaf caused by other animal inducers => 4

4a Cartilaginous, yellowing downward rolls of leaflet margins. Containing several whitish midge larvae, often together with orange-yellow pupae. Obolodiplosis robiniae

4b Leaflets curled, ± bluish discoloured, ± rolled at margin. Aculops allotrichus

5a Leaflet rolled downwards, curled. Aphis craccivora

5b Similar malformations. Aphis fabae

gallers on Peltaria

Last modified 15.vi.2020

Dichotomous table for gallers on Peltaria

by Hans Roskam

1a On parts above ground => 2

1b Rotund, about pea-size, fleshy swellings on root collar. Containing a curved beetle larva. P. alliacea: Ceutorhynchus assimilis

2a Leaf blade buckled downwards, undulately curled, the margins bent downwards; locally deep green. P. alliacea, turkmena: Philaenus spumarius

2b Stalk of inflorescence stunted and ± bent. The only short stalked flower buds clustered; slightly swollen; unopened. Containing yellowish larvae. P. alliacea: Unidentified gall midge

gallers on Pelargonium

Last modified 15.vi.2020

Dichotomous table for gallers on Pelargonium

by Hans Roskam

1a On parts above ground => 4

1b On root collar or roots => 2

2a Conspicuous gall formation on root collar => 3

2b Roots with nodular swellings. Pelargonium spp.: Meloidogyne hapla

3a About walnut-sized proliferations, irregularly tuberculate on surface, at first succulent, whitish, then browned or blackened, ± globular. Pelargonium spp.: Agrobacterium tumefaciens

3b Clumpy accumulation of severely stunted shoots, swollen in all their parts. “Leafy gall”. Pelargonium spp.: Rhodococcus fascians

4a Leaf blades variously deflected, with conspicuous necrotic spotting and strong malformations. Pelargonium spp.: Aulacorthum solani

= The “Pelargonium aphid” occurring in greenhouses in central Europe, Acyrthosiphon malvae lives on P. grandiflorum, more rarely on P. peltatum, tricolor, zonale, and affects especially the terminal shoots, which are conspicuously crumpled. The aphid may transmit Pelargonium-Virus 1, which, by localised stunting, results in bulging and occasional rupturing of the leaf blades of the often severely distorted plants

= Cultivated “geraniums” (Pelargonium zonale and hybrids) are often affected by Puccinia pelargonii-zonalis with cinnamon uredinia at underside of leaf and teliospores when present formed in the uredinia

gallers on Pedicularis

Last modified 15.vi.2020

Dichotomous table for gallers on Pedicularis

by Hans Roskam

1a Malformations of vegetative plant parts => 2

1b Galls in swollen flower buds caused by various undescribed Dasineura spp.

2a Galls wart-like, or, bulge-shaped or rolls of leaf margin => 3

2b Shoot axis stunted; leaves ± curled, locally deep green, converging, deflected, almost nest-like. P. palustris: Philaenus spumarius

3a Wart- or ± spindle-shaped galls caused by fungi => 4

3b Leaf tips ± crookedly rolled downwards, often reddened, densely felt-like, inside, sparsely pubescent on outside. P. lapponica, palustris, sylvatica, verticillata: Aculops pedicularis

4a Less than 1 mm long, multicellular yellow warts on leaf blades, stalks and stems, sometimes coalescing and additionally disfiguring the organs. Pedicularis spp.: Synchytrium aureum

4b Yellow, often distinct, spindle-shaped bulges on petioles or stems; rotund on the leaf blade, with arched pads on underside bearing aecia; Spermogonia develop on upperside. P. mixta, palustris, resupinata, sceptrum-carolimum, sylvatica: Puccinia paludosa

Longitarsus cerinthes

Last modified 11.ix.2020

Longitarsus cerinthes (von Paula Schrank, 1898)

on Cerinthe, etc.

parasite

Larvae at the roots.

host plants

Boraginaceae, oligophagous

Cerinthe minor; Cynoglossum cheirifolium, creticum; Echium albicans, arenarium, vulgare; Heliotropium europaeum.

distribution within Europe

(PESI, 2020).

synonyms

Longitarsus nervosus Wollaston, 1854.

references

Baselga & Novoa (2002b), Bastazo, Vela & Petitpierre (1993a), Baviera & Biondi (2015a), Gómez-Zurita, Sacarés & Petitpierre (1996a), Ouda, Čížek & Boža (2013a), Petitpierre, Sacarés & Jurado-Rivera (2017a), Rheinheimer & Hassler (2018a).

gallers on Oxytropis

Last modified 13.vi.2020

Dichotomous table for gallers on Oxytropis

by Hans Roskam

1a On above ground organs => 2

1b Oval to cylindrical nodules, terminally sometimes hand-shaped or forked, coralloid. Oxytropis spp.: Rhizobium leguminosarum

2a On stems, leaf axis or shoot tips => 5

2b On leaflets => 3

3a Galls caused by animals => 4

3b Large parts of plants slightly disfigured and etiolated by a perennial mycelium. Aecia usually often many on the undersides of many leaves, distinguished by their pale colour. O. campestris & subspp. sordida + tyroliensis, jacquinii: Uromyces lapponicus

4a Halves of leaf blade folded together, slightly thickened. Containing one or two at first yellowish larvae. O. jacquinii – Unidentified gall midge

4b Halves of leaf blade folded upwards, pod-like, distinctly thickened. O. campestris: Unidentified gall midge

5a Whole plant stunted. Shoot tip and side shoots transformed into a mass of strongly felt-like pubescent leaflets. Shoot axis ± bent. Larvae pale yellow. O. pilosa: Unidentified gall midge

5b Shoot axis, petiole and midrib (rarely also midrib of a leaflet), with single or several, mainly one-sided, 2–5 mm long, tough, one-chambered, often yellowish swellings; occasionally coalescing on stem into multi-chambered galls. O. pilosa: ? gall midge, ? chalcid

gallers on Oxyria

Last modified 13.vi.2020

Dichotomous table for gallers on Oxyria digyna

by Hans Roskam

1a On leaves => 2

1b Flower buds almost globularly swollen. Perigone enlarged. Flesh-coloured spore masses in ovaries, also at base of stamens. Usually many diseased buds, clustered in inflorescence. Microbotryum vinosum

2a Leaf blade curved and distorted downwards at margin. Locally strongly curled, deep green. Philaenus spumarius

2b Leaf blade ± uniformly strongly curled and deflected. Aphis fabae

gallers on Ornithogalum

Last modified 13.vi.2020

Dichotomous table for gallers on Ornithogalum

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodular swellings. Ornithogalum spp.: Meloidogyne hapla

1c Cotyledon thickened and often ± crisp. O. candicans: Ditylenchus dipsaci

2a Expanded bulges on green parts => 3

2b Galls just visible to the naked eye, developing from epidermis cells; simple hemispherical, dirty white, brown margined; single or in groups, resulting in curling of the leaf. O. umbellatum: Synchytrium niesslii

3a Bulges compact, slightly protruding, yellow or yellow-margined, soon covered with dark-brown sori containing 2-celled teliospores. Species only distinguishable microscopically => 5

3b Bulges ± swollen, bladder-like, at first vitreous, lead-grey translucent, then breaking open and producing dusting of black smut spores. Species only distinguishable microscopically => 4

4a Spores single. O. boucheanum, narbonense, umbellatum: Vankya ornithogali

4b Spores united in larger balls, with (1) 2–3 or more, enveloped by a layer of sterile auxiliary cells. Ornithogalum spp.: Urocystis ornithogali

5a Teliospores glabrous, 50–70 x 25–35 µm. Ornithogalum spp.: Puccinia liliacearum

5b Surface of teliospores covered with coarse warts; on average about 24‒35 x 49–52 µm. Ornithogalum spp.: Puccinia lojkaiana

gallers on Onosma

Last modified 12.vi.2020

Dichotomous table for gallers on Onosma

by Hans Roskam

1a Large globular leaf bud rosette at vegetative tip, about 15 mm across, composed of many little disfigured leaves. Gall midge larvae develop among leaves, each folded leaf containing a single larva. O. frutescens: Janetiella onosmae

gallers on Onopordum

Last modified 12.vi.2020

Dichotomous table for gallers on Onopordum

by Hans Roskam

1a Receptacle thickened and hardened, with several oblong oval chambers vertical to surface, each containing a single maggot. O. acanthium, cynarocephalum: Tephritis postica

1b Similar malformations. O. acanthium: Urophora mauritanica

1c Larger parts of rosette leaves strongly curved downwards and curled; discoloured dark green close to the froth-covered nymph O. acanthium: Philaenus spumarius

gallers on Ononis

Last modified 12.vi.2020

Dichotomous table for gallers on Ononis

by Hans Roskam

1a On parts above ground => 2

1b Egg-shaped or cylindrical, often apically forked nodules. Ononis spp.: Rhizobium leguminosarum

2a On vegetative organs => 3

2b Pod swollen; inner wall with mycelium. Containing single yellow larva. O. minutissima, natrix & subsp. hispanica, spinosa & subspp. hircina + procurrens, talaverae, tridentate: Asphondylia ononidis

2c Flowers unopened, containing a single midge larva. O. repens: Undescribed gall midge

3a On expanded parts of shoots or lateral buds => 4

3b Leaflets folded upwards, pod-like, weakly thickened, swollen belly-like. O. minutissima, pusilla, spinosa subsp. hircina: Dasineura columnae

4a Locally restricted galls => 5

4b Main- and side shoots terminally with dense bushy clustering of small, mainly stunted, abnormally pubescent leaflets, witches’ broom-like. Stipules enlarged; flowers aborted. O. arvensis, natrix, spinosa & subsp. hircina +procurrens, tridentata: Aceria ononidis

5a Terminal internodes of shoot axis shortened, leaves ± disfigured, at top in bushy clusters. Containing yellow larvae. . O. natrix, repens, spinose & subsp. procurrens: Contarinia ononidis

5b A bud-like, egg-shaped, weak fleshy gall in leaf axils or terminally on side shoots, emerging from enlarged, folded stipules; leaflets atrophied. Inner wall with mycelium. Containing a yellow larva. O. minutissima, natrix & subsp. hispanica, spinosa & subspp. hircina + procurrens, talaverae, tridentate: Asphondylia ononidis

gallers on Oenanthe

Last modified 11.vi.2020

Dichotomous table for gallers on Oenanthe

by Hans Roskam

1a On stems and leaves => 2

1b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. O. aquatica: Lasioptera carophila

1c Bladder-like fruit galls on O. pimpinelloides: Kiefferia pericarpiicola

2a Galls conspicuous, oval or elongate spindle-shaped => 3

2b Galls less than 1 mm across, multicellular, wart-shaped, yellow translucent; usually many on lower stem parts, petioles, leaf veins and -blades. O. aquatica:
Synchytrium aureum

3a Bulges yellowish, soon bearing aecia. O. aquatica, crocata, fistulosa, globulosa, lachenalii: Uromyces lineolatus

3b Vitreous, yellow-green, unopened bulges of various size on all green parts. O. crocata, fistulosa: Protomyces macrosporus

3c Leaves, especially young ones, blistered and with white down covering underside. O. crocata: Plasmopara baudysii

gallers on Nigella

Last modified 11.vi.2020

Dichotomous table for gallers on Nigella arvensis

by Hans Roskam

1a Stem bulging, swollen, also bent, with oval, rimmed, shallow depressions, which contain inducer. Planchonia arabidis

1b Yellowish, often conspicuous bulges on ± curved stems, petioles, leaves and cotyledons bearing aecia and spermogonia. Puccinia actaeae-elymi

1c In similar aecia in Nigella species develops the usually weakly cecidogenic. Puccinia actaeae-agropyri

gallers on Nicotiana

Last modified 11.vi.2020

Dichotomous table for gallers on Nicotiana

by Hans Roskam

1a On roots or root collar => 2

1b ale green, spongy, bladder- or bulging expanded swellings, 5–20 mm long or more; on young plants mainly at stem base, on older ones higher on stem. Ditylenchus dipsaci

1c Stunting of growing points, curling of leaves. Myzus persicae subsp. nicotianae

2a oots with spindle- shaped or nodular swellings. Nicotiana spp.: Meloidogyne hapla

2b Conspicuous cancer-like malformations of various size, mainly on root collar, but also on higher situated stem parts. Nicotiana spp.: Agrobacterium tumefaciens

2c On the root collar, especially of N. glutinosa, less on N. tabacum occur the leafy galls Rhodococcus fascians

gallers on Neslia

Last modified 10.vi.2020

Dichotomous table for gallers on Neslia paniculata

by Hans Roskam

1a On parts above ground => 3

1b On roots or on root collar => 2

2a Long cylindrical- to short barrel-shaped swellings on main- and adventitious roots. Plasmodiophora brassicae

2b Root collar with ± globular swellings; containing a curved beetle larva.
Ceutorhynchus assimilis

3a Malformations caused by fungi => 4

3b talks of flowers or young inflorescences stunted, often ± bent, parts ± disfigured. Brevicoryne brassicae

4a On the leaf blades rotund, on axial parts of leaves, on stems and inflorescences spindle-shaped, at first lacquered glossy, then with white dusting, sometimes curved bulges. Albugo candida

4b Diseased leaves locally swollen or if totally infected ± spoon-like, bent downwards. Stem often infected over large expansion, slightly thickened and variously distorted. On leaf underside and stems expanded white down of branched conidiophores develop. Hyaloperonospora nesliae

gallers on Mespilus

Last modified 10.vi.2020

Dichotomous table for gallers on Mespilus germanica

by Hans Roskam

1a Malformations on leaves => 3

1b Galls on shoot axis => 3

2a Young shoots with small bulge-like, oval swellings, which contain the causer in a central depression. Epidiaspis leperii

2b Older shoot stems with spindle- to club-shaped swellings. Viscum album

3a Galls caused by aphids => 5

3b Galls induced by other causes, locally delimited => 4

4a Underside of leaf blades with felt-like pubescence. Eriophyes pyri

4b Yellowish or brownish bulges on the underside of leaf blades, rotund-oval, elongate spindle-shaped on venation, developing fibrous aecia that tear open. Gymnosporangium confusum

5a Extensive malformations caused by aphids => 6

5b Leaf margin rolled downwards. Aphid covered with white woolly wax. Prociphilus pini

6a Leaves on stunted shoot tips hardly discoloured, strongly rolled and curled; aphid 2 mm long, leaf- to dark-green with dark brown-black siphunculi. Aphis pomi

6b Similar malformations; aphid yellowish-green, with segmental dark-green stripes on back and pale siphunculi, only dark at tip. Rhopalosiphum oxyacanthae

gallers on Matthiola

Last modified 10.vi.2020

Dichotomous table for gallers on Matthiola

by Hans Roskam

1a On parts above ground => 2

1b Roots with ± expanded, spindle-shaped to cylindrical, compact swellings. M. longipetala subsp. bicornis, tricuspidata: Plasmodiophora brassicae

2a Galls of irregular shape are expanded to involve several organs or larger parts of single organs => 3

2b White bulges, up to about 10 mm long, at first glossy, porcelain-like, later on dusty on axial parts of leaves or on stems. M. fruticulosa, incana: Albugo candida

3a Malformations caused by animals => 4

3b Stems or leaf axis diseased and swollen over different lengths, sometimes curved and soon covered by a down of white conidiophores. M. incana: Peronospora matthiolae

4a One-sided infected axis ± curved, leaves clustered, deflected over their tip and slightly curled. M. incana: Philaenus spumarius

4b Locally restricted or extensive on young leaves, ± discoloured folds and curls of the leaf blade. M. incana: Brevicoryne brassicae

gallers on Lobularia

Last modified 9.vi.2020

Dichotomous table for gallers on Lobularia maritima

by Hans Roskam

1a On parts above ground => 2

1b Conspicuous, spindle-shaped to cylindrical, fleshy swellings on roots.
Plasmodiophora brassicae

2a Upperside of the leaf with purple, ultimately brown spots. Underside with a greyish-white fungal down consisting of erect conidiophores; towards the tip these are several times branching at right angles. Conidia egg-shaped. Hyaloperonospora lobulariae

2b Usually all flowers of a single or several inflorescences greened. Aceria drabae

gallers on Hydrangea

Last modified 9.vi.2020

Dichotomous table for gallers on Hydrangea macrophylla

by Hans Roskam

1a On parts above ground => 3

1b On root collar or on roots => 2

2a Roots with slender- to broad spindle-shaped galls, a few mm long.
Meloidogyne hapla

2b Root collar or also basal axial parts with conspicuous proliferations, irregularly fissured at surface, almost walnut-size. Agrobacterium tumefaciens

3a Malformations mainly on leaf blades => 4

3b Stem shortened, spongy, thickened and ± distorted; the stalks and basal vein parts at infestation site clustered, leaves bloated, the leaf blades variously curved. Flowers, if present close to infestation, disfigured and ± greened, stalks ± strongly thickened. Ditylenchus dipsaci

4a Curling, arching and upwards development of leaf blade caused by aphids; or malformations of flowers => 5

4b Leaf blade with pustule-shaped galls which are soon surrounded by an expanded area of dead tissue. Cause unknown – ? gall midge

5a Malformations on plants cultivated in greenhouse. Aulacorthum solani and/or Macrosiphum euphorbiae

5b Flowers on variously stunted stems more densely arranged, greened; corolla leaves usually stunted in development. Stamens and ovaries sometimes leafy. Virus disease

gallers on Hymenolobus

Last modified 9.vi.2020

Dichotomous table for gallers on Hymenolobus

(incl. Hornungia, Hutchinsia, Pritzelago)

by Hans Roskam

1a On green plant parts => 2

1b On root collar, a one-sided rotund one-chambered swelling, up to 5 mm long. Containing a single white larva. Hornungia alpina: Ceutorhynchus assimilis

2a On leaves or stems => 3

2b Flowers greened. Hornungia alpina: Aceria drabae

3a More or less spindle-shaped galls on shoot axis => 4

3b Wart-shaped, multi-cellular, often variously coalesced galls on stems and flowers. Pritzelago alpina: Synchytrium infestans

3c Occasional infestation. Hornungia petraea: Peronospora hornungiae

4a Vegetative part of stem spindle-shaped swollen. Hornungia alpina:
Unidentified snout beetle

4b Stem predominately swollen over variable length in inflorescence region and bearing white, later on vitreous, dusting of sori. Hornungia alpina, petraea; Hymenolobus procumbens; Pritzelago alpina incl. subp. auerswaldii: Albugo candida

4c 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. Hornungia alpina: Hyaloperonospora parasitica

gallers on Humulus

Last modified 8.vi.2020

Dichotomous table for gallers on Humulus lupulus

by Hans Roskam

1a On axial parts of shoots or leaves => 2

1b On ± distinctly swollen roots erupt, at first white, later on pale brown eelworm cysts, dropping, about poppy-seed size. Heterodera humuli

2a Extensive malformations on shoot tips or on higher situated leaves => 4

2b Galls on root collar or on basal parts => 3

3a Root collar with conspicuous distorted buds, up to even 6 cm large, inside white, at surface at first glabrous, greenish to pale brown, later on fissured or wart-like, dark brown proliferations. Also encroaching onto rhizomes. Agrobacterium tumefaciens

3b Basal organs with many warts, hardly 1 mm long, ± golden-yellow, many-celled, ± joining on leaf underside into crusts; or into ridges on leaf veins, -stalks or stems. Synchytrium aureum

4a Malformations caused by fungi fruiting on outside of malformation => 5

4b Malformations caused by aphids. Phorodon humuli

5a Axial parts of often systemically infected terminal or axillary young shoots are severely stunted, ± conspicuously thickened. Leaves densely clustered, leaf blades often greatly reduced, ± deflected, spoon-like, pale green, apically rapidly decreasing in size, covered on the underside with dense, dark violet down of conidiophores. Pseudoperonospora cubensis

5b Almost identical malformations, which are on upperside as well as underside, covered by a mealy white dusting, later on often ± browned mycelium. Podosphaera aphanis

gallers on Meum

Last modified 21.vi.2020

Dichotomous table for gallers on Meum

(incl. Haloscias, Ligusticum)

by Hans Roskam

1a On above-ground parts => 2

1b Nodular swellings on roots. Ligusticum scoticum: Meloidogyne hapla

2a Malformations of vegetative plant parts => 3

2b Inflorescence disfigured, flowers greened. Ligusticum mutellina, scoticum: Tegonotus scoticus

2c Similar malformations on Ligusticum mutellina are induced by: Aceria peucedani

3a Malformations caused by animals => 4

3b Malformations caused by fungi => 4

4a Development of leaf blade stunted, spoon-like deflected downwards, curled; in case of strong infestation yellowing early. Ligusticum mutellina, scoticum: Tegonotus scoticus

4b Leaf midrib and stalks of leaflets shortened, distorted; leaf blades curled and deflected, nest-like. M. athamanticum; Ligusticum mutellina: Philaenus spumarius

5a Galls with sori on their surface => 6

5b Spindle-shaped, vitreous, at first ± pale green, later grey-brown bulges which reach a length of up to 10 mm on stems or petioles but are often only 1 mm across on midrib and veins. Ligusticum mutellina, mutellinoides; Meum athamanticum: Protomyces macrosporus

6a Bulging swellings, yellowish and usually similarly margined on stem parts and main veins of leaves, bearing aecia. Ligusticum mutellina:. Fungus host-alternating; uredinia, telia on Persicaria alpina, bistorta => 8

6b Similar, but brown to black telia bearing bulges => 7

7a Teliospores 3-celled, bearing several long sturdy spines. Ligusticum mutellina; Meum athamanticum: Nyssopsora echinata

7b Teliospores 2-celled. Ligusticum mutellinoides, scoticum: Puccinia thomasii

8a Aecia dense, cup-shaped, the margin not bent outwards. Ligusticum mutellina; Meum athamanticum: Puccinia mei-mamillata

8b Aecia countersunk, opening with pore, not with cup. Ligusticum mutellina; Meum athamanticum: Puccinia bistortae

8c Spindle-shaped, weak swellings on leaf axis and veins, also on stems, soon bearing telia. Ligusticum scoticum: Puccinia halosciadis

gallers on Glyceria

Last modified 8.vi.2020

Dichotomous table for gallers on Glyceria

by Hans Roskam

1a On above-ground parts => 2

1b Root hairs variously swollen, usually bottle- or club-shaped; each containing a rotund, hollow, multipartite spore ball. G. fluitans: Sorosphaerula radicalis

2a On culms and leaves => 3

2b 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. G. striata, Glyceria sp.: Epichloë glyceriae

2c On inflorescences or flowers. Spikelets elongated; flowers ± greened, bleached if strongly infected. G. fluitans: Aceria tenuis

3a Malformations caused by fungi => 4

3b Leaf blade rolled, irregularly curved and twisted; caused by a dull green to reddish, 2 mm long aphid. G. declinata, fluitans, maxima, notata, striata: Sipha glyceriae

3c Yellow-red midge larvae living under leaf sheaths. G. maxima: Octodiplosis glyceriae

4a Fungus, usually completely pervading many shoots, sporulates mainly all around the internodes of the at least initially excessively elongated, non-flowering shoots. G. fluitans: Tranzscheliella hypodytes

4b The infestation usually affects all shoots of infected plant, in which sterile culms often grow initially rigidly erect and bear stunted, pale-green leaves. The smut sori extend over the complete length of the leaf blades in several parallel stripes. G. arundinacea, declinata, fluitans, lithuanica, maxima, nemoralis, notate: Ustilago filiformis

4c Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. Glyceria spp.: Puccinia striiformis

= In similar sori on G. fluitans, notata: Ustilago davisii, differing from U. longissima by its larger spores (8–14 x 6–12 μm)

= Another smut fungus, sporadically occurring on Glyceria, distinguished by its spores clustered in balls, belongs to the Urocystis agropyri species complex

gallers on Gladiolus

Last modified 7.vi.2020

Dichotomous table for gallers on Gladiolus

by Hans Roskam

1a On leaves and scapes => 4

1b On roots or tubers => 2

2a Malformations on tubers => 3

2b Roots with nodular swellings. G. x gandavensis, x hybridus: Meloidogyne hapla

3a Bulge-like galls on tuber surface => 4

3b Yellow-brown large “leafy galls”, tuber- or scale-shaped accumulations at the base of the tuber, up to 40 mm in cross section. Gladiolus spp.: Rhodococcus fascians

4a Blackish, partially yellow margined bulge-like swellings on leaves, stems and tubers. Releasing a dark brown powder consisting of spore balls after breaking open. G. imbricatus, italicus, palustris: Urocystis gladiolicola

4b Less severely infected tubers that are partially destroyed internally develop only some variously bleached and curved leaves, bearing ± oblong spindle-shaped, spongy bulges. Gladiolus spp.: Ditylenchus dipsaci

gallers on Galinsoga

Last modified 7.vi.2020

Dichotomous table for gallers on Galinsoga

by Hans Roskam

1a On above-ground parts => 2

1b Roots with spindle- to nodule-shaped swellings. G. parviflora: Meloidogyne hapla

2a Distortion of leaves => 4

2b Galls mainly on stems => 3

3a Initially hyaline, later on browned, glabrous ± spindle-shaped swellings of the stems on all sides or, if on one side, bent, occasionally on petioles and leaf veins, even on involucral bracts, exceptionally on adventitious roots; of various shapes and dimensions. Young plants swollen at stem base. G. parviflora: Protomyces buerenianus

3b Blunt, spongy swellings of the stems, ± uneven, at their surface, the inside with eelworms. G. parviflora: Ditylenchus dipsaci

4a Tight curling of the locally intensively green coloured leaf blade caused by a froth-covered nymph. G. quadriratiata, parviflora: Philaenus spumarius

4b Wrinkling and downward bending of the leaf blade. G. parviflora: Unidentified aphid

gallers on Gagea

Last modified 7.vi.2020

Dichotomous table for gallers on Gagea

by Hans Roskam

1a Expanded galls on all green parts, according to the plant part affected => 3

1b Inconspicuous galls, consisting of a single swollen epidermis cell, on all green parts => 2

2a 1-celled warts, very small, punctiform, slightly protruding, yellowish; inside the spindle-shaped, swollen nutritive cell is a single 100 x 150 μm, or several (up to 10), globular or oval to flattened resting sporangia with colourless contents. G. pratensis: Synchytrium punctatum

2b Galls similar. The nutritive cell contains 1–3 resting spores, with red-orange or yellow contents. G. lutea, minima, pratensis: Synchytrium laetum

3a Bulging galls caused by smut fungi => 4

3b Leaves stunted; with irregular, pale, rugose-spongy swellings at base. Leaf blades twisted and curved. G. pratensis: Ditylenchus dipsaci

4a Rotund to oval smut pustules, about 2–10 mm long bulging, bladder-like, sometimes coalescing, which erupt rather late with longitudinal slits and release a blackish-olive-brown spore mass. Spores single. Gagea spp.: Vankya ornithogali

4b Similar but predominantly isolated, often extensive smut bulges on leaves and scapes; spores single or clustered in balls of 2–3 (5), enveloped by sterile auxiliary cells. G. pauciflora: Urocystis ornithogali

gallers on Fumaria

Last modified 7.vi.2020

Dichotomous table for gallers on Fumaria

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. F. vaillantii: Meloidogyne hapla

2a Malformations of organs at shoot tip, fruits => 4

2b Galls on base of stem => 3

3a Unilocular stem gall with a solitary weevil larva. F. officinalis, vaillantii: Sirocalodes quercicola and/or S. depressicollis

3b Petioles in most cases mainly stunted at base, thickened, ± pale green, spongy, swollen; containing the inducers inside. Fumaria spp.: Ditylenchus dipsaci

4a Malformations caused by animals => 5

4b Malformations caused by fungi, developing grey-violet down on the surface of the malformations. Fumaria spp.: Peronospora affinis

5a Malformations densely crowded with black aphids. Fumaria spp.: Aphis fabae

5b Malformations caused by froth-covered nymphs. Fumaria spp.: Philaenus spumarius

5c Larva solitary in a slightly enlarged, and partially reddish coloured fruit; hibernation as larva in the (usually fallen) gall. F. cf. agraria, officinalis:
Neaylax versicolor

gallers on Falcaria

Last modified 7.vi.2020

Dichotomous table for gallers on Falcaria vulgaris

by Hans Roskam

1a Malformations on leaves => 3

1b On inflorescence and in flowers => 2

2a Centre of (partial) umbel swollen, globular or club-shaped; gall mostly uni-, also multi-chambered, each containing a red larva. Lasioptera carophila

2b Fruit strongly swollen, often reddened; protruding above the umbel. Containing a single orange-red larva. Kiefferia pericarpiicola

3a Malformations caused by animals => 4

3b Leaves rigidly erect, longer stalked than normal ones; leaf blades pale, narrower, sometimes curved and twisted, usually bearing spermogonia over whole surface and aecia on underside. Puccinia sii-falcariae

4a Malformations with conspicuous curling and distortion of the leaf blade => 5

4b Irregular thickenings, up to about 10 mm long, pale, wrinkled, often variously curved, often radiating from the midrib ± into the leaf blade; sometimes arranged into several rows. Ditylenchus dipsaci

4c About 8–15 mm long, broad spindle-shaped, strongly bent, glabrous swellings on petioles or midribs of leaves. On the inside of the curving is a depression containing the causer. Planchonia arabidis

5a Leaf sheaths swollen, belly-like, ± bulging, simultaneously often curling and twisting of leaf blades caused by yellowish aphids. Ammiaphis sii

5b Leaf blade strongly deflected, undulately curled, sometimes converging, nest-like. Philaenus spumarius

gallers on Euphrasia

Last modified 21.vi.2020

Dichotomous table for gallers on Euphrasia

(see also Odontites)

by Hans Roskam

1a Wart-shaped, small swellings on ± distorted green organs => 4

1b Malformations expanded => 2

2a Malformations at least partially with abnormal pubescence or down of branched conidiophores => 3

2b Axis bulging over variable length, sometimes curved; galls at surface with rimmed depressions, containing froth-covered nymph. E. picta: Planchonia arabidis

3a Systemic diseased shoots developing faster than healthy ones; leaves paler, narrower, deflected at margin, appearing arched, with whitish down of branched conidiophores on underside. E. nemorosa, rostkoviana, stricta: Plasmopara euphrasiae

3b Complete plant ± distorted, often non-flowering, abnormally pubescent over large parts. Leaves often bent, spoon-like, yellowish or reddish discoloured, white-erineum on underside. Flowers, if present, disfigured, often transformed into rotund masses of small, abnormal leaves. Excessive branching. Euphrasia spp.: Aceria euphrasiae

3c Young growth and in inflorescences which become slightly curved and stunted; malformations caused by aphids. E. frigida: Hyperomyzus thorsteinni

4a Warts greenish, hemispherical, 0.3–1 mm across, usually clustered, close to ground on stems and leaves of dwarfed plants; occasionally also on calyx of flowering plants. E. picta: Physoderma negeri

4b Warts similar but golden-yellow translucent, on basal organs, isolated or occasionally joined into crusts or ridges. E. picta: Synchytrium aureum

gallers on Delphinium

Last modified 5.vi.2020

Dichotomous table for gallers on Delphinium

(incl. Consolida)

by Hans Roskam

1a On plant parts above ground => 2

1b Roots with nodular swellings. D. elatum: Meloidogyne hapla

1c Leafy galls, caused on the root collar by Rhodococcus fascians

2a Closed stem galls, contain insect larva => 3

2b Leaves or petioles with rotund to oval, yellowish, aecia bearing bulges. Consolida ajacis, hispanica, regalis; Delphinium spp.: Puccinia actaeae-elymi

2c In similar malformations on Consolida ajacis, regalis; Delphinium cashmerianum, elatum, exaltatum develop aecia of a less cecidogenic rust fungus alternating on Elymus caninus: Puccinia actaeae-agropyri

3a Small spindle-shaped swelling on stem, 5–10 mm long and 2–4 mm in cross section, red or brown, close to an insertion of leaf, with large cavity. Consolida hispanica, regalis; Delphinium longipes: Thamnurgus delphinii

3b Stem just below the still undeveloped inflorescence ± spindle-shaped, or irregularly barrel-shaped, swollen over a length of 20–35 mm. The increasingly developed, also outside the gall irregularly eaten, pith containing a single or several larvae. Delphinium elatum, ? oxysepalum: Ranunculiphilus pseudinclemens

gallers on Daphne

Last modified 21.vi.2020

Dichotomous table for gallers on Daphne

by Hans Roskam

1a Galls on parts above ground => 2

1b Root collar with conspicuous, at first succulent, later on ± woody, cancer-like proliferations. D. mezereum: Agrobacterium tumefaciens

2a On twigs, shoot tips or leaves => 3

2b Perianth at base rounded, swollen, disfigured, up to 3–5 mm long. Containing several, whitish larvae. D. gnidium, laureola, mezereum, striata: Dasineura daphnephila

3a On shoot tips or leaves => 4

3b Swelling of twig, about 50–60 mm long, 5 mm broad, contains long tunnels sometimes with several larvae. D. gnidium, laureola, mezereum: Phyllobrostis eremitella

4a Leaves loosely rolled downwards and curved. D. aureola, mezereum, striata:
Macrosiphum daphnidis

4b More or less distinct malformation on leaves. D. mezereum: Aculus daphnes

4c Leaves on stunted shoot tip clustered, tuft-like, elongated, locally thickened, ± discoloured red, developing into an oblong-oval or spindle-shaped gall, up to 30 mm long and 5–10 mm thick, sometimes sickle-shaped. Contains several white larvae. D. cneorum, laureola, mezereum, striata: Dasineura daphnes

gallers on Vincetoxicum

Last modified 5.vi.2020

Dichotomous table for gallers on Vincetoxicum hirundinaria

by Hans Roskam

1a On flowers or fruits => 4

1b On vegetative organs => 2

2a Leaf blades converging, distorted or curled => 3

2b Leaf margin narrowly rolled upwards, more rarely downwards, discoloured.
Unidentified gall mite

3a Young axis locally stunted; several leaves clustered, converging, ± nest-like. Leaf blades curled, deep green close to the froth-covered nymph. Philaenus spumarius

3b Leaf blades slightly clustered, curved and distorted. Inducer unknown – ? insect

4a On fruits; malformations facultative, usually minor => 5

4b Flower buds enlarged, cartilaginously thickened; ± reddish; later on rupturing, with thick, short lobes. Containing white to yellowish, jumping larva. Contarinia vincetoxici

5a Fruit slightly swollen; often hardly changed, sometimes ± wrinkled and discoloured. Containing several slender, white, jumping larvae. Contarinia asclepiadis

5b Fruit swollen, sometimes curved, ± yellowish, reddish or violet. Containing many cylindrical larvae. Euphranta connexa

gallers on Chondrilla

Last modified 3.vi.2020

Dichotomous table for gallers on Chondrilla juncea

by Hans Roskam

1a On leaves and stems => 2

1b On shoot tips or in the leaf axils densely crowded about 10–15 mm long tufts of shoot-like proliferations, composed of scale-shaped leaves. Shoot stem stunted; sometimes with fasciation: Aceria chondrillae

= In flower heads may develop larvae of the gall midge Jaapiella chondrillae

2a Malformations mainly or exclusively on the stems => 4

2b Malformations of the leaves => 3

3a Leaf blade with rotund pustules, up to 5 mm long, protruding on the upper side, ± reddish, usually brighter in the middle, closed on the underside only by the smooth epidermis, with translucent yellow-red larva. Cystiphora schmidti

3b Leaf blade curled with undulate margin. Uroleucon chondrillae and/or Chondrillobium blattnyi

4a Galls caused by animal inducers => 5

4b Stem, sometimes the leaf stems with short, wart- to bulge-shaped swellings up to twice the size of the respective plant part. With brown sori on the upper side. Puccinia chondrillina

5a Galls about 40 mm long and 15 mm broad, consisting of two swollen parts separated by a constriction. Timaspis chondrillae

5b Shoots with lateral, oval galls, up to 2.5 mm long and 0.75 mm wide. Cystiphora schmidti

gallers on Microrrhinum

Last modified 3.vi.2020

Dichotomous table for gallers on Microrrhinum

(ex Chaenorhinum p.p.)

by Hans Roskam

1a On stems or leaves => 2

1b Fruit swollen, ± disfigured. M. litorale, minus: Rhinusa antirrhini

2a Galls on stems => 3

2b Shoot tips, if heavily infected, slightly stunted, slightly thickened; the inserted leaves clustered, leaf blades stunted, their margins rolled, ± distorted; bearing down of branched conidiophores. M. minus: Peronospora linariae

2c Complete plant disfigured, additionally branched; leaves curled and twisted; flower primordia, if present, aborted. M. minus: Cause unknown – ? gall mite

3a Shoot axis with conspicuous, one-chambered, rotund or multi-chambered, oblong swellings. Each chamber containing a single larva. M. minus: Rhinusa pilosa

= Inquiline in galls of R. pilosa: Rhinusa eversmanni

3b Stem with weak spindle-shaped swelling. Containing a single larva. M. minus: Mecinus janthinus

gallers on Carlina

Last modified 3.vi.2020

Dichotomous table for gallers on Carlina

(incl. Atractylis)

by Hans Roskam

1a In leaves or inflorescences => 3

1b In stem parts => 2

2a Root collar bumpy swollen. C. vulgaris: Ditylenchus dipsaci

2b Stem gall. Spindle-shaped very elongate swelling, 35 x 5 mm. Large thin-walled larval chamber with lateral large round exit hole. A. serratuloides: Unidentified lepidopteran

3a In inflorescences => 5

3b In leaves => 4

4a Leaves at primary veins already in early spring with minor oval swellings, yellowish, up to 0.5 mm with pycnidia on the upper side and areas with primary, cinnamon-brown, dusty uredinia. C. acaulis: Puccinia carlinae

4b Leaf blade transformed into a fleshy tissue, elliptical, about 11 mm high and 5 mm in cross section; surface green, covered with fine white hairs and leaf lobes provided with spines. Large irregular thick fleshy-walled cavity, dark coloured. C. gummifera: Unidentified stem eelworm

4c Leaf blade covered with a thick layer of long whitish hairs. C. gummifera: Aceria carlinae

5a Malformations of receptacle => 6

5b Flowers greened. Excessive branching. C. vulgaris: Cause unidentified – ? gall mite

6a Capitula swollen, hardened, remaining ± closed, with several long oval gall chambers, placed upright on receptacle. One larva per chamber without distinct head capsule. C. vulgaris: Urophora solstitialis

6b Capitula slightly enlarged; the fleshy parts consumed by a larva with a distinct head capsule. C. vulgaris: Larinus planus

6c Similar malformations in greatly hardened receptacles can be caused by caterpillars of Metzneria aestivella subsp. aestivella

gallers on Bunias

Last modified 3.vi.2020

Dichotomous table for gallers on Bunias

by Hans Roskam

1a On flowers or leaves => 3

1b On root collar or on roots => 2

2a Rotund, succulent, usually one-sided, one-chambered gall, up to 8 (10) mm long, on root collar. Containing a single larva. B. erucago. Ceutorhynchus assimilis

2b Roots with conspicuous, succulent, compact swellings, with masses of minute spores in many cells. B. erucago, orientalis: Plasmodiophora brassicae

3a On leaves => 4

3b Flower buds swollen, unopened. Containing a single or several whitish to pale yellow, jumping larvae. B. erucago, orientalis: Contarinia nasturtii

4a Malformations caused by animal inducers => 5

4b Leaf blades of younger leaves often close to main venation with minor, pale green upward swellings; on the underside with a white down of branched conidiophores. B. orientalis: Peronospora buniadis

5a Basal leaves with expanded loose downward rolls, usually on one side. Infected leaf blade parts ± bumpy, arched, darker green; on underside a single or several froth-covered nymphs. B. orientalis: Philaenus spumarius

5b Petioles or axis with spindle-shaped swellings, 10–15 mm long, also deep green inside. Containing a single larva. B. erucago: Ceutorhynchus chalybaeus

gallers on Atropa

Last modified 24.viii.2020

Dichotomous table for gallers on Atropa bella-donna

by Hans Roskam

1a On leaves => 2

1b Roots hardly changed, with giant cells inside at proximal part of eelworm. The first white, soon yellow, eventually brown females (cysts) detach from the roots and drop when mature. Globodera rostochiensis

2a Malformations caused by animals => 3

2b Leaf blade with slightly thickened, yellowish, later on pale brownish spots; with white aecia on underside, spermogonia on upper side. Aecidium belladonnae

3a Large parts of leaf blades, often loosely rolled downwards over its top and mostly one-sided; strongly curled and deep green, especially close to the froth-covered nymph. Philaenus spumarius

3b Leaf blade of single or several terminal leaves slightly deflected and curled on all sides. Macrosiphum euphorbiae

3c In similar malformations. Myzus persicae

gallers on Astrantia

Last modified 2.vi.2020

Dichotomous table for gallers on Astrantia

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodule-shaped swellings. A. carniolica, major: Meloidogyne hapla

2a Malformations with sori of fungi on surface => 4

2b Malformations caused by insects => 3

3a Leaves with ± thickened folds, contain white midge larvae. A. major: Macrolabis sp.

3b Leaves converged downwards, nest-like; curled and dark-green close to the froth-covered nymph on underside. A. carniolica: Philaenus spumarius

4a Leaf veins and-stalk bulging, thickened, distorted. Bulges yellowish, soon bearing brown 2-celled telia. A. major, minor: Puccinia astrantiae

4b Leaf blade with hemispherical swellings which are ± spindle-shaped on leaf veins. Aecia countersunk; peridium not protruding. A. minor: Puccinia polygoni-vivipari

gallers on Arctostaphylos

Last modified 2.vi.2020

Dichotomous table for gallers on Arctostaphylos

by Hans Roskam

1a Malformations on stems and leaves => 3

= (For root swellings see Vaccinium)

1b Galls on lateral buds or on fruits => 2

2a Buds enlarged and disfigured. A. uva-ursi: Aceria jaapi

2b Young berries disfigured, prematurely reddened and dropping; often ± angular, split to the middle; lobes sometimes elongated, snout-like. Usually containing several orange-coloured larvae. A. uva-ursi: Unidentified gall midge

3a Malformations only on leaves => 4

3b Malformations of complete shoots, partially witches’ broom-like. Leaves smaller or larger than normal ones; sometimes arched, pale green or ± intensively brown-red coloured; partially with whitish down on underside. A. uva-ursi: Exobasidium uvae-ursi

4a Leaf blade with loose, ± discoloured, slightly succulent marginal downwards roll. Containing several orange-red larvae. A. uva-ursi: Unidentified gall midge

4b Larger or smaller segments strongly arched downwards, depressed on upperside; leaf blades sometimes groove-shaped; often conspicuously reddened. Infestation occasionally at shoot tips encroaching onto all parts. Axial parts swollen, leaves reduced, succulent thickened, spoon-like. Infected parts on underside of leaf blade at maturity of fungus covered with chalk-white layer. A. alpina, uva-ursi: Exobasidium vaccinii

4c Leaves with small thickened orange spots, sometimes also on thickened stems. A. uva-ursi: Exobasidium sydowianum

4d Leaves slightly enlarged and thickened, yellowish white to dark purple; shoots clustered, slightly elongated and deformed. A. alpina: Exobasidium angustisporum

gallers on Aposeris

Last modified 3.vi.2020

Dichotomous table for gallers on Aposeris foetida

by Hans Roskam

1a Malformations on the plant surface not occupied by fungi => 2

1b Leaf blade on the underside with round 1 (2) cm large, yellowish to reddish-brown spots with many close and distinctly bordered aecia. Sporulating areas on the veins with slightly cushion-like bulges. Puccinia poae-aposeridis

2a Galls on the leaf blade or on the margin => 3

2b Hyaline callus on the midrib, radiating to lateral veins; venation strongly swollen; leaf blade sometimes ± malformed; centre yellowish discoloured. Spores predominantly in phloem. Protomyces kreuthensis

2c On the leaf blade, in many usually brownish spots, up to 1 mm long, sometimes slightly bulged. Entyloma aposeridis

3a Leaf blade glabrous, margin rolled upwards. Unidentified thrips

3b Leaf blade on the underside with small depressions and corresponding swellings on the upper side; strongly infected leaves sometimes ± twisted and rolled at the margin. Trioza dispar

3c Browning of leaf blade; at high densities rusting may occur. Epitrimerus protrichus

gallers on Apera

Last modified 1.vi.2020

Dichotomous table for gallers on Apera spica-venti

by Hans Roskam

1a Galls of various shape on panicles, flowers or fruits => 4

1b Galls on vegetative parts => 2

2a Localised galls on stems or leaves => 3

2b Young plants severely stunted. Shoots swollen, spongy especially at base; leaves reduced and bent. Ditylenchus dipsaci

3a Stem with weak, locally rimmed depressions below the slightly swollen sheath. Containing single orange-yellow larvae. Lasioptera calamagrostidis

3b Leaf blades at base usually with reddish to violet, slim bulging, swellings, 5–30 mm long. Anguina graminis

4a Malformations of ovaries => 5

4b Axial parts of panicles especially at base strongly wriggled, therefore appearing shortened; spikelets gathered together, usually remaining closed; flower parts and glumes not enlarged, sometimes greened. Unidentified eelworm

4c Inflorescence and flowers disfigured. Reproductive organs aborted. Glumes twisted or irregularly folded; in case of weaker infestation often dark red or violet, bleached if strongly infected. Aceria tenuis

5a Ovaries swollen bottle-shaped, usually discoloured violet, glumes not enlarged. Anguina agrostis

= Sometimes the sac fungus Dilophospora alopecuri occurs in ovaries of many grasses when eelworms are associated

5b Ovaries temporarily swollen, soon transformed into rotund to oblong smut grains, in the pendant panicles. Fresh sori smelling. Plant hardly disfigured. Tilletia separata

gallers on Aesculus

Last modified 1.vi.2020

Dichotomous table for gallers on Aesculus

by Hans Roskam

1a On leaves or on branches => 2

1b Inflorescence with abnormal felt-like pubescence. A. hippocastanum: Unidentified gall mite

2a On leaves => 3

2b Thicker branches with spindle- to club-shaped swellings, bearing Viscum album

3a Localised galls on leaf blade => 4

3b Leaves rolled downwards. A. hippocastanum, pavia: Aphis fabae

4a Lenticular gall on leaf underside. A. hippocastanum: Unidentified gall midge

4b Abnormal tufts of hairs on underside of vein axils; on upper side a corresponding arching. Hairs many-celled, long, weakly club-shaped. Aesculus spp: Aculus hippocastani

4c Rusting and abnormal hairiness of leaf blade. A. hippocastanum, glabra, neglecta: Shevtchenkella carinata

gallers on Adoxa

Last modified 1.vi.2020

Dichotomous table for gallers on Adoxa moschatellina

by Hans Roskam

1a Bulging or expanded thickenings caused by smut- or rust fungi => 2

1b Above ground organs often with many small, glass pearl-like, mainly 1-celled wart-shaped galls. Synchytrium anomalum

2a Malformations caused by fungi fruiting at gall surface => 3

2b Bulges on shoot parts above or below ground, containing black smut spores. Melanotaenium adoxae

3a Malformation covered with aecia => 4

3b The fungus develops only dark brown sori with 2-celled telia. Puccinia adoxae

4a Aecia on leaf underside rather uniformly distributed or on petioles and stems loosely distributed on ± thickened pads. Puccinia argentata

4b Aecia, as in previous rust; uniformly distributed, more dense or loose, usually over large areas and soon systemically infected, pale plants. Puccinia albescens

gallers on Sempervivum

Last modified 31.v.2020

Dichotomous table for gallers on Sempervivum

(incl. Jovibarba)

by Hans Roskam

1a On parts above ground => 2

1b Roots with conspicuous swellings, up to 8 mm long and 5 mm broad, rotund- to oblong-oval. Sempervivum spp.: Meloidogyne hapla

2a Malformations partially excessively pubescent, usually caused by gall mites => 3

2b Several to many leaves of the rosette upright, pale green, narrowed, partially elongated, up to twice the normal size; with small, sunken, orange-red, conically protruding spermogonia and scattered aecia-like sori on upper side. Jovibarba globifera & subsp. arenaria + hirta; Sempervivum arachnoideum, calcareum, montanum, tectorum, wulfenii: Endophyllum sempervivi

3a Malformations densely pubescent => 4

3b Complete plant shortened and disfigured. Jovibarba globifera: Unidentified gall mite

3c From S. arachnoideum has been reared Aizobius sedi

4a On Jovibarba hirta. Leaves paler and densely pubescent, usually with many small, cone-shaped outgrowths, especially on upper side. Unidentified gall mite

4b On S. montanum. Rosette disfigured, ± irregular; grey-looking because of dense pubescence. Leaves sometimes with wart-like protuberances. Flowers leafy (phyllanthy). Unidentified gall mite

gallers on Saponaria

Last modified 31.v.2020

Dichotomous table for gallers on Saponaria

by Hans Roskam

1a On flowers or flower parts => 4

1b On vegetative organs => 2

2a Expanded malformations on stems and leaves => 3

2b Leaf blades with several rotund pads, up to about 5 mm broad, protruding on underside; yellow-brown, sometimes slightly swollen, soon covered with brown spores. Occasionally more elongated sori on main veins and young stems. S. cerastioides, ocymoides, officinalis, orientalis, persica: Puccinia arenariae

3a Young shoots stunted, thickened and shortened, leaves ± clustered; their bases often spongy, strongly swollen; leaf blades distorted and curled. Saponaria spp.: Ditylenchus dipsaci

3b Leaf strongly deflected, ± bent and curled, deep green at infestation site; sometimes several leaves similarly disfigured on stunted shoot tips which are usually cracked on one side. Saponaria spp.: Philaenus spumarius

4a Malformation of flowers, or predominantly of anthers, caused by fungi => 6

4b Malformations of flowers caused by animals => 5

5a lowers unopened variously swollen conically. Containing several yellowish, jumping larvae. S. officinalis: Contarinia steini

5b Slightly bloated, ± largely unopened calyx encloses the other flower parts which are transformed into scale-like, ± greened leaves. Saponaria spp.: Cause unknown – ? gall mite

6a Flower buds ± globular, swollen to about pea-size, ± brown-red discoloured galls. Inner parts soon largely destroyed. Bud at first unopened, eventually bursting open and with dusting of brown-yellow spore balls. S. ocymoides, officinalis: Thecaphora saponariae

6b Anthers ± globularly swollen in unopened, usually little altered flowers, rigidly connected to their filaments, soon filled with reddish- to brown-violet spore masses. S. lutea, ocymoides, officinalis, pumilio: Microbotryum violaceum

gallers on Reseda

Last modified 31.v.2020

Dichotomous table for gallers on Reseda

by Hans Roskam

1a Malformations on parts above ground => 3

1b Galls on root collar => 2

2a Root collar with weakly globose protruding one-chambered swelling, less than 10 mm long, laterally attached to root as a glabrous gall. R. luteola:
Unidentified snout beetle

= Nodular malformations have been reported on R. luteola, which may be attributed to Meloidogyne hapla

2b Root collar with mainly one-sided, 20–25 mm long, 15–20 mm broad, facultatively originating swellings, soon bearing dying rosette leaves. Containing several larvae. R. luteola: Unidentified snout beetle

3a On inflorescences, shoot tips or leaves => 4

3b Stem with spindle-shaped swelling. R. luteola: Unidentified snout beetle

4a Malformations caused by animal parasites => 5

4b Axial parts of leaves with at first porcelain-white, closed bulges, later on with mealy dusting. R. luteola: Albugo resedae

4c Upperside of the leaf with yellow spots. Underside with a brownish fungal down of erect conidiophores that apically several times are dichotomously branching, each terminal branch ending in an ovoid conidium. R. lutea, luteola: Hyaloperonospora crispula

5a Internodes of stem twisted, ± flattened, strongly curved. Flowers clustered. R. lutea: Unidentified aphid

5b Leaves clustered ± nest-like on severely stunted shoot tips, ± stunted, with several converging, curled, deep green close to the froth-covered nymph. Reseda spp.: Philaenus spumarius

gallers on Pulmonaria

Last modified 31.v.2020

Dichotomous table for gallers on Pulmonaria

by Hans Roskam

1a On flowers or fruits => 4

1b On leaves and occasionally on stems => 2

2a Malformations caused by aphids => 3

2b On the leaf blades, even on calyx lobes, rotund, elongated oval, yellowish, aecia and spermogonia bearing bulges, weakly protruding on underside stronger on leaf axis, -stalk or stem. Pulmonaria spp.: Puccinia recondita

3a Basal leaves with transverse- or marginal roll downwards, also upwards. Leaf blades irregularly curled or bulging. Apterous aphids 1.8–2.9 mm long. Body pear-shaped, pale yellowish to green, with a dark, green spot at each insertion of pale, very short siphunculi. P. obscura, officinalis: Aulacorthum solani

= As causer of disfigured leaves on P. obscura, the aphid Aphis symphyti has been reported, living mainly on Symphytum

3b Malformations similar. Aphid 1.5–2 mm long, pale yellowish to yellow-green. Siphunculi pale, longer than those of previous species, reaching about 1/5 to ¼ of body length. P. officinalis: Brachycaudus helichrysi

4a Flowers thickened, unopened. Containing several white larvae. P. obscura, officinalis: Unidentified gall midge

4b Mericarps greatly enlarged, as long as calyx. Pistil slightly changed. Containing orange-red larvae. P. montana, etc.: Unidentified gall midge

gallers on Petasites

Last modified 30.v.2020

Dichotomous table for gallers on Petasites

by Hans Roskam

1a Galls on above-ground parts => 2

1b Roots with several nodule-shaped, massive swellings. P. paradoxus: Meloidogyne hapla

2a Galls wart-, cushion- or bulge-like => 4

2b Extended malformations on the leaf blades => 3

3a Leaves mostly stunted, leaf blades markedly curved downwards, sometimes bag-like, undulating, curled. Rolls partially markedly thickened. P. hybridus: Inducer unknown

3b eaf blade parts strongly curved downward, curled, the site of infestation dark green close to the froth-covered nymph. P. hybridus: Philaenus spumarius

4a Less than 1 mm long, multicellular, usually yellow, sometimes coalescing warts on green parts situated close to the ground. Petasites spp.: Synchytrium aureum

4b Larger, cushion- or bulge-like malformations => 5

5a Rotund or oblong flat aecia cushions, in yellowish or reddish spots, up to about 6–10 mm long situated, on leaf blades and veins, rarely on petioles. Petasites spp.: Aecidium petasitidis

5b Rotund cushions, the underside clearly bulged, and occupied by dark brown telia. P. frigidus, paradoxus: Puccinia expansa

gallers on Ornithopus

Last modified 30.v.2020

Dichotomous table for gallers on Ornithopus

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Nodular swellings in root. O. sativus: Meloidogyne hapla

2b Often only small nodules attached to roots, usually oval, more rarely cylindrical, apically sometimes flattened or grooved. Ornithopus spp.: Rhizobium lupini

3a Malformations on leaves, as well as conspicuously on petioles and stems => 4

3b Leaflets rolled upwards or folded together; sickle-shaped, also spirally distorted. Flowers atrophied and aborted; sometimes develop leaves instead of bracts. Plants often ± stunted, infected extensively. Diseased parts sometimes abnormally haired. O. perpusillus, sativus, ? compressus: Aceria plicator

4a Stems with spongy swellings on conspicuously stunted young plants. Inserted leaves ± stunted and disfigured. Many eelworms live in the prematurely withering tissue. O. perpusillus, sativus: Ditylenchus dipsaci

4b Systemically infected young plants or shoots often largely stunted in longitudinal growth, rigidly erect. Leaves and leaflets reduced, thickened due to defective differentiation of tissue, soon covered with a dirty grey down of branched conidiophores. O. perpusillus, pinnatus, sativus: Peronospora ornithopi

gallers on Oenothera

Last modified 3.vi.2020

Dichotomous table for gallers on Oenothera

(incl. Kneiffia)

by Hans Roskam

1a On parts above ground => 2

1b Nodular, almost rotund galls on roots. O. fruticosa: Meloidogyne hapla

2a Expanded malformations on single or several organs => 4

2b Small wart-shaped galls on leaves and stems => 3

3a Warts multicellular, orange to crimson-red translucent, often densely clustered, mainly on basal plant parts. O. biennis: Synchytrium fulgens

3b Warts multicellular, glass bead-like. O. biennis: Synchytrium mercurialis

4a Causers on host surface and visible with naked eye => 6

4b Causers inside galls or, if on outside, only microscopically => 5

5a Outer rosette leaves stunted and disfigured. Midrib spongy, swollen. Neighbouring leaf blade areas undulate-lacerate. O. biennis: Ditylenchus dipsaci

5b Malformation of complete, severely stunted plants with partially greened flowers. O. biennis: Inducer unknown

6a Axial parts of shoots stunted or curved on one side; leaves ± clustered, deflected over tip and margins, ± curled and locally deep green. Oenothera spp.: Philaenus spumarius

6b Plant distorted, shoot axis shortened. Leaves smaller, folded between side veins, also ± curled. Flowers greened and thickened Oenothera spp.:
Brachycaudus cardui

=Aphis holoenotherae has been recorded from many Oenothera species. This is the only aphid that is fully dependent on evening primrose. Not a true gall causer

gallers on Nasturtium

Last modified 30.v.2020

Dichotomous table for gallers on Nasturtium

(see also Rorippa)

by Hans Roskam

1a Galls on parts above ground => 2

1b Roots conspicuously curved and swollen. N. officinale: Spongospora nasturtii

= The snout beetle Ceutorhynchus assimilis, inducing root collar galls on many crucifers, also occurs on N. officinale, but occasionally without causing galls

= The cyst developing eelworm Heterodera cruciferae has been recorded on Nasturtium

2a Malformations on vegetative organs => 3

2b Flowers swollen, unopened. Corolla stunted, like other parts disfigured and ± thickened. Larvae whitish to lemon-yellow. N. microphyllum, officinale: Contarinia nasturtii

3a Malformations caused by fungi, with fruiting bodies on their surface => 4

3b Axis of young shoots stunted, inserted parts clustered. leaves or leaflets deflected, curled and discoloured deep green close to the froth-covered nymph. N. microphyllum, officinale: Philaenus spumarius

4a Fungus sori dense, at first closed, glossy, porcelain-like, conidia developing in rows, later on with mealy dusting. N. microphyllum, officinale: Albugo candida

4b Fungus fruiting on branched conidiophores, developing in loose down of branched conidiophores. N. officinale: Hyaloperonospora nasturtii-aquatici

gallers on Myagrum

Last modified 24.viii.2020

Dichotomous table for gallers on Myagrum perfoliatum

by Hans Roskam

1a On parts above ground => 3

1b On roots or root collar => 2

2a About pea-size, ± globular galls on root collar containing a curved beetle larva. Ceutorhynchus assimilis

2b Main- and side roots with conspicuous, spindle-shaped to cylindrical, fleshy galls of variable size. Plasmodiophora brassicae

3a On flowers => 6

3b On vegetative organs => 4

4a Galls caused by animals => 5

4b White bulges on leaves and stems, at first glossy, porcelain-like, later on with mealy dusting. Albugo candida

5a Margins of young leaves bent upwards; leaf blades variously wrinkled or undulate and discoloured pale green. On vegetative shoots several terminal leaves are sometimes accumulated and conspicuously disfigured. Brevicoryne brassicae

5b Terminal leaves or axillary buds clustered; the outer one ± disfigured, at base discoloured and ± thickened, enveloping the bud-like inner leaves. Containing several lemon-yellow, jumping larvae. Contarinia nasturtii

6a Flowers swollen, unopened. Larvae white, non-jumping. Gephyraulus raphanistri

6b Similar galls. Larvae lemon-yellow, jumping. Contarinia nasturtii

gallers on Minuartia

Last modified 28.v.2020

Dichotomous table for gallers on Minuartia

(incl. Honckenya. ‒ Comp. Arenaria, Stellaria)

by Hans Roskam

1a On stems and leaves => 3

1b On flowers => 2

2a Flowers ± swollen globularly, unopened. Inner organs soon destroyed and replaced by spore balls consisting of a yellowish-brown powdery dust. Arenaria pungens; Minuartia hybrida: Thecaphora saponariae s.l.

2b Flowers outwardly not conspicuously changed; anthers shortened and swollen; later on filled with a dusty violet spore powder. M. recurva: Microbotryum violaceum

3a Malformations caused by fungi fruiting at surface => 5

3b Malformations caused by animals => 4

4a Leaves on slightly stunted shoots more densely arranged, the leaf blades a little deflected over their tip, curved upwards at margin. Honckenia peploides: Myzus certus

4b Shoot axis stunted, bent at infestation site. Leaves more clustered, leaf blades distorted. Honckenia peploides: Philaenus spumarius

5a Leaves or stem with rotund- oblong-oval, yellowish brown pads, occasionally slightly bent, protruding on underside, soon bearing a brown sorus at surface. Arenaria montana, retusa, serpyllifolia, tenuifolia; Minuartia hybrida, laricifolia, verna: Puccinia arenariae

5b Systemic diseased shoots growing rigidly erect; leaves reduced, slightly thickened and ± bent, spoon-like. On leaf underside and stem grey down of conidiophores develop. Honckenia peploides: Peronospora honckenyae

5c Bushy accumulation on twisted and thickened stems; capsules inflated. M. viscosa: Inducer unknown

gallers on Mercurialis

Last modified 28.v.2020

Dichotomous table for gallers on Mercurialis

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. M. annua: Meloidogyne hapla

2a Inducer living inside galls => 4

2b Inducer living and/or fruiting on gall surface => 3

3a Young leaves of disfigured shoot tip curled. M. annua, perennis: Aulacorthum solani

3b Orange-yellow, soon dusty, spindle-shaped, ± distorted bulges of various length on underside of main venation, on petioles as well as occasionally on young stem parts. Patches developing on leaf blades are small, rotund and not swollen. M. perennis: Melampsora populnea

4a Stem or leaves with localised, well defined galls => 6

4b Malformations usually extending over several organs => 5

5a Large parts, sometimes the entire plants, including primordia of flowering parts, with vitreous, pearl-like, compound small warts; these often join into crusts or ridges and variously disfigure the severely stunted plants during their development. M. perennis: Synchytrium mercurialis

5b On M. annua. Young plants severely stunted. Internodes spongy, swollen, pale green. Leaves distorted, with ± swollen stalks and veins. Ditylenchus dipsaci

6a Rotund, one-chambered swellings on stems, leaf- or inflorescence axial parts. Containing a single curved larva. M. annua. Kalcapion semivittatum

6b Slender, narrow and compact, about 5–30 mm long, soon browned upwards roll of leaf margin. M. perennis: Thrips fulvipes

gallers on Lycopsis

Last modified 28.v.2020

Dichotomous table for gallers on Lycopsis arvensis

by Hans Roskam

1a Galls on parts above ground => 2

1b Side roots often with many nodular to spindle-shaped swellings, which bear some lateral roots. Meloidogyne hapla

2a On flowers or inflorescences => 5

2b On vegetative organs => 3

3a Large parts of plant disfigured => 4

3b Leaf blade, especially in venation, with rotund to ± acuminated, oval, often conspicuous yellow to yellow-brown swellings, occurring especially on underside, which are marbled, sieve-like. Occasionally on stems. Puccinia recondita

4a Growth stunted, leaves rolled downwards, curled. Also on disfigured, ± etiolated flowers. Dictyla echii

4b Basal stem parts variously swollen, spongy ± pale green. Ditylenchus dipsaci

5a Inflorescence clustered, ball-like. Brachycaudus helichrysi

5b lowers greened, densely white pubescent, clustered, ball-like. Aceria eutricha

gallers on Lilium

Last modified 3.vi.2020

Dichotomous table for gallers on Lilium

by Hans Roskam

1a On above-ground parts => 2

1b Nodular swellings on roots. Lilium spp.: Meloidogyne hapla

1c Conspicuous galls on subterranean buds. Lilium spp.: Rhodococcus fascians

2a On severely etiolated flower buds which are occasionally galled => 3

2b Pale, sometimes brownish margined, occasionally inconspicuously swollen spots on leaves and stems, occupied by hardly protruding cups, up to 1 cm long. L. bulbiferum, canadense, candidum, carniolocum, martagon: Uromyces aecidiiformis

2c Underside of the leaves with a whitish fungal down consisting of vertical conidiophores that apically are dichotomously branching several times, each branch ending in an elliptic conidium. L. candidum: Peronospora lilii

3a Malformations lacking additional pubescence => 4

3b The ± disfigured flower buds or also the slightly spreading perianth leaves are covered with long white hairs. Containing many pale yellow larvae. L. martagon: Contarinia martagonis

4a Malformations caused by larvae with inconspicuous head => 5

4b Malformations caused by larvae with distinct head. Flower buds usually not opening, partially swollen, ± crippled, sometimes bent on one side, containing several yellowish-white, elongate oval larvae, which feed on variously disfigured stamens and ovaries or mine into the perianth leaves or also extend into the flower peduncles. L. martagon, rarely candidum: Liriomyza urophorina

5a The compact, mostly stunted buds contain several yellowish, jumping larvae. L. martagon: Contarinia lilii

5b lower buds severely stunted and etiolated. Larvae red. L. candidum: Contarinia liliacea

gallers on Leymus

Last modified 27.v.2020

Dichotomous table for gallers on Leymus arenarius

by Hans Roskam

1a On above-ground parts => 2

1b Roots with many nodular or elongated spindle-shaped swellings, about 0.5–5 mm long and 3–5 mm broad, ± obliquely bent, crooked; containing eelworms inside the ± spongy tissue. Subanguina radicicola

2a On vegetative parts => 3

2b Inflorescence variously disfigured and bleached. Aceria tenuis

3a Malformation with black fungus sori => 5

3b Galls in culm, caused by animals => 4

4a Culm locally weakly swollen; containing a single larva. Tetramesa brischkei

4b Culm stunted in development. Upper internode sometimes appearing thickened. Inflorescence aborted, stuck in the sheaths, disfigured and ± dishevelled. Containing a yellowish-white, up to 4 mm long larva. Oscinella pusilla

5a Diseased shoots at first showing enhanced development; number of internodes and leaves increased. Organs weaker and usually paler than healthy ones. Leaves rigid, erect; plant looking weak; exceptionally with primordia of usually crippled and curved inflorescences. Internodes below the leaf sheaths, rarely also the sheaths, with expanded smut sori developing, on their surface. Tranzscheliella hypodytes

5b Smut patches on the leaves or sheaths. Ustilago striiformis

gallers on Lapsana

Last modified 27.v.2020

Dichotomous table for gallers on Lapsana communis

by Hans Roskam

1a On above-ground parts => 2

1b Roots with several small, spindle- to nodule-shaped swellings, bearing lateral roots. Meloidogyne hapla

2a On vegetative parts => 3

2b Florets ± stunted and greened. Unidentified gall mite

3a On leaves => 4

3b Irregular swelling in stem, up to 6 cm long by 10 mm wide; containing several chambers each with a white larva or pupa. Timaspis lampsanae

4a Galls mainly in leaf blade => 5

4b Petiole, mid- and main veins or also the leaf blades of the rosette leaves already in early spring with conspicuous, usually reddish margined or overflowed, yellowish, aecia bearing bulges. Puccinia lapsanae

5a Expanded malformations of leaves => 6

5b Leaf blades with rotund wide pads, up to 5 (7) mm, usually protruding on the underside and concave on the upper side, bearing ± deep yellow aecia. Exceptionally also spindle-shaped galls on bent leaf ridges and petioles. Puccinia opizii

6a Curvings and curlings of the leaf blade caused by aphids => 7

6b Leaf blade more or less deflected, ± bulge-like curled, dark green coloured, close to the froth-covered nymph occasionally a clustering of disfigured leaves on often one-sided stunted, bent shoots. Philaenus spumarius

7a Distinct malformations of the leaf, associated with deflected curving of the margin and curling of the leaf blade. Aphid 1.8–3 mm long, straw yellow, green or reddish; wingless adults on the dorsal side with a pattern of dark spots. Siphunculi slender, cylindrical. Nasonovia ribisnigri

7b Similar malformations. Aphid 2.5–3.5 mm long, body white. Siphunculi notably swollen, widest in the middle. Hyperomyzus lampsanae

gallers on Laburnum

Last modified 27.v.2020

Dichotomous table for gallers on Laburnum

(incl. Laburnocytisus, Lembotropis)

by Hans Roskam

1a On parts above ground => 2

1b Oval to cylindrical, also hand-shaped to coralloid branched nodules, laterally attached to the roots; occasionally coalesced into larger clusters. Laburnum spp.: Rhizobium leguminosarum

2a On inflorescences or pods => 5

2b On vegetative organs => 3

3a On axial parts => 4

3b Buds swollen, walls of cavity inside lined with black mycelium. L. anagyroides: Asphondylia sp.

3c Leaves stunted, sometimes deflected over their top, margin ± curved downwards, leaf blade folded or curled. Laburnum alpinum, anagyroides, watereri; Lembotropis nigricans: Aphis cytisorum

4a Thicker branches with spindle- to club-shaped swellings bearing mistletoe. Laburnum spp.: Viscum album

4b Bark of young shoots with rimmed depressions, each containing a flat froth-covered nymph. Laburnum spp.: Chionaspis salicis

5a nflorescence variously disfigured. Laburnum anagyroides; Lembotropis nigricans: Aculops cytisicolus

5b Fruit with conspicuous swelling. Laburnum spp.: Inducer unknown

gallers on Juglans

Last modified 24.viii.2020

Dichotomous table for gallers on Juglans regia

by Hans Roskam

1a On leaflets of leaves => 4

1b On axial parts of shoots => 2

2a The causers of malformations are on the outside => 3

2b Axial parts of shoots, especially on young plants, with rotund proliferations, up to fist-size, with fissured surface. Agrobacterium tumefaciens

3a Bark of twigs with minor, rimmed depressions; containing causer. Epidiaspis leperii

3b Branches with spindle- to club-shaped swellings, bearing: Viscum album

4a Leaf roll and distortion caused by aphids => 6

4b Leaf blade and sometimes young fruits with pocks or felt-like upward archings on underside, caused by gall mites => 5

4c Leaves browned; at high densities vagrant mites may cause russeting Aculops unguiculatus

4d Yellowish spots or blotches apparent on both sides of leaflet, with whitish patches on underside. Microstroma juglandis

5a Pocks, up to 2 mm long, on both sides or only visible on upperside, rotund, if mature, black-brown with irregular cavity. Often many. Also on skins of fruits. Aceria tristriata

5b Crook-backed usually upward arching, reticulately striate by thickened venation and often angularly restricted. In depression on underside are whitish erinea consisting of long, cylindrical acuminate hairs. Aceria erinea

6a Loose roll of young leaflets, ± sickle-like distortion of midrib. Aphids on upper side of midrib. Panaphis juglandis

6b Similar roll of leaflets; aphids on leaf underside. Chromaphis juglandicola

gallers on Forsythia

Last modified 26.v.2020

Dichotomous table for gallers on Forsythia

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular, compact swellings. F. x intermedia: Meloidogyne hapla

2a Galls on twigs => 3

2b Leaves on shoot tips ± disfigured, caused by aphids. F. suspense: Unidentified aphid

3a Rotund galls, usually situated on nodes, developing into strongly fissured woody proliferations, up to several cm large. F. suspense: Agrobacterium tumefaciens

3b Conspicuous, ± wart-like, at first succulent, later on tough galls of variable size, which develop on young shoots instead of lateral buds. Rhodococcus fascians

gallers on Erophila

Last modified 26.v.2020

Dichotomous table for gallers on Erophila verna

by Hans Roskam

1a On parts above ground => 2

1b Roots with ± spindle-shaped, fleshy swellings, containing masses of minute spores. Plasmodiophora brassicae

2a Malformations at surface with sori of fungus => 5

2b Malformations caused by animals => 3

3a On stems, leaves or flowers => 4

3b Fruit slightly swollen, often oblique. Containing a single larva. Unidentified beetle

4a Complete plant ± disfigured, leaves usually shorter and broader, ± arched. Inflorescence stalk stunted. Flowers stunted tuft-like, ± greened or leafy, sometimes abnormally pubescent. Cecidophyes borealis

4b Similar malformations. Aceria drabae

4c Stem at base with swelling up to 4–7 mm long and 2–4 mm thick. Containing a single white larva. Ceutorhynchus hirtulus

5a Sori expanded, consisting of branched conidiophores. Plant completely or largely stunted, sometimes excessively leafy. Leaves etiolated, pale, slightly thickened, sometimes arched spoon-like. Infected stem parts shortened, thickened, ± bent. Inflorescences and buds stunted. Hyaloperonospora erophilae

5b At the tip of the older leaves of the rosette a faint fungal down, consisting of erect, distally strongly branched conidiophores. The plant is not disfigured, and the leaves are not bleached or galled. Hyaloperonospora praecox

5c Sori compact, at first closed, glossy, porcelain-like, with mealy dusting after rupturing; short bulge-like to long expanded. On all green parts. Infected stems often distorted; inflorescences ± disfigured. Diseased flowers with conspicuously enlarged calyx and ovaries. Albugo candida

gallers on Dryopteris

Last modified 26.v.2020

Dichotomous table for gallers on Dryopteris

(incl. Lastrea, Nephrodium)

by Hans Roskam

1a On the leaflet leaf blades => 2

1b Tip of frond shortened, spirally rolled upward, including the crowded, only slightly changed side leaflets making a conspicuous nest with a white larva on the ± thickened midrib. D. carthusiana, cristata, dilatata, filix-mas: Chirosia betuleti

2a Leaf blade on underside sometimes ± fleshy because of enlarging of mesophyll- or epidermis cells; occasionally swollen, almost blister-like yellowish-brownish discoloured; fungus galls => 4

2b Malformations caused by animal parasites => 3

3a Leaflets with small pustules which contain eggs, mainly situated at margin, rapidly becoming necrotic after larval emergence. “Procecidia”, oviposition scars, not true galls. D. filix-mas: Aneugmenus coronatus

3b Margin of leaflets folded, discoloured, slightly thickened. Thelypteris palustris: Undescribed gall midge

3c Rounded swelling on rachis, about 2 mm long; containing a pale green caterpillar which bites a hole and ejects froth that covers the gall. Dryopteris spp.: Blasticotoma filiceti

4a On D. campyloptera and relatives

I Mycelium intercellular. Causes ± fleshy localised swellings in tissues of thickened leaflets. D. carthusiana, dilatata: Taphrina filicina

II Mycelium only below cuticule

a Often distinctly protruding galls on leaflets, up to 5 mm broad, ± fleshy. D. carthusiana, dilatata, “rigida var. australis”, villarii: Taphrina fusca

b Up to 5 mm long galls on leaf blade. D. carthusiana, dilatata, filix-mas: Taphrina athyrii

4b On D. affinis, borreri, carthusiana, filix-mas. Small, up to 5 mm long, often many per leaf blade, ± fleshy swollen, yellow-greenish to brownish galls: Taphrina vestergrenii

gallers on Dorycnium

Last modified 26.v.2020

Dichotomous table for gallers on Dorycnium

by Hans Roskam

1a On parts above ground => 2

1b Roots usually with laterally inserted oblong-oval or cylindrical swellings, apically often forked or branched, almost coralloid, sometimes clustered. Dorycnium spp.: Rhizobium leguminosarum

2a On flowers or fruits => 5

2b On vegetative parts => 3

3a On shoot tips or leaves => 4

3b Shoot axis with oblong, reddened swelling. D. pentaphyllum subsp. Germanicum: cf. Melanagromyza cunctans

3c Conspicuous spindle-shaped swelling, bright red coloured, flattened on one side, with rimmed depressions containing the causer. D. pentaphyllum: Planchonia arabidis

4a Leaflets folded. D. pentaphyllum subsp. germanicum + herbaceum: Unidentified gall mite

4b Terminal leaflets of leaf folded, pod-like, reddish discoloured. Containing several at first yellowish-white later orange larvae. D. hirsutum: Dasineura sp.

4c Tip of side shoot with greenish, closed, strongly white pubescent gall, up to 7 mm long and 3 mm thick. D. hirsutum, pentaphyllum: Asphondylia dorycnii

5a Galls on pods => 6

5b lowers disfigured and ± greened, as well as other organs present on shoot tip variously disfigured organs abnormally pubescent. Dorycnium spp.: Aceria euaspis

6a Pod swollen. Inner wall covered with fungus. D. hirsutum, pentaphyllum: Asphondylia dorycnii

6b Pods swollen; mycelium absent. Containing a curved larva with head capsule. D. pentaphyllum & subsp. germanicum + herbaceum: Ischnopterapion aeneomicans

gallers on Dipsacus

Last modified 25.v.2020

Dichotomous table for gallers on Dipsacus

(incl. Virga)

by Hans Roskam

1a On above-ground parts => 2

1b Side roots with nodular swellings. D. sativus: Meloidogyne hapla

2a On vegetative parts => 4

2b On capitula => 3

3a Infected capitula often strange-looking. Several petals enlarged, ± disfigured, discoloured. Anthers and ovaries largely aborted. Loose down of branched conidiophores on petals of usually completely diseased capitula. D. fullonum, laciniatus, pilosus: Peronospora violacea

3b Many parts of capitula disfigured; diseased tissue hypertrophied, soon browning and dying. Infected fruits reduced, twice as thick as normal ones; pappus sessile, swollen. Seed coat thickened, rounded. D. fullonum, sativus: Ditylenchus dipsaci

4a Malformations on rosette leaves => 6

4b Malformations of higher situated parts => 5

5a Leaf blades of larger stem leaves, including tip, mainly deflected on one side; strongly curled and deep green close to the froth-covered nymph. Dipsacus spp.: Philaenus spumarius

5b Undescribed gall-like malformations caused by aphids. D. sativus: cf. Aulacorthum solani

= On D. laciniatus and D. fullonum the gall mite Leipothrix dipsacivagus has been described causing rusting and wrinkles on the longitudinal folds of leaves

6a Usually several inner leaves of spring rosettes infected, more erect; leaf blades narrowed, slightly thickened and ± brittle; usually to a large extent the infected parts alongside the midrib are pale green, bulging upwards over the normally coloured marginal areas, covered on underside by a dirty pale grey down of branched conidiophores. D. fullonum, laciniatus, pilosus: Peronospora dipsaci

6b Rosette leaves in spring stunted, shortened, spongy and swollen, especially at base, pale, sometimes clustered, cabbage-like. D. sativus: Ditylenchus dipsaci

6b Leaves with small gregarious pustules, less than 0.5 mm across. D. fullonum: Synchytrium succisae

gallers on Crambe

Last modified 12.ix.2020

Dichotomous table for gallers on Crambe

by Hans Roskam

1a On leaves and stems => 3

1b On roots or on root collar => 2

2a Roots with conspicuous spindle-shaped or acuminated, cylindrical succulent, compact swellings. C. abyssinica, maritima, tataria: Plasmodiophora brassicae

2b Rotund, about pea-size, one-chambered galls on root collar. Containing a single larva. C. maritima: Ceutorhynchus assimilis

3a Expanded malformations caused by aphids => 5

3b Galls of lesser expansion, ± pad- or bulge-shaped => 4

4a Galls spindle-shaped, 15‒20 mm long, also green inside, on petioles, leaf veins or thinner stems. Containing a single larva. C. abyssinica, maritima, tataria: Ceutorhynchus chalybaeus

4b At first closed glossy, porcelain-like, later on rupturing and with mealy dusting, rotund to oblong-oval pads or bulges on leaves, stems and stalks of inflorescences. C. maritima, tataria: Albugo candida

4c 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. maritima, tataria: Hyaloperonospora parasitica

5a Complete plant disfigured, leaves rolled, flowers greened. C. maritima: Lipaphis hedickei

5b Leaf blades of basal leaves with irregular paler green, sometimes ± red-violet marbled archings. C. abyssinica, maritima: Brevicoryne brassicae

gallers on Conium

Last modified 25.v.2020

Dichotomous table for gallers on Conium maculatum

by Hans Roskam

1a On inflorescences or fruits => 5

1b On vegetative parts => 2

2a Malformations caused by animal parasites => 3

2b Bulge-shaped, sometimes distorted, about 10 mm long swellings on leaf veins, -midrib and -stalk, bearing cinnamon-brown uredinia, occasionally also on younger stem parts and even in inflorescence. Puccinia conii

3a Malformations caused by aphids => 4

3b Leaf blade over large parts nest-like downwards deflected; leaf tips slightly curled and deep-green. Philaenus spumarius

4a Axis of leaf tip conspicuously distorted and twisted; leaf blades folded and curled. Aphid about 2 mm long; pale green, with pale siphunculi, these much longer than cauda, which bears an appendage. Antennae shorter than half the body length. Cavariella pastinacae

4b Malformations similar. Aphid 1.5–2.4 mm, grey-green, often blackish-brown. Siphunculi very dark, about as long as cauda. Antennae ⅓–½ body length. Hyadaphis foeniculi

5a Stalk at centre of (partial) umbel ± globular to club-shaped swollen. Inner wall covered with mycelium. Containing a red larva. Lasioptera carophila

5b Fruit strongly swollen, globular to rotund-oval; galls protruding above the umbel; glabrous, ± reddened. Containing an orange-red larva. Kiefferia pericarpiicola

5c Inside disfigured fruits of C. maculatum develop uredinia of Puccinia conii

gallers on Callistephus

Last modified 25.v.2020

Dichotomous table for gallers on Callistephus chinenis

(comp. Aster)

by Hans Roskam

1a On leaves and shoot => 2

1b Lateral roots with 2–4 mm long, ± spindle-shaped swellings, with some partially adventitious roots. Meloidogyne hapla

2a Malformations by aphids and spittlebugs => 3

2b Stems of young plants very much shortened, spongy, swollen, bushy clustered; petioles of basal- or stem leaves, sometimes including the under leaf blade areas galled in a similar way. Ditylenchus dipsaci

3a Malformations by aphids => 4

3b Leaves on the stunted and ± bent stem nest-like converging; curled and dark green close to the froth-covered nymph. Philaenus spumarius

4a Malformation, curling and curving of apical young leaves, caused by yellowish or greenish aphids => 5

4b Similar malformations caused by black aphids. Aphis fabae

5a Malformations by yellowish to bright green aphids lacking segmentally arranged brown dots on the dorsal surface. Brachycaudus helichrysi

5b Adult apterous aphids yellowish, possessing segmentally arranged brown dots on the dorsal surface. Myzus ornatus

gallers on Anethum

Last modified 24.v.2020

Dichotomous table for gallers on Anethum graveolens

by Hans Roskam

1a On stems or leaves => 2

1b Centre of umbel- or partial umbel stalk swollen ± club-shaped or globular; sometimes ± spindle-shaped galls on stalks close to branching points. Containing a single orange-yellow to red larva. Lasioptera carophila

2a Malformations mainly on leaves => 3

2b Stem of young plants below the attachment of petiole swollen, barrel-shaped, also partially distorted. Complete plant stunted. Leaves ± curled and rolled. Containing a white larva. Unidentified gall midge

3a Leaves distorted or rolled inwards, ± curled => 4

3b Leaf rachis and -stalk, also stem, with, ± distinctly swollen, oblong-oval, yellowish bulges, up to about 4 mm long bearing spermogonia and brown sori of 1-celled uredinia. Puccinia nitida

4a Malformations caused by aphids => 5

4b Stem of developing plants locally stunted, sometimes distorted; leaves clustered, their tips ± nest-like converging downwards, partially curved. Infected umbels variously stunted and distorted; flowers ± disfigured. Containing a froth-covered nymph. Philaenus spumarius

4c Leaves on the underside with a white fungal down of erect conidiophores that apically bear a few short branches, each one ending in a conidium. Plasmopara anethi

5a Younger leaves variously distorted. Tips curled. Aphid black. Aphis fabae

5b Similar galls caused by green aphids with “double” cauda.
Cavariella aegopodii and/or C. pastinacae

gallers on Stipa

Last modified 24.v.2020

Dichotomous table for gallers on Stipa

(incl. Orthoraphium)

by Hans Roskam

1a On inflorescences, florets or fruits => 6

1b On leaves, stems or stalks of ± undeveloped panicles => 2

2a Several internodes of the initially elongate culm occupied by extensive patches of smut. Also on possible primordia of panicles; sometimes on leaves => 5

2b Malformations caused by animal parasites => 3

3a Culm with elongate spindle-shaped swellings => 4

3b Inner side of leaf sheaths covering parts of culm, or undeveloped stalks of panicles and occasionally even the glumes, often with long expanded rows or crusts of blister-like, at first white, then dark brown tuberculi. S. capillata: Steneotarsonemus graminis

3c In similar galls on S. capillata, pennata: Steneotarsonemus canestrinii

4a Culm above the 3th or 4th node with oblong, weak swelling. Pith containing a single larva. S. capillata: Tetramesa aciculata

4b Elongate spindle-shaped, weak swelling on culm of S. pennata. Containing a single larva. Tetramesa sp.

4c On S. capensis: Tetramesa stipae

5a Culms and possibly stalks of inflorescences with expanded blackish patches of smut on all sides. S. capillata, pennata: Sphacelotheca valesiaca

5b Similar infestation. Spores smaller, 4–6 x 3–5µ, reddish-brown, glabrous. S. capillata, dasyphylla, eriocaulis, pennata, pulcherrima: Tranzscheliella minima

6a Midrib of spikelets abnormally elongated, with swellings up to about 10 mm long, spindle-shaped, occasionally 2- or 3-winged, grain-like, sometimes ± curved. Containing a single larva. S. borysthenica, eriocaulis subsp. austriaca, pennata: Tetramesa scheppigi

6b Glumes and flower parts coalesced, transformed into a 7–10 mm long, elongate spindle-shaped, fruit-like gall. Containing a single larva. S. capillata, parviflora: Tetramesa cylindrica

6c Spikelet swollen, with lateral exit hole. S. capillata, parviflora: Tetramesa cylindrica

gallers on Spergula

Last modified 24.v.2020

Dichotomous table for gallers on Spergula

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular to slender spindle-shaped swellings, bearing some side roots. S. arvensis: Meloidogyne hapla

1c Roots inside with giant cells, outwardly hardly changed or with excessive development of side roots above the infestation site. S. arvensis: Heterodera schachtii

2a Malformations of expanded parts of plant => 3

2b Local, rotund- to oblong-oval pads, sometimes resulting in distortions, up to about 5 mm long, occasionally slightly thickened, often yellow-margined, soon covered with 2-celled brown telia.  S. arvensis, morisonii, pentandra: Puccinia arenariae

3a Malformations caused by fungi which fruit at surface => 6

3b Malformations caused by animals => 4

4a Parasites live at surface of malformations => 5

4b Young plants completely stunted. Stem severely stunted, especially spongy, swollen at base. Basal- and gall-bearing leaves similarly disfigured. Containing many eelworms. S. arvensis, pentandra, morisonii: Ditylenchus dipsaci

5a Stem terminally stunted; organs clustered, with reduced and bent leaves and partially also with stunted, disfigured flower buds; flowers a little opened, ± greened and leafy. S. arvensis, pentandra: Inducer unknown – ? gall mite

5b Gall-like twisting, bending or S-shaped or right-angled distortion of ± discoloured leaves. S. arvensis: Taeniothrips atratus

6a Internodes of strongly infected young plants shortened, slightly thickened, sometimes curved. Leaf whorls accumulated; leaves stunted, pale green, slightly swollen as result of defective differentiation of tissue. The usually many diseased flower buds ± bloated, globular. All diseased parts soon covered with a loose down of branched conidiophores, partially containing oospores. S. arvensis: Peronospora obovata

6b Similar malformations on S. morisonii, pentandra: Peronospora vernalis

gallers on Silaum

Last modified 24.v.2020

Dichotomous table for gallers on Silaum silaus

by Hans Roskam

1a On stalks of umbels, flowers or fruits => 6

1b On leaves => 2

2a Localised or extensive malformations caused by animal parasites => 5

2b Small wart-shaped or larger spindle-shaped galls caused by fungi => 3

3a Galls mainly wart-shaped; spores inside host tissue => 4

3b Leaf veins, -midrib or -stalk spindle-shaped, swollen, galls usually conspicuous, sometimes ± curved, often with yellowish margins; bearing dark brown spores. Puccinia angelicae

4a Galls less than 1 mm across, multi-cellular, wart-shaped, ± golden-yellow; usually many on basal leaves, on stalks, midrib as well as on stems; sometimes coalescing into crusts or ridges. In central nutritive cell an up to 180 µm large perennial (“dauer”) sporangium. Synchytrium aureum

4b Galls similar, usually larger, ± black-brown; often clustered into densely situated groups on ± curved leaf veins, -axis or -stalk. Nutritive cells with several, ± rotund, 20–35 x 15–30 µm large perennial (“dauer”) spores. Physoderma vagans

5a Leaf blades and tips of leaflets on the often stunted midrib folded over the midrib or otherwise distorted; ± discoloured and thickened. Containing several yellowish, terminally ± reddened larvae. Jaapiella dittrichi

5b Leaf blade curved; often with curled side leaflets ± clustered, nest-like. Philaenus spumarius

6a On flowers or fruits => 7

6b Centre of (partial) umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. Lasioptera carophila

7a Flower bud unopened, swollen to a globular or obovate gall. Unidentified gall midge

7b Fruit disfigured into a bladder-like swollen, often reddened, thin-walled gall, protruding above the partial umbel. Containing 1 (–3) orange-red larvae. Kiefferia pericarpiicola

gallers on Rhinanthus

Last modified 23.v.2020

Dichotomous table for gallers on Rhinanthus

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. R. minor, serotinus: Meloidogyne hapla

2a On shoot tips, stems or leaves => 4

2b On flowers => 3

3a Flowers transformed into white-woolly, felt-like, succulent masses. Containing many larvae. R. alectorolophus, angustifolius, crista-galli, minor: Rhopalomyia cristaegalli

3b Flowers unopened or half opened. Calyx normal. Corolla poorly developed, reduced, greenish. Stamens and ovaries ± reduced. R. angustifolius: Taeniothrips atratus

4a On stems and leaves => 5

4b Side shoots terminally stunted. Younger leaves clustered, stunted, folded upwards, sometimes ± distorted, transformed into a bud-like to loose tuft-like gall, about 5–8 mm long. Between the mainly basally thickened leaf blades live yellowish-white larvae. R. angustifolius, serotinus: Macrolabis sp.

5a Malformations with erinea, consisting of hairs or conidiophores, on underside of leaves and occasionally also on stems => 8

5b Curling of leaf or swelling of stem => 6

6a Curling of several, usually terminal leaves => 7

6b Shoot axis sponge-like thickened to varied extent, ± curved. More strongly infected plants conspicuously stunted. R. angustifolius: Ditylenchus dipsaci

7a Shoot tip stunted, sometimes curved to one side. Leaves shortened, deflected, locally strongly curled and deep green. R. alectorophus, angustifolius, minor: Philaenus spumarius

7b Tips of vegetative shoots ± stunted. Leaves clustered, slightly curled and deflected. Infected inflorescences with slightly disfigured bracts and ± lacerate flowers. R. alectorolophus, angustifolius: Brachycaudus helichrysi

8a Completely diseased shoots develop faster than healthy ones, internodes thinner and longer, leaves paler, narrowed, appearing arched by deflection of margins. On the leaf underside, usually of the complete leaf blade, a very dense layer of branched conidiophores develops; usually absent from stem parts. R. alectorolophus, alpinus, angustifolius, glacialis, minor, serotinus: Plasmopara densa

8b Underside of the leaves with a greyish purple fungal down, consisting of erect, distally repeatedly dichotomously branched conidiophores. The conidia are elliptic. The host plant does not become disfigured. R. alectorolophus, angustifolius, serotinus: Peronospora pocutica

8c Leaf underside completely or partially with white floccose pubescent pads. Hairs branched or ± club-shaped. Erinea also occurring on stems. R. angustifolius: Unidentified gall mite

gallers on Phlomis

Last modified 23.v.2020

Dichotomous table for gallers on Phlomis

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. P. tuberosa: Meloidogyne hapla

2a Leaf blades, stalks or stems with fruiting bodies of rust fungi or leaf blades with erinea => 9

2b Galls caused by insect larvae => 3

3a Galls on vegetative parts => 4

3b Galls caused on inflorescences and flowers. Flower heads contain gall wasp larvae. P. tuberosa: Aulacidea dyakonchukae

= As causer of flower galls, one more gall wasp has been described for P. tuberosa, namely Vetustia investigata

= The gall wasp Panteliella bicolor causes on P. tuberosa outwardly inconspicuously disfigured stems

4a Leaf galls => 6

4b Stem galls caused by cynipid larvae => 5

5a The empty inside of the stem is filled up with monolocular, thin-walled, white, rounded galls, up to 2 mm in diameter. P. tuberosa: Aulacidea phlomica

5b Similar stem gall without externally visible malformation. P. tuberosa: Phanacis phlomidis

6a Leaf galls contain gall midge larvae lacking conspicuous mouth parts => 8

6b Leaf galls contain gall wasp larvae with conspicuous mandibles => 7

7a Leaf blade on upper side with globular, 2–3.5 mm long galls; covered with long, white hairs; on underside conspicuous as small tuft. Containing a single larva. P. tuberosa: Panteliella fedtschenkoi

7b Veins with yellow to brown, spindle-shaped, 1–3 mm long swellings; two larval chambers per gall each containing a single larva. P. tuberosa: Panteliella sp.

8a Subglobular gall, 3–5 mm across, protruding equally on both sides of leaf blade, often close to margin, which is incised; sometimes on petiole, rarely on stem. One-chambered, thin walled. P. cretica, fruticosa, tuberosa: Asphondylia phlomidis

8b Flat irregular pustules on leaves, 3-4 mm in diameter, on the upperside slightly greener than the remaining part of the leaf, on the lower side of the leaf with a slightly hypertrophied epidermis and a partly swollen vein; inside each gall is a chamber where two to four larvae develop together. Usually four to six galls develop on one leaf but up to sixty galls were found on one leaf. In such cases the galls are joined, forming a large irregular pustule with several separated chambers. Larvae pupate in galls, each larva in a white cocoon. P. fruticosa: Phlomidiomyia pustularis

9a Galls with fruiting bodies of fungi on surface => 10

9b Leaf underside with erinea, infestations ± arched. P. tuberosa: Unidentified gall mite

= Similar galls, caused by unidentified gall mites, have been described for P. samia and P. herba-venti subsp. pungens

= The gall mite Aceria onychia causes abnormally hairy disfigured parts on Phlomis fruticosa, tuberosa

10a Up to 10 mm broad, yellow, rotund sori, protruding on underside bearing aecia, on upperside ± depressed pads with spermogonia or ± elongated bulges on main venation, on petioles and young stems. P. tuberosa: Puccinia stipina

10b Aecia on underside, especially on expanded parts or on complete leaf blade; sori occasionally also on petioles and stems, weakly disfiguring the infected organs. Phlomis spp.: Puccinia phlomidis

gallers on Petroselinum

Last modified 23.v.2020

Dichotomous table for gallers on Petroselinum crispum

by Hans Roskam

1a On parts of flowering- or fruiting inflorescences => 6

1b On stems and leaves => 2

2a Expanded malformations of variable shape => 4

2b Oval or spindle-shaped galls on stems, petioles or leaf veins => 3

3a Small galls on root collar or stem base or leaves of young plants, basally distinctly broadened and swollen. Containing a single larva. Calosirus terminatus

3b Spindle-shaped, sometimes coalescing, usually only weak and slightly expanded bulges on petioles, midrib, main veins and young stems. Puccinia nitida

4a Malformations mainly of leaf blades => 5

4b Petioles, midrib, sometimes also the basal parts of leaflets of severely stunted young plants are variously disfigured, swollen and spongy. Ditylenchus dipsaci

5a Leaf midrib ± shortened and curved, with clustered, curled, deflected leaflets. Philaenus spumarius

5b The tips of leaflets, usually of many severely stunted and disfigured leaves, are deflected and sometimes swollen and tuberculate. Trioza apicalis

5c Malformation caused by aphid. Upper leaves curled, lower leaves atrophied; leaf blade sometimes arched downwards and curled on upperside. Hyadaphis foeniculi

6a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. Lasioptera carophila

6b Fruit strongly inflated, bladder-like; galls ± reddened, protruding above the umbel; containing a single orange-red larva. Kiefferia pericarpiicola

gallers on Oxalis

Last modified 22.v.2020

Dichotomous table for gallers on Oxalis

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. O. stricta: Meloidogyne hapla

2a On vegetative organs => 4

2b On flowers and fruits => 3

3a Flowers greened, ovaries elongated. O. acetosella, articulata, corniculata, stricta: Aceria oxalidis

3b Anthers and ovaries slightly swollen, later on containing reddish-brown spores. Diseased capsules sterile. Infestation not distinct before dusting of spores. O. fontana, stricta; not on O. corniculata: Thecaphora oxalidis

4a Malformations extended over several organs => 6

4b Galls localised => 5

5a Less than 1 mm long, sometimes joined, yellow many-celled warts on basal leaf- and stem parts. O. stricta: Synchytrium aureum

5b Slightly thickened cushions on leaves and petioles, with distinctly arched, cup-shaped aecia. ~, in NW-Eu on O. corniculata, fontana, stricta: Puccinia sorghi

6a Leaflets stunted, shorter stalked. Leaf blade rolled inwards, ± folded and twisted, finely wrinkled. O. acetosella, articulata, corniculata, stricta: Aceria oxalidis

6b Plant stunted, variously disfigured. Oxalis spp.: Aphis fabae

gallers on Odontites

Last modified 22.v.2020

Dichotomous table for gallers on Odontites

(see also Euphrasia)

by Hans Roskam

1a On parts above ground => 2

1b Roots with small, nodular or spindle-shaped swellings. O. verna: Meloidogyne hapla

= Cysts of a Heterodera species may occur on this host

2a On vegetative parts => 3

2b Ovaries irregularly swollen, containing a yellow larva. O. verna: Unidentified gall midge

3a Single galls wart-shaped, caused by fungi fruiting inside the host cells => 6

3b Malformations more expanded => 4

4a Malformations caused by fungi, fruiting at surface or sporulating after rupturing of bulges => 5

4b Spindle-shaped or irregularly expanded, spongy, pale-green swellings on stems and leaf veins of plants which are severely stunted. Odontites spp.: Ditylenchus dipsaci

5a Systemically infected plants or shoots developing faster, rigidly erect. Leaves pale-green, narrowed, curved downwards at margin, arched; soon covered with a dense white down of branched conidiophores. O. litoralis, vulgaris: Plasmopara densa

5b Stem with thinner or thicker quill-like swellings, up to several cm long, blue-grey, at first closed, later on rupturing and dusty. Infestation sometimes as bulge-shaped sori encroaching onto leaves. O. lutea: Urocystis schizocaulon

6a Wart-shaped, multi-cellular galls on leaves and stems, less than 1 mm across, occasionally coalescing; nutritive cells with golden-yellow perennial sorus. O. verna: Synchytrium aureum

6b Complete plant disfigured. Shoot axis and leaves with rotund red warts, usually gregarious, up to 1 mm across. Perennial spores inside a single (rarely in 2–3) enlarged parenchyma cells. O. verna, vulgaris: Physoderma negeri

gallers on Molinia

Last modified 22.v.2020

Dichotomous table for gallers on Molinia caerulea

by Hans Roskam

1a On vegetative plant parts => 3

1b In inflorescences or single flowers => 2

2a On inflorescence stalks or spikes. Inflorescence partially ± severely stunted and greened or bleached. Aceria tenuis

2b Single ovaries of a panicle strongly swollen and transformed into an oval or oblong smut body, up to 10 mm long; inside develop brown-black spore masses, at first clotted, later on crumbling and forming dust of spores. Neovossia moliniae

3a On above-ground parts => 4

3b Root hairs distinctly swollen; inducer inside the hair. Sorosphaerula radicalis

4a On culms => 5

4b Leaf sheath at base swollen, bellied out. Containing a large, whitish larva, almost 5 mm long. Unidentified gall midge

5a Culm with spindle-shaped or bellied swelling => 6

5b Shoot axis immediately above the ground below the leaf sheath with weak, slightly rimmed depression. Containing a single white larva. Mayetiola moliniae

6a Culm just above the ground swollen to bellied out, apically conically narrowed gall up to 10 mm long, which erupts from the leaf sheath. Larvae white, gregarious. Mayetiola ventricola

6b Culm weakly swollen, containing a single, orange-yellow larva almost 5 mm long. cf. Lasioptera moliniae

gallers on Lupinus

Last modified 21.v.2020

Dichotomous table for gallers on Lupinus

by Hans Roskam

1a On parts above ground => 5

1b On roots => 2

2a Outside of root hardly changed, only disfigured inside or with rotund galls having central chamber => 4

2b Distinctly protruding galls, larval chamber absent => 3

3a Nodular galls, occupying all sides of root body. Lupinus spp.: Meloidogyne hapla

3b Main roots with protrusions up to about 15 mm long, broadly attached, usually many, often clumped close to root collar, coalescing, tuberculate, on perennial species even up to 50 mm wide; less often rotund or oblong-oval smaller nodules also on the adventitious roots. Lupinus spp.: Rhizobium lupini

4a Galls not recognisable from the outside; with giant cells inside. Lupinus spp.: Heterodera schachtii

4b Roots with rotund, 4–6 mm long gall with chamber containing beetle larva. L. luteus: Unknown snout beetle

5a Malformations of leaves, stems and flowers => 6

5b Pod disfigured, slightly atrophied; inner wall with mycelium. Containing a single larva. L. albus: Asphondylia lupini

6a Malformations caused by aphids => 7

6b Development of plant severely stunted; axial parts irregularly swollen, spongy. Infestation often encroaching onto stalk and venation of severely disfigured leaves. L. angustifolius: Ditylenchus dipsaci

7a Apterae are pale bluish-grey-green, dusted with white wax; body length 3.2‒5.1 mm. Alatae have a brown pterothorax. Lupinus spp.: Macrosiphum albifrons

7b Apterae and alatae black. Leaf blades distorted, also strongly curved, rolled or folded. L. angustifolius, luteus: Aphis fabae

gallers on Ligustrum

Last modified 21.v.2020

Dichotomous table for gallers on Ligustrum

by Hans Roskam

1a On vegetative organs => 2

1b Flower buds inflated, thickened, unopened, usually normally coloured. Containing pale yellow larvae. L. vulgare: Placochela ligustri

1c Root with rounded or spindle-shaped swelling, 2–5 mm across; containing eelworms, some may be glistening white pear-shaped females with eggs. L. vulgare: Meloidogyne ardenensis

2a On leaves => 5

2b On buds or axial parts => 3

3a On axial parts => 4

3b Several axillary buds, rarely the apical bud, slightly swollen, stunted, developing leaves often only scale-like. Malformation resulting in compact, ± pyramidal witches’ broom-like structures. L. ovalifolium, vulgare: Aceria loewi and/or Aculus ligustri

4a Axial parts, mainly at base, with conspicuous proliferations, up to walnut-size, soon woody, irregularly wrinkled, on surface, dark-brown. “Bacterial cancer” L. vulgare: Agrobacterium tumefaciens

4b Bark swollen, with rimmed irregular depressions, containing causer. L. ovalifolium, vulgare: Chionaspis salicis

5a Malformation of many leaves at shoot tip => 6

5b Leaf blade with rotund, yellowish-green pads, sometimes slightly swollen if on venation, bearing cups on underside. L. ovalifolium, vulgare: Puccinia obtusata

6a Axis of young shoots and stalks of young leaves shortened. Infected leaves loosely clustered. Prociphilus bumeliae

6b xis of young shoots not shortened; usually deflected from the tip, bearing many, distant, downwardly rolled or slightly curved leaves, sometimes twisted, yellow- to rust-spotted. L. ovalifolium, vulgare: Myzus ligustri

gallers on Lens

Last modified 21.v.2020

Dichotomous table for gallers on Lens

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Rotund- to oblong-oval nodules, about 3 mm long laterally attached on main- and side-roots. L. culinaris, nigricans: Rhizobium leguminosarum

2b Outside of roots hardly disfigured, inside containing giant cells; bearing temporarily white to dark, about poppy seed- sized egg capsules (cysts). L. culinaris, nigricans: Heterodera schachtii

3a Leaflets of many terminal leaves rolled inwards and upwards, ± bent. L. culinaris, nigricans: Aceria trifolii

3b Flower bud swollen, unopened. L. culinaris: Contarinia sp.

= Early records of Dasineura viciae and Asphondylia ervi on “lentils’” need confirmation.

c Flower bud swollen, unopened. L. culinaris: Contarinia lentis

gallers on Homogyne

Last modified 21.v.2020

Dichotomous table for gallers on Homogyne alpina

by Hans Roskam

1a On vegetative plant parts => 2

1b Capitula deformed; receptacle thickened. Unidentified tephritid fly

= Midge larvae of an undescribed Dasineura occur in capitula of Mediterranean H. alpina

2a Leaf blade or petiole with galls caused by fungi, spores of which develop on the outside, or shine through the gall surface => 5

2b Malformation of the leaf blade by animal inducers => 3

3a Localised galls => 4

3b Leaf blade deflected ± curled, locally intense green. Philaenus spumarius

4a Leaf blade with pock-like swellings, which are especially arched on the underside. Unidentified gall mite

4b Leaf blade between the veins bulging and swollen. Larvae on the underside. Trioza thomasii

5a The fruiting bodies develop on the surface of spindle-shaped galls => 6

5b Wart-shaped, less than 1 mm long galls, the ± golden yellow spores develop inside and shine through the gall surface. Synchytrium vulgatum

6a Only just protruding, orange-coloured thickenings on petioles and on the underside of leaf veins bearing densely, ± circular arrangements of aecia and with pycnidia developing on the upperside. Uromyces veratri

6b Telia in small to extended brown sori. Stronger infestation sites on leaf blades with upperside impressions and with rotund, protruding, compact pads on underside; on veins and petioles developed as ± elongated spindle-shaped, often yellow margined bulges. Puccinia conglomerata

gallers on Helianthus

Last modified 21.v.2020

Dichotomous table for gallers on Helianthus

by Hans Roskam

1a On above-ground parts => 2

1b Roots with almost rotund swellings, up to 4 mm long, sometimes clustered. H. annuus: Meloidogyne hapla

= Heterodera schachtii is known from H. annuus

2a Galls on root collar or on stem. The inducers are inside the galls => 4

2b Malformations predominantly on leaves. The inducers live on the surface of the malformations => 3

3a Leaves variously curled or bulging; malformations by aphids. Helianthus spp.:

a Brachycaudus helichrysi

b Aulacorthum solani

c Aphis fabae

3b Leaf blades of young plants over extensive parts and in various ways bent downwards, curled, and dark green close to the froth-covered nymph. Helianthus spp.: Philaenus spumarius

3c Dull white spots, pustules, even crusts on underside of leaves, largely consisting of a mass of conidia. H. annuus: Pustula helianthicola

4a Up to walnut- size or extensive, rugose proliferations on root collar or the basal stem parts. H. annuus, tuberosus, etc.: Agrobacterium tumefaciens

4b Spongy swellings of various shape on stems, petioles, leaf veins of young plants. H. annuus, tuberosus: Ditylenchus dipsaci

gallers on Foeniculum

Last modified 20.v.2020

Dichotomous table for gallers on Foeniculum vulgare

by Hans Roskam

1a On above-ground plant parts => 2

1b Nodular swellings on roots. Meloidogyne hapla

2a On parts of inflorescence or on fruits => 6

2b On vegetative parts => 3

3a Malformations caused by animal parasites => 4

3b Stalks, midrib or veins of leaves, also stalk of umbel or fruit with bulging swellings bearing spermogonia and pale-yellow aecia. Uromyces graminis

4a Rosette leaves or terminal parts of vegetative shoots variously disfigured by aphids; midrib ± stunted and distorted; tips of leaflets clustered, curved and curled => 5

4b Globular swelling of ramification of leaflet; gall inside covered with mycelium. Containing a single gall midge larva. Lasioptera carophila

4c Midrib of leaf locally severely stunted and including some side spindles strongly converging downwards, nest-like. Philaenus spumarius

5a Aphid black. Aphis fabae

5b Aphid green. Cavariella aegopodii

6a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a single red larva. Lasioptera carophila

6b Spindle-shaped swelling of stalk of umbel. Containing a single yellow larva. Lasioptera umbelliferarum

= Lasioptera foeniculi has been described causing fruit galls. Galls from September up to November; larvae pupate in soil, adults emerge about 10 days afterwards.

6c ruit conspicuously swollen, ± reddened, often protruding above the partial umbel. Containing a single orange-red larva. Kiefferia pericarpiicola

gallers on Eupatorium

Last modified 20.v.2020

Dichotomous table for gallers on Eupatorium cannabinum

by Hans Roskam

1a Malformations of leaves at the tips of the shoots => 3

1b Swellings of the shoot stems => 2

2a Spindle-shaped or cylindrical swelling in main- or side stem near a node or in axils of flower peduncles, about 10–15 mm long, with round opening when mature; one or several yellowish-white caterpillars with a yellow-brown head, in pith with frass. Upper stem parts stunted, often conspicuously discoloured. Adaina microdactyla

2b Stem mainly close to the ground, with differently situated and expanded, sometimes curved swelling. A scale insect in a depression. Planchonia arabidis

3a Malformations by aphids or spittlebugs => 4

3b Leaves on stunted shoot tips clustered, rolled upwards, rudiments of inflorescences stunted. All infected parts conspicuously white pubescent. Aceria eupatorii

4a Aphid malformations => 5

4b Leaf segments nest-like converging, the leaf blades curled, dark green close to the froth-covered nymph. Philaenus spumarius

5a Leaves on ± stunted shoots more or less stunted, the margins curved downwards, the leaf blade ± curled. Aphid 1.5–2 mm long, bright yellowish to yellow green, with short conical yellowish to green cauda. Brachycaudus helichrysi

5b Similar malformations by dark green aphids; siphunculi and cauda dark to black. Aphis frangulae

gallers on Draba

Last modified 20.v.2020

Dichotomous table for gallers on Draba

by Hans Roskam

1a On parts above ground => 2

1b Roots with ± expanded spindle-shaped, fleshy swellings, which contain densely crowded masses of minute spores in some cells. D. incana, muralis: Plasmodiophora brassicae

2a Malformations caused by fungi fructifying at surface of gall => 6

2b Malformations caused by animals, or by fungi fructifying inside galls => 3

3a Galls localised => 4

3b Infected shoots extensively disfigured, phyllanthy; leaves shorter and broader, ± disfigured; flowers often accumulated, tuft-like, atrophied or ± greened. D. aizoides, daurica, incana, muralis, nivalis, “rupestris”: Aceria drabae

3c On the same hosts and other Draba species in similar malformations. D. aizoides, daurica: Cecidophyes borealis

4a On leaves or stem parts => 5

4b Diseased shoots slightly swollen, slightly shorter than healthy ones; young seed soon distorted and filled with yellowish- to grey-violet sori. D. aizoides, alpina, incana: Thecaphora thlaspeos

5a Galls hardly 1 mm across but conspicuous, ± golden-yellow translucent; on leaves, stalks and even bracts; often coalescing into crusts. D. aizoides: Synchytrium drabae

5b Stalk of inflorescence shortened at tip, slightly thickened, curved. D. muralis: Cause unknown – ? dipteran

6a At first glossy, porcelain-like, with mealy dusty bulges on all green parts after rupturing. D. aizoides, cuspidata, hispanica, incana, sauteri: Albugo candida

6b Infected organs, mainly the upper stem parts, variously ± bulge-like, swollen and disfigured. Draba spp.: Puccinia drabae

6a Shoots etiolated. Underside of leaves often bearing dense, rotund sori. D. cinerea, daurica: Puccinia thlaspeos

6b Leaves with pales spots. Underside with a dense white down, consisting of erect conidiophores that apically are branching several times, each branch ending in a conidium. D. muralis, nemorosa: Hyaloperonospora drabae

6a Similar malformation. D. daurica, nemorosa: Hyaloperonospora norvegica

gallers on Dahlia

Last modified 20.v.2020

Dichotomous table for gallers on Dahlia pinnata

by Hans Roskam

1a Leaf blades arched and curled, caused by aphids or cercopids => 3

1b On root collar or roots => 2

2a Roots with small nodule-shaped swellings. Meloidogyne hapla

2b Conspicuous succulent, cauliflower-shaped proliferations on tubers, on root collar or stem base. Agrobacterium tumefaciens

2c Irregular proliferations of the stem base, combined with an abundant development of buds. Rhodococcus fascians

2d Extensive malformations usually accompanied by R. fascians. Aphelenchoides fragariae

3a Deformities caused by aphids => 4

3b nfected young shoots severely stunted, the leaves curved downwards, curled, dark green close to the froth-covered nymph. Philaenus spumarius

4a Aphid black. Aphis fabae

4b Aphid green. Aulacorthum solani

gallers on Chaenomeles

Last modified 20.v.2020

Dichotomous table for gallers on Chaenomeles

by Hans Roskam

1a Malformations on leaves => 3

1b Malformations on stems => 2

2a Witches’ broom-like malformations with only little, often reddish leaves on sap-rich, whip-shaped shoots. C. speciosa: Inducer unknown, presumably caused by a fungus, Exoascaceae

2b Considerable cancer-like proliferations on basal stems. C. speciosa: Agrobacterium tumefaciens

3a Malformations on several terminal leaves caused by aphids => 4

3b Leaves with ± protruding bladder-like, pale-green or reddened swellings, later on withering, which at maturity are occupied by a grey-white layer of fungal asci. ? C. speciosa: Taphrina bullata

4a Leaves rolled inwards and crumpled, clustered nest-like on the ± shortened shoots => 5

4b Leaves obliquely bent downwards and ± rolled. C. japonica: Myzus persicae

5a Aphid with rather long siphunculi. Chaenomeles spp.: Aphis pomi

5b Aphid with short, thick, green siphunculi. C. japonica, speciosa: Rhopalosiphum oxyacanthae

gallers on Brachypodium

Last modified 19.v.2020

Dichotomous table for gallers on Brachypodium

by Hans Roskam

1a On inflorescences or flowerd => 7

1b On vegetative plant parts => 2

2a Leaves with long stripes caused by smuts => 6

2b Malformations caused by animal parasites => 3

2c 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. Brachypodium spp.: Epichloë sylvatica

3a Localised galls on culms => 5

3b Shoot tip with tuft-like clustering of leaves or complete plant disfigured => 4

4a Especially the tips of subterranean runners with short sheath-like, tuft-like accumulated leaves. Gall up to 40 mm long and 12 mm broad. Larva white with black buccal skeleton. B. pinnatum, sylvaticum: Unidentified chloropid fly

4b Tip of above-ground shoot with spindle-shaped tuft of leaves. Inside a larva causing a severely stunted, broadened culm. B. pinnatum, sylvaticum: Tetramesa brachypodii

5a Stem closely just above a node with 10–12 mm long and 4–5 mm broad, saddle-like depression, thickened at both ends, containing a white larva. Usually ± enclosed by leaf sheaths. B. pinnatum, sylvaticum: Mayetiola hellwigi

5b Culm above one of the lower nodes with an egg-shaped swelling about wheat grain size. Containing a single larva. B. sylvaticum: Tetramesa sp.

6a Often all parts of host diseased, exceedingly leafy; initially developing faster, soon severely stunted, remaining small and sterile. Leaves with long, at first slightly arched patches of smut, then breaking open, ± fraying out the leaves, releasing a black-brown mass of spores. B. pinnatum, retusum, rupestre, sylvaticum: Tilletia olida

6b Similar stripes of smut on the leaf blades of often further developed, hardly additionally leafed plants. Spores rotund to oblong-oval, with many blunt warts. B. pinnatum, sylvaticum: Ustilago striiformis

6c Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. B. pinnatum, sylvaticum: Puccinia striiformis

7a Spikelets elongated; flowers ± greened, bleached if strongly infected. B. pinnatum: Aceria tenuis

7b lowers leafy; glumes ± enlarged, occasionally enclosed in the spikelet; the midrib bent zig-zag-like. B. pinnatum: ? Ditylenchus sp.

7c Complete plant stunted by scale insects, especially the inflorescence. B. pinnatum, retusum, rupestre, sylvaticum: Eriopeltis festucae

gallers on Asparagus

Last modified 19.v.2020

Dichotomous table for gallers on Asparagus

by Hans Roskam

1a On A. officinalis => 2

1b On A. acutifolius, aphyllus. Young twigs irregularly swollen and curved, terminally with tufts of compressed leaves with broadened bases, discoloured or reddish. Overwintering buds variously abnormally hypertrophied. Containing flesh-coloured larvae: Dasineura turionum

1c Usually the whole shoot, just after budding, is transformed into a gall. Leaf scales are swollen and broadened at base. The white midge larvae are located under the swollen scales. A. acutifolius, albus, tenuifolius: Dasineura minardii

1d Fruits changed into spongy mass. A. aphyllus: Dasineura sp.

2a On above-ground parts => 3

2b Roots with nodular swellings. A. officinalis: Meloidogyne hapla

3a On vegetative parts => 4

3b Flower buds globular, perianth succulent, swollen, dark-green; not opening. Containing several white- to orange larvae. A. officinalis: Contarinia florum

4a Stunting of stems with terminal green shoots; caused by aphids => 5

4b Stem of young, pale or greened shoots crippled. Tip ± curved, crooked, dying off early. Often several yellowish-white larvae, up to 10 mm long in extended tunnels. A. officinalis: Plioreocepta poeciloptera

4c Terminally distorted and discoloured spines of young twigs transformed into swellings with broadened base. Gregarious white larvae between the spines. A. acutifolius, aphyllus, officinalis: Dasineura asparagi

5a Leaves of solitary or of several neighbouring shoot tips accumulated densely like bottle brushes, shortened, ± rounded, rigid, dark green; with colonies of grey-powdered aphids in between. A. aethiopicus, densiflorus, officinalis: Brachycorynella asparagi

5b Similar malformations; however more loosely tuft-like; leaves softer, ± downwardly deflected. Aphid black. Asparagus spp.: Aphis fabae

gallers on Antirrhinum

Last modified 19.v.2020

Dichotomous table for gallers on Antirrhinum

(A. orontium see Misopates orontium)

by Hans Roskam

1a On parts above ground => 2

1b On roots or on root collar. Nodular swellings on roots. Galls partially with side roots. Antirrhinum spp.: Meloidogyne hapla

2a On leaves => 3

2b Swelling of stem. A. latifolium, majus: Mesoscyonyx sicardi

2c Capsule slightly swollen and disfigured; a single or several beetle larvae inside. A. majus: Rhinusa antirrhini and/or Rhinusa neta

3a Leaves ± curled and margins deflected; bearing aphids on underside => 4

3b Leaves stunted on shortened shoot tips, pale green, deflected over tip and margins, brittle, appearing slightly thickened; with down of branched conidiophores on underside. A. hispanicum, majus, sempervirens: Peronospora antirrhini

4a Leaf blades strongly curled. Antirrhinum spp.: Aulacorthum solani

4b Leaf blades spoon-like arched, curled, ± discoloured, bearing aphids on underside. A. barrelieri: Myzus persicae

gallers on Amelanchier

Last modified 21.v.2020

Dichotomous table for gallers on Amelanchier

by Hans Roskam

1a On buds and shoot axis => 6

1b On leaves (or occasionally fruits for fungi) => 2

2a Galls ± bulge-shaped, usually yellowish, with patches of spores on upper side => 5

2b Malformations caused by animals => 3

3a Galled leaves not conspicuously clustered => 4

3b Terminal leaves clustered. A. ovalis: Dysaphis parasorbi

3c Leaves terminal on severely stunted shoots mainly on tip rolled downwards, usually densely clustered. Amelanchier spp.: Aphis pomi

3d Shoots with several leaves ± curved and variously obliquely downwardly curved along the midrib. Amelanchier spp.: Rhopalosiphum oxyacanthae

4a Leaf blade ± pod-like folded upwards along the midrib, thickened in the middle. A. ovalis: Unidentified gall midge

4b Leaf blade with many pocks, protruding on both sides of leaf. A. ovalis: Eriophyes aroniae

5a Leaves, sometimes also young shoots, with yellow, later on reddened in the middle, swollen, aecia bearing pads. Peridium cylindrical, 2–3 mm long, open above, deeply thread-like lacerate; lateral walls of cells with many tubercles of various shape and size. Amelanchier spp.: Gymnosporangium clavariiforme

5b Galls similar. Peridium usually oblong-cornicular, 3–4 mm long, conical apex, at first closed, then opening, slightly or not lacerate at margin; lateral walls of cells ± densely tuberculate, or very short, with obliquely running ridges. A. ovalis, asiatica: Gymnosporangium cornutum

6a On shoot axial parts => 7

6b Buds swollen, not opening; scales enlarged, thickened, densely white pubescent. A. ovalis: Eriophyes amelancheus

7a Bark of stems or branches with cracked cancer-like proliferations; with white powdered aphids in cracks. Amelanchier spp.: Eriosoma lanigerum

7b Major branches with spindle-shaped swellings. A. ovalis: Viscum album

gallers on Alcea

Last modified 18.v.2020

Dichotomous table for gallers on Alcea

(incl. Althaea)

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Side roots with mainly rounded, nodular swellings. Althaea officinalis; Alcea rosea & var. nigra: Meloidogyne hapla

2b Main root thickened, beet-like. Central chamber contains a single larva. Althaea hirsuta: Unidentified coleopteran

3a Malformations caused by animal parasites => 4

3b Leaves and all other green organs, as well as stem, epicalyx and even young ovaries, with rotund, 1‒2 mm broad, cushion-shaped swellings, soon bearing at first yellow-red, later on brown telia. Telia germinating immediately, giving them a whitish-powdery appearance. Alcea spp.; Althaea spp.: Puccinia malvacearum

4a Malformations lacking conspicuous additional pubescence => 5

4b Leaves on Althaea officinalis with localised erinea. Unidentified gall mit

5a Malformation of leaf blades => 6

5b A single mericarp contains a beetle; there also pupation takes place. Infected flowers fade prematurely. Alcea dissecta, rosea, setosa: Rhopalapion longirostre

6a Leaf blades, usually of many terminal leaves, on ± stunted shoots loosely arched downwards and ± curled. Alcea biennis, nudiflora, rosea; Althaea officinalis: Aphis althaeae

6b Leaf blade ± strongly wrinkled, margins deflected. Sometimes the flower buds are also disfigured. Contain pale green aphids with siphunculi half as long or equalling cauda. Alcea rosea, Althaea officinalis, cannabina: Acyrthosiphon malvae

6c Venation close to infestation stunted and deflected; neighbouring leaf blade part curled, deep green, rolled- or curved downwards, nest-like. Contains a froth-covered nymph. Alcea spp.; Althaea spp.: Philaenus spumarius

gallers on Agrostemma

Last modified 18.v.2020

Dichotomous table for gallers on Agrostemma githago

by Hans Roskam

1a On vegetative organs => 2

1b Anthers in rarely disfigured flowers temporarily swollen; later filled with black-violet spores. Microbotryum violaceum

2a Malformations with surface fruiting fungi, at least temporarily => 5

2b Malformations caused by animals => 3

3a Malformations on stems or leaves of ± developed plants => 4

3b Young plants severely stunted; especially the basal parts swollen, spongy. Swellings pale green, undulate at surface. Ditylenchus dipsaci

4a Stem with localised swellings. Unidentified lepidopteran

4b Tuft-like accumulation of basally strongly pubescent leaves. Inducer unknown

4c Stem stunted locally, one or two neighbouring leaves strongly rolled over their tips; close to the froth-covered nymph undulate, deep-green. Philaenus spumarius

5a Leaves on underside with rotund, ring-shaped or sometimes oblong compact crusts of coalescing sori on slightly swollen bulges; at first bearing pale, later on with black-brown telia. Bulges also developing on calyx teeth and stems. Puccinia arenariae

5b Leaves and stems with yellowish, ± swollen spots; diseased leaf blades, and even the corolla, often characteristically curled; sori ± grey frosted when asci are mature. Taphrina githaginis

gallers on Aethusa

Last modified 18.v.2020

Dichotomous table for gallers on Aethusa cynapium

by Hans Roskam

1a On stems or leaves => 2

1b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Contains a red larva. Lasioptera carophila

2a Large parts of plant disfigured => 4

2b Stem or leaves with localised galls => 3

3a Stem, and stalks of partial umbels with lateral rounded swellings, 2–3 mm long; with an irregular larval chamber inside. Unidentified beetle

3b Minor, weak bulge-like archings on leaf veins, rachis, -stalk or stem; soon bearing spermogonia and primary uredinia. Puccinia nitida

4a Curled leaf blades caused by aphids or cercopids => 5

4b Younger plants severely stunted. Leaf axis and possibly basal stem parts distinctly shortened, spongy, pale-green, with undulate-wrinkled surface. Ditylenchus dipsaci

5a Larger composite leaves ± nest-like or bell-shaped converged downwards; strongly curled, deep-green close to the froth-covered nymph. On developing plants often several leaves on locally markedly shortened stems are similarly disfigured. Philaenus spumarius

5b Leaves remaining small, rolled, closely accumulated, dark-green discoloured; bearing green aphids. Cavariella aegopodii and/or C. pastinacae

= Also living in summer on several umbellifers is the aphid Hyadaphis foeniculi which might be responsible for the malformations

5c Several leaves stunted and curled; tips deflected. Leaf blades ± knobby swollen, not discoloured. On underside several flat froth-covered nymphs surrounded by a border of white wax hairs. Trioza apicalis

2a Expanded or locally narrowly confined malformations caused by animal inducers => 5

2b Bulge-like swellings on leaf venation, -stalk or young stem parts, caused by fungi => 3

3a Conspicuous, often ± curved swellings, bearing uredinia or telia => 4

3b Bulges of various size on ± curved leaf blades and axis, bearing yellowish spermogonia and aecia. S. carvifolia: Puccinia bistortae

3c Vitreous bulges. S. carvifolia: Protomyces macrosporus

3d Leaves on the underside a white fungal down of erect conidiophores that apically bear a few short branches, each one ending in an ovoid conidium. S. carvifolia: Plasmopara selini

4a Fungus develops only 3-celled teliospores bearing distal spines. S. carvifolia: Nyssopsora echinata

4b Sometimes up to 30 mm long sori coalescing into ± protruding bulges on stems are induced by a mycelium developing primary uredinia and spermogonia. Teliospores 2-celled. S. carvifolia: Puccinia selini-carvifoliae

5a Malformations caused by aphids, spittlebugs or mites => 6

5b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. S. carvifolia: Lasioptera carophila

6a Malformations caused by aphids or spittlebugs => 7

6b Complete plant variously stunted. Young stems ± distorted. Umbels stunted; flowers ± greened or leafy. S. carvifolia, dubium, silaifolium: Aceria peucedani

7a Leaflets converging, axis ± deflected, leaf blades curled, wrinkled and deep green at site of infestation. S. carvifolia: Philaenus spumarius

7b Stalks of umbel, sometimes in the same umbel, variously shortened. Flowers clustered; the severely stunted organs sometimes variously greened or also leafy. S. carvifolia: Unidentified aphid

gallers on Rhododendron

Last modified 17.v.2020

Dichotomous table for gallers on Rhododendron

(incl. Azalea)

by Hans Roskam

1a On leaves or flowers => 2

1b Conspicuous, at first whitish, succulent, later on strongly browned, woody proliferations on root collar. Rhododendron spp.: Agrobacterium tumefaciens

2a On shoot tips or leaves => 3

2b The flowers are irregularly ± double. R. ferrugineum, hirsutum, intermedium: Aceria alpestris

3a Malformations of leaf blades => 5

3b Malformations of shoot tips => 4

4a Conspicuous bud-like tuft of leaves on shoot tip. R. ferrugineum: Dasineura rhododendri

4b Terminal buds crippled; often increased in number. Leaves reduced and disfigured. Buds dying prematurely. ‘Shoot tip mite’. R. simsii: Tarsonemus sp.

5a Leaf blade with rolls of margin or pouch-like to spherical galls => 6

5b Leaf blade otherwise weakly disfigured. R. ferrugineum, hirsutum: Cacopsylla rhododendri

6a Roll of leaf margin => 8/p>

6b Succulent galls on leaf blade => 7

7a Leaf blade largely or completely thickened, pale-green, later on densely chalk-white frosted, especially on underside. Sometimes several, almost rosette-like clustered leaves terminally on severely stunted, thickened, young shoots similarly disfigured; galls sometimes also on calyx leaves and even on corolla. “Earlobe disease”. R. caucasicum, indicum, nudiflorum, obtusum: Exobasidium japonicum

7b Up to about cherry-size, succulent, yellowish or often one-sided reddened, later on white frosted, often almost globular galls on leaves, sporadically even on flower parts, as well, sometimes, ± clustered, raceme-like, on shoot tips. R. ferrugineum, hirsutum, x intermedium: Exobasidium rhododendri

7c Galls succulent red-orange. R. luteum, ponticum: Exobasidium horváthianum

8a Leaves on unshortened shoot tip usually narrowly rolled upwards over all their length, lighter; with small 1-celled hairs on both sides. R. ferrugineum, hirsutum, intermedium: Aceria alpestris

8b Leaf margin rolled downwards, ± curled and crippled. R. indicum, molle: Phyllocoptes azaleae

8c Mites living in buds and free on the underside of the leaves. They can cause bronzing and rusting of the young leaves, downwards rolling of the leaf margins and eventually stunting; in nurseries. R. atlanticum, japonicum: Aculus atlantazaleae

8d Rolling of the leaf margin. R. ferrugineum: Aculus thomasi

gallers on Phlox

Last modified 17.v.2020

Dichotomous table for gallers on Phlox

by Hans Roskam

1a On roots or on root collar => 5

1b On parts above ground => 2

2a Malformations on vegetative parts => 3

2b nflorescence ± half-globularly clustered as result of shortening of axis. Development of flowers stunted, usually unopened. P. paniculata: Unidentified dipteran

3a Causers on outside of malformations => 4

3b Single or all shoots of a plant strongly shortened by eelworms living inside the tissue, variously swollen, leaves ± curved and curled, partially strongly reduced, narrowed, almost thread-like. Shoot tuft- to broom-like. P. amoena, paniculata, etc.: Ditylenchus dipsaci

4a Leaves strongly rolled and curled over their tips, locally deep green. Phlox spp.: Philaenus spumarius

4b Malformations of leaf blades caused by aphids. P. paniculata: Unidentified aphid

5a On root collar => 6

5b Roots with small swellings bearing several side roots. P. paniculata, etc.: Meloidogyne hapla

6a Considerable proliferations with only small partitioned surface. P. paniculata: Agrobacterium tumefaciens

6b Clustering of crook-backed branched, markedly shortened, fleshy thickened shoots. P. paniculata, etc.: Rhodococcus fascians

gallers on Origanum

Last modified 17.v.2020

Dichotomous table for gallers on Origanum

by Hans Roskam

1a On vegetative parts => 2

1b Corolla unopened, lower part thickened, leather-like, colourless to brown, up to 4 mm long, 2 mm broad; not joined with the slightly swollen calyx. Containing a single larva. O. vulgare: Asphondylia hornigi

2a Malformations of undefined shape on several organs, mainly at tips of shoots => 4

2b Galls on shoot tips, as well as lateral buds or on axial parts of shoots => 3

3a Shoot axis with spindle-shaped or oblong, bulging, multi-chambered swelling. O. vulgare: Thamnurgus kaltenbachii

3b Small, unilateral stem galls, containing a weevil larva or its pupa. O. vulgare: Squamapion origani

3c Shoot tip or lateral buds transformed into oval tufts of leaves, up to 15 mm long and 10 mm broad, greenish, compact. Leaves broadened, thickened, arched, on upperside often with long white hairs. Containing several red larvae. O. compactum, vulgare & subsp. virens: Blastomyia origani

4a Malformations caused by animals => 5

4b Large parts of plant or only single shoots transformed into little, rigid, erect witches’ brooms as result of excessive branching and leafiness. Diseased shoot axis distinctly narrowed; leaves conspicuously reduced. Brownish sori soon develop on axial parts. O. vulgare: Puccinia thymi

4c Leaf blades, especially of young leaves at shoot tip, with thick purple patches bearing spermogonia and aecia, followed by uredinia and telia. O. vulgare & subsp. virens: Puccinia menthae

5a Malformations lacking excessive pubescence => 6

5b Tip of non-flowering or flowering shoots disfigured; developing ± dense masses of felt-like pubescent leaves, and leafy or greened flowers. O. majorana, vulgare: Aceria labiatiflorae

6a Galls caused by aphids => 8

6b Galls caused by gall midges or spittlebugs => 7

7a Roll of leaf margin caused by gall midge larvae. O. vulgare: Unidentified gall midge

7b Shoot axis buckled, bent locally, bearing several deflected, curled, partially deep green leaves. O. vulgare: Philaenus spumarius

8a Several to many leaves at the end of shoots apically increasingly stunted, laterally ± narrowly rolled, curled. Plants often largely disfigured. O. majorana, vulgare & subspp. gracile + virens + viridulum: Aphis origani

8b Leaves curled. O. vulgare: Aphis nepetae

8c Malformations caused by aphids on terminal vegetative- or developing flowering shoots. O. majorana: Myzus ornatus

gallers on Nepeta

Last modified 17.v.2020

Dichotomous table for gallers on Nepeta

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. N. cataria: Meloidogyne hapla

2a On flowers or fruits => 6

2b On vegetative organs => 3

3a On leaves => 5

3b On shoot tips or axial parts => 4

4a Tip of shoot ± disfigured. Youngest leaves erect, folded together, yellowish with cartilaginously rolled margin. Containing orange-yellow larvae. N. cataria: Wachtliella stachydis

= Midge described from Stachys, on which it also induces inflorescence galls. Identity of the midge on Nepeta is doubtful

4b Shoot axis with multi-chambered, elongate and bulging swellings, up to 30 mm long. In each chamber is a single, curved, lemon-yellow beetle larva. N. cataria: Squamapion vicinum

5a Leaves curled or loosely rolled. N. cataria, nepetella & subsp. aragonensis, nuda: Aphis nepetae

5b Leaves folded or rolled. N. cataria: Aulacorthum solani

6a Gall on flowers => 7

6b One mericarp transformed into a ± globular gall, up to 5 mm long, the three remaining ones aborted. Calyx enlarged, cup- or bell-shaped, later on rupturing over its length. Corolla atrophied. Containing a single larva. N. nuda, also N. beltranii, cataria, grandiflora, latifolia, nuda & subsp. albiflora, ucranica & subsp. parviflora: Liposthenes kerneri

7a Flowers swollen at base, disfigured, often unopened. Containing red larvae. N. cataria: Jaapiella catariae

7b Flower buds swollen, egg-shaped, dark-green, unopened. N. nuda: Asphondylia sp.

gallers on Malva

Last modified 16.v.2020

Dichotomous table for gallers on Malva

(incl. Lavatera, Malope)

by Hans Roskam

1a On parts above ground => 2

1b Root with nodular swellings. M. sylvestris: Meloidogyne hapla

2a Malformations on vegetative parts, only sometimes encroaching onto primordia of inflorescences => 3

2b Single mericarps between the other hardly changed mericarps conspicuously swollen, up to twice the normal size. Containing a curved beetle larva. M. alcea, multiflora, neglecta, pusilla, subovata, sylvestris, trimestris: Malvapion malvae

3a Expanded malformations of leaves caused by animals => 5

3b Localised galls on stems or small pads bearing sori on all green organs => 4

4a Leaf blades, -stalks, axial parts of shoots, even calyx and green fruits with many small, rotund or oblong, yellowish, eventually red- to dark brown spores bearing bulges. Malva spp.: Puccinia malvacearum

4b Plant ± atrophied; stem thickened, distorted; inner wall browned. M. moschata: Inducer unknown

5a Malformations with abnormal pubescence; caused by mites => 8

5b Malformations lacking abnormal pubescence; caused by aphids, scale insects or spittlebugs => 6

6a Malformations contain aphids => 7

6b Shoot axis often with several oval to spindle-shaped swellings with centrally rimmed depressions which contain a flat froth-covered nymph. M. thuringiaca: Planchonia arabidis

6c eaves curled, deflected, nest-like; often deep green at infestation site. Infestation on erect young plants usually similarly involving several leaves. Containing a froth-covered nymph. Malva spp.: Philaenus spumarius

7a Leaf margin deflected or rolled downwards. Leaf blade variously curled to undulate, sometimes arched, umbrella-like. Infestation often on terminal leaves. Aphids green. Malva spp.: Aphis umbrella

7b Similar, less conspicuous malformations caused by black aphids. M. neglecta, sylvestris: Aphis fabae

7c Leaf blade wrinkled. M. neglecta, sylvestris, thuringiaca: Aphis althaeae

7d Leaf blade ± strongly wrinkled, margins deflected. Containing pale green aphids with siphunculi half as long as to equalling cauda. M. neglecta, parviflora, pusilla, sylvestris, thuringiaca, trimestris: Acyrthosiphon malvae

8a Shoot tip stunted. Leaf blade variously disfigured and atrophied, ± thickened, rolled inwards, curled or undulate and excessively haired; often yellowing prematurely. M. alcea, moschata, thuringiaca: Aceria gymnoprocta

8b Segments of older leaves ± converging and disfigured, bag-like; usually on leaf underside on the thickened veins with dense, yellowish, felt-like pubescence. Younger leaves, densely clustered at shoot tips, similarly but more severely disfigured, often haired on both sides. Erinea also on petioles, shoot axis and calyx. M. alcea, moschata, thuringiaca: Aceria gymnoprocta

gallers on Myosoton

Last modified 16.v.2020

Dichotomous table for gallers on Myosoton

(incl. Malachium)

by Hans Roskam

1a On flowers => 8

1b On vegetative plant parts => 2

2a On shoot tips or on many terminal leaves => 5

2b Galls on leaf blade or malformation of a few leaves at any point of insertion => 3

3a Wart- or spindle-shaped galls on leaf blades, occasionally on stems => 4

3b Usually several ± nest-like clustered, deflected, curled, locally deep green leaves on one-sided stunted axial parts. Philaenus spumarius

4a Yellowish, multi-cellular warts, less than 1 mm long, occasionally coalescing into crusts or ridges. Also on lower stem parts. Synchytrium aureum

4b Leaf blades with sori up to about 5 mm long, rotund, sometimes slightly arched on underside on usually yellow-green spots or spindle-shaped weak bulges on leaf veins, -stalks and stems; eventually covered by dark-brown sori. Puccinia arenariae

5a Malformations of shoot tips => 7

5b Malformation of complete shoots, or of many leaves on shoot tips => 6

6a Diseased complete shoots develop ± rigidly erect, internodes elongated; the bleached leaves ± stunted and bearing loose yellow sori on underside.
Melampsorella caryophyllacearum

6b Leaves on apically progressively shortened stems ± twisted and curled, the halves bent upwards. Brachycolus stellariae

7a One-, occasionally also two outer leaf pairs inserted on terminal or lateral shoots stunted, pale, basally thickened, converging, transformed into an erect, ± conical gall. Containing several pale- to lemon-yellow larvae. cf. Macrolabis stellariae

= Also a gall associated with disfigured flowers might be caused by this midge

7b Strongly clustered, tuft-like accumulation of stunted, upwardly rolled and bulging leaves. Brachycolus stellariae

8a Flowers greened or leafy. Cause unknown – ? gall mite

8b Anthers in hardly disfigured flowers temporarily swollen; later on filled with dark-violet spores. Microbotryum stellariae

gallers on Linum

Last modified 16.v.2020

Dichotomous table for gallers on Linum

by Hans Roskam

1a On shoot parts => 2

1b Roots with nodular swellings. L. usatissimum: Meloidogyne hapla

2a On shoot tips or flowers => 4

2b On leaves or stems mainly of young plants => 3

3a Weak swellings bearing pale yellow spermogonia and orange aecia on cotyledons or young stems. Linum spp.: Melampsora liniperda

= On L. catharticum lives Melampsora lini

3b Young plants largely disfigured, excessively leafy, shoots thickened basally, sometimes ± curved. Leaves clustered, undulate, ± swollen and twisted. Occasionally localised, ± irregular, spongy, pale green swellings also on higher inserted, stunted stem parts and leaves of further developing plants. L. usitatissimum, tenuifolium: Ditylenchus dipsaci

4a On shoot tips or terminal shoots => 5

4b Greened flowers on ± stunted plants. L. catharticum: Unidentified gall mite

= The gall midge Contarinia lini is galling flower buds of L. austriacum

5a Terminal leaves widened, keel-like, making a larval chamber, about 8 x 4 mm long, containing a single larva. Neighbouring leaves ± disfigured and clustered, rosette-like. L. alpinum, austriacum, bienne, catharticum, tenuifolium, usitatissimum: Dasineura sampaina

5b Variously disfigured, pale leaves clustered on shoot tips of distorted plants. L. usitatissimum: Thrips linarius and/or Th. angusticeps

gallers on Koeleria

Last modified 15.v.2020

Dichotomous table for gallers on Koeleria

by Hans Roskam

1a On vegetative plant parts => 2

1b Ovaries transformed into a purple-violet gall up to 3 mm long and 1 mm thick gall. K. glauca, pyramidata: Anguina agrostis

2a Locally restricted or expanded malformations on culms and leaves => 3

2b Complete plant disfigured. Shoots of undeveloped plants stunted and ± spongy, swollen. Leaves ± stunted, partially disfigured. K. pyramidata: Ditylenchus dipsaci

3a Only on leaves => 7

3b Only on culms or on their tips => 4

4a Locally restricted galls on the internodes => 5

4b Shoot axis markedly shortened. Development of leaves ± stunted, accumulated into a loose tuft, the outer ones shorter than the inner ones. K. glauca: Unidentified chloropid fly

5a Galls on higher internodes => 6

5b Long spindle-shaped swelling at the base of the culm. Containing a single larva. K. glauca, pyramidata: Tetramesa schlechtendali

6a Sharply shouldered swelling, up to 12 mm long and 4 mm thick. K. pyramidata: Tetramesa sp.

6b Weak swelling, hardly protruding, 1–2 cm above the upper node. K. glauca, pyramidata: Tetramesa sp.

7a Leaf blades, occasionally also the sheaths, with elongated, parallel narrow bulges, at first grey translucent, then with dusting of spores. K. pyramidata: Tilletia sterilis

7b Similar sori. Spore mass black. Spores irregular globular to rotund oval, 10–15 x 8–11 µm. Wall densely covered with short, blunt warts. K. glauca, pyramidata: Ustilago striiformis

gallers on Impatiens

Last modified 15.v.2020

Dichotomous table for gallers on Impatiens

by Hans Roskam

1a On parts above ground => 2

1b Broad spindle-shaped to globular fleshy galls on roots, also variously coalescing. I. balsamina: Meloidogyne hapla

2a On leaves or flowers => 4

2b On stems => 3

3a Mainly basal stem part with considerable, fleshy proliferations. I. balsamina, noli-tangere: Agrobacterium tumefaciens

3b Stem, also petioles, weakly to moderately swollen over a length of 5–100 mm, often variously distorted and densely covered with aecia. I. amphorata, balsamina, capensis, firmula, parviflora, scabrida, sodenii; not on I. noli-tangere: Puccinia komarovii

4a On leaves or cotyledons => 5

4b Flower buds swollen, small and unopened. I. noli-tangere: Unidentified gall midge

4c On flower stalks. I. noli-tangere: Semiaphis noli-tangere

5a On leaves => 6

5b The usually completely diseased cotyledons are paler than the healthy ones, often weakly spoon-like, arched upwards; on underside with whitish-grey down of branched conidiophores. I. balsamina, ?capensis, noli-tangere, walleriana: Plasmopara obducens

6a Leaf blade curled and ± strongly curved => 7

6b Leaf blade with rotund, almost bladder-like swellings. I. noli-tangere: Trioza sp.

7a Malformations caused by aphids => 8

7b Leaf blade deflected, strongly curled, especially close to infestation, often deep green; also clustering, nest-like, of all reduced parts, bulging, ± curved and twisted terminal leaves. Impatiens spp.: Philaenus spumarius

8a Apterae are bright green, pink or red, with extensive shiny brown-black dorsal shield, black siphunculi and yellow to whitish cauda; body length 2.1‒3.1 mm. On undersides of leaves along main veins, and later in dense colonies on flower stalks, of Impatiens spp., especially I. balsamina, balfourii, glandulifera, parviflora: Impatientinum asiaticum

8b Apterae are green with an extensive shiny black dorsal shield, black siphunculi and a pale cauda; body length 2.0‒2.7 mm. Singly or in small colonies on undersides of leaves of Impatiens spp. but especially associated with I. noli-tangere: Impatientinum balsamines

8c Leaf blade ± discoloured, curled and marginally ± deflected by black aphids. I. balsamina, glandulifera, parviflora: Aphis fabae

gallers on Iberis

Last modified 15.v.2020

Dichotomous table for gallers on Iberis

by Hans Roskam

1a On parts above ground => 5

1b On root collar or on roots => 2

2a On main- or side roots => 3

2b Up to 8 mm long, almost globular, fleshy gall on root collar. Containing a single larva in a central chamber. I. amara: Ceutorhynchus assimilis

3a Short nodular or long cylindrical galls => 4

3b Outside of roots little changed, temporarily bearing white to brown, poppy seed sized cysts. Giant cells develop inside. I. amara, umbellata: Heterodera schachtii

4a Nodular to spindle-shaped galls, a few mm long, mainly on side roots. I. sempervirens: Meloidogyne hapla

4b Up to several cm long spindle-shaped to cylindrical, fleshy galls, usually on side roots. Iberis spp.: Plasmodiophora brassicae

5a On stems and leaves => 6

5b Flower buds swollen, unopened. I. sempervirens: Unidentified gall midge

6a Stem slightly stunted, with ± discoloured leaves, folded upwards, usually additionally curled. I. sempervirens: Brevicoryne brassicae

6b Glossy white, later on with mealy dusting, ± bulging swelling additionally usually slightly curved young axial parts or midribs of leaves. Also rotund dusty pads, in many Iberis species with violet-red margin, on yellowing leaf blades enclosed by a “chlorophyll isle”, on underside. I. amara, carnosa, “pruittii”, umbellata: Albugo candida

6c Upperside of the leaves with yellowish spots. Their underside with a white down, consisting of erect conidiophores that apically are dichotomously branching several times, each branch ending in a conidium. I. amara, gibraltarica, “pruitti”, saxatilis, sempervirens: Hyaloperonospora iberidis

gallers on Hirschfeldia

Last modified 15.v.2020

Dichotomous table for gallers on Hirschfeldia

by Hans Roskam

1a On parts above ground => 2

1b Main- or side roots with conspicuous swellings, usually more than 5 mm long, spindle-shaped to cylindrical, succulent, compact. H. incana: Plasmodiophora brassicae

1c Much smaller swellings, only 3–4 mm long. H. incana: Meloidogyne hapla

2a On shoot tips, leaves, flowers or fruits => 4

2b On stems, petioles or midrib => 3

3a White sori of variable size, at first closed and glossy, porcelain-like, later with mealy dusting after rupturing, on ± swollen and disfigured green parts. H. incana: Albugo candida

3b Midrib of leaf or stem with swellings 12–15 (20) mm long, also deep green inside, one-chambered, spindle-shaped. Containing a single larva. H. incana: Ceutorhynchus chalybaeus

4a On flowers => 6

4b On shoot tips or leaves => 5

4c Silique swollen, containing a single orange midge larva. H. incana: Asphondylia stefanii

5a Axis, especially of developing axillary buds, severely stunted, between the bases of clustered leaves, especially at thickened bases, are several whitish to lemon-yellow jumping larvae. H. incana (incl. adpressa): Contarinia nasturtii

5b Leaf blades of young rosette leaves in variable expansion rolled upwards undulate or bent, usually pale green. Older leaves with variously expanded pale green, often deflected, folds. On upper side or underside in the galls are colonies of mealy dusted aphids H. incana: Brevicoryne brassicae

6a Flowers swollen, unopened; calyx enlarged, corolla and anthers necrotic; anthers and ovaries stunted and thickened. Midge galls => 7

6b Flowers conspicuously disfigured; calyx and corolla strongly enlarged, thickened and greened; stamens ± aborted; ovaries swollen, wide tube-shaped; partially with white sori, at first glossy, porcelain-like, later on with mealy dusting. H. incana: Albugo candida

7a Larvae with several, whitish- to lemon yellow, jumping. H. incana: Contarinia nasturtii

7b Several larvae, non-jumping when mature. H. incana: Gephyraulus raphanistri

7c Silique swollen, containing a single orange midge larva. H. incana: Asphondylia stefanii

gallers on Helleborus

Last modified 14.v.2020

Dichotomous table for gallers on Helleborus

by Hans Roskam

1a Malformations caused by fungi with erupting or clearly transparent sori => 4

1b Malformations caused by animal inducers or fungi with fruiting bodies which are not apparent externally => 2

2a Pustule-shaped or minor bulge-like swellings on stems and leaves => 3

2b Leaf blades ± twisted, with margins downwardly deflected. H. foetidus, lividus & subsp. corsicus, niger, orientalis, purpurascens, viridis & subsp. bocconei: Macrosiphum hellebori

3a Leaf blade, more rarely petiole, with pustule-like necrotic oval swellings, up to 3 mm long, visible on both sides or on underside only; usually in two rows along the midrib. Each pustule containing a greenish-white egg; after emerging the larva lives freely on the leaf blade. “Procecidium” (oviposition scar, not a true gall). H. foetidus, niger, viridis: Monophadnus latus

3b Weak, at first ± vitreous, spindle-shaped swellings on stems and petioles. H. viridis: Physoderma deformans

4a Galls caused by rusts and smuts => 5

4b Galls caused by false mildew. Systemic infection of overwintering mycelium in rhizome. The diseased leaves are smaller, yellowish, the segments ± distinctly spoon-shaped downwardly deflected and curved; soon covered by a widespread, dense layer of conidia. H. dumetorum, foetidus, niger, odorus, purpurascens, viridis & subsp. istriacus: Peronospora pulveracea

5a Initially grey translucent smut bulges of variable size on all green parts, soon erupting and with black dusting. Helleborus spp.: Urocystis floccosa

5b Yellow aecia pads associated with spermogonia on gall-like swollen, sometimes ± bent petioles and leaf blades. Helleborus spp.: Puccinia actaeae-elymi

5c In similar aecia. Helleborus spp.: Puccinia actaeae-agropyri

gallers on Helichrysum

Last modified 14.v.2020

Dichotomous table for gallers on Helichrysum

(see also Gnaphalium)

by Hans Roskam

1a On root collar, inner basal rosettes or on above-ground plant parts => 2

1b Spindle- or nodule-shaped swellings on roots, up to 5 mm long. Helichrysum spp.: Meloidogyne hapla

2a On upper stem parts, leaves or inflorescences => 4

2b Inside basal rosettes or on root collar => 3

3a Top of rosettes including an almost onion-shaped gall, up to 8 mm high and 5 mm wide. One larva inside. H. arenarium: Actinoptera discoidea

3b Globular or nodular, up to 1 mm long galls which are sometimes clustered and variously coalesced on root collar. The inside filled with initially bright-, later on chestnut brown spore masses. H. arenarium: Entyloma magnusii

4a On leaves and inflorescences => 6

4b On shoots => 5

5a Spindle-shaped swellings of the stems or inflorescence, up to 25 mm long. Later on the caterpillar bores downward in the pith over various length. H. arenarium: Unidentified lepidopteran

5b Spindle-shaped stem swellings about 6 mm long and 4 mm thick. Containing a single larva. H. arenarium: Actinoptera discoidea

5c Terminal leaves grouped in a subspherical mass of 10–15 mm in diameter, or terrminal bud swollen, ovoid or spindle-shaped (10 x 4.5 mm), covered with pubescent leaves. Large axial cavity containing a single larva. H. italicum, litoreum, pendulum, stoechas: Actinoptera mamulae

6a On inflorescences or capitula => 7

6b The middle part of single or several leaves variously bent downward and ± curled by froth-covered nymphs. H. bracteatum: Philaenus spumarius

7a Inflorescence stunted, bunched. Leaves ± rolled. Helichrysum spp.: Brachycaudus helichrysi

7b Capitula deformed; receptacle hardened. Containing a single larva. H. arenarium: Actinoptera discoidea

gallers on Eryngium

Last modified 14.v.2020

Dichotomous table for gallers on Eryngium

by Hans Roskam

1a On leaves or stems => 2

1b On inflorescences or flowers => 5

2a Malformations lacking fructifying fungal sori on surface => 3

2b Leaf veins and -stalks with yellowish, spindle-shaped or elongated sometimes curved bulging swellings bearing aecia. E. campestre, creticum, falcatum, glomeratum, tricuspidatum: Puccinia eryngii

2c Leaves with fawn-coloured raised spots, 1–3 mm across, containing yellow-brown smut spores. E. planum: Entyloma eryngii-plani

3a Malformations on leaf blades => 4

3b Conspicuous swellings, up to 15 mm thick, usually expanded, multi-chambered, on stems and petioles. Inner wall of chamber covered with fungal hyphae. Each chamber containing a red larva. E. amethystinum, campestre, maritimum, tricuspidatum: Lasioptera eryngii

3c Malformation of stem. E. campestre, planum: Inducer unknown

4a Leaf blade reduced, rolled upwards, curled and discoloured. E. campestre, maritimum: Unidentified aphid

4b Leaf blade often with many distinct protruding or indistinct, rotund or angular pustules, 1–3 mm across, at first sometimes violet, soon browned, with many spores inside. E. alpinum, campestre, maritimum, planum: Entyloma eryngii

5a Style of flower thickened, ovary stunted. E. campestre: Unidentified gall midge

5b Centre of (partial) umbel swollen, globular or club-shaped; gall uni-, also multi-chambered, each containing a red larva. E. campestre: Lasioptera carophila

gallers on Erucastrum

Last modified 14.v.2020

Dichotomous table for gallers on Erucastrum

by Hans Roskam

1a On parts above ground => 3

1b On roots or root collar => 2

2a Succulent, broad spindle-shaped or acuminate cylindrical, compact swellings on main- and major side roots. E. gallicum, nasturtiifolium: Plasmodiophora brassicae

2b Almost globular, 5‒10 mm long, one- also several-chambered swellings close to root collar. Containing a single white larva. E. gallicum: Ceutorhynchus assimilis

3a On leaves and stems => 4

3b Flowers swollen; unopened. Calyx enlarged, corolla and anthers necrotic. Stamens and stigma thickened. At maturity containing several white, non-jumping larvae. E. gallicum: Gephyraulus raphanistri

4a Malformations caused by animals => 5

4b Pads of at first closed, glossy, porcelain-like, with mealy dusting sori on various plant parts after rupturing. E. gallicum, nasturtiifolium: Albugo candida

5a Leaf blade with conspicuous, pale green swellings and deflected margins. E. gallicum, abyssinicum: Brevicoryne brassicae

5b Spindle-shaped often deep green swellings on petioles, midrib or stems, up to about 15 mm long. Containing a single larva. E. gallicum, abyssinicum: Ceutorhynchus chalybaeus

5c Leaves clustered on shoot tip or young inflorescences and transformed into a ± fleshy to spongy gall. E. incanum: Contarinia nasturtii

gallers on Eruca

Last modified 14.v.2020

Dichotomous table for gallers on Eruca

by Hans Roskam

1a On parts above ground => 4

1b On roots or root collar => 2

2a On roots => 3

2b Almost globular, fleshy swellings on root collar, up to 7 (10) mm long, one-chambered. Containing a single larva. E. vesicaria: Ceutorhynchus assimilis

3a Small swellings, up to 5 mm long, nodular or ± spindle-shaped on side roots bearing some adventitious roots. E. vesicaria: Meloidogyne hapla

3b Conspicuous, fleshy swellings of variable size mainly in main- and major side roots. Many cells containing masses of minute spores inside. E. vesicaria: Plasmodiophora brassicae

4a On flowers or fruits => 8

4b On vegetative parts => 5

5a Malformations caused by animals => 6

5b Dense, at first closed glossy, porcelain-like bulging swellings on all green parts, with after rupturing mealy dusting of sori. E. vesicaria: Albugo candida

6a On stems or leaves => 7

6b Shoot tips, also axillary buds, stunted. Leaves as well as flower buds densely clustered; leaf base fleshy swollen, gall bodies variously enveloped by disfigured parts. Containing several white to pale yellow larvae. E. vesicaria: Contarinia nasturtii

7a Spindle-shaped, up to 15 (20) mm long, often deep green swelling on petioles, leaf veins or stems. Containing a single larva. E. vesicaria: Ceutorhynchus chalybaeus

7b Leaf blade deflected at margin; leaf blade variously strongly arched or folded, often pale green, sometimes reddish marbled. E. vesicaria: Brevicoryne brassicae

8a Flowers swollen, unopened. Containing several white to pale yellow larvae. E. vesicaria: Contarinia nasturtii

8b Similar flower galls; but contrary to the ± rotund-oval previously reported galls on Eruca usually ± conical and more conspicuous. Containing several non-jumping, also white when mature, larvae. E. vesicaria: Gephyraulus raphanistri

8c Large part of silique swollen, yellowish. Containing several white larvae. E. vesicaria: Dasineura napi

gallers on Diplotaxis

Last modified 13.v.2020

Dichotomous table for gallers on Diplotaxis

by Hans Roskam

1a On parts above ground => 3

1b On roots or root collar => 2

2a Roots with conspicuous, mostly, spindle-shaped to cylindrical, fleshy swellings. Inside the galls are cells containing spore masses. D. erucoides: Plasmodiophora brassicae

2b Root collar with one to several rotund galls, up to 5 mm long, with a curved larva inside. D. muralis: Ceutorhynchus assimilis

3a On flowers and siliques => 7

3b On stems or leaves => 4

4a Localised or extensive deformations caused by animal gall causers => 5

4b Leaf blade on the underside with flat, rotund cushions. Leaf axial parts or stem with ± expanded, sometimes distorted bulge-like swellings, initially covered with closed dense white sori, at first-glossy, porcelain-like, with mealy dusting after opening. D. muralis, tenuifolia: Albugo candida

5a Deformations caused by aphids => 6

5b About 10–15 mm long, spindle-shaped, partially deep green swellings on the midribs or stems. Containing a single larva. D. muralis, tenuifolia: Ceutorhynchus chalybaeus

6a oung lateral shoots distinctly stunted; occupied by conspicuously reduced and deformed, more densely situated, leaves. D. tenuifolia: Lipaphis rossi

6b Leaf blades folded locally, leaf margins rolled. D. muralis, tenuifolia: Brevicoryne brassicae

7a Malformations caused by gall midges => 9

8b Other causers => 8

8a Greening of flowers. D. muralis, tenuifolia: Brevicoryne brassicae

8b Ovaries in one or several flowers of an inflorescence deformed, narrowed and elongated; anthers shrivelled, corolla stunted; ± greened; calyx partially conspicuously enlarged. On many parts bulge-like white fungal sori occur. D. erucoides, muralis, tenuifolia, virgata: Albugo candida

9a Malformations of flowers or flower parts => 10

9b Swelling of silique => 11

10a Single or several buds per inflorescence distinctly swollen, unopened. Similar galls; calyx and corolla sometimes less swollen. larva usually lighter yellow, jumping. D. muralis, tenuifolia: Contarinia nasturtii

10b Swollen flower buds. White, non-jumping larvae. D. muralis, D. catholica, D. erucoides: Gephyraulus diplotaxis

10c Swollen siliques, inside only one larva. Pupation in gall. Two generations. D. tenuifolia: Asphondylia stefanii

11a Spindle-shaped swelling of silique, often silique bent at right angle. D. tenuifolia: Dasineura napi

11b Siliques swollen, containing a single orange midge larva. D. tenuifolia:
Asphondylia stefanii

11b Siliques turgid, deformed and curved. D. tenuifolia: Dasineura napi

gallers on Buxus

Last modified 14.v.2020

Dichotomous table for gallers on Buxus

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. B. sempervirens: Meloidogyne hapla

2a On buds, shoot tips or leaves => 3

2b Flowers greened; inner parts thickened, succulent; without abnormal pubescence. B. sempervirens: Eriophyes canestrinii

= Also Eriophyes buxi has been recorded, presumably as inquiline, from such galls

3a On leaves => 6

3b On buds or shoot tips => 4

4a Malformation of many terminal leaves => 5

4b Buds enlarged, transformed into a globular gall, up to 4 mm long, loosely grey pubescent. Leaves with small bladder-like swellings. B. sempervirens: Aceria unguiculata

5a Leaves on shoot tip clustered, tuft-like, almost hemispherical or arched, spoon-like, often sticky on inner side. Froth-covered nymphs flattened, greenish covered with whitish pubescence. B. balearica, sempervirens, microphylla: Psylla buxi

5b Young leaves deflected, black aphids on underside. B. sempervirens: Aphis fabae

6a Malformations induced by animals => 7

6b Up to about 2 mm wide, almost half-globular, compact, at first yellowish-green, later on dark brown telia; containing 2-celled teliospores. Often several sori on the underside of locally hypertrophied leaves. B. microphylla, sempervirens: Puccinia buxi

6c The infested leaf parts eventually dry and fall out; after that it looks as if the plant has been grazed by an insect. B. sempervirens: Mycosphaerella buxicola

7a Leaf blade usually with yellowish-green, vaguely defined, ± rotund-oval blisters, often close to midrib on upper side, on underside later on ± translucent, flat bulging. Often several per leaf, ± coalescing. Each contains one or more larvae, at first white, later on orange-yellow. B. balearica, microphylla, sempervirens, wallichiana: Monarthropalpus flavus

8b Leaf blades with small pustules. Parenchyma loosened from lower epidermis. Cavity contains many gall mites. B. sempervirens: Eriophyes hypophyllus

gallers on Arctium

Last modified 13.v.2020

Dichotomous table for gallers on Arctium

(incl. Lappa)

by Hans Roskam

1a Malformations of above-ground parts => 2

1b Root with node-shaped tumefaction. A. lappa: Ceratapion onopordi

1c Gall in root or root collar; spindle-shaped, about 5–10 mm, containing a larva or pupa. A. minus: Cleonis pigra

= Caterpillars of the tortricid Epiblema scutulana, with yellowish brown head, bore into the stem and underground parts. They hibernate in the upper section of their gall cavity. The plant may show a local swelling or shortening of the internodes

2a On leaves => 3

2b Capitula malformed. Larvae in the swollen receptacle. A. lappa, minus, tomentosum: Tephritis bardanae

= Gall-like inflation of the ovary is caused by the tephritid fly Chaetostomella cylindrica

2c Mature achene slightly swollen, with tiny larval entrance hole in upper third and larger hole at base blocked with debris; contains a larva. A. lappa, minus, tomentosum: Terellia tussilaginis

2d Woody galls in capitula. Arctium sp.: Urophora solstitialis

= Hardening and gall-like malformation of the capitula on burdocks might be attributed to the larva of the gelechiid moth Metzneria lappella

3a Leaf blades over extensive areas curled, rolled => 6

3b Leaves with galls => 4

4a Malformations caused by fruiting bodies of fungi situated on the surface => 5

4b Leaves of young plants, close to the ground, on the underside or on the petioles with many ± hemispherical, golden yellow warts, less than 1 mm long. A. lappa, minus: Synchytrium aureum

5a Aecia bearing, ± distinctly upraised yellow bulges on the underside of the leaves; usually on the leaf blades, rotund, up to 10 mm long; less frequently on the main veins, but more conspicuous there, long oval to spindle-shaped. A. lappa, nemorosum: Puccinia silvatica

5b Yellowish, ± oval, 2–5 mm long, weak bulges and curves on the leaf upperside on the main veins. Bulges only on the upperside, soon occupied by cinnamon dusty uredinia. A. lappa, minus, tomentosum: Puccinia calcitrapae

6a Margins of younger leaves rolled inwards, curved and ± curled; older leaves with dark green, slightly bulging spots. Black aphids on the underside. Arctium spp.: Aphis fabae

6b Larger leaf blades with extensive loose downward rolls, mostly obliquely over the top; smaller ± trowel-shaped converging; below close to the froth-covered nymph crooked and tubercular; dark green. Arctium spp.: Philaenus spumarius

gallers on Anthoxanthum

Last modified 13.v.2020

Dichotomous table for gallers on Anthoxanthum

by Hans Roskam

1a On above-ground parts => 2

1b Roots with spindle-shaped, crooked or half screw-shaped bent swellings a few mm long. A. odoratum: Subanguina radicicola

2a On inflorescences or flowers => 6

2b On vegetative parts => 3

2c 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. A. odoratum: Epichloë typhina

2d At the base of stem, weak swelling containing one (or maybe sometimes several) white larva or flax seed like puparium. A. odoratum: Mayetiola sp.

3a Leaves with several parallel stripes caused by smuts => 5

3b Complete plant stunted in development => 4

4a Shoot at base slender onion-like swollen; plant more densely foliate. Stem not or only slightly developed. Leaves ± undulate and thickened; many eelworms inside. A. odoratum: Ditylenchus dipsaci

4b Complete plant stunted; inflorescence discoloured; contains a fly maggot. A. odoratum: Unidentified dipteran

5a Spores solitary, 8–12 µm across. Mass black. Stripes also occurring on stems and parts of spikes which remain closed for a longer time. A. odoratum: Ustilago striiformis

5b Spores in clusters of 2–5, enveloped by sterile auxiliary cells. Smut stripes occasionally also on leaf sheaths, stems and affected spikes. A. odoratum: Urocystis roivainenii

6a Inflorescence disfigured by animal parasites => 7

6b Ovary transformed into inconspicuous smut grains about 2 mm long, 1 mm wide. A. odoratum: Tilletia anthoxanthi

7a Axis of inflorescence wriggled; spikelets conglomerate. A. odoratum:
Unidentified tarsonemid mite

7b Inflorescence and flowers disfigured. Reproductive organs aborted. Glumes twisted or irregularly folded; in case of weaker infestation often dark red or violet, bleached if strongly infected. A. odoratum: Aceria tenuis

gallers on Abies

Last modified 13.v.2020

Dichotomous table for gallers on Abies

by Hans Roskam

1a On needles, on young, ± stunted shoots or on developing buds => 4

1b On lignified younger or older stem parts => 2

1c arvae develop gregariously (1−8 together) inside young seeds in cones. A. alba, cephalonica, nordmaniana: Resseliella piceae

= Fresh resin masses of damaged shoots of A. alba rarely may contain gall midge larvae of Resseliella crassa and/or R. resinophaga

2a Older lateral shoots, sometimes also the stems, occupied by conspicuous witches’ brooms or mistletoes => 3

2b Axial parts of younger shoots often severely stunted, with ± club-like to nodule-shaped, also forked and twisted swellings, or older stem parts with irregularly expanded, ± bulging proliferations of bark. Sometimes also the buds are transformed into globular or egg-shaped galls. Abies spp.: Dreyfusia piceae

2c A very similar aphid may occur on young plants of A. alba, nordmanniana: Dreyfusia merkeri

3a Witches’ brooms with erect main shoots, abundantly branched, developing from globular to barrel-shaped, often conspicuous thickenings. Needles distinctly shortened, thickened, yellow-green, directed to all sides, falling in autumn. A. alba and several foreign species. Melampsorella caryophyllacearum

= In Melampsorella galls and other cancer-like malformations on conifers the tortricid moth Cydia duplicana, as well as the gelechiid Chionodes electella occasionally develop

3b From bulges, club- and barrel-like swellings of branches or stems arise
Viscum album subsp. abietis

4a On young shoots or on needles => 5

4b Developing buds severely stunted, globular swollen and disfigured, hard and browned. Mites inhabit strobili, apparently causing deformation and atrophy. A. alba, concolor, pectinata: Trisetacus floricolus

5a On many curved needles of ± shortened side shoots => 6

5b Lower third of needles predominantly with brown or red swelling, up to 2 (3) mm long, especially rotund-oval to compact spindle-shaped at base and laterally protruding, expanded over only one or over both needles. Larvae orange-yellow, jumping. A. alba and foreign species: Paradiplosis abietispectinatae

6a Top of shoot slightly shortened. Needles of young shoots weakly swollen, ± tuft-like upwardly converging, exposing wax stripes on the underside; many white woolly aphids between the needles during April-June. Abies spp.: Mindarus abietinus

= Between the needles are pale green aphids of Mindarus obliquus occur in white fluffy wax, resembling those of M. abietinus. Contrary to that species, no malformation of the needles occurs.

6b Needles on the stunted tips of young shoots, predominantly of smaller plants, accumulated, bottle brush-like, partially downwardly deflected. A. alba, nordmanniana etc.: Dreyfusia nordmannianae and/or D. merkeri

6c Another inhabitant on bark of Nordmann fir, also alternating with Picea orientalis: Dreyfusia prelli

gallers on Zea

Last modified 12.v.2020

Dichotomous table for gallers on Zea

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodular or slender spindle-shaped swellings. Meloidogyne chitwoodi

2a Malformations caused by weakly dusting fungi => 7

2b Malformations caused by animals => 3

3a Malformations mainly on young plants caused by animals developing inside => 6

3b More or less distinct leaf rolls caused by aphids => 4

4a Greenish aphids => 5

4b Aphids glossy dark-brown. Young leaf blades, if weakly infected, slightly rolled and discoloured mainly at base, soon withering. Sipha maydis

5a Adult wingless aphids oblong-oval, 1.75–2.6 mm long, powdered, dark green to bluish black, with very dark, brown-black extremities. Rhopalosiphum maidis

5b Wingless aphids rotund-oval, 1.6–2.4 mm, not powdered, dull olive-green to dark grey-green, with green translucent to brown, at the tip dark-brown extremities. Rhopalosiphum padi

6a Plant excessively leafy. Leaves contorted and disfigured, partially twisted. Shoots stunted, at base spongy, swollen; internodes distinctly shortened and thickened. Ditylenchus dipsaci

6b Shoots of young plants stunted; slightly swollen just above ground; plants additionally leafy; inner leaf destroyed. Leaf sheaths and -blades ± twisted. Usually several yellowish-white maggots at base of shoots, up to 4 mm long, which feed on various plant parts Oscinella frit

6c In addition to frit fly occurring on maize and with similar biology is the closely related: Oscinella pusilla

7a Different plant organs with pea- to even child head size, at first white-grey covered, bulging swellings, which release the previously smeary, then dusty, blackish single smut spores when ripped open. Mycosarcoma maydis

7b The female and also the looser male inflorescences completely or only partially transformed into a unified smut mass, initially enveloped by a whitish to reddish membrane. Diseased flowers sometimes with leaf-like structures. Spores united in balls. Sphacelotheca reiliana

7c Inconspicuous and ephemeric fungal down on the underside of yellowing leaves of seedlings. It consists of erect conidiophores that apically are dichotomously branching several times, each terminal branch ending in a conidium. Peronosclerospora maydis

gallers on Valerianella

Last modified 12.v.2020

Dichotomous table for gallers on Valerianella

by Hans Roskam

1a On leaves, stems or/and inflorescences => 2

= As causer of root galls on V. locusta has been recorded the Root knot eelworm Meloidogyne hapla

1b Ovary swollen, up to 7 mm long, disfigured. Containing a single white larva. V. carinata, dentata, locusta, rimosa: Cecconia valerianellae

2a Malformations on vegetative organs, sometimes encroaching onto inflorescence primordia => 3

2b Many flowers in an inflorescence conspicuously disfigured. Corolla greatly enlarged, transformed into a lobed, succulent annular disc. Stamens corolla-like. Valerianella sp.: Unidentified gall mite

3a Malformations caused by fungi fruiting on outside => 5

3b Malformations caused by animals => 4

4a Young plants severely stunted. Leaves from basal part upwards variously spongy swollen, the higher situated parts ± disfigured. Stem primordia similarly thickened. V. dentata, locusta: Ditylenchus dipsaci

4b Leaves widened and shortened, ± distorted or rolled. Inflorescence axis shortened. Flowers clustered into rotund, pale green balls. Calyx enlarged, often deeply incised. Tips almost leaf-like, greened or leafy. Stamens aborted. Bracts folded and distorted. V. carinata, coronata, dentata, locusta, rimosa: Trioza centranthi

5a Fungi in expanded, not distinctly restricted malformations => 6

5b Plants usually infected systemically and often not reaching the flowering stage. Organs variously disfigured. Sori on leaf underside, or on all sides of axial parts with ± uniformly arranged whitish aecia. V. carinata, dentata, locusta, rimosa: Puccinia gladioli

6a Plants largely or completely covered by a loose, dusty mycelium. Infected parts variously ± disfigured or often not gall-like V. carinata, dentata, eriocarpa, locusta, rimosa: Golovinomyces orontii

6b On various Erysiphaceae [powdery mildews] develops the widely distributed and rather frequent Ampelomyces quisqualis

6c Systemically infected shoots pale green, on axial parts weakly hypertrophied; leaves slightly thickened, leaf blades ± stunted, margins slightly deflected, with a down of dirty white, branched conidiophores on underside. V. carinata, dentata, discoidea, locusta, rimosa: Peronospora valerianellae

6d Leaves and stem, usually with many, minute greenish to brown globular warts. V. locusta: Synchytrium valerianellae

gallers on Trisetum

Last modified 12.v.2020

Dichotomous table for gallers on Trisetum

(incl. Trisetaria)

by Hans Roskam

1a On above-ground parts => 2

1b Roots sometimes with minor swellings, from which cysts erupt up to 1 mm long, lemon-yellow later on. Trisetum sp.: Heterodera avenae

2a On vegetative organs => 4

2b Galls on ovaries => 3

3a Ovary transformed into an oblong gall protruding far outside the spike. T. flavescens: Anguina agrostis

3b Ovaries within the unopened, not disfigured, glumes strongly elongated, abnormally thin, sometimes conspicuously curved. Each floret containing a pale brick- to orange-red larva. T. flavescens: Dasineura triseti

4a Malformations caused by animals on culms or leaves => 6

4b Leaf blades, rarely sheaths, culms and parts of spikes with several long parallel stripes of smut => 5

5a The long stripes of smut contain a black spore powder. Spores 2–8 in balls, completely enveloped by many sterile auxiliary cells. T. alpestre, flavescens, spicatum: Urocystis triseti

5b The smut mass consists of 8–12 μm single spores. Trisetaria panicea, Trisetum spicatum: Ustilago striiformis

6a On culms => 7

6b Leaf blades ± thickened, longitudinally upwardly rolled inwards and curved, screw-like. T. flavescens: Unidentified tarsonemid mite

7a Culm slightly swollen at base of the ± stunted inflorescence. T. flavescens: Oscinella frit

7b Culm, with weak, slightly rimmed depressions underneath the sometimes slightly arched leaf sheaths, usually close to a node; each containing an orange-yellow larva. T. flavescens: Lasioptera calamagrostidis

gallers on Sanguisorba

Last modified 12.v.2020

Dichotomous table for gallers on Sanguisorba

by Hans Roskam

1a Malformations on leaves, sometimes extending onto the stems => 2

1b Shoot axis or petiole ± buckled or swollen spindle-shaped, sometimes conspicuously curved; often with several flat, oval, rimmed depressions, containing inducer. S. minor: Planchonia arabidis

2a Malformations without conspicuous pubescence => 3

2b Above-ground parts variously disfigured, on most expanded areas with abnormal, dense, whitish, hair felts. Hairs long, twisted. S. minor & subsp. balearica, officinalis, verrucosa: Aceria sanguisorbae

3a Leaf fold, roll or curl caused by animals => 6

3b Small, wart-like or expanded bulging galls caused by fungi => 4

4a Galls bulging, several mm long. Spores develop on gall surface => 5

4b Galls wart-shaped, many-celled, less than 1 mm across, yellow; with many on leaf underside, on leaf midrib, -stalk or young stems; sometimes coalescing into crusts or ridges and causing bends. S. minor, officinalis: Synchytrium aureum

5a Leaf veins, -midrib or stalk, sometimes also young stems, with slightly bulging, sometimes distinctly bent swellings of different length; leaf blades with rotund red-brown pads on upperside, mainly protruding on underside. Galls often brick-red, soon covered with orange spores. Teliospores (2) 4 (5)-celled. S. minor & subsp. balearica, officinalis, rupicola, verrucosa: Phragmidium sanguisorbae

5b Expanded, often ± curved bulges on leaf veins, -spindles, -stalks, also on stems; leaf blade with rotund pads, mainly on underside. Gall soon covered with brick-red spores; telia develop on both sides in arched carbon-black pads, sometimes coalescing with caeoma-sori. Teliospores 4‒22-celled. S. officinalis, verrucosa: Xenodochus carbonarius

5c Malformation of leaf. S. alpina, canadensis, minor & subsp. balearica, officinalis, verrucosa: Podosphaera ferruginea

5c Leaves curled and reddened. S. minor, officinalis: Peronospora sanguisorbae

6a Leaflets curled and ± rolled downwards => 7

6b Halves of leaflet folded upwards, pod-like; especially slightly thickened at veins; outside often ± grey-green, inside ± reddened. Often all leaflets of a leaf are galled. Larvae very many, orange-red. S. officinalis, much rarer on S. minor, officinalis: Dasineura sanguisorbae

7a Malformations caused by spittlebugs or sawfly larvae => 8

7b Leaf blades contracted, curled. S. minor: Unidentified aphid

8a Midrib and leaflet stalks of the still young often pale green leaves slightly thickened and ± stunted, bunched together; axis curled variously up to almost spirally. Leaf blades of leaflet ± folded upwards, often deflected in apical part. S. minor, officinalis: Claremontia puncticeps

8b Especially apical part of leaf midrib distinctly shortened and curved downwards. Leaflets ± bunched together, crumpled, partially dark-green. Froth-covered nymph on underside. S. minor, officinalis: Philaenus spumarius

gallers on Sambucus

Last modified 12.v.2020

(For a dichotomous table for galls on Sambucus by Hans Roskam click here)

1a On parts above ground => 2

1b Roots with little, ± spindle-shaped swellings. S. nigra: Meloidogyne hapla

2a On flowers => 6

2b On stems, buds or leaves => 3

3a On leaves => 4

3b Buds swollen, unopened. S. nigra: ? gall midge

4a Leaf blade loosely rolled downwards or curled or distorted without rolling => 5

4b The margins usually of all leaflets of several terminal leaves narrowly rolled upwards. Leaf blades narrowed, often curled or furrowed and ± discoloured. S. canadensis, ebulus, nigra, racemosa: Epitrimerus trilobus

4c Deformation and discolouration of the leaves, inrolling of the leaf margin. Sambucus spp.: Callyntrotus trilobus

= Despite the confusing identity of the specific name, this is not a synonym of Epitrimerus trilobus, which often is cited as (the only) causer of leaf margin galls in elder. Whether both species co-occur in the same gall, perhaps the one as an inquiline of the other, is not clear

5a Large leaflets, complete leaves or also several leaves disfigured on the ± stunted shoot tip. Leaf blades strongly curved downwards, curled, locally deep green. Sambucus spp.: Philaenus spumarius

5b Leaf blade is strongly infected ± rolled downwards. S. ebulus, maderensis, nigra, racemosa: Aphis sambuci

6a Corolla globularly swollen, slightly leather-like; tube slightly elongated. Flowers unopened. Midge galls containing usually several non-jumping larvae => 7

6b Similar malformation. Filaments shortened and thickened. Ovaries ± irregularly swollen. Contain several yellow, jumping larvae. Sambucus spp.: Contarinia sambuci

7a Gall similar to previous one, often slightly smaller; corolla more irregular and less compactly closed. Containing usually only a single pale- to orange-yellow non-jumping larva. Sambucus spp.: Placochela nigripes

7b Similar malformation; containing several white larvae. S. ebulus, nigra:
Arnoldiola sambuci

gallers on Lycopersicon

Last modified 20.v.2020

Dichotomous table for gallers on Lycopersicon

(= Lycopersicum. ‒ Comp. Solanum)

by Hans Roskam

1a On parts above ground => 4

1b On roots or subterranean stem parts => 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. Phytophthora infestans

2a Nodular or slender spindle-shaped galls, on roots located distant from surface => 3

2b Buds or adventitious buds of subterranean stem parts, also roots, developing into smaller proliferations, exceptionally up to 20 mm long. Synchytrium endobioticum

3a Nodular swellings, often many and ± coalescing. Meloidogyne hapla etc.

3b Roots usually with shorter or longer, sometimes interrupted, slender, 2–3 mm broad swellings and sometimes excessive development of side roots; this ‘root beard’ is usually situated above the galls. Globodera rostochiensis

3c Tips, often of many roots, slightly swollen over various lengths. Plant often conspicuously stunted. Also many eelworms inside and outside the tissue: Pratylenchus pratensis

3d Root with rounded galls, usually several together like a string of beads; on tomato in glasshouses. Nacobbus cf. aberrans

= Nacobbus serendipiticus (tomato eelworm) is causing spindle-shaped galls on roots in glasshouses

4a On leaves and flowers => 6

4b On stems, sometimes encroaching on leaf midrib => 5

5a Up to 20 (30) mm long, rotund bulge, mainly on root collar, secondarily also on higher stem parts. Agrobacterium tumefaciens

= In cases of the moderately frequent “tomato cancer”, better known as “bacterial tomato withering/drooping” the causer is Corynebacterium michiganense

5b Pale green, spongy, ± expanded swelling, often associated with distortion of ± stunted parts. Ditylenchus dipsaci

6a Various curls or rolls, often of several terminal leaves, caused by aphids => 7

6b Malformations of flowers often with bladder-like swelling, extensively conjoined calyx leaves as well as largely stunting of partially greened corolla leaves and stamens and sometimes enlarged and disfigured ovaries on plants with reduced, often bulging leaves. Stolburg disease

6c Individual flower or part or all of inflorescence greened and leafy (phyllanthy), very haired, containing mites. Aceria lycopersici

7a Aphid dull-black, about 2.5 mm long. L. esculentum: Aphis fabae

7b Aphids pale yellowish to green, 1.8–2.9 mm long, siphunculi pale at base, darker, with a dark spot at tip. Aulacorthum solani

7c Aphid green, often with a dark, green longitudinal stripe on back. Body spindle-shaped oval, glossy in adults, dusted with greyish wax in froth-covered nymphs. 1.7–3.6 mm. Siphunculi brownish, ¼–⅓ of body length, twice as long as cauda. Alates with pale brownish-yellow thorax, otherwise lacking pigmentation on back. Macrosiphum euphorbiae

gallers on Lunaria

Last modified 8.v.2020

Dichotomous table for gallers on Lunaria

by Hans Roskam

1a On parts above ground => 3

1b On roots or root collar => 2

2a Irregular cylindrical, usually swelling on all sides, of variable length, on side roots and younger parts of main root. L. annua, rediviva: Plasmodiophora brassicae

2b Globular galls on root collar, with central larval chamber. L. annua, rediviva: Ceutorhynchus assimilis

3a On flowers or fruits => 9

3b On vegetative parts => 4

4a Malformations caused by animals => 6

4b Malformations caused by fungi => 5

5a Sori at first closed, glossy, porcelain-like, the conidia later develop on basal conidiophores in rows on rupturing, dusty pads. L. annua, rediviva: Albugo candida

5b Sori dull, conidia on branched conidiophores. L. annua, rediviva: Hyaloperonospora lunariae

6a Malformations caused by external plant feeders, aphids or spittlebugs => 8

6b Causers inside malformations; larvae of weevils => 7

7a Up to about 15 mm long, rotund to flattened spindle-shaped galls, also deep green inside with central larval chamber, on midrib, also petioles; occasionally on younger stem parts. Containing a single larva. L. annua: Ceutorhynchus chalybaeus

7b The shorter petioles of higher leaves as well as the lower part of the midrib are ± conspicuously deflected; inside are translucent, dark feeding tunnels, with wall cells often regenerating, causing swelling of the organs and sometimes even rupture. Containing a single beetle larva. L. annua: Ceutorhynchus pallidactylus

8a Leaf blades rolled- or deflected, almost nest-like. On main venation close to the froth-covered nymph curled and darker green than the parts towards leaf blade margin. L. annua, rediviva: Philaenus spumarius

8b Malformation of several, incompletely unfolded leaves on shoot tips, caused by mealy powdered grey-green aphids. L. annua, rediviva: Brevicoryne brassicae

9a Flowers thickened, unopened. L. annua: Contarinia nasturtii

9b Siliques severely disfigured, slightly discoloured, warty and bulging; seeds aborted. L. annua: Brevicoryne brassicae

gallers on Hesperis

Last modified 8.v.2020

Dichotomous table for gallers on Hesperis

by Hans Roskam

1a Galls on stems, leaves, flowers or fruits => 2

1b Swellings on roots, up to several cm long, 5–10 mm wide. Hesperis spp.: Plasmodiophora brassicae

2a On flowers or fruits => 6

2b On stems or leaves => 3

2c Malformation of all organs caused by mildew. H. matronalis: Albugo candida

3a On leaves => 4

3b Shoot axis on root collar with rotund, one-chambered fleshy swellings, sometimes with several coalesced, hence multi-chambered, bulging. H. matronalis: Ceutorhynchus assimilis

3c Cancer-like galls. H. matronalis: Agrobacterium tumefaciens

4a Rolled margins or curling of leaf blade => 5

4b Petiole or midrib with spindle-shaped swelling, up to 15 mm long, often deep green. H. matronalis, nivea: Ceutorhynchus chalybaeus

4c Leaf underside with a greyish down of erect conidiophores that distally are several times branched. At each tip an egg-shaped conidium. H. matronalis: Hyaloperonospora hesperidis

5a Leaf margin at leaf blade base, often up to the middle of the leaf blade or farther with 2 mm wide, compact roll. H. matronalis: Inducer unknown

5b Loose roll of leaf margin or upward fold of leaf blade. H. matronalis: Brevicoryne brassicae

6a Flower buds swollen, unopened. H. laciniata, nivea: Cause unknown – ? gall midge

6b Fruit locally disfigured, sometimes bent and swollen. H. matronalis: Inducer unknown

gallers on Gnaphalium

Last modified 8.v.2020

Dichotomous table for gallers on Gnaphalium

(incl. Filaginella, Laphangium, Omalotheca, see also Helichrysum)

by Hans Roskam

1a On above-ground parts => 2

1b Roots with 2–3 mm long, spindle-shaped swellings, on which occasionally some lateral roots have developed. G. uliginosum: Meloidogyne hapla

2a Whole plant, or major parts, deformed by aphids or cercopids => 8

2b Galls on shoots => 3

3a Spindle-shaped or globular galls of almost constant shape, but of various size => 5

3b Malformations of various shape and nature => 4

4a Galls on young, often severely stunted, plants. Basal parts, especially stems, also including the leaf bases, spongy, swollen, with many eelworms inside. G. uliginosum: Ditylenchus dipsaci

4b Sometimes strong swelling of the stem on the tip of ± developed shoots or the inflorescence. Leaves clustered, with swollen base, abnormally pubescent. G. sylvaticum: Cause unknown – ? gall mite

5a Galls spindle-shaped, with larvae inside => 6

5b Rotund, up to 5 (10) mm long galls; the inside containing whitish-yellow, later on rust brown, spore masses; predominantly on root collar, occasionally concentrated in groups. More rarely small galls on higher stem parts, even in the inflorescence. Laphangium luteo-album, G. sylvaticum, G. uliginosum: Entyloma magnusii

6a Inside the galls are larvae with head capsules => 7

6b Spindle-shaped swellings, up to 6 mm long and 4 (5) mm thick, usually in upper stem parts, the inside with a sometimes laterally situated whitish larva without distinct head capsule. G. sylvaticum, uliginosum: Actinoptera discoidea

7a Hard ovoid, one-chambered swelling in flower head or stalk. One larva. G. sylvaticum: Acentrotypus brunnipes

7b Spindle-shaped swelling on terminal part of shoot. With a yellowish-white, transversely lightly pink striate caterpillar with pale to dark brown head inside. Laphangium luteo-album: Eucosma albidulana

8a Caused by aphids => 9

8b Shoot stem usually stunted on one side, leaves clustered, the leaf blades curved downward, ± curled and dark green close to the froth-covered nymph. G. sylvaticum: Philaenus spumarius

9 Central part of rosettes deformed; or top of vegetative shoots, also the inflorescence, with shortened and sometimes twisted stem; leaves, sometimes capitula, clustered, rolled, curved. Aphids white frosted by copious secretion of wax. Filago arvensis, germanica, lutescens; Gnaphalium sylvaticum, uliginosum: Pemphigus populinigrae

9b Top of shoot stem stunted, leaves clustered, curved. Aphid bright yellow to yellowish-green, 1.5–2 mm long, without secretion of wax. G. sylvaticum, G. uliginosum: Brachycaudus helichrysi

gallers on Gentiana

Last modified 8.v.2020

Dichotomous table for gallers on Gentiana

(incl. Gentianella, Gentianopsis)

by Hans Roskam

1a Galls on higher situated organs or on rosette leaves => 2

1b Rotund swellings, 2–3 mm long on root collar or stem base. G. campestris, etc.: cf. Smicronyx reichi

2a On higher situated parts or on single organs => 3

2b Leaves clustered, rosette-like. Gentianella amarella: Unidentified gall mite

3a On flowers => 7

3b On vegetative organs => 4

4a On shoot tips, axial parts of shoot or leaves => 5

4b Rotund ± one-sided ± bulging galls, up to 4 mm long, on axial parts of shoots, usually close to a node. On ± severely stunted stems symmetrical barrel- to spindle-shaped galls, up to about 8 (10) mm long. With a large chamber inside which may continue into the pith. Gentianopsis ciliata, Gentianella germanica: Smicronyx reichii

4c Stem, usually in lower half, with broad spindle-shaped one-sided flattened and often strongly deflected swelling, 6–10 mm long, containing the causer in the sharp bend below an arched scale. Gentianopsis ciliata, germanica: Planchonia arabidis

5a Malformations by other causers than aphids => 6

5b Malformations of shoots associated with atrophied flowers and discoloured leaves. Gentiana asclepiadea, cruciata: Aphis gentianae

6a Axial parts stunted and distorted on one side. Inserted leaves deflected and variously curled. Gentiana/ Gentianella spp.: Philaenus spumarius

6b Rarely developing aecia in spring on sometimes slightly bulging, oblong-oval areas on stems, flower peduncles, less so on petioles and leaf veins. Gentiana/ Gentianella spp.: Puccinia gentianae

7a Malformations caused by gall mites => 8

7b Flowers slightly disfigured, unopened. Gentiana pneumonanthe; Gentianella amarella, campestris, germanica: Dasineura gentianae

7c Capsule rarely swollen; containing a weevil larva or pupa. Gentianella amarella, campestris, germanica: Smicronyx reichii

8a Inflorescence transformed into a rosette of small leaves; flowers variously ± greened or leafy, occasionally filled with ± disfigured organs or developing further. Gentiana/ Gentianella spp.: Aculus kerneri and/or Eriophyes gentianae

8b Malformations on flowers with conspicuous wrinkling of calyx and corolla. Gentiana bavarica: Unidentified gall mite

gallers on Erodium

Last modified 8.v.2020

Dichotomous table for gallers on Erodium

by Hans Roskam

1a On parts above ground => 3

1b On roots or on root collar => 2

2a Roots with small nodular or spindle-shaped swellings. E. cicutarium:
Meloidogyne hapla

2b Adventitious buds on root collar circularly developing into ± cauliflower-like galls, up to 20 mm broad, not excessively pubescent. E. cicutarium: Aceria schlechtendali

3a On vegetative organs => 4

3b Flowers swollen, unopened; ovary sometimes slightly disfigured. Containing several orange coloured larvae. E. sanguineum, cicutarium: Dasineura geranii

3c Flower bud disfigured and swollen, perianth hypertrophied, stamens normally developed, staminodes and ovary atrophied. E. chium, ciconium: Aceria erodii

3d Flower swollen, corolla disfigured. E. chium, cicutarium, ciconium, malacoides: Limobius borealis

4a Localised wart- or bulge-shaped galls on vegetative organs => 7

4b Expanded malformations on leaves or several other organs => 5

5a Malformations on basal organs => 6

5b Leaf margins deflected, leaf blades of several leaves curled and bent. E. ciconium, cicutarium, malacoides, moschatum, trichomanifolium: Acyrthosiphon malvae

6a Plant ± stunted. Terminal organs clustered on often distinctly shortened internodes. Leaves almost sessile, lacerate, rolled downwards and bent; flower primordia stunted or variously leafy; inhabited parts often excessively pubescent. E. cicutarium: Aceria schlechtendali

6b Petioles, also lower parts of leaf blade of ± stunted plants, variously swollen, spongy and disfigured. Galls ± wrinkled, also on basal part of stem. E. cicutarium: Ditylenchus dipsaci

7a Indistinctly swollen, ± yellowish, often reddish to crimson margined sori bearing aecia on leaf midrib and leaf blades. E. cicutarium: Puccinia polygoni-amphibii

7b Aecia may occur on leaf midrib in conspicuously swollen bulges. E. cicutarium: Aecidium erodii-cicutarii

7c Less than a mm wide, purplish red, semiglobular warts, mainly on the lower leaves, often in large numbers. E. cicutarium: Synchytrium papillatum

gallers on Bupleurum

Last modified 5.v.2020

Dichotomous table for gallers on Bupleurum

by Hans Roskam

1a On inflorescences or fruits => 5

1b On (terminal) shoots or leaves => 2

2a Galls on stems and shoot tip or distortion of complete shoots => 4

2b Leaves rolled at margin => 3

3a Leaf blade at margin narrowly rolled in; upper side with rotund flat grooves. B. rotundifolium: Unidentified psyllid

3b One or both halves of leaf blade loosely rolled upwards, slightly thickened and brittle; ± discoloured pale-green or violet; the roll contains flat, brown, mainly solitary froth-covered nymphs, white fringed at margins. B. falcatum: Eryngiophaga hungarica and/or Eryngiophaga lautereri

3c Youngest leaves at shoot tip or side shoots rolled in over one another, weakly cartilaginously thickened, pale-green or violet. Gall spindle-shaped, 10–25 mm long, often with its base geniculate, also complete malformation laterally bent outwards. Larvae yellow to orange-red. B. falcatum: Dasineura bupleuri

4a Basal part of stem with broad spindle-shaped, one-sided flattened, curved swelling, contains a froth-covered nymph under an arched scale. B. falcatum: Planchonia arabidis

4b Usually all shoots of plant diseased and pale-green. Shoots already running ahead in early spring, etiolated, often remaining sterile; leaf blades narrowed, at first with many spermogonia on underside, then with abundant aecia. Sori sometimes also occurring on slightly distorted stalks and stems. Bupleurum spp.: Puccinia bupleuri

4c In similar malformations on B. stellatum: Puccinia bupleuri-stellati

5a On bladder-like inflated fruits => 6

5b Centre of (partial) umbel ± swollen, club-shaped; gall sporadically also ± one-sided on stalk of umbel. Contains a red larva. B. falcatum, fruticescens, rigidum, rotundifolium: Lasioptera carophila

6a Inside an orange-red larva. B. falcatum, longifolium, praealtum, ranunculoides: Kiefferia pericarpiicola

6b Several red-yellow, jumping larvae. B. falcatum, longifolium: Parallelodiplosis bupleuri

gallers on Arenaria

Last modified 5.v.2020

Dichotomous table for gallers on Arenaria

(incl. Eremogone)

by Hans Roskam

1a On flowers or fruits => 6

1b On vegetative organs => 2

2a Malformations expanded over ± substantial areas of the shoot => 3

2b On smaller leaves, petioles or sometimes locally bent stems, spots pad-like arched on underside, bearing ± elongated bulges with terminally papilla-like narrowed telia with 2-celled teliospores which fall apart easily and then seemingly 1-celled. Sori on underside of larger leaf blades usually in circular arrangement in discoloured not thickened spots. Sori soon becoming powdery white because of direct germination of the teliospores. A. montana, retusa, serpyllifolia, tenuifolia: Puccinia arenariae

2c Sori usually more expanded. Fungus distinguished by black, terminally rounded, 2-celled telia. A. serpyllifolia: Puccinia hysteriiformis

3a Diseased parts etiolated, with sori of fruiting bodies of fungi => 5

3b Galls caused by animals => 4

4a Stem ± stunted, spongy, swollen; galls at surface ± rugose, pale green. A. serpyllifolia: Ditylenchus dipsaci

4b Leaves rolled downwards at tip of weakly stunted shoots. A. serpyllifolia: Myzus certus

5a Plants usually completely diseased. Shoots developing earlier and rigidly erect leaves pale green, narrowed, with yellow sori on underside. A. serpyllifolia: Melampsorella caryophyllacearum

5b Early infected buds or shoots develop further rigidly erect. Leaves pale green, small, partially spoon-like, arched downwards, with a down of branched conidiophores on underside. A. ciliata, foliosa, serpyllifolia: Peronospora campestris

6a Malformations of fruits => 7

6b Flower buds outwardly hardly changed. Anthers temporarily swollen, soon filled with black-violet spore masses, with dusting later on. A. ciliata: Microbotryum violaceum

6c Flowers ± swollen globularly, unopened. Inner organs soon destroyed and replaced by spore balls consisting of a yellowish-brown powdery dust. A. tenuifolia: Thecaphora saponariae

7a Capsule enlarged on thickened fruit peduncle, oval; contains a beetle larva. A. serpyllifolia: Unidentified snout beetle

7b Capsule outwardly hardly changed. Seed rudiments, also placenta, temporarily swollen, soon filled with red-brown spore masses. A. ciliata, graminea, obtusiflora incl. subsp. ciliaris, serpyllifolia: Microbotryum duriaeanum

gallers on Arabidopsis

Last modified 5.v.2020

Dichotomous table for gallers on Arabidopsis

(incl. Cardaminopsis)

by Hans Roskam

1a On parts above ground => 2

1b Main- and side roots with conspicuous, spindle- to barrel- shaped succulent swellings. Inside with many cell masses with minute spores. A. arenosa, lyrata subsp. petraea, suecica, thaliana: Plasmodiophora brassicae

2a Malformations caused by fungi, with fructifications developing at surface => 6

2b Malformations caused by animals => 3

3a Malformations of flowers or siliques => 8

3b Spindle-shaped or expanded swellings on stems or petioles => 4

3c Large parts or complete plant disfigured. Shoot severely stunted; flower parts severely disfigured, often greened or reddened. Aphid more frequent on Arabis: A. lyrata subsp. petraea, thaliana: Lipaphis rossi

3d Leaf blade stunted, rolled upwards, curved; covered with abnormal pubescence. A. arenosa: Aceria drabae

4a Swellings ± spindle-shaped and glabrous => 5

4b Shoot severely stunted, like the basal parts of lower leaves variously swollen, spongy, pale green. A. thaliana: Ditylenchus dipsaci

5a tem with about 5–7 mm long, 2 mm thick, spindle-shaped swelling. The pith contains a single larva. A. arenosa, suecica, thaliana: Ceutorhynchus atomus and/or C. griseus

5b Rotund, fleshy swelling of the root collar, up to 10 mm; the single gall chamber containing a single legless, curved larva. A. arenosa: Ceutorhynchus assimilis

5c Spindle-shaped gall, 10‒20 mm long, in the leaf stalk (less often in the stem or a thick vein). A. arenosa: Ceutorhynchus chalybaeus

5d Shoot axis or petiole with spindle-shaped, often strongly arched thickening. Side branches of inflorescence ± shortened. A. thaliana: Inducer unidentified – ? lepidopteran

6a Malformations caused by fungi with white fruiting bodies => 7

6b Diseased shoots ± etiolated; internodes ± elongated and narrowed. Leaves often smaller, pale green; leaf blades slightly thickened, on underside over large areas with dense, ± rust brown sori. A. arenosa, halleri, petraea, thaliana: Puccinia thlaspeos

7a Sori densely clustered, bulging, at first closed, glossy, porcelain-like, then rupturing and with mealy dusting; oblong-oval on stems and inflorescence stalks, often arching the stems. On leaf underside rotund, often without malformations. Conidia developing in chains. A. arenosa, halleri, suecica, thaliana: Albugo candida

7b Sori expanded, with loose cover of branched conidiophores. Infected stems pale green, slightly thickened and arched, especially in flowering part; flowers severely stunted. A. thaliana: Hyaloperonospora arabidopsidis

7c Leaves somewhat disfigured with pale spots on the upperside, that correspond with a fungal bloom on the underside, consisting of erect, apically strongly branched conidiophores. A. arenosa, ? halleri, ? petraea: Hyaloperonospora cardaminopsidis

8a Flowers swollen, unopened; containing several pale yellow, jumping larvae. A. arenosa, cebennensis: Contarinia nasturtii

8b Flowers disfigured, ± leafy; abnormally pubescent. A. arenosa: Aceria drabae

8c Siliques slightly disfigured, hardly inflated. Young seed soon filled with yellowish to grey-violet masses of spores. A. petraea: Thecaphora thlaspeos

gallers on Allium

Last modified 5.v.2020

Dichotomous table for gallers on Allium

by Hans Roskam

1a On above-ground parts => 2

1b Roots with small spindle-shaped or nodular swellings, up to 6 mm long. Allium spp.: Meloidogyne hapla

2a Locally restricted to expanded, bulging or non- protruding galls => 3

2b Complete plant stunted and disfigured. Leaves as well as sheaths and stems stunted, spongy thickened, curved and sometimes twisted, ± pale green, with undulately rugose surface. Onions occasionally ± bursting, inner scales more swollen than the outer ones, soon rotting. Many eelworms inside the galls. Allium spp.: Ditylenchus dipsaci

3a Galls distinct from the outside => 4

3b The externally normal leaves of A. senescens show rows of chambers in the locally more compact parenchyma, each containing a single larva. Larvae white to yellow. Unidentified gall midge

4a Bulges of minor or larger expansion, with black spore balls inside; at first lead-grey translucent, then with black spore dust when broken open => 5

4b Flat, 1.5–5 mm broad, brown-red bulges on leaves, scapes and sheaths of inflorescences. A. schoenoprasum: Physoderma allii

4c The plant elongates above the bulb. Cultivated Allium spp.: Peronospora destructor

5a Leaves of young plants, also bulb scales, with one to several stripes, about 10–20 mm long, bulging, bluish-green, later-on with black dusting of smut spores. Allium spp.: Urocystis cepulae

5b Yellow spots on ± disfigured leaves. Allium spp.: Puccinia allii

5c Spermogonia on both sides leaf, orange, often visible between the aecia. Aecia on underside leaf, in loose, often circular clusters on large, irregular, yellow spots; cup-shaped, with a white peridium and an orange mass of spores. Allium spp.: Puccinia sessilis

gallers on Adenostyles

Last modified 5.v.2020

Dichotomous table for gallers on Adenostyles

(incl. Cacalia)

by Hans Roskam

1a On vegetative parts => 2

1b Capitula greatly enlarged, bell-shaped, up to 10 mm long and 4 mm thick; receptacle spongy, swollen. A. alliariae: Unidentified tephritid fly

Galls callus-like, with sori of rust fungi => 4

2b Leaf blades bent and curled => 3

3a Leaf blades over large areas or completely curled. A. alpina: Unidentified aphid

3b Additionally, the bright yellow to yellow-green facultative gall causer, known from many host species. A. alliariae: Brachycaudus helichrysi

3c Leaf blade strongly recurved, strongly curled and dark green close to the froth covered froth-covered nymph. A. alpina: Philaenus spumarius

4a Leaf blade on underside with small, rotund, compact, brownish swellings, covered with 2-celled telia. A. alliariae, alpina, leucophylla: Puccinia expansa

4b Weak, ± extended, usually yellow-bordered, densely covered with aecia cushions or callus on the leaf undersides of A. alliariae, alpina: Uromyces veratri

gallers on Coronilla

Last modified 4.v.2020

Dichotomous table for gallers on Coronilla

(incl. Securigera, see also Hippocrepis)

by Hans Roskam

1a On parts above ground => 3

1b Galls on roots => 2

2a Main- and side roots often with many fleshy nodules, up to about 7 mm long and 4 mm broad, oblong-oval, or at proximal part flattened and ± subdivided, laterally inserted. Coronilla spp.; Securigera spp.: Rhizobium leguminosarum

20b Irregular rotund, little galls on main root with central larval chamber. Each gall contains a single beetle larva. C. scorpioides: Catapion pubescens

3a On stems, buds or fruits => 6

3b On leaves => 4

4a Leaf blade folded or rolled inwards, caused by animals => 5

4b Internodes of completely diseased young shoots elongated; petioles and midrib ± thickened; leaf blades reduced, thickened, soon covered with grey-violet down of branched conidiophores on underside, Coronilla coronata, repanda subsp. dura, scorpioides; Securigera varia: Peronospora coronillae

5a Leaflets folded pod-like on midrib, the middle part especially strongly thickened. Securigera varia: Unidentified gall midge

5b Pale, indistinct pod-like folds of leaf blades of Securigera varia: Unidentified thrips

5c Leaflets twisted, folded, rolled inwards at margin. Coronilla coronata, Securigera varia: Aculus coronillae

5d Malformation of leaves and/ or inflorescences, flowers. Coronilla valentina subsp. glauca + pentaphylla: Hemitrichapion andalusicum

6a Midge galls in axillary buds or in pods => 7

6b Basal stem parts with ± expanded, often curved, bulging swellings, with single- or several rimmed depressions. Coronilla spp.; Securigera spp.: Planchonia arabidis

7a Pods disfigured => 10

7b Malformation of vegetative tissues => 8

8a Gall cavity absent, or if present, not covered with mycelium => 9

8b Gall cavity lined with mycelium. Leaf axil with bud-like gall, mainly arising from the fleshy thickened lower part of petiole and enlarged stipules. Inner wall with mycelium. Containing a single larva. Coronilla minima: Asphondylia coronillae

9a Irregular clusters consisting of hypertrophied leaflets, terminally on stem, rotund or egg-shaped, of variable size (averaging 8–9 x 7–8 mm), succulent, green- or pink-coloured. Containing several red, dull midge larvae. Coronilla juncea, valentina subsp. glauca: Dasineura coronillae

9b Leaflets pod-like swollen. Larvae glossy and jumping. Securigera varia: Contarinia coronillae

10a Pod with rotund to egg-shaped swelling. Inner wall with mycelium. Containing a single larva. Coronilla coronata, minima; Securigera varia: Asphondylia baudysi

10b Locally ± globularly swollen pods. Coronilla minima: Asphondylia coronillae

gallers on Spinacia

Last modified 4.v.2020

Dichotomous table for gallers on Spinacia

by Hans Roskam

1a On leaves and stems => 2

1b Roots with slender spindle-shaped or cylindrical galls, up to about 4 mm long, bearing several side roots. S. oleracea: Meloidogyne hapla

1c Malformations known from many hosts as “leafy galls” on young spinach plants of S. oleracea, are caused by the widely distributed bacterium Rhodococcus fascians

2a Malformations caused by aphids or spittlebugs => 4

2b Malformations caused by eelworms or fungi => 3

3a Main venation as well as petioles spongy swollen; galls pale-green, ± largely encroaching into locally similarly disfigured and lacerate leaf blade. S. oleracea: Ditylenchus dipsaci

3b Developing leaves ± stunted; with yellowish-green, hunch-backed swellings and loose rolling of leaf margin. Diseased parts thickened, ± yellow-green, brittle; covered on underside with a dense, violet-grey down of branched conidiophores. S. oleracea: Peronospora farinosa

4a Malformations bearing aphids => 5

4b Malformation with conspicuous localised stunting and bending of midrib; leaf blade close to infestation deeper green; undulately lacerate and hunch-backed curled. S. oleracea: Philaenus spumarius

5a Aphids without conspicuous wax secretion => 6

5b Aphid with white-grey wax secretion. Leaf blades mainly with local, ± discoloured folds close to tip or margin, containing aphids. S. oleracea: Hayhurstia atriplicis

6a Aphid about 2.5 mm long, dull black. S. oleracea: Aphis fabae

6b Aphid 1–1.5 mm long, yellow or light- to yellow-green. S. oleracea: Aphis nasturtii

gallers on Serratula

Last modified 3.v.2020

Dichotomous table for gallers on Serratula

(inc. Klasea)

by Hans Roskam

1a Galls on stems and leaves => 2

1b Receptacle hardened, partially deformed into a bulging, tough-walled, short, conical to egg-shaped gall. One larva per chamber. S. tinctoria: Trupanea stellata and/or Urophora spoliata

1c Galls located at the base of the flower head, unilocular, ovate, thin-walled, up to 1.5 mm in length; usually the flower head is not malformed and enlarged, galls inconspicuous externally Klasea radiata, Serratula coronata: Aulacidea serratulae

1d Galls in flower heads. Klasea erucifolia, lycopifolia, nudicaulis, radiata:
Isocolus serratulae

1e Galls in flower heads, without symptoms of external deformation. Serratula spp.: Phanacis eugeniae

2a Galls in the shoot tips => 7

2b Leaves with localised or expanded malformations, which may extend into the stems => 3

3a Wart-shaped rotund or spindle-shaped swellings caused by fungi => 5

3b Expanded, glabrous or pubescent malformations caused by animal inducers => 4

4a Leaves curved at the tip, leaf blade curled, the margin ± curved downwards. Sometimes on several similarly malformed leaves terminally clustered on ± shortened internodes. S. tinctoria: Philaenus spumarius

4b More or less conspicuously stunted leaves with curved, curled or bulge-like swollen leaf blades; leaf tips often rolled. Rolls either glabrous or, like the leaf blades, with spotted, striped white or reddish erinea. S. tinctoria: Aculus rigidus

4c Conspicuous spindle-shaped galls, about 8 x 3 mm long, on petioles, also on midribs, to a lesser extent on lateral veins of the leaf blade of S. tinctorial: Loewiola serratulae

4d Lignified but relatively soft stem deformation, differently shaped, which depends on the number of larval chambers. Klasea erucifolia: Aulacidea ascanica

5a Malformations with fruiting fungal sori on the surface => 6

5b Galls hardly 1 mm long, multicellular, wart-shaped, ± golden yellow translucent; many on the underside of basal leaves. S. tinctoria: Synchytrium aureum

6a Leaf blade with rotund spindle-shaped swellings, up to 8 mm long, on the venation, usually conspicuous yellow or red margined, on the underside sometimes weakly arched, with cylindrical cup-shaped aecia occupied sori. S. coronate, tinctoria: Puccinia schroeteriana

6b Slightly bulging swellings on the midribs, less often on the lateral veins; occupied by bright brown uredinia. S. coronata, tinctorial: Puccinia hieracii

6c In SE-, C-Eu; with similar biology on Klasea bulgarica, lycopifolia, radiata; Serratula coronata, tinctoria: Puccinia schirajewski

7a Galls at the shoot tips => 8

7b Shoot terminally with spindle-shaped swelling. In the pith is a single caterpillar. S. tinctoria: Eucosma albidulana

8a Leaves on the shoot tip transformed into an erect, up to 15 mm long, cone-shaped pale gall. Several red larvae. S. tinctoria: Unidentified gall midge

8b More or less rosette- or sometimes almost bud-shaped clustering of leaves on stunted shoot tips. Infected organs often with conspicuously white or reddish pubescence. S. tinctoria: Aculus rigidus

gallers on Phaseolus

Last modified 3.v.2020

Dichotomous table for gallers on Phaseolus

by Hans Roskam

1a On roots or root collar => 4

1b On stems or leaves => 2

2a On leaf blade or -stalk => 3

2b Stem with spongy, pale green swelling; leaves stunted and ± curled. P. vulgaris: Ditylenchus dipsaci

3a Leaves loosely deflected at margin, slightly discoloured and curled, caused by black aphids. P. vulgaris: Aphis fabae

3b Minor hypertrophies on leaf axis, occasionally also slight arching of infected, usually pale green parts of leaf blade. Caused by a mycelium developing spermogonia and aecia. P. acutifolius, coccineus, vulgaris: Uromyces appendiculatus

4a Malformations on root => 5

4b Compact, succulent, mainly one-sided proliferations on root collar. “Root cancer*. P. vulgaris: Agrobacterium tumefaciens

5a Roots with distinctly protruding galls => 6

5b Roots not changed from the outside; inside with giant cells; temporarily bearing ± lemon-shaped lighter to darker egg capsules. Phaseolus vulgaris: Heterodera sp.

6a Nodular swellings, often occupying all sides of the complete root body, bearing several side roots. Phaseolus vulgaris: Meloidogyne hapla

6b Globular or egg-shaped nodules, up to about 5 mm long, inserted laterally, usually many and occasionally clustered. Phaseolus vulgaris: Rhizobium phaseoli

gallers on Melilotus

Last modified 3.v.2020

Dichotomous table for gallers on Melilotus

by Hans Roskam

1a On above ground parts => 3

1b On roots => 2

2a Nodular or spindle-shaped swellings. M. officinalis: Meloidogyne hapla

2b Globular or up to 8 mm long, cylindrical, forked or coral-like branched nodules. Melilotus spp.: Sinorhizobium meliloti

3a On inflorescences, flowers or fruits => 9

3b On vegetative organs => 4

4a On shoot axis or leaves of fully developed plants => 5

4b Young plants considerably stunted. Stems shortened, spongy, thickened. Leaves clustered, occasionally the axial parts swollen, leaf blades distorted. Melilotus spp.: Ditylenchus dipsaci

5a On shoot axis => 7

5b On leaves => 6

6a Leaflets folded upwards, halves at base ± adnate and swollen, together with midrib, into a globular or oblong gall, up to 6 mm long, protruding on underside. Containing a yellowish beetle larva. M. albus, altissimus, dentatus, officinalis: Tychius crassirostris

6b Weaker swelling of midrib of leaflet. Containing a single larva. M. albus, altissimus, officinalis: Tychius meliloti

7a Inducer inside the gall => 8

7b Acuminate-rotund- to oblong oval, often snapped off, or ± bent, expanded bulging swellings of stem, containing in rimmed depressions the inducer. M. dentatus, officinalis: Planchonia arabidis

8a Rotund to spindle-shaped swelling, 5–15 mm long. The pith containing a maggot. M. albus, dentatus, officinalis: Melanagromyza submetallescens

8b Weak swelling, inside a compact pith containing several white larvae. M. albus: Unidentified dipteran

9a All flowers of a plant occasionally disfigured and ± pubescent. Calyx hardly disfigured, corolla and anthers often reduced, ovary developing into a short, leafy cone, transformed together with the axils of stipules, developing shoots into a ± dense leafy inflorescence. M. albus, altissimus, dentatus, officinalis: Unidentified gall mite

9b Flower buds swollen, unopened. M. altissimus, officinalis: Contarinia sp.

9c Flowers strongly greened; beetle larva living inside stem just below inflorescence. M. albus, altissimus, dentatus, officinalis: Stenopterapion meliloti

9d Beetle larvae feed within the pod on the developing seed; this may cause some galling of the pods. M. albus, ? altissimus, officinalis: Tychius breviusculus

gallers on Lythrum

Last modified 2.v.2020

Dichotomous table for gallers on Lythrum

(incl. Peplis)

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular, compact swellings. L. salicaria: Meloidogyne hapla

1c Swelling in root; containing a chamber with a weevil larva. L. salicaria: Hylobius transversovittatus

2a Malformations on various vegetative as well as generative parts => 5

2b Globular to spindle-shaped galls on shoot axis => 3

3a Galls caused by weevils. In the gall a legless, curved weevil larva => 4

3b Weak, oblong swellings close to shoot tip. L. salicaria: Unidentified gall midge

4a Long spindle-shaped or rotund swelling, usually one-sided, succulent, one- or more-chambered on lower parts of shoot axis. Apically organs sometimes severely stunted. L. hyssopifolia, ? salicaria: Nanomimus hemisphaericus

4b In similar one- or more-chambered galls. L. hyssopifolia, salicaria: Nanomimus circumscriptus

4c Side shoots with a swelling, up to 8 mm long, rotund-oval, one-chambered. Containing a single larva. L. portula: Dieckmanniellus gracilis

4d Slender spindle-shaped stem galls, 12–18 mm long, usually at leaf insertions of several L. hyssopifolia, junceum, salicaria: Dieckmanniellus nitidulus and/or D. helveticus

4e Small conspicuous swelling of stem, laterally protruding, variously expanded. L. acutangulum, hyssopifolia, salicaria: Nanophyes globiformis

4f Inconspicuous swelling of the stem. L. salicaria: Nanophyes rubricus

5a Malformations mainly involve unfolded leaves => 6

5b Lateral buds or tips of vegetative shoots disfigured. All leaves of infected axillary buds severely stunted, adnate at base, developing into a gall up to 6 mm long, ± reddened with free terminating apex over differing length. Infestation of shoot tip results in stunting of axial parts with tuft-like clustering of basally largely stunted leaves. Infected flower buds swollen at base; calyx hardened. Stunting of all other parts; usually unopened. Depending on gall size a single or several orange-yellow larvae. L. salicaria: Bayeriola salicariae

6a Malformations caused by aphids or spittlebugs => 7

6b Petioles swollen over a length of about 10 (15) mm, slender pear-shaped. Galls succulent, one-chambered. Leaf blades severely stunted. Containing a single larva. L. hyssopifolia, salicaria: Nanomimus circumscriptus

6c Minor swellings of leaf. L. portula: Chlorochytrium rubrum

7a Malformations caused by aphids => 8

7b Leaf blade deflected, curled, locally deep green; infestation close to shoot tip results in one-sided stunting and distortion of axial parts, associated with clustering of similarly disfigured leaves. L. salicaria: Philaenus spumarius

8a Clustering of disfigured leaves or also failed flowers on ± stunted shoot tips caused by aphids, about 2 mm long, pale to yellowish-green. L. hyssopifolia, salicaria, virgatum: Myzus lythri

b8 Clustering of ± stunted, deflected and curled leaves on less stunted shoot tips or similar malformations on several lower situated leaves caused by black aphids. L. salicaria: Aphis fabae

gallers on Teucrium

Last modified 2.v.2020

Dichotomous table for gallers on Teucrium

by Hans Roskam

1a Flower galls => 17

1b On stems, shoot tips, buds or leaves => 2

= Root galls of Meloidogyne hapla are known from Teucrium

2a Localised or expanded galls restricted to the leaf blades of single or several leaves => 13

2b On shoot tips, terminal leaves, buds or stems => 3

3a On buds or on tips, terminally on shoots => 8

3b On stems, partially encroaching into lateral leaves and buds => 4

4a The causers live, and/or fruit inside the galls => 7

4b The animal causers live on the outside of the galls or fungi develop their fruiting bodies on the outside => 5

5a Malformations expanded, slender and elongate, of irregular shape, large parts covered with dark-brown telia at maturity => 6

5b Mainly basal part of stem with spindle-shaped to irregularly bulging, often distorted swellings which contain in a single or several rimmed depressions single froth-covered nymphs. Teucrium spp.: Planchonia arabidis

6a The ± dusty, black-brown sori develop on stems, sometimes also on petioles, as well as on leaf undersides, ± disfiguring the organs. T. montanum, orientale: Puccinia constricta

6b Sori similar, black. Gall-like malformations facultative, rare, of variable shape. Diseased shoots sometimes with extensive sori, occasionally distorted and curved, sometimes almost witches’ broom-like disfigurations, usually sterile. Teucrium spp.: Puccinia polii

7a Irregular, compact swellings or proliferations on root collar or stem base on one side or enveloping the stem. Black spore masses develop inside the galls. T. montanum: Melanotaenium jaapii

7b Only a few swellings, ± irregular spindle-shaped or nodule-like, up to 10 mm long. Shoot necrotic above gall. Containing single to many larvae. T. fruticans, scorodonia: Thamnurgus kaltenbachii

8a On shoot tips or lateral buds => 12

8b On several leaves terminally, usually on only slightly stunted shoots => 9

9a Malformations caused by gall mites => 11

9b Malformations caused by aphids or spittlebugs => 10

10a Leaves on shortened shoot tips clustered into loose, almost cone-like galls. Teucrium spp.: Aphis teucrii

10b Stem terminally ± distorted and curved over ± 3 internodes, leaves inserted nest-like, converging, curled, locally dark-green. T. scordium, scorodonia: Philaenus spumarius

11a Plants usually excessively branched. Leaves disfigured. T. montanum: Unidentified gall mite

11b Leaves and stem on sometimes shortened tip of vegetative shoots with densely felt-like pubescence. T. scorodonia: Unidentified gall mite

12a Buds on main- and side shoots compact. Outside leaves almost normal, arranged artichoke-like, the inside ones bear single to several orange-red larvae. T. capitatum & subsp. lusitanicum, chamaedrys, salviastrum, scorodonia: Dasineura teucrii

12b Leaves clustered terminally on ± stunted shoots, thickened, disfigured, forming densely pubescent tufts. T. scorodonia: Unidentified gall midge

13a Leaves often with yellowish bulges in the leaf blades, rotund, protruding on underside; on venation or stalks ± spindle-shaped to oblong-oval, soon covered with sori densely covered with brownish telia => 16

13b Malformations without externally protruding sori of fungus => 14

14a Galls a few mm across, pustule- or wart- shaped or ± oblong-oval => 15

14b Leaf blade twisted and curled. Containing many larvae. T. chamaedrys: Unidentified gall midge

15a Leaf blades, especially of the middle and upper stem leaves, with many uneven bulges, protruding at upperside, often situated along the margins; pale yellow on upperside, sometimes ± strongly pubescent; open on underside, inside with emergentia or strong abnormal pubescence T. capitatum subsp. gracillimum, chamaedrys, murcicum, scordium: Aculus teucrii

15b Leaf blades of basal leaves with many swellings, mainly protruding on underside, 1–3 mm long, at first yellowish-green, later on almost black-brown, ± pock-like. Sometimes joined into dense groups on the ± curved veins or stalks; more rarely in the bark of lower stem parts. T. scorodonia: Physoderma vagans

16a Sori with grey-brown spores, often many; arched on the underside of leaves; on upperside often ± depressed; occasionally causing distortions of axial parts of younger leaves. More rarely but then similarly on stems. T. botrys, chamaedrys, pyrenacium: Puccinia chamaedryos

16b Similar pads or bulges, causing conspicuous distortions on axial parts. Teucrium spp.: Puccinia annularis

17a Malformations of flowers caused by gall midge larvae => 19

17b Galls caused by lacebugs => 18

18a Corolla weakly thickened, especially upper part slightly enlarged, unopened, stamens and sometimes pistil weakly swollen. T. canum, chamaedrys, polium, scorodonia: Copium clavicorne

18b Flower swollen up to two or three times the normal size. Corolla strongly swollen, especially at base. Calyx disfigured, lacerated, ± thickened, yellowish. Stamens and pistil ± stunted. Gland hairs abnormally enlarged. T. capitatum & subsp. gracillimum, gnaphalodes, montanum, polium: Copium teucrii

19a Galls on T. scordium or scorodonia => 20

19b On T. montanum. Flower disfigured. Corolla inflated, bladder-like. Unidentified gall midge

20a On T. scordium. Flower swollen, unopened. Containing a single larva.
Unidentified gall midge

2b On T. scorodonia. Flowers clustered, enlarged, unopened. Ovary almost capsule-like, stalked, enlarged, pubescent. Pistil shortened. Unidentified gall midge

gallers on Larix

Last modified 2.v.2020

Dichotomous table for gallers on Larix

by Hans Roskam

1a On tips of main and side shoots, on male flower buds or on needles => 5

1b On stem parts, branches or twigs => 2

1c Orange-red larvae develop in cones of L. decidua, x polonica: Resseliella skuhravyorum

2a On older stem parts or on thicker branches => 4

2b On thinner twigs => 3

3a Oblong or often nodule-shaped, cherry- to hazelnut-size swelling on younger stems or twigs, often at the base of a branching and ± covered with a grey resin blister. L. decidua: Cydia zebeana

3b Elongate resinous swelling about twice stem width at its widest; soft and spongy, becoming hard and woody after adult emerges in May, June. Containing caterpillar for 22 months from June onwards, pupa April, May second year. L. decidua: Cydia millenniana

3c Bark of twigs with small swellings, pubescent inside. L. decidua: Trisetacus laricis

4a Long club-shaped swelling on stems and branches, bearing a bush of mistletoe. L. kaempferi: Viscum album

4b Scurfy, cracked, ± dark coloured, 15–40 cm long patches of bark ± deeply depressed, rimmed at margin with resin reacting with cancers on at first sometimes swollen parts of branches, occasionally also on the stems. Infections starting from 2–4 year old branches. L. decidua: Lachnellula willkommii

5a On the tips or short- and long shoots, also on male flower bud => 7

5b Needles slightly thickened, discoloured, almost bent over at right angles; an aphid present at the bending point => 6

6a Aphid dark brown to black, naked or covered with wax flakes. L. decidua, x eurolepis, gmelinii, kaempferi, laricina, lyallii, sibirica: Adelges laricis

6b Aphid yellow-green to dark green, without wax cover, only slightly frosted. L. decidua, x eurolepis, kaempferi, sibirica: Sacchiphantes viridis

6c To the same species group belongs the anholocyclic (only asexual females known), only on Larix spp. living: Sacchiphantes segregis

7a Tips of previous year’s short shoots swollen ± hemispherically. Galls up to pea-size, also the male flower buds occasionally transformed to similar, more or less egg-shaped, usually larger galls. Galls to August with brown scales, covered later on at first with bright fluid, then white crumbly resin, driving neighbouring needles widely apart, star-like. Containing a single brick-red larva in the upper part of the gall. L. decidua, occidentalis: Dasineura kellneri

7b Similar, globular to oblong-egg-shaped brown galls; often also on terminal buds of long shoots; in contrast with the previous midge galls, which may also be present, always dry, lacking a resin cover. L. decidua: Trisetacus laricis

gallers on Thalictrum

Last modified 1.v.2020

Dichotomous table for gallers on Thalictrum

by Hans Roskam

1a On plant parts above ground => 2

1b Roots with slender spindle-shaped swellings, up to 5 mm long. T. aquilegiifolium, simplex: Meloidogyne hapla

2a On inflorescences, flowers or fruits => 17

2b On stems, shoots and leaves => 3

3a Malformations mainly on stem, or usually involving many severely stunted leaves, clustered at shoot tips, or extending over many leaflets of largely disfigured leaves => 12

3b Galls mostly on unfolded leaves; locally restricted, usually wart- or spindle-shaped. Caused by fungi => 4

4a Galls several mm long, in the leaf blades ± rotund, protruding on underside; on leaf veins, -midrib, -stalk, or flower parts spindle-shaped to oblong-oval. Bulges with sori of black telia or with densely positioned, yellowish aecia => 5

4b Galls wart-shaped, multi-cellular, up to 1 mm long, golden-yellow; single or ± coalescing, usually on underside of basal leaves, also on axis, stalks and basal stem parts. T. alpinum, flavum, lucidum, simplex, squarrosum: Synchytrium aureum

5a Bulges on leaves usually downwardly arched and predominantly only there bearing aecia; on upper side usually ± depressed, partially bearing spermogonia, often ± crimson to violet-red margined => 6

5b Sori on leaf underside, also on stem; of variable size, often conspicuous, slightly arched, black, weakly glossy, compact. T. alpinum: Puccinia rhytismoides

6a Aecia densely positioned, in smaller or larger groups on underside of ± arched bulges. Several, especially biologically different rust fungi, alternating on grasses, indistinguishable by their galls and usually also by the microscopic morphology of their aecia => 8

6b Aecia positioned loosely => 7

7a Aecia positioned on expanded, thickened, often dark violet discoloured spots, usually on both sides. Peridium usually with deflected border. Spermogonia develop rarely. T. alpinum: Puccinia septentrionalis

= On same host, with similar distribution, alternating on Agrostis, the rust fungus Puccinia recondita develops only in low number (8–12) in dense groups on underside leaf; aecia occur on discoloured, not noticeably thickened spots.

7b Aecia on often yellow-brown discoloured, hardly swollen leaf spots, protruding on underside, associated with honey-coloured spermogonia, developing on both sides. Peridium cup-shaped, with deflected, lacerate border. T. foetidum: Puccinia thalictri-koeleriae

8a Frequent fungi with aecia on several Thalictrum species => 11

8b More locally recorded fungi, which develop aecia on only a few species => 9

9a Aecia with several Thalictrum species as main host => 10

9b Aecia on T. foetidum as main host; in rounded groups on leaf underside, also occurring on fruits and in elongated patches on disfigured leaf midrib, -stalk and stem. Peridium cup-shaped or ± cylindrical, with lacerate white border: Puccinia thalictri-distichophylli

10a Aecia with cup-shaped or funnel- to tube-shaped peridium, at maturity with deflected, ± frayed border. T. aquilegiifolium, foetidum, minus: Puccinia poae-nemoralis

10b Aecia not further described, on T. aquilegiifolium, minus: Puccinia elymi

11a Aecia in smaller or larger groups on slightly thickened spots, often violet-brown on upperside, on underside yellowish and usually brown-bordered. Peridium cup-shaped, with deflected, frayed border. Thalictrum spp.: Puccinia alternans

11b Aecia and the often conspicuous spermogonia, positioned in a circle, usually developing on upperside on often distinctly swollen pads. Peridium whitish or yellowish with deflected, irregularly serrate or slightly fringed border. T. flavum, minus, simplex: Puccinia recondita species complex

12a Differently furnished malformations caused by animal parasites => 14

12b Malformations bearing early brown sori or exhibiting at first ± lead-grey bulges, with dusting of black spores later on => 13

13a Lead-grey swollen bulges, occurring on the often largely stunted leaf blades especially on venation protruding on both sides, often also on the ± bent leaf-midrib, -stalk, on stems and even flower parts. At first closed, later on erupting and with black dusting. Thalictrum spp.: Urocystis sorosporioides

13b Mycelium perennial, the developing host organs changing considerably. Shoots with lanky, elongated internodes, developing faster than normal ones. Leaf axis squat, leaf blade narrower and pale, diseased parts bearing many dark-brown telia. Thalictrum spp.: Tranzschelia anemones

14a Mainly curling or slightly swollen malformations of ± stunted leaves => 15

14b Leaflets curled, margin folded upwards, forming a subglobular gall of variable size. Containing several reddish larvae. T. speciosissimum: Dasineura bragancae

15a Malformations not conspicuously pubescent => 16

15b Up to 10 mm long, bud-like clustering of markedly stunted, ± whitish haired leaves on tips of main- and side shoots or in stunted axillary buds on the longitudinal growth. Larvae glossy red. T. aquilegiifolium, flavum, minus, simplex: Jaapiella thalictri

16a Malformations of terminal leaves and possibly of neighbouring inflorescences caused by midges or aphids => 17

16b Leaf blades of usually basal leaves on the ± stunted midrib converging. Leaflets shortened, mostly spoon-like, converging, thickened, strongly rugose and curled. T. flexuosum, minus: Phyllocoptes jaapi

16c A few internodes of apical part of stem stunted, bent when infestation is one-sided. Leaves and sometimes stem of the similarly stunted and disfigured inflorescence variously clustered. Leaf blades ± converging, curved and curled, dark green close to infestation site. Thalictrum spp.: Philaenus spumarius

17a On inflorescences or single flowers => 18

17b Fruit distinctly swollen, globular or acuminated, egg-shaped, up to 5 mm long, seeds absent; wall succulent, thickened; gall in dry condition ribbed. Containing one or two yellow larvae. T. aquilegiifolium, flavum, lucidum, minus incl. subsp . majus, simplex, speciosissimum: Ametrodiplosis thalictricola

18a Malformation of inflorescence or galls on single or clustered flowers; caused by animal inducers => 19

18b Expanded or localised malformations in the axis of the panicle, flower peduncles or perianth leaves caused by fungi => 5

19a Single flowers globularly swollen, stamens and especially anthers little developed; sometimes on shortened stalks and axis of panicle with several clustered in the otherwise normally flowering or already fruiting inflorescences. Larvae glossy red. T. aquilegiifolium, flavum, minus, simplex: Jaapiella thalictri

19b Inflorescence markedly stunted, densely occupied by disfigured, ± greened flowers. T. aquilegiifolium, alpinum, delavayi, flavum, lucidum, minus: Aphis thalictri

gallers on Thlaspi

Last modified 1.v.2020

Dichotomous table for gallers on Thlaspi

by Hans Roskam

1a On parts above ground => 4

1b On root collar or on roots => 2

2a On roots => 3

2b Rotund swellings on root collar, up to 6 mm long one-chambered. Containing a single larva. T. arvense, Noccaea perfoliata: Ceutorhynchus assimilis

2c Rotund root collar galls, 3–5 mm long. Noccaea perfoliata: Ceutorhynchus carinatus

3a Conspicuous, spindle-shaped or cylindrical thick-succulent compact galls, often more than 10 mm long, on main- and side roots, often in smaller sizes on secondary roots. “Clubroot”. Thlaspi spp.: Plasmodiophora brassicae

3b Roots often with many slender, 2–4 mm long cylindrical swellings, provided with several lateral roots. T. arvense, Noccaea brachypetala: Meloidogyne hapla

= Cyst eelworms, both Heterodera cruciferae and H. schachtii have been reported from T. arvense

4a Malformations of indefinite shape extending over several organs or localised to extensive malformations caused by fungi fruiting at surface, sori of which usually occur simultaneously on several organs => 8

4b Locally definite galls of rather similar shape on single organs => 5

5a On inflorescences, flowers or fruits => 17

5b On stems or leaves => 6

6a Galls conspicuous, spindle-shaped or globular => 7

6b Galls wart-shaped, less than 1 mm across, usually many on the underside of basal leaves. Sometimes ± coalesced crust-like; also on petioles and basal parts of young stems. T. rotundifolium: Synchytrium infestans

7a Galls ± globular to acuminated, spindle-shaped, about 5–6 mm long. Containing a single larva. Noccaea perfoliata: Ceutorhynchus carinatus

7b Spindle-shaped glabrous galls, about 20–25 (35) mm long, usually on all sides of stems, sometimes almost node-like, on petioles or midrib ± flattened; especially on leaves also deep green inside; partially with rather long tunneled channels. Containing a single larva. T. arvense, Noccaea brachypetala, perfoliata: Ceutorhynchus chalybaeus

8a On the malformations develop white or brown fruiting bodies of fungi => 14

8b Malformations caused by animals => 9

9a The animals develop outside on the galls, partially distinctly visible, partially hidden by the malformation => 10

9b Young plants largely stunted. Hypocotyls, petiole, and leaf blade base shortened, pale green, spongy. Neighbouring shoots severely stunted and thickened. Later infected stems are swollen over different lengths on one- or all sides, shortened, occasionally bent. Galls at surface undulately wrinkled, ± necrotic, with many eelworms inside. Thlaspi spp.: Ditylenchus dipsaci

10a Malformations caused by aphids or spittlebugs => 12

10b Malformations caused by larvae of gall midges => 11

11a Leaves terminally or laterally on stunted shoots, also in axillary buds ± tuft-like clustered, stunted, thickened at base and discoloured. Primordia of inflorescence are included in the gall, or display densely clustered, severely disfigured buds. Between the organs develop whitish or yellowish-white, jumping larvae. T. arvense: Contarinia nasturtii

11b Shoot tip disfigured. T. montanum: Unidentified gall midge

12a Malformations caused by aphids => 13

12b Young stems stunted and bent over a few internodes. Inserted leaves stunted, ± nest-like converging, undulately curled, locally dark green. T. arvense, Noccaea brachypetala: Philaenus spumarius

13a Tips of vegetative or generative shoots stunted; organs clustered, severely stunted. Aphid 1.5–2 mm long, grey-green to grey-yellow, siphunculi yellow, twice as long as the oblong yellow-green cauda. T. arvense: Lipaphis erysimi

13b Similar malformations, mainly restricted to the tips of shoots or inflorescences on severely disfigured leaves and flower buds, and on fruits and younger parts. Aphid 2–2.5 mm long, yellow-green, with 2 longitudinal rows of small black cross stripes; densely grey powdered; siphunculi short, swollen, brownish-black, about as long as the oblong, dark-green cauda. T. arvense: Brevicoryne brassicae

14a Sori white; infestation very variable, often without distinct malformations => 15

14b Mycelium disfigures the infected shoots completely or in the terminal parts, which bear smaller, thickened, paler leaves and which usually remain sterile. Exceptionally developing flowers are largely disfigured and ± greened. On expanded parts mainly of the leaf undersides develop many punctiform sori with rust- to dark-brown telia. T. alliaceum, arvense, “bulbosum”; Noccaea spp.: Puccinia thlaspeos

15a The sori protruding from the malformations consist of branched conidiophores => 16

15b Sori consist of dense pads, at first closed, glossy, porcelain-like, later on rupturing and with mealy dusting, usually with several, which are rotund on leaf blade underside, ± oblong oval to spindle-shaped and occasionally bent on leaf veins, – stalks and stem parts. T. arvense; Noccaea caerulescens, perfoliata: Albugo candida

16a Infected stem parts pale green, hypertrophied and ± distorted; sometimes slightly swollen during the development of infected leaves. On infected axial parts inserted organs, especially flower buds, severely stunted; diseased siliques usually crippled, occasionally enlarged and swollen. T. arvense: Hyaloperonospora thlaspeos-arvensis

16b On Noccaea brachypetala, caerulescens, causing similar damage: Peronospora thlaspeos-alpestris

16c Similar malformations on Noccaea perfoliata: Hyaloperonospora thlaspeos-perfoliati

17a Galls on single or several flowers or fruits => 18

17b Internodes of inflorescence distinctly shortened. Buds, flowers or young siliques clustered. Flowers partially ± greened. T. arvense: Thrips tabaci

18a Malformations usually inconspicuous, without involvement of other organs, on older ovaries or fruits => 20

18b Flower galls => 19

19a Already largely developed, single or sometimes clustered flower buds strongly swollen, almost globular. Larvae inside the organs or also between densely clustered flower buds; white to pale yellow, jumping. T. arvense; Noccaea brachypetala, caerulescens: Contarinia nasturtii

19b Calyx of opened flowers strongly hypertrophied. Corolla and the broadened stamens ± greened. Ovary severely disfigured, narrowed and elongate. Locally oblong-oval white sori on the diseased organs. T. arvense; Noccaea caerulescens, perfoliata: Albugo candida

20a In largely developed shoots, not or only slightly swollen, develop ivory white to lemon yellow coloured, jumping midge larvae. T. arvense: Contarinia thlaspeos

20b In the seed primordia of hardly disfigured fruits develop yellow-brown to grey-violet spore masses. Noccaea brachypetala, caerulescens, crantzii: Thecaphora thlaspeos

gallers on Convolvulus

Last modified 1.v.2020

Dichotomous table for gallers on Convolvulus

(incl. Calystegia)

by Hans Roskam

1a On parts above ground => 2

1b Roots with small nodular to spindle-shaped swellings. Convolvulus sp.:
Meloidogyne hapla

2a On shoots and leaves => 3

2b vary, and also capsules, in usually conspicuously smaller flowers hardly changed; sometimes remarkably narrowed in apical part; anthers almost always sessile, swollen, at first like the nectar ring temporarily bearing whitish to yellowish sori containing conidia. Spores in balls, pale brown-red; mainly in several or all, at first slightly swollen, later on aborted seed primordia. Convolvulus arvensis, Calystegia sepium, soldanella: Thecaphora seminis-convolvuli

3a Malformations caused by aphids, psyllids or spittlebugs => 7

3b Malformations caused by different inducers => 4

4a Galls caused by parasitic animals => 5

4b Usually aecia arranged in a circle on the underside of undisfigured leaves. Sori on veins, stalks and axial shoot parts sometimes slightly swollen. Convolvulus spp.; Calystegia spp.: Puccinia convolvuli

4c Stems with a white cover, at first shiny, later powdery. Parts of the plant may become disfigured. C. pentapetaloides, siculus, tricolor: Albugo convolvulacearum

5a Malformation of many terminal leaves => 6

5b Shoots or petioles with ± expanded swellings on all- or one-side, pale green, spongy, on surface ± wrinkled. Leaves ± distorted. Convolvulus arvensis: Ditylenchus dipsaci

6a Terminal shoots or plant completely and severely stunted, axial parts shortened; leaf blades folded upwards, variously curved and rolled loosely, swollen, yellowish or crimson discoloured, abnormally, ± densely pubescent. Convolvulus althaeoides, arvensis, cantabrica, thunbergii: Aceria convolvuli

6b Similar, but glabrous malformations usually without distinct stunting of shoots, on loosely arranged, ± erectly folded and sickle-shaped disfigured leaves. Convolvulus arvensis: Aculus convolvuli and or Aceria malherbae, the latter also on Calystegia sepium

7a Malformations of often numerous leaves on shoots. Caused by aphids => 8

7b Leaves on the distinctly shortened terminal internodes clustered and stunted, with several converging ± nest-like; leaf blades partially distorted and deep green. Contain a froth-covered nymph. Convolvulus arvensis, Calystegia sepium: Philaenus spumarius

7c Pustule, 2 mm across, protruding on both sides of leaf blade, with exit hole on leaf underside, surrounded by white hairs. Convolvulus canariensis: Unidentified psyllid

8a Leaves folded, partially rolled, ± curled; contain black aphid. Convolvulus arvensis, Calystegia sepium: Aphis fabae

8b Leaves curled, curved downwards. Aphid green. Convolvulus arvensis, Calystegia sepium: Myzus persicae

gallers on Camelina

Last modified 24.viii.2020

Dichotomous table for gallers on Camelina

by Hans Roskam

1a On parts above ground => 3

1b On root collar or on roots => 2

2a Root collar with about 6–8 (10) mm long, rotund, often one-sided, succulent, one-chambered galls. Containing a single larva. C. microcarpa, sativa: Ceutorhynchus assimilis

2b Roots with conspicuous spindle-shaped or acuminated, cylindrical, thick fleshy compact swellings of variable size. Camelina spp.: Plasmodiophora brassicae

3a On inflorescences, flowers or fruits => 9

3b On vegetative parts => 4

4a Malformations bearing white fungus sori at surface => 8

4b Malformations caused by animal parasites => 5

5a Inducers inside malformations => 7

5b Leaves on ± stunted shoots clustered, stunted, deflected, sometimes twisted => 6

60a Aphid 2–2.5 mm long, yellowish-green, densely grey powdered. C. alyssum, microcarpa, sativa: Brevicoryne brassicae

6b Aphid 1.5–2 mm long, pale yellowish to yellow-green, not powdered. Camelina spp.: Brachycaudus helichrysi

7a Stems, also leaf axis, with swellings up to about 15 mm long, spindle-shaped. Containing a single larva. C. alyssum, sativa: Ceutorhynchus chalybaeus

7b Stem of young plants severely stunted, spongy, pale green, wrinkled at surface; leaves often considerably stunted, galled from midrib onwards, especially the basal part. Infestation of older plants results in spongy, ± expanded, pale-green, often curved bulges on stems or similar malformations encroaching onto the leaf blades. C. microcarpa, sativa: Ditylenchus dipsaci

8a Fungus sori dense, at first closed, glossy, porcelain-like, later on mealy dusted; their vicinity hardly discoloured, on underside leaf blade rotund, often non-cecidogenic; on midrib and shoot axis elongate oval, often in 2–15 mm long bulges, sometimes curved. Camelina spp.: Albugo candida

8b Malformations expanded, with loose, whitish down of branched conidiophores. Infestation site pale green; on younger leaves often arched upwards. Expanded infestation of young shoots results sometimes in conspicuous thickenings and bendings of stems, as well as to stunting of pale green leaves with margins deflected, slightly thickened and ± brittle. Camelina spp.: Hyaloperonospora camelinae

9a On ± expanded parts of inflorescence or on flowers => 10

9b Silique ± disfigured, soon maturing; inside are several white larvae. C. sativa: Dasineura napi

10a Flowers greened. Axis of inflorescence stunted, sometimes together with neighbouring stem parts. Leaves thickened at margin, rolled downwards, abnormally pubescent. C. microcarpa, sativa: Aceria drabae

10b Inflorescence ± severely stunted, axis sometimes thickened. Flower buds ± densely clustered, swollen. Larvae whitish to pale yellow, jumping. Camelina spp.: Contarinia nasturtii

gallers on Bidens

Last modified 30.iv.2020

Dichotomous table for gallers on Bidens

by Hans Roskam

1a On above-ground parts => 2

1b Roots with slender, spindle-, club- or nodule-shaped swellings. B. tripartita: Meloidogyne hapla

2a On vegetative parts => 3

2b Tephritid larvae in flower heads. B. cernuus, tripartita: Dioxyna bidentis

3a Leaf blades with conspicuous ripples => 4

3b Basal leaves, especially on the underside of the leaf blades, with many golden-yellow translucent warts, less than 1 mm long, ± hemispherical. B. tripartita: Synchytrium aureum

4a Leaf blade areas in different ways ± loose nest-like, curved downwards. Strongly curled and dark green, especially close to the froth-covered nymph. Bidens spp.: Philaenus spumarius

4b Leaf blade partially at the margin loosely curved and curled downwards. B. cernuus, frondosus, pilosus, tripartitus: Brachycaudus helichrysi

gallers on Armoracia

Last modified 30.iv.2020

Dichotomous table for gallers on Armoracia

by Hans Roskam

1a On parts above ground => 4

1b On roots and root collar => 2

2a On root collar => 3

2b Side roots with usually 4–6 mm long, slender, spindle-shaped succulent swellings. Inside the galls cells contain masses of minute spores. Plasmodiophora brassicae

3a Rotund, up to 8 mm long one-chambered galls with a glabrous surface, contain a curved larva. Ceutorhynchus assimilis

3b Proliferations of conspicuous bulging, at surface ± subdivided, up to almost fist size galls, ± one-sided attached to the plant part. Agrobacterium tumefaciens

4a On flowers => 9

4b On stems or leaves => 5

5a Malformations caused by animals => 6

5b eaves on the underside with dense, rotund pads, sometimes in large numbers, rotund on the leaf blades, on the veins bulging, at first glossy, porcelain-like, later opening with mealy dusting of white sori. Albugo candida

5c Leaves somewhat disfigured with pale spots on the upperside, that correspond with a fungal bloom on the underside, consisting of erect, apical strongly branched conidiophores. Hyaloperonospora cochleariae

6a Galls predominate on petioles, leaf veins or on stems => 8

6b Malformations on expanded plant parts or on leaves => 7

7a Basal leaves of young plants loosely deflected over their length, ± curled. Many black aphids on underside. Inducer unidentified – ? aphid

7b Stems of younger main- or side shoots stunted, sometimes curved, leaves deflected, curled, their margins rolled inwards. Inflorescences stunted, flowers densely clustered ball-like. Contain a froth-covered nymph. Philaenus spumarius

8a Galls spindle-shaped, on leaves mainly on underside, 15–25 mm long, glabrous, also green inside, on midribs, petioles, more rarely on rather young stems. Containing a single larva. Ceutorhynchus chalybaeus

8b Spongy, at surface undulate-wrinkled, pale green swellings of variable length on stalks and lower part of midrib of basal leaves. Ditylenchus dipsaci

9a Flower buds strongly swollen, ± globular, about 5–7 mm across, unopened. Several, mainly yellow, non- jumping larvae. Dasineura armoraciae

9b Galls similar, but more slender and smaller, 2–4 mm long. Larvae whitish to pale yellow, jumping. Contarinia nasturtii

gallers on Anthyllis

Last modified 30.iv.2020

Dichotomous table for gallers on Anthyllis

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Roots with 3–5 mm long, slender spindle-shaped swellings, situated on root body with primordia of adventitious roots. Anthyllis spp.: Meloidogyne hapla

2b On inflorescences, flowers or fruits => 3

3a On inflorescences, flowers or fruits => 7

3b On stems or leaves => 4

4a Galls larger than 1 mm => 5

4b Under 1 mm long wart-shaped, ± golden-yellow translucent galls in large numbers on underside of leaves; also on stems. A. vulneraria: Synchytrium aureum

5a Malformations caused by animals => 6

5b Petiole, rachis or midrib with yellowish sori of occasionally slightly gall-like swollen pads, about 1–3 mm long, oval, soon bearing spores, arched on underside. Anthyllis spp.: Uromyces anthyllidis

6a Longitudinal growth of plant stunted; sometimes strongly branched; stem at base spongy. Developing side shoots thickened and stunted as well, ± bushy, clustered. Leaves and stipules variously disfigured. A. vulneraria: Ditylenchus dipsaci

6b Stem with ± expanded spindle-shaped swelling; rind with rimmed groove-like depressions containing single froth-covered nymphs. A. vulneraria: Planchonia arabidis

6c Galls on leaf buds. A. cytisoides, polycephala: Asphondylia sp.

7a Malformations in flowers => 8

7b Beetle larvae feed within the pod on the developing seeds; this may cause some galling of the pods. A. vulneraria & subsp. polyphylla: Tychius schneideri and/or T. junceus

8a Several or single flowers slightly swollen at base, unopened. Larvae orange-coloured. A. vulneraria: Unidentified gall midge

8b Several or usually all flowers of an inflorescence completely disfigured, transformed into ± spiny-globular, densely whitish or yellowish-white pubescent balls. A. vulneraria: Unidentified gall mite

gallers on Anchusa

Last modified 29.iv.2020

Dichotomous table for gallers on Anchusa

(for Anchusa arvensis [= Lycopsis arvensis], see Lycopsis)

by Hans Roskam

1a On flowers or inflorescences => 4

1b On stems and leaves => 2

2a Malformations in rosette or on base of young stem => 3

2b Leaf blade with conspicuous, rotund, yellowish to brown pads or distinctly arched, oblong-oval bulges, arched on underside, upper side ± depressed also on midribs or stalks of leaves as well as on young axial parts; soon bearing aecia and spermogonia. A. azurea, calcarea, capensis, leptophylla, ochroleuca, officinalis, undulata: Puccinia recondita

3a Rosettes additionally branched. All parts greatly shortened, swollen, transformed into a ± compact gall. A. caespitosa: Aphelenchoides fragariae and/or Rhodococcus fascians

3b Young stem parts ± severely stunted, sometimes slightly swollen at base. Containing a yellowish-white caterpillar; head and neck black. Anchusa spp.: Cynaeda dentalis

3c More frequent on Anchusa in inflated leaf mines, later on occasionally also in ± crippled, sometimes gall-like disfigured stems occurs the caterpillar of the very close Epascestria pustulalis

4a Malformations on flowers, without distinct involvement of inflorescence rachis => 6

4b Young inflorescences with shortened axial parts; bracts and flower primordia ± strongly clustered => 5

5a Flowers ± distorted, bracts curled, deflected. A. officinalis: Dictyla echii

5b In sometimes similar malformations on inflorescence with stunted axis, clustered, ± disfigured flowers, curled and curved bracts or also on similarly disfigured vegetative shoots. Anchusa spp.: Philaenus spumarius

5c Flowers distorted, corolla ± greened or leafy; bracts and calyx lobes rolled inwards. A. officinalis: Anthocoptes aspidophorus

6a Flower buds swollen, unopened. Containing many mites. A. officinalis: Unidentified gall mite

6b Similar malformation caused by gall midges. A. officinalis: Unidentified gall midge

gallers on Alyssum

Last modified 30.iv.2020

Dichotomous table for gallers on Alyssum

(incl. Aurinia, Ptilotrichum)

by Hans Roskam

1a On parts above ground => 4

1b On roots or root collar => 2

2a On roots => 3

2b Root collar with rotund succulent, one-chambered swelling, up to 8 mm long. Contains a single larva. A. alyssoides: Ceutorhynchus assimilis

3a Galls ± rotund, up to 5 mm long, succulent, many on side roots. A. montanum: Meloidogyne hapla

3b Main- and side roots with conspicuous, spindle- to barrel- shaped, succulent swellings. Inside many cell masses with minute spores. Alyssum spp.: Plasmodiophora brassicae

4a Malformations with white pads caused by fungi => 10

4b Malformations caused by animals => 5

5a On inflorescences or flowers => 9

5b On vegetative parts => 6

6a Stem with localised swellings. Galls with midge larvae inside or containing causers in rimmed depressions => 7

6b Young shoots ± stunted and arched; leaves clustered; often nest-like deflected; close to the froth-covered nymph ± deep green discoloured. Alyssum spp.: Philaenus spumarius

7a Larvae are inside gall => 8

7b Stem bulging over variable length, variously distorted, outside with single or several rimmed depressions containing a scale insect. Alyssum spp.: Planchonia arabidis

8a Terminal part of stem stunted, transformed into a 10‒15 mm long, 6–8 mm wide gall. Leaves densely clustered, swollen at base. A. alyssoides, gmelinii, murale: Janetiella fallax

8b Shoot with up to 4 mm long, about pea-size, spindle-shaped swellings. A large chamber contains several red larvae. A. alyssoides, montanum: Dasineura alyssi

9a Inflorescence disfigured over a substantial part. Flowers greened and/or leafy; abnormally white pubescent. A. alyssoides, hirsutum, Ptilotrichum halimifolium, tortuosum: Aceria drabae

9b Flowers swollen, unopened. Containing a single larva. Aurinia saxatilis: Unidentified gall midge

= The gall midge Dasineura auriniae is described from swollen flower buds of Aurinia petraea.

10a Rotund to oval, several mm long, at first closed, glossy, porcelain-like ± swollen bulges on stems and leaves. Later on with mealy dusting of closely arranged conidiophores. Alyssum spp.: Albugo candida

10b Leaves often distorted, usually with several, solitary or clustered, little wart- to bulge-like swellings on upper side, more rarely on underside. In the cavities branched conidiophores make narrow erinea. Sometimes expanded covers on bulging midribs or variously disfigured flowering or non-flowering shoots. Alyssoides utriculata; Aurinia saxatilis: Hyaloperonospora galligena

gallers on Alliaria

Last modified 29.iv.2020

Dichotomous table for gallers on Alliaria

by Hans Roskam

1a On above-ground parts => 4

1b On roots or root collars => 2

2a On main- or side roots => 3

2b Root collar with rotund succulent, one-chambered swelling, up to 8 mm long. Contains a single larva: Ceutorhynchus assimilis

3a Main- and side roots with conspicuous, spindle- to barrel- shaped succulent swellings. Many cell masses inside with minute spores: Plasmodiophora brassicae

3b Spindle-shaped or nodular swellings of side roots, up to 5 mm long: Meloidogyne hapla

4a Malformations at surface with fungus sori => 10

4b Malformations without fungal sori => 5

5a Malformations on shoot tips or on leaf blades => 7

5b Galls on shoots or petioles => 6

6a Stems or petioles, rarely leaf veins, with spindle-shaped, 10–20 (25) mm long, at first also internal deep green swellings. Containing a single larva: Ceutorhynchus chalybaeus

6b Stem with bulges of variable size, later on blackish; containing many oospores inside the tissue: Hyaloperonospora niessliana

7a Galls caused by aphids or spittlebugs => 8

7b Mite gall. Shoot with irregular development of disfigured leaves. Inducer unidentified – ? gall mite

8a Malformations caused by aphids => 9

8b Malformations caused by spittlebugs. Leaf blade often strongly deflected, at margin ± bent inwards. Leaf blade, especially between the veins, ± bulging; deep green close to the froth-covered nymph: Philaenus spumarius

9a Vegetative and flowering shoot tips clustered, usually with several disfigured together. Leaf blades ± deflected, curled. Flower parts disfigured, ± greened. Fruits sometimes distorted and thickened: Lipaphis alliariae

9b Malformation inconspicuous, usually restricted to single or several terminal leaves: Myzus persicae

10a Sori of fungus expanded, loose covers, consisting of branched conidiophores: Hyaloperonospora niessliana

10b Conidiophores not branched, united into dense, at first glossy, porcelain-like, sometimes bulging swollen sori which release mealy dusting of spores after rupturing: Albugo candida

gallers on Alchemilla

Last modified 29.iv.2020

Dichotomous table for gallers on Alchemilla

by Hans Roskam

1a Leaves remarkably long stalked, more erect, their leaf blades smaller, ± pale green, with orange-yellow to -red, often crowded fungal sori on the underside => 8

1b Malformations on leaf blades or -stalks without conspicuously coloured sori => 2

2a Malformations on leaf blades caused by aphids or spittlebugs => 7

2b Other causes => 3

3a On leaf blades => 4

3b Petiole thickened. A. vulgaris: Planchonia arabidis

4a Leaf blade folded, twisted, or with minor bulge-like swellings => 5

4b Leaf blade crumpled. Infestation sites sometimes conspicuously yellowish to reddish. With single or gregarious froth-covered nymphs on underside with black margined and castellated scale surrounded by a white margin of wax. A. alpina, glabra, pratensis, vulgaris: Bactericera femoralis

5a Leaf blade folded or twisted => 6

5b Leaf blade with slightly bulge-like, ± discoloured swellings, depressions on the underside of whitish covers of sori with branched conidiophores. Alchemilla spp.: Peronospora alchemillae

6a Leaf blade irregularly folded, here and there on underside with flat, rotund depressions, not abnormally pubescent. A. vulgaris: Unidentified gall mite

6b Leaf blade variously twisted, yellowish spotted. A. fissa: Unidentified gall mite

6c Minor swellings on ± stunted leaves. A. glomerulans, murbeckiana, xanthochlora: Calepitrimerus alchemillae

7a Leaf blade acutely bent downwards over large part; crumpled and dark green close to the froth-covered nymph. Alchemilla spp.: Philaenus spumarius

7b Leaf blade strongly curled; colonies of aphids on undersides. Alchemilla spp.: Aulacorthum solani

8a Underside often completely occupied with rotund or oblong, soon coalescing, orange-yellow to red lead sporangia. Alchemilla spp.: Trachyspora alchemillae

8b Similar malformations on A. alpigena, alpina, hoppeana, indivisa, nitida, velebitica: Trachyspora melospora

8c Very close to this fungus is a species occurring with expanded mycelium on hypertrophied chlorotic shoots of A. pentaphylla, with similar biology: Trachyspora pentaphylleae

gallers on Rorippa

Last modified 29.iv.2020

Dichotomous table for gallers on Rorippa

(incl. Nasturtium, Sisymbrella)

by Hans Roskam

1a On parts above ground => 3

1b On roots or on root collar => 2

2a Roots with expanded spindle- to barrel-shaped succulent swellings, ± bulging. “Clubroot”. R. austriaca, islandica, sylvestris: Plasmodiophora brassicae

2b Globular, pea- to cherry sized succulent galls on root collar, occasionally clustered. R. amphibia, islandica: Ceutorhynchus assimilis

3a On shoot tips, leaves, inflorescences or flowers => 6

3b Galls mainly or only on shoot axis => 4

4a Galls expanded, of very variable shape => 5

4b Axis with spindle-shaped, 10–15 (30) mm long, usually deep green swelling. Containing a single larva. R. amphibia: Ceutorhynchus chalybaeus

5a Youngest shoot parts swollen over ± extended length, soon covered with a loose, white down of branched conidiophores. R. amphibia, austriaca, islandica, palustris, sylvestris: Hyaloperonospora rorippae-islandicae

5b Young parts of non-flowering or flowering shoots with elongate bulges, at first glossy-white porcelain-like, later on with mealy dusting, sometimes coalescing into larger clusters, also curved swellings. Rorippa spp.: Albugo candida

6a On leaves, inflorescences or flowers => 8

6b On the tip of shoots, developing leaves or inflorescences => 7

7a Tip of main- and side shoots, also axial buds transformed into spongy, whitish, coalescing masses; the neighbouring, partially normally developed organs densely clustered, basal parts of petioles or flower buds variously swollen close to the gall. Sometimes the inflorescence galls are overtopped by some atrophied flowers. Containing several yellow- to orange-coloured larvae. R. amphibia, x anceps, austriaca, palustris, pyrenacia, sylvestris & subsp. kerneri: Dasineura sisymbrii

7b Longitudinal growth of axis stunted. Leaves or all parts of infected inflorescence clustered. All parts at base ± succulent, but not swollen and spongy, gall very variable. Containing several whitish- to lemon yellow, jumping larvae. R. palustris, pyrenaica, sylvestris: Contarinia nasturtii

8a On inflorescences or flowers => 13

8b On leaves => 9

9a Galls caused by animals => 12

9b Galls caused by fungi => 10

10a Sori white => 11

10b Leaves, also stem, with rotund, dull brown to black warts, or petioles with oblong, up to 1.5 mm long, bulge-like swellings; organs if strongly infected ± curved. R. amphibia: Physoderma vagans

10c On the same host the very similar punctiform, rotund, nodular protruding swellings on leaf blades or in flat brown bulges on petioles are attributed to Physoderma magnusianum

10d Small hard gregarious pustules, less than 0.5 mm across. Rorippa spp.: Synchytrium aureum

11a Leaf midrib, also stalks and venation, with spindle-shaped bulges. Leaf blade with ± rotund, pale green swellings. Sori at first closed, white and glossy, porcelain-like, then with dusting. Rorippa spp.: Albugo candida

11b Largely similar malformations, covered with loose down of conidiophores. R. amphibia, austriaca, islandica, palustris, sylvestris: Hyaloperonospora rorippae-islandicae

12a Basal leaves stunted. Midrib shortened, leaf blade ± nested, dark green, bent or rolled upwards. Strongly infected plants do not flower. R. amphibia: Aphis triglochinis

12b Leaves deflected over their top. Variously distorted and ± curled; sometimes the axis is stunted on one side and bearing several clustered disfigured leaves Rorippa spp.: Philaenus spumarius

13a Galls restricted to flowers => 15

13b Malformations on other parts of inflorescence => 14

14a Upper leaves disfigured. R. austriaca: Unidentified gall mite

14b Axis stunted. Flowers clustered, aborted. R. sylvestris: Aphis gossypii and/or Aphis nasturtii

15a Flowers unopened, often reddish discoloured on the outside, ± spongy thickened; stalk sometimes slightly elongated, resulting in a deflected gall. R. x anceps: Unidentified gall midge

15b Flowers swollen, ± egg-shaped, unopened. Corolla absent. Stamens short, thickened; ovary thickened. Containing several whitish- to pale yellow jumping larvae. R. palustris, pyrenaica, sylvestris: Contarinia nasturtii

gallers on Torilis

Last modified 28.iv.2020

Dichotomous table for gallers on Torilis

by Hans Roskam

1a Malformations on inflorescences or their parts, or fruit galls => 7

1b Malformations on leaves or stems => 2

2a Leaves with expanded malformations => 4

2b Vitreous bulges or pads bearing fruiting bodies on leaves, -stalks, or on stems => 3

3a Spindle-shaped, vitreous bulges on basal stem part, on petioles, midrib and leaf veins. T. japonica: Protomyces macrosporus

3b Bulges yellowish, soon bearing aecia, on the axis of leaves, also on younger stem parts. T. arvensis & subsp. neglecta, japonica, nodosa: Uromyces lineolatus

3c T. japonica has furthermore been indicated as host for Puccinia chaerophylli

4a Malformations caused by aphids or spittlebugs => 5

4b Tip of leaflets variously rolled or strongly curled. T. arvensis, japonica: Aceria peucedani

5a Malformations caused by aphids => 6

5b Main- and side midrib, together with ± curled leaflets, strongly deflected; usually with several similarly disfigured leaves changed into a nest-like cluster. T. arvensis, japonica: Philaenus spumarius

6a ip of leaflet at first with small, upwardly open folds; causer also in ± swollen leaf sheaths. The side shoots that develop later in these sheaths curled; the umbels ± greened and/or leafy. T. arvensis, japonica: Hyadaphis foeniculi

6b Leaflets densely clustered on ± shortened midrib, disfigured; leaf blades irregularly deflected, twisted, curled and ± bulging. T. arvensis, japonica: Semiaphis anthrisci

7a Extensive malformations on inflorescences => 9

7b Localised galls on fruits or stalks of inflorescences => 8

8a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall, rough, covered with mycelium. Containing a single red larva. T. japonica: Lasioptera carophila

8b Fruit inflated, bladder-like; ± globular or flattened on one side, oblong-oval. Gall thin-walled sometimes reddened, protruding above the umbel. Containing 1 (–3) orange-red larvae. T. japonica: Kiefferia pericarpiicola

9a (Partial) umbels severely stunted; ± ball-like clustered; aphid galls => 10

9b Flowers in umbel clustered with umbel stalk often little stunted, variously leafy or only partially greened. T. arvensis, japonica: Aceria peucedani

10a Stalks of umbels and flowers often variously stunted, resulting in irregularly stunted parts. Flower bud disfigured, often mostly greened or even leafy. T. arvensis, japonica: Semiaphis anthrisci

10b Similar malformations. T. japonica: Cavariella pastinacae

gallers on Scrophularia

Last modified 28.iv.2020

Dichotomous table for gallers on Scrophularia

by Hans Roskam

1a On inflorescences, flowers and fruits => 10

1b On vegetative organs => 2

2a Localised or extensive malformations mainly on leaves or terminally on higher placed parts of shoot => 5

2b Galls on lower or middle stem parts => 3

3a The causers develop inside the galls => 4

3b Stem with bulging swellings of different length, mainly close to ground, bearing on their surface several rimmed depressions containing a nymph. Scrophularia spp.: Planchonia arabidis

4a Young shoots close to ground, or also on higher placed parts of side shoots, completely or locally severely stunted, spongy, often conspicuously curved with wrinkled surface. Occasionally encroaching onto petioles and basal parts of ± disfigured leaf blades. S. nodosa: Ditylenchus dipsaci

4b Stem with localised nodular or spindle-shaped, variously distorted swelling. Gall wall browned inside. Leaves clustered at infestation; complete plant ± disfigured. S. nodosa: Cause unknown – ? insect

5a Wart-shaped galls or expanded, variable malformations caused by fungi => 8

5b Malformations caused by animals => 6

6a Single or many leaves with bladder-like swellings or curls => 7

6b Leaves clustered, rosette-like; leaf blades thickened. S. umbrosa: Unidentified gall midge

7a Leaves stunted, with bulging reddened swellings. S. nodosa: Unidentified ? thrips

7b Leaf blade curled, strongly bent downwards at infestation, there deep green. Internodes ± stunted if infected, resulting in clustered ± curled leaves. S. umbrosa, nodosa: Philaenus spumarius

8a Malformations of undefined extent => 9

8b Galls wart-shaped, multi-cellular, less than 1 mm across, ± golden-yellow. Usually many on underside of basal leaves; also on petioles and young stems; sometimes joined into crusts or ridges. S. nodosa, umbrosa: Synchytrium aureum

9a Leaf blades on hardly swollen, rotund to widely expanded spots with usually yellow or reddish bordered sori of fungus. On main veins, petioles and stems developing sori more strongly thickened; bulges of variable size; diseased leaves and stems often severely distorted. At first with spermogonia and aecia, soon also bearing telia. Scrophularia spp.: Uromyces scrophulariae

9b Completely diseased young shoots at first develop faster and firmer than healthy ones, remaining lanky and bear pale-green leaves with narrowed, slightly thickened leaf blades, which are soon covered with a down of branched conidiophores on underside. S. nodosa, scopolii, umbrosa: Peronospora sordida

10a Flower or inflorescence galls => 11

10b Fruit slightly swollen and disfigured only if infected in right phase. Usually containing a single larva. Scrophularia spp.: Rhinusa tetra

11a Flower galls => 12

11b Inflorescence curved; terminal leaves curled. Flower buds contain several at first white, later on orange coloured larvae. S. nodosa, scorodonia: Macrolabis scrophulariae

12a Flowers strongly swollen, unopened. Calyx slightly changed; corolla thickened, especially the tube; stamens with thickened filaments transformed into irregular, leaf-like organs. Ovaries swollen; inner wall covered with dirty white mycelium. Containing a single yolk-yellow larva. S. canina, decipiens, grossheimii, nodosa, umbrosa: Asphondylia scrophulariae

12b Flowers swollen, globular, usually unopened. Stamens and pistil enlarged. Larvae live between flower parts, white to lemon-yellow, jumping. S. auriculata, canina, nodosa, schousboei, umbrosa: Contarinia scrophulariae

gallers on Scorzonera

Last modified 28.iv.2020

Dichotomous table for gallers on Scorzonera

(incl. Arachnospermum, Podospermum)

by Hans Roskam

1a On above-ground parts => 4

1b On roots or root collar => 2

2a Considerable galls on root collar => 3

2b Roots with elongated spindle-shaped swellings, up to 5 mm long, bearing some lateral roots. Coalescing in rows in cases of heavy infestation. S. hispanica: Meloidogyne hapla

2c Lateral roots terminally thickened, ± curved, longitudinal growth stunted, prematurely shrivelled. Whole plant becoming stunted. S. hispanica: Paralongidorus maximus

3a Uniformly succulent, up to walnut size, ± rotund-ovoid proliferation on root collar, sometimes on root- and stem parts close to the surface. “Crown gall disease”. S. hispanica: Agrobacterium tumefaciens

3b Almost globular, glabrous, one-chambered swellings on root collar. Often several variously coalesced, depending upon the number of galls, to form crook-backed structures. One larva per chamber. S. humilis: Aulacidea hieracii

4a On capitula or flowers => 13

4b On stems or leaves => 5

5a Malformations on leaves => 6

5b Stems with conspicuous, crooked swellings at the surface mostly on all sides, 40–60 mm long, about 10 mm thick. Inside the stem are many, clustered rotund galls, each about 2 mm long, and each with one larva. S. austriaca, hispanica, humilis; Podospermum purpureum: Aulacidea scorzonerae

6a On leaf blades or leaf veins => 7

6b Leaf sheaths ± bladder-like swollen and discoloured. Enclosed shoot stunted, with severely stunted development. S. hispanica: cf. Brachycaudus tragopogonis

7a Malformations caused by superficial sori => 11

7b Galls with living animal inducers inside => 8

8a Galls predominantly on the leaf blade or on the secondary veins => 9

8b Midrib on the underside often with several galls, in loose or more clustered constellations appearing pale green, rotund-ovoid, 2–3 mm long, one-chambered. Containing a single larva. S. austriaca, hispanica, humilis; Podospermum purpureum: Aulacidea scorzonerae

9a Galls of definite shape; surface glabrous, usually ± reddened. Midge galls => 10

9b Flat, pale green, ± spongy, rugose galls, especially swollen at the veins and extending over at least 15 mm in length on the leaf blade, ± curved as result of the infestation. S. hispanica: Ditylenchus dipsaci

10a Leaf blade with round pustules, several millimetres wide; bulging on the upperside, yellowish or dirty crimson-red, sometimes surrounded by a reddish discoloured area; the underside lighter, flat. A pale orange-yellow larva. S. austriaca, humilis: Cystiphora scorzonerae

10b Elevated, elongated to spindle-shaped galls, up to 5 mm long, protruding from both leaf surfaces, often yellow or reddish bordered. Often many per leaf blade, the longitudinal stem predominantly situated in a secondary vein and extending on both sides on the leaf blade. Containing a single larva. S. humilis: Unidentified gall midge

11a Malformations with sori of true rust fungi (Uredinales) => 12

11b Oomycetes. Sori oblong-oval, initially closed and porcelain-glossy, white, opening later and with mealy dusting. S. austriaca, hispanica, humilis, parviflora; Podospermum canum, laciniatum; Scorzoneroides autumnalis, helvetica: Pustula obtusata

11c Oomycetes; upperside of the leaves with yellow or brown spots; on the underside a greyish brown fungal down consisting of erect, distally several times branched conidiophores; the final branches ending in an ovoid conidium. S. hispanica, humilis: Novotelnova scorzonerae

12a The primary uredomycelium usually pervades the whole host, whose parts are paler, more lanky or deformed in another way. Spores brown. Podospermum purpureum, roseum; S. austriaca, hirsuta, hispanica, humilis, mollis, papposa: Puccinia scorzonerae

12b Shoot etiolated by the expanded aecial mycelium. Leaves in case of heavy, infection, usually one-sided, conspicuously curved or even twisted. Aecia cup-shaped, later opening with frayed border, widely dispersed over leaves, stems and involucres; yellowish. S. austriaca, hispanica, humilis; Podospermum purpureum, roseum: Puccinia jackyana

13a Malformations induced by insects => 14

13b Diseased capitula already stunted early in development, shortened, initially turgid. Flowers soon completely destroyed and replaced by a black-violet, sparsely dusting spore mass. Podospermum canum, puurpurum, roseum; S. aristata, calyculata, hispanica, humilis, mollis: Microbotryum scorzonerae

14a Receptacle of the unopened flower head ± egg-shaped, swollen. In case of one-sided infestation ± curved. Usually containing one larva. Podospermum purpureum; S. parviflora; Scorzoneroides autumnalis: Trupanea stellata

14b Capitula conspicuously swollen, rotund to elongated ovoid. Galls in the shortened and broadened fruits. Wall thick and woody. Pappus shortened, with withered corolla mounted on the gall. Often many galls per flower head. One yellowish-white larva per gall. Podospermum purpureum, roseum; Scorzonera humilis, parviflora: Aulacidea abdominalis

14c Base of flower head is usually enlarged; the conglomerate of galls lignified, hard. Larval chamber is round or slightly ovate, developing in seeds which are slightly swollen. Pdospermum purpureum, roseum; Scorzonera humilis, parviflora: Aulacidea abdominalis

14d A stem swelling-like gall, usually located under the flower head, sometimes in the lower part of the stem; spindle-like or cylindrical stem enlargement, 30‒60 mm long, 10 mm in diameter; the surface with longitudinal ribs, as on the stem, sometimes the ribs are waved and distance between them is larger, depending on the diameter of the gall. In a longitudinal dissection, single 2 mm long larval cells are visible which are located near one another. The number of larval cells is larger towards the periphery of the gall. The stem above the gall is shortened and the flower head terminates its development. S. austriaca, hispanica, humilis; Podospermum purpureum: Aulacidea scorzonerae

14e Galls induced in achenes. Podospermum laciniatum: Aulacidea laurae

gallers on Satureja

Last modified 27.iv.2020

Dichotomous table for gallers on Satureja

(incl. Acinos, Calamintha, Clinopodium, Micromeria)

by Hans Roskam

1a On axial parts of shoots, shoot tips, swollen buds or leaves => 2

1b Flowers disfigured; calyx swollen; corolla, stamens and ovaries aborted. Clinopodium acinos, Micromeria graeca, Clinopodium vulgare: Unidentified gall mite

1c Flowers disfigured. Micromeria graeca: Aceria saturejae

1d Calyx inflated, flower disfigured or aborted. Micromeria graeca subsp. fruticulosa: Asphondylia sp.

2a Malformation of many leaves on shoot tips, terminally on shoots or single leaves => 6

2b Galls on axial parts of shoots, sometimes encroaching onto leaves => 3

3a Swollen buds contain solitary gall midge larvae. Clinopodium alpinum, nepeta subsp. glandulosum. Asphondylia calaminthae

3b Shoot axis and underside of leaves long-haired white-erineum. Inflorescence stunted, especially along venation. Clinopodium vulgare: Unidentified gall mite

4a Causers occur inside galls => 5

4b Stem ± spindle-shaped or bulging, with several rimmed, irregular depressions containing the inducer. Clinopodium acinos: Planchonia arabidis

5a Stem with rotund to acuminated, egg-shaped swelling, up to 5 mm long, tough- and smooth-walled. Containing a single lemon-yellow larva. Clinopodium acinos, vulgare: Squamapion vicinum

5b Complete plant stunted. Stem distinctly shortened, spongy, swollen. Side shoots of more developed plants and basal leaf parts similarly disfigured to varied extent. Satureja hortensis: Ditylenchus dipsaci

6a Malformation of many leaves on shoot tips or terminally on shoots => 8

6b Localised galls on leaves, sometimes on basal young shoots => 7

7a Galls less than 1 mm across, multi-cellular, wart-shaped, ± golden-yellow; usually many on leaf underside, sometimes on petioles. Clinopodium vulgare: Synchytrium aureum

7b Leaf blades with yellowish rotund pads, several mm long, on leaf underside; their surface bearing aecia. Similar, more spindle-shaped bulges on leaf veins and -stalks as well as on shortened basal parts of shoot axis, sometimes strongly swollen and distorted. Clinopodium spp.; Micromeria hyssopifolia, varia; Satureja hortensis, thymbra: Puccinia menthae

7c Lower leaves turn brown and wither. On the underside a purple fungal down, consisting of vertical conidiophores that apically several times are dichotomously branching, each branch ending in a globular conidium. S. hortensis: Peronospora saturejae-hortensis

8a Curling of leaves caused by aphids or spittlebugs => 9

8b Leaves and generative primordia on shoot tip severely stunted, accumulated, tuft-like; ± disfigured and densely white pubescent. Clinopodium acinos, vulgare: Unidentified gall mite

9a Malformations caused by aphids => 10

9b Some internodes of stem shortened, sometimes ± bent. Leaves ± clustered, with several deflected over their tips, ± distorted, converging, nest-like, containing a froth-covered nymph. S. hortensis, montana: Philaenus spumarius

10a Terminal part of shoot axis ± shortened; side shoots variously stunted. Leaves ± clustered, curled, ± rolled inwards and downwards. Clinopodium acinos, grandiflorum, menthifolium, nepeta incl. subsp. glandulosum, vulgare: Aphis calaminthae

10b Leaf blade curled. Clinopodium acinos, menthifolium, vulgare: Aphis clinopodii

10c Similar malformations on Clinopodium vulgare: Aphis nepetae

10d Similar malformations on Satureja hortensis: Unidentified aphid

10e eaf blade swollen. Aphid green or yellow. Clinopodium alpinum, nepeta subsp. glandulosum: Aphis origani

gallers on Tragopogon

Last modified 27.iv.2020

Dichotomous table for gallers on Tragopogon

by Hans Roskam

1a On plant parts situated higher above-ground => 4

1b On roots, root collars or basal stem parts => 2

2a Galls on root collar or on neighbouring stem parts => 3

2b Roots with bulging, chambered swellings. Each chamber containing one larva. T. porrifolius: Aulacidea hieracii

= On T. porrifolius the eelworm Meloidogyne hapla has been recorded

2c Swelling on roots of T. porrifolius, pratensis: Orellia falcata

3a Root collar or basal stem parts with one-chambered, rotund, sometimes isolated, one-sided, succulent tough-walled swellings, or galls often in groups or rows coalesced into ± bumpy tubercles or even into several cm long, irregular bulges. In each rotund- oblong-oval 1–1.5 mm long larval chamber is one whitish larva. T. dubius & subsp. major, porrifolius, pratensis & subsp. orientalis: Aulacidea tragopogonis

3b Conspicuous, 2.5–3.5 x 4–5 cm large, rotund to oblong-oval, succulent proliferations on root collar, undulate on the surface. T. porrifolius: Agrobacterium tumefaciens

4a On capitula, florets or achenes => 10

4b Localised or elongate malformations on leaves or shoots, sometimes extending into the green parts of the inflorescence => 5

5a Malformations with sporulating fungal sori on the surface => 9

5b Malformations caused by animal inducers => 6

6a Malformations predominantly developing on leaves => 7

6b On the base of the main stem, one-sided brown-yellowish multi-chambered swelling. T. dubius & subsp. major, porrifolius, pratensis & subsp. orientalis: Aulacidea tragopogonis

7a Inducers inside the galls => 8

7b Leaves sometimes ± twisted, curled; also the sheaths abnormally inflated. T. crocifolius, dubius, porrifolius, pratensis & subsp. orientalis: Brachycaudus tragopogonis

7c Malformations have been recorded caused by froth-covered nymphs. T. orientalis: Philaenus spumarius

8a Leaf blade with several slight swellings, separated from each other and therefore inconspicuous, about 1 x 2 mm long, situated between the veins. Each containing a larva. T. pratensis: Unidentified gall midge

8b Basal leaves with petioles and basal leaf blades distinctly shortened, pale green, in ± expanded areas swollen, spongy-undulate; other parts of leaf blade ± stunted. T. pratensis: Ditylenchus dipsaci

9a Shoots over large parts ± disfigured and etiolated, often remaining sterile. Leaves narrowed, ± shortened, pale green; like the stem occupied with many distantly, honey-yellow spermogonia and white margined, orange-red aecia. Infestation also occasionally extending into similarly deformed involucres and even into achenes. Tragopogon spp.: Puccinia hysterium

9b Similar malformations on T. dubius, porrifolius, pratensis & subsp. orientalis: Puccinia brachycyclica

9c Oblong-oval sori, initially closed and porcelain-glossy, later breaking open and with mealy dusting, occur rather often on all green parts and induce excessive branching and other malformations on early affected developing buds. Tragopogon spp.: Pustula obtusata

10a Malformations on capitula => 12

10b Galls on single or several florets, especially on achenes of capitula that look normal from the outside => 11

11a Basal part of the achene transformed into a mustard seed-like gall, large, thin- and hard-walled, one-chambered. Containing a single larva. T. pratensis: Unidentified gall wasp

11b chene spindle-shaped, swollen. T. pratensis: Unidentified gall midge

12a Capitula greened or disfigured by fungi which later produce dusting of spores => 15

12b Malformations caused by animal inducers => 13

13a Malformations caused by fly maggots or midge larvae => 14

13b Capitula remaining closed. Florets ± atrophied, embedded by a bladder-like malformation, swollen, conspicuously cornicular converging, one-sided enclosed by involucral bracts. T. pratensis: Cause unknown – cf. Brachycaudus tragopogonis

14a Capitula remaining closed; slightly swollen at base, variously disfigured and curved. Containing several whitish to yellow jumping larvae. T. dubius, pratensis: Contarinia tragopogonis

14b Hardly conspicuous, often one-sided malformation of the flower head caused by single larvae, usually living between the achenes. T. pratensis: Ensina sonchi

15a Developing capitula shortened, ± globular to broad oval, swollen. Flower parts soon to a large extent affected by blackish-dark violet discolouration, later with dusting of spore masses. Tragopogon spp.: Microbotryum tragopogonis-pratensis

15b Malformation and ± greening of all florets in a flower head. T. pratensis subsp. orientalis: Cause unknown – ? gall mite

gallers on Phyteuma

Last modified 27.iv.2020

Dichotomous table for gallers on Phyteuma

(inc. Asyneuma)

by Hans Roskam

1a On inflorescences, bearing flowers or fruits => 6

1b On vegetative organs => 2

2a On axial parts of shoots => 5

2b On leaves => 3

3a Malformations on leaf blade or spindle-shaped swellings on stems => 4

3b Wart-shaped many-celled galls, less than 1 mm long, on leaf blades, more rarely on petioles. P. hemisphaericum: Synchytrium vulgatum

4a More or less expanded malformations on leaves, occasionally also on stems, caused by only telia developing rust fungi. Leaves of usually systemically infected plants grow more erect and develop faster; they exhibit an abnormal shape of leaf blades, are longer stalked than healthy ones and large parts of underside are covered with rather densely arranged dark-brown telia. Phyteuma spp.: Uromyces phyteumatum

4b Rather loosely arranged aecia on leaf underside of large parts of sometimes long stalked, etiolated leaf blades; exceptionally also densely arranged on longer, slightly spindle-shaped swellings of leaf veins, -stalks and stems. Phyteuma spp.: Puccinella caricis-sempervirentis

5a Shoot axis with successive lobular constricted swellings on twigs. P. spicatum: ? gall midge, pteromalid wasp

5b Shoot axis in the middle or in upper part swollen like rope of pearls. Gall chambers alternating, each containing a single larva. P. orbiculare: ? gall midge, gall wasp

6a Malformations mainly of flowers or their parts => 7

6b Inflorescence shortened and thickened. P. spicatum: Unidentified lepidopteran

7a Flowers or their ovaries strongly swollen => 8

7b Flowers disfigured, their parts variously greened or leafy. P. limonifolium: Aculus schmardae

7c lowers abnormally hairy, greened, leafy. Asyneuma [= Podanthum] canescens, limonifolium: Aculus podanthi

8a Corolla strongly swollen, bladder-like, unopened, inside at base with involute hairs, with several orange-coloured larvae in between. Often on several flowers of an inflorescence. Phyteuma spp.: Dasineura phyteumatis

8b Strongly swollen ovaries associated with other malformations usually on many flowers in a spike. Phyteuma spp.: Miarus campanulae

gallers on Taraxacum

Last modified 26.iv.2020

Dichotomous table for gallers on Taraxacum

by Hans Roskam

1a On above-ground parts => 3

1b On root and root collar => 2

2a Roots with spindle-shaped to slightly nodular swellings, bearing isolated lateral roots. T. officinale: Meloidogyne hapla

2b Considerable tuft-like proliferations on root collar. T. officinale:
Agrobacterium tumefaciens

3a On inflorescences or capitula => 16

3b On leaves => 4

4a Exclusively or predominantly on petiole, midrib and main veins => 12

4b Extensive malformation, or localised galls on leaf blade => 5

5a Galls local, sometimes clustering into larger groups => 8

5b Leaf blade with extensive malformations of irregular composition => 6

6a Malformations caused by aphids or cercopids => 7

6b Leaf blade ± shrivelled, converging, curled, twisted or rolled upwards, roll may be haired; leaflets narrowed, margin sometimes lacerate. T. officinale: Aculus rigidus

6c Curled leaves, contain froth-covered nymphs. T. officinale: Philaenus spumarius

7a Leaf blades sometimes spirally twisted; contain dark brown aphids. T. officinale: Uroleucon taraxaci

7b Leaf blade curled, with bladder-like swellings. Aphid green. T. officinale: Aulacorthum solani

7c Little indentation of the leaf blade. T. officinale, palustre: Trioza dispar

8a Single galls more than 4 mm long => 11

8b Single galls smaller => 9

9a Leaf blades with many bulges or yellowish-white spots on the upper side caused by smut fungi => 10

9b Leaf blade on under-, more rarely on upperside, with many reddish-yellow to dark orange-red multicellular warts, up to 1 mm long; solitary or sometimes coalescing to expanded crusts. Also occurring on inflorescence stalks or even the involucre. T. officinale: Synchytrium taraxaci

10a Leaf blades with usually several rotund or irregularly margined, yellowish-green, later pale brownish spots, up to about 3 (4) mm across, sometimes slightly thickened. Containing yellowish spores. T. officinale: Entyloma picridis

10b Leaf blade often with many small protruding swellings on the upperside; containing flat larvae in the depressions on the underside. T. officinale, palustre: Trioza dispar

11a Leaf blade with flat circular blister, up to 5 mm across, usually several in a leaf; rim of gall becomes dark red or purple; containing a yellow-red larva under a translucent epidermis. T. campylodes, officinale: Cystiphora taraxaci

11b Swellings protruding on the leaf underside, bearing clustered yellow sporulating aecia; rotund to oblong-oval, up to about 10 (15) mm long, including the main venation, irregularly margined; often with yellowish or reddish discoloured rim. T. officinale: Puccinia dioicae

12a Galls glabrous, confined to the midrib or a main lateral vein; possible malformations of the leaf blade develop as secondary growth disturbances => 13

12b Spongy, soft swellings, visible on both sides, the surface undulate rugose, often pale green, sometimes ± reddened, extending variously from the mid- and lateral veins to the neighbouring, sometimes ± arched leaf blades. T. officinale: Ditylenchus dipsaci

13a Malformations remaining closed. Inducers inside the galls => 14

13b Swellings inconspicuous, ± elongate-oval, 2–3 mm long, predominantly bulging on the underside of the leaf; on the midrib with yellow rim; on the surface bearing 1-celled, brown spores. T. officinale: Puccinia hieracii

13c Minor bulges in the midrib caused by primary uredina, spermogonia lacking. T. officinale, serotinum: Puccinia taraxaci

14a Galls about 12 (15) mm long, causing localised swellings of the venation, predominantly on the central and apical part of the leaf blade => 15

14b Midrib swollen at the leaf base; swelling fading away into the central and apical part of disfigured leaf blade which is sometimes undulate in the galled area. Gall most prominent on the underside. A mining larva in the galled tissue, making a round exit hole which protrudes into the upper epidermis just before pupation. T. officinale: Phytomyza wahlgreni

15a Swellings abruptly discontinued; especially conspicuous on the underside, ± rotund to oblong-oval, about 2–6 mm across; often several partially or completely fused into a bulge up to 4 cm long; pale green or often reddened; soon tough-walled. individual swellings develop, each with one chamber and containing one white larva or pupa. T. officinale: Phanacis taraxaci

15b Galls gradually terminating, flat spindle-shaped, initially yellowish-green, later on reddened to dark brown, of very different size, 2‒7 (15) cm long; also on the sometimes strongly curved inflorescence stalks and main leaf venation; in case of abundant occurrence secondarily also disfiguring the leaf blade. With many, spores situated in and on the vascular bundles. T. officinale: Protomyces pachydermus

16a On inflorescence stalks => 17

16b On capitula. Receptacle of the externally often hardly disfigured flower head weakly swollen; containing a larva with conspicuous mandibles. T. officinale: Campiglossa producta

17a Swellings several mm long => 17

17b Single galls multicellular, only up to about 1 mm long, yellow- dark orange, sometimes additionally coalescing into disfigured, tubercular ridges or crusts. T. officinale: Synchytrium taraxaci

18a The inducer is situated inside the galls => 19

18b Spindle-shaped yellowish swellings bearing aecia. T. officinale: Puccinia dioicae

19a Galls locally confined, with tough, glabrous surface => 20

19b Galls without cavities, of different sizes and situations; spongy soft, yellowish-green, the surface ± undulately rugose; strongly curving the inflorescence stalk; also sometimes extending from the stem into the receptacle of the swollen and ± curved flower head. T. officinale: Ditylenchus dipsaci

20a Inflorescence stalk usually with many massive bulges over its complete length, spindle-shaped ± vitreous, yellow-green, which sometimes cause slight bending of the stem. T. officinale: Protomyces pachydermus

20b Base of inflorescence stalk slightly swollen over a length of several cm, close to the ground with several irregular humped protruding bulges, conspicuous when compared with unaffected shoots by their more compact structure. In the proliferated, more compact pith are 1‒2 (3) tunnelling larvae. T. officinale: Phytomyza wahlgreni

20c Localised tough-walled unilocular galls, 2–4 mm long, distinctly defined, pale green or also conspicuously reddened, often coalesced into much larger 25 mm long and 10 mm thick, ± tuberculate structures. Containing one white larva per chamber. T. officinale: Phanacis taraxaci

gallers on Phragmites

Last modified 30.iv.2020

Dichotomous table for gallers on Phragmites

by Hans Roskam

1a On vegetative plant parts => 2

1b Ovary infected by smut fungus: Neovossia danubialis

1c In florets; a solitary pinkish larva replacing the ovary. Unidentified gall midge

2a On shoots, leaf-blades or -sheaths => 6

2b On lower internodes of the culm => 3

3a Culm distinctly or weakly swollen => 5

3b Galls inside the culms, which are not remarkably changed on the exterior => 4

4a Wall of the culm with single or many grain-like swellings, oval to spindle-shaped, rarely over 6 mm long, thin- and later tough-walled, unilocular; mostly protruding inside the culm, if heavily infected also protruding externally on the ± turgid culm. One white to orange-coloured larva per gall: Giraudiella inclusa

4b Rarely visible swelling on the clearly stunted culm. Larvae solitary in separate chambers in pith, which are sometimes present in large number per internode: Tetramesa phragmitis

5a Culm in the non-flowering unshortened upper part slightly swollen. Many orange-coloured larvae present in the dark or black pith. Infestation often inconspicuous: Lasioptera flexuosa

5b Several internodes of the culm, occasionally also the rhizomes, shortened and sometimes noticeably swollen beyond the normal diameter. Body of the gall sometimes constricted at the nodes; therefore reminiscent of slim concatenate spadixes of Typha. Covered for a long time by the black-brown sori, which remain closed until spores are released at about flowering time: Ustilago grandis

6a Galls in or on the shoot tips => 7

6b Leaf blades of the younger, already ± unfolding leaf blades rolled over their length and bleached: Hyalopterus pruni

7a The galls develop on the shoot tips as swellings of the culm => 9

7b The galls develop partially or completely from terminal leaves of the shoot => 8

8a Internodes compressed at the shoot tip; the adjacent youngest leaves swollen, transversely and longitudinally folded, ± twisted; the inwardly facing epidermal cells developed into club-shaped, brown, hairs in dry conditions. Usually the upper part gradually narrowed, heavily wrinkled, sometimes covered by normal leaf blades, gall breaks with its basal parts in ± buckled curves through the enveloping leaf sheaths: Steneotarsonemus phragmitidis

8b Leaves and the stunted, non-leafing shoot tips similarly deformed. Infected parts usually less swollen. Gall at its base often likewise curved and protruding. Club-shaped hairs absent. Between the swollen, dark coloured parenchyma are many dark orange-coloured gall midge larvae: Giraudiella inclusa

9a On the tips of main shoots => 10

9b Longitudinal growth of lateral shoots ± stunted, deformed to 15‒30 (50) cm long obliquely ascending slightly spindle-shaped swollen, tough-walled shoots. Leaf sheaths well developed, ± gaping, the closely converging leaf blades markedly shortened. In the dark brown to blackish coloured pith are many white to bright reddish-yellow gall midge larvae living in isolated chambers: Lasioptera arundinis

10a Gall usually less than 8 cm long and slim => 11

10b The characteristic “cigar” galls are up to 15 cm long and 1.5 cm wide. Terminal internodes markedly shortened and swollen; cross walls are missing in the older, initially still green galls which, from autumn onwards, turn brown and woody. Leaves converging, sheaths well developed, tight fitting, development of leaf blades variable, often considerably stuntedA fat, in mature condition 7‒10 mm long, cylindrical white-yellow maggot lives inside the tube-shaped chamber: Lipara lucens

11a Especially in the stem parts less conspicuously developed gall without chamber and no thickening of the stem. Wall hardly lignified. Sheaths spindle-like swollen; leaf blades usually normally developed, clearly separate from the gall. The larva lives between the leaf sheaths growing from the two terminal nodes, its position marked by a dark brown rotting channel: Lipara similis

11b Gall slender, c. 1.8 x diameter of normal shoot, central chamber not woody. The upper leaf is not normally developed but shortened and remains ± boat-shaped. Leaf sheaths broadened; leaf blades of the lower leaves normal, dropping off in autumn. Larva situated above growing point: Lipara rufitarsis and/or L. pullitarsis

gallers on Papaver

Last modified 26.iv.2020

Dichotomous table for gallers on Papaver

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. P. argemone, rhoeas: Meloidogyne hapla

1c Cyst -developing eelworm in hardly disfigured roots. Papaver sp.: Heterodera schachtii

2a On flowers and fruits => 6

2b On vegetative organs => 3

3a Malformations caused by animals => 4

3b Malformations caused by fungi. Leaves of often completely diseased and severely stunted young plants narrowed, pale and thick. Partially infected young leaves on usually expanded infestation area yellow-green, between veins bladder-like swollen, fleshy thickened, the margins rolled downwards and on underside covered with a dense, white-grey to pale violet down of conidiophores. Diseased flower- or capsule stalks, variously distorted due to stunting; buds and capsules crippled and disfigured. P. dubium, rhoeas, somniferum: Peronospora arborescens

3c Similar malformation, mainly on leaves. P. argemone: Peronospora argemones

4a Malformations caused by aphids and spittlebugs => 5

4b Midrib of rosette leaves stunted, especially at base, spongy thickened; leaf blades ± nested, curved; young axial parts basally greatly shortened or with local, ± distorted pale swellings. Papaver spp.: Ditylenchus dipsaci

4c Stem from the outside not disfigured; many rotund, thin-walled galls inside; “cryptocecidia”. Each gall containing a single larva. P. bracteatum, lasiothrix, pseudoorientale, somniferum: Iraella luteipes

4d Midge larvae developing in stems of P. nudicaule: Karshomyia caulicola

5a Complete plant disfigured; leaves rolled downwards, curled, ± discoloured. Papaver spp.: Aphis fabae

5b Leaf blade strongly deflected, curled and deep green close to the froth-covered nymph. P. orientale, rhoeas, somniferum: Philaenus spumarius

6a On or in fruit capsules => 7

6b Double flowers. P. alpinum: Unidentified gall mite

6c Flower buds transformed into a rosette of short leaves and bracts wrapping an irregular globular area with a plurilocular gall containing 2‒6 cells, flowers aborted. P. dubium, rhoeas: Iraella hispanica

7a Galls not or hardly visible from the outside => 8

7b Large parts or complete capsule strongly swollen and disfigured. Septa absent or reduced to short ridges. Tissue inside capsule soft, towards margin ± cracked with many tough-walled larval chambers. P. argemone, dubium, rhoeas, somniferum: Aylax papaveris

8a Tough walled, small, white galls located on the septa, up to 2 mm long, developing from seed primordia. Containing a single white larva. P. argemone, dubium, hybridum, rhoeas: Aylax minor

= Inquiline cynipid wasp: Parnips nigripes

8b Between strongly swollen septa of sometimes ± distorted capsules live many orange-red midge larvae. P. argemone, dubium, fugax, rhoeas, somniferum: Dasineura papaveris

gallers on Lithospermum

Last modified 25.iv.2020

Dichotomous table for gallers on Lithospermum

(incl. Aegonychon, Buglossoides)

by Hans Roskam

1a Malformations on terminal shoot parts => 4

1b Localised galls on leaves of shoot axis => 2

2a Locally defined galls mainly on leaves, occasionally on shoot axis => 3

2b Stem with ± pronounced swellings, with froth-covered nymph in rimmed depressions. Aegonychon purpurocaeruleum, Lithospermum officinale: Planchonia arabidis

3a Less than 1 mm long, at first yellow-red, later on brownish warts, often joined into crusts; mainly on leaves, sometimes on calyx. Buglossoides arvensis: Synchytrium myosotidis

3b Much larger, on leaf blade rotund or oval, on axial parts spindle-shaped elongated, yellowish pads bearing aecia. Aegonychon purpurocaeruleum, Buglossoides arvensis, Lithospermum officinale: Aecidium lithospermi

4a Malformations, not restricted to shoot tips => 5

4b At base spoon-like broadened, thickened and abnormally haired leaves are bud- to rosette-like, clustered on the tips of main- and lateral shoots. Aegonychon purpurocaeruleum, Buglossoides arvensis, Lithospermum officinale: Dasineura lithospermi

5a Malformations caused by animals => 6

5b Fungal causers. Completely diseased leaves narrowed, pale, slightly hypertrophied and rolled downwards at margin. Covered with down of branched conidiophores on underside. Often many leaves are diseased at ends of shoots. Buglossoides arvensis, Lithospermum officinale: Peronospora lithospermi

6a Similar malformations, associated with curling and twisting of leaf blades, caused by aphids. Aegonychon purpurocaeruleum, Buglossoides arvensis, Lithospermum officinale: Brachycaudus helichrysi

6b Shoot axis usually stunted on one side and distorted, inserted leaves deflected over their tip, ± curled and rolled downwards, deep green close to the froth-covered nymph. Buglossoides arvensis: Philaenus spumarius

gallers on Cucumis

Last modified 25.iv.2020

Dichotomous table for gallers on Cucumis

(inc. Citrullus)

by Hans Roskam

1a On parts above ground => 4

1b On roots or on root collar => 2

2a On roots => 3

2b Several shoots on root severely stunted, thickened, developing into a compact “leafy gall”: Rhodococcus fascians

3a 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. C. sativus: Xiphinema diversicaudatum

3b Roots with small nodular to spindle-shaped swellings, occasionally with side roots. C. melo, sativus: Meloidogyne hapla

4a Malformations of leaves caused by aphids => 5

4b Nodular swellings on stem, twigs and roots. C. melo: Eriosoma lanigerum

4c Development of young plants severely stunted. Lower stem parts shortened, irregularly spongy, swollen, plants often with increased development of often similarly disfigured lateral shoots. Later infestations result in locally ± confined pale green, spongy swellings on stems, leaves and even young fruits. C. melo: Ditylenchus dipsaci

5a Leaf blades disfigured and curled. Aphids lighter to darker green or yellowish => 6

5b Aphids black. Cucumis spp.: Aphis fabae

6a Aphids lacking frontal protuberances on head; siphunculi cylindrical or weakly conical => 7

6b Protuberances on head present. Siphunculi weakly club-shaped. Body glossy, greenish-yellow to green or reddish. Cucumis spp.: Myzus persicae

7a Apterous aphids dark-spotted to dirty yellow. Siphunculi black, slightly conical. Cucumis spp.: Aphis gossypii

b Apterous aphids yellow to greenish-yellow. Siphunculi yellowish-green with brownish tip. Cucumis spp.: Aphis nasturtii

gallers on Vaccinium

Last modified 25.iv.2020

Dichotomous table for gallers on Vaccinium

by Hans Roskam

1a Galls on parts above ground => 2

1b Roots with sometimes almost star-shaped swellings, 2–3 mm long, white on outside- and inside. Inducer unknown

2a Galls on leaves, on tips, also terminally on shoots or witches’ broom-like malformations => 4

2b Galls on axial parts of shoot => 3

3a Young stem parts locally broadened, with small, rimmed depressions, which harbour the causer under a pear-shaped white scale. V. myrtillus, vitis-idaea: Chionaspis salicis

3b Stem, usually over several internodes, swollen on all sides, up to 2–3 times the normal volume. Diseased parts rigidly erect, abnormally elongated; galls sometimes interrupted by normal parts, at first white or pink to reddish, later on cork-brown. Epidermis cells contain fruiting bodies. Lower leaves on galled shoots disfigured, usually dropping prematurely. V. corymbosum, membranaceum, vitis-idaea: Pucciniastrum goeppertianum

4a Malformation of several leaves or organs on tips or terminally on sometimes witches’ broom-like disfigured shoots => 9

4b Leaves, exceptionally also flowers, with ± expanded, localised galls => 5

5a Leaf blade with rolled margins or weak protrusions => 6

5b Smaller or larger parts of leaf blade or flowers often strongly swollen; on leaf upperside crimson-red or yellow, usually ± depressed; the arching on underside at maturity densely covered with dusty, chalk-white, basidia with 4 (‒6) spores. V. vitis-idaea: Exobasidium vaccinii

6a Roll of leaf margin => 7

6b Small depressions on lower surface of leaves. The upper part of the gall is usually red coloured and surrounded by a yellow patch. V. uliginosum: Contarinia sp.

7a Leaf margin rolled; on V. oxycoccos, uliginosum => 8

7b Roll of margin on V. myrtillus, vitis-idaea. Roll narrow, 1–1.5 mm broad, compact, often downwards, sometimes upwards, cartilaginously thickened; at first not, later on yellowish discoloured, margin ± concave. Containing a single larva: Dasineura myrtilli

8a On V. oxycoccos. Roll downwards, compact, slightly thickened and reddened. Containing several yellow-red larvae. Unidentified gall midge

8b On V. uliginosum. Leather-like thickened, yellowish or reddened downward roll. Containing a single yellow or reddish larva: Hygrodiplosis vaccinii

9a Leaves on shortened shoot tips keel-shaped, slightly thickened, uneven, imbricate; developing into a gall, sometimes ± blood-red, up to 8 mm long and 5 mm broad, in which the exterior leaf mostly encloses the inner ones containing a single red larva. V. myrtillus: Jaapiella vacciniorum

9b Malformations of larger expansion => 10

10a Malformations by fungi; at maturity densely covered by white fruiting bodies => 12

1b Malformations caused by animal parasites => 11

11a Leaf blades of several leaves reduced, ± undulately folded or wrinkled; margin and tip curved ± upwards. V. myrtillus, uliginosum: Phyllocoptes vaccinii

11b Several leaves on shoot tips slightly twisted; glossy green-yellow aphids occur on underside. V. vitis-idaea: Wahlgreniella vaccinii

12a Malformations without conspicuous thickening of stem => 13

12b Terminal part of stem or axis of inflorescence conspicuously succulent to varied extent. Leaves inserted on the galled part or flowers also variously strongly thickened. V. vitis-idaea: Exobasidium vaccinii

13a Stem usually not hypertrophied, in often large expansion and bearing several often vividly red or more yellowish coloured leaves. Leaf blades often larger, sometimes smaller than normal ones, less glabrous and glossy, weakly thickened, arched in many cases. Mycelium on underside. Malformations almost witches’ broom-like. Flowers usually atrophy on such shoots; sometimes all parts are moderately enlarged, but hardly thickened. On V. myrtillus, uliginosum, vitis-idaea => 14

13b Similar malformations on V. oxycoccos. The diseased parts slightly hypertrophied, distinguished from healthy parts by their erect growth. Leaves thickened and enlarged: Exobasidium oxycocci

13c Slightly disfigured shoots; first-year leaves sometimes enlarged, pale green or rarely becoming red. V. uliginosum: Exobasidium expansum

14a Basidia usually 4-spored. Spores 10–13 x 3–4 µm: Exobasidium myrtilli

14b Basidia 2-spored. Spores 18–32 x 7–12 µm: Exobasidium vaccinii-uliginosi

14c Furthermore may occur the following closely related smuts:

a Red thickened spots on V. macrocarpon, microcarpum, oxycoccos: Exobasidium rostrupii

b Distorted twigs on V. macrocarpon, microcarpum, oxycoccos: Exobasidium oxycocci

c Red malformations of twigs and leaves. V. myrtillus: Exobasidium myrtilli and rarer: E. aequale

d Red spots on leaves of. V. uliginosum: Exobasidium pachysporum

e Red distortions of twigs and leaves on V. vitis-idaea: Exobasidium juelianum and/or E. splendidum

gallers on Valeriana

Last modified 24.iv.2020

Dichotomous table for gallers on Valeriana

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular, club- or spindle-shaped slender swellings, a few mm long, which bear side roots. V. excelsa subsp. sambucifolia, officinalis: Meloidogyne hapla

2a On flowers or inflorescences => 10

2b On leaves and stems => 3

3a Malformations bearing sori => 9

3b Malformations lacking sori on outside => 4

4a Galls on leaves, sometimes encroaching onto stem parts => 5

4b Shoot axis stunted. Leaves variously deflected, curled, locally deep green. Infected inflorescences ± clustered, ball-like. The froth-covered nymph occurs also on single, similarly disfigured leaves. Valeriana spp.: Philaenus spumarius

4c Stem swollen. V. officinalis: Ditylenchus dipsaci

5a Leaves rolled inwards, frayed or curled => 6

5b Many multicellular warts, less than 1 mm long, at first golden-yellow, later on ± browned, on leaf blades, -stalks and basal stem parts. Sometimes coalescing, crust- or ridge-like, additionally disfiguring the infected parts. V. dioica, montana, officinalis: Synchytrium aureum

6a Leaf blades slightly rolled inwards => 8

6b Leaf blades otherwise ± severely disfigured => 7

7a Tips of leaves sometimes excessively deeply dentate or frayed, rolled upwards or twisted, discoloured, sometimes abnormally haired. V. dioica, montana, tripteris: Unidentified gall mite

7b Leaf tips converging and curled, inflated, twisted, thickened and discoloured. Containing single to several white jumping larvae. V. excelsa subsp. sambucifolia, montana, officinalis, tripteris: Contarinia crispans

8a Leaf blade loosely rolled. V. tripteris: Unidentified psyllid

8b Leaf blade loosely rolled inwards, black aphids on underside. Valeriana spp.: Aphis fabae

9a Distinct swellings, ± yellowish, sometimes curved, up to 15 (20) mm long, often yellowish margined on leaf veins, -stalks or stems, bearing irregularly or circularly arranged aecia, as well as spermogonia. Valeriana spp.: Uromyces valerianae

9b Aecia in coherent, expanded sori on slightly thickened, sometimes ± distorted, occasionally discoloured pads, which may, depending on condition of organ, measure up to 10 cm. The teliospores also soon develop in the same sori. II absent. Sori on leaf blades, -midrib and -stalks, on axial parts of shoot and inflorescence, also occurring on bracts and calyx. V. excelsa & subsp. sambucifolia, montana, officinalis, procurrens, tripteris: Puccinia commutata

10a Flowers leafy or greened (phyllanthy) => 11

10b Axial parts of inflorescence ± stunted. Flowers sometimes densely gathered together, unopened and infertile. Containing several, white to ivory jumping larvae. V. excelsa & subsp. sambucifolia, officinalis & subsp. collina: Contarinia valerianae

11a On V. dioica, montana, tripteris => 12

11b On V. officinalis. Axial parts of inflorescence shortened; flowers irregularly clustered, ball-like. Calyx hardly changed; inner flower parts variously leafy. V. doica, officinalis. Aceria macrotuberculata

12a On V. montana. Flowers disfigured, ± greened or double. Unidentified gall mite

12b Flowers leafy. All parts transformed into green, hairy small leaves. Often excessively branched. Bracts ± disfigured. Flowers double if weakly infected; calyx and corolla greened; stamens and ovaries corolla-like. V. dioica, tripteris: Unidentified gall mite

gallers on Viburnum

Last modified 30.iv.2020

Dichotomous table for gallers on Viburnum

by Hans Roskam

1a On parts above ground => 3

1b On root collar or on roots => 2

2a On stem base gall-like, clumpy accumulation of stubby, succulent, swollen, ± branched and broadened shoots. “Leafy gall”. V. opulus: Rhodococcus fascians

2b Roots with nodular to spindle-shaped swellings. Viburnum spp.: Meloidogyne hapla

3a On flowers => 13

3b On axial parts of shoots, shoot tips or leaves => 4

4a On shoot tips and leaves => 6

4b On axial parts of shoots => 5

5a Pencil- to finger-thick twigs bear on several nodes globular to spindle-shaped swellings, up to 20 (33) mm thick, at first succulent, soon woody, slightly longitudinally grooved on their surface, which extends more than halfway around the axis. V. opulus: Agrobacterium tumefaciens

5b Thinner axial parts with rimmed depressions containing causer under pear-shaped scales up to 3 mm long. V. lantana, opulus: Chionaspis salicis

6a Malformations of indefinite shape, mainly on several terminal leaves => 9

6b Leaves with localised galls, ± constant in shape or with ± expanded pubescence => 7

7a Galls lenticular or spherical => 8

7b Underside of leaves with dense, abnormal pubescence on ± expanded rotund spots. Hairs ± stalked, star-shaped, slightly larger and more rigid than normal ones. V. lantana: Unidentified gall mite

7c Clusters of hairs causing depressions in vein axils. V. tinus: Unidentified gall mite

8a Pouch galls protruding on upperside, usually many, short-stalked, pinhead-shaped; sometimes ± reddened, covered with rigid hairs. With a strongly pubescent exit hole on underside. V. carlesii, lantana, rhytidophyllum: Eriophyes viburni

8b Leaf blades often with many parenchyma galls, up to 6 mm broad, rotund, flat on both sides often ± reddened on upperside, pale green on underside. Each containing a single orange-yellow larva. V. lantana, maculatum: Sackenomyia reaumurii

9a Malformations of many leaves on often conspicuously shortened shoot tips of younger or older bushes; caused by aphids => 10

9b Leaf blades of young plants or older bushes or basal shoots at infestation site deflected, especially over the tip; leaf blade curled and locally deep green. Viburnum spp.: Philaenus spumarius

10a Malformations on V. opulus and several cultivated species, rarely on V. lantana => 11

10b Malformations only on V. lantana. Leaf margin loosely rolled. Aphid olive-yellow to –green, with broad transverse brown-black bands: Aphis lantanae

11a Leaves strongly curved or curled => 12

11b Leaves usually slightly curled and slightly rolled inwards at margin. Galls only in spring. V. opulus and several cultivated species: Aphis fabae

12a Malformations inhabited throughout the year. V. opulus, lantana and many cultivated species. V. carlesii, cotinifolium, dilatatum, lantana, opulus, rhytidophyllum, tinus: Aphis viburni

12b Similar malformations, but only inhabited in spring. V. lantana, opulus: Ceruraphis eriophori

13a Flowers swollen, unopened, often partially reddened. Corolla thickened, slightly leathery. Stamens partially aborted. Ovary ± swollen. Containing yellow, jumping larvae. V. lantana, opulus: Contarinia lonicerearum

13b Similar flower galls with 2–3 white to sulphur-yellow jumping larvae. V. lantana, opulus, tinus: Contarinia viburnorum

gallers on Vinca

Last modified 24.iv.2020

Dichotomous table for gallers on Vinca

(incl. Catharanthus)

by Hans Roskam

1a On stems, buds or leaves => 2

1b Roots with nodular to slender spindle-shaped swellings. V. minor: Meloidogyne hapla

2a Malformations of leaves or shoot tips caused by animals => 5

2b Perennial mycelium disfigures complete shoots, which grow with elongated, thinner internodes rigidly erect. Leaves pale green, shortened and thickened; the younger ones curved upwards over their length, keel-shaped. Shoots non-flowering or rarely developing some disfigured flowers => 3

3a Fungi on V. herbacea, minor => 4

3b On V. major: Puccinia vincae

4a On V. herbacea. Infected shoots grow erect, not prostrate like healthy ones, and are etiolated. Leaves distinctly reduced, pale green on underside with many spermogonia and often in lines arranged uredinia and later on ± punctiform telia: Puccinia anatolica

4b Malformations on V. minor similar to fungi occurring on previously reported hosts, but distinguished by lacking uredinia: Puccinia cribrata

5a Malformations caused by aphids => 9

5b Other gall causers => 6

6a Leaf margins loosely rolled inwards or with kidney-shaped swellings. Leaves not conspicuously clustered => 8

6b Buds severely stunted with thickened leaves or top parts of shoots shortened with leaves more clustered => 7

7a Buds severely stunted terminally on end- or side shoots. Between thickened leaf blades of still unfolded buds are several reddish larvae. V. herbacea, major: Dasineura vincae

7b Terminal part of shoot ± shortened. Leaves erupting from buds, more clustered. Leaf blades pod-shaped, often rolled upwards to midrib; lighter, rough, ± bent and twisted. V. herbacea: Aceria liszkai

8a Leaf margin loosely rolled inwards. V. minor: Unidentified psyllid

8b Leaf margin with kidney-shaped swelling. ? V. minor: Inducer unknown

9a Young leaves slightly twisted. Aphid 1.5–2.3 mm long, pale yellow to greenish-yellow, with variable black marks, reminiscent of a horse shoe. V. difformis. major, minor: Aulacorthum circumflexum

9b Malformations may also be caused by Rhopalosiphoninus staphyleae

9c Young leaves severely disfigured, with many pale green or browned spots, resulting from stunting. V. minor: Aulacorthum solani

gallers on Berberis

Last modified 24.iv.2020

Dichotomous table for gallers on Berberis

(incl. Mahonia, × Mahoberberis)

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodular swellings. B. vulgaris, aquifolium: Meloidogyne hapla

2a Malformations on ± more expanded parts, bearing spores => 7

2b Galls caused by animals => 3

3a Galls on vegetative parts => 4

3b Fruits greatly enlarged; containing up to 4 non-jumping, pale green larvae. B. thunbergii: Unidentified gall midge

4a Malformations of leaves => 5

4b Stem with lateral, many-chambered swellings, crooked on surface, often red-brown. Containing several red larvae. B. vulgaris: Lasioptera berberina

5a Galls caused by insect inducers => 6

5b Galls caused by gall mites. Leaf blade reddish-brown with rusting. B. thunbergii, vulgaris: Phyllocoptes granulatus

6a Leaves on axillary buds, more rarely on shoot tips, rolled upwards, at first densely clustered, later on pushed apart; rolled part wrinkled or with small protuberances, cartilaginous, thickened; discoloured or ± dark red to violet on outside. Larvae at first translucent, later on white. B. vulgaris: Dasineura berberidis

6b Leaf blades on underside with lighter depressions, up to 3 mm long; with corresponding archings on upper side. Leaf margin bent downwards. B. vulgaris, x Mahoberberis neuberti: Trioza scottii

6c Leaves disfigured, ± distorted; more strongly infected shoots stunted. Aphid 2–2.5 mm long, yellow, also red or greenish. B. aquifolium, hispanica, thunbergii, vulgaris; x Mahoberberis neubertii: Liosomaphis berberidis

6d Shrivelled egg capsules, with several arranged in a half circle. “Procecidia” (oviposition scars, not true galls). B. vulgaris: Arge berberidis

7a Aecia on locally defined cushions => 8

7b Aecia on witches’ broom-like disfigured shoots. Berberis spp.: Puccinia arrhenatheri

8a Aecia cup-shaped, with deflected, frayed margin; on rotund or oval bulges on leaf underside, up to about 5 mm long, strongly arched, often orange-coloured to red, sometimes also on the green parts of inflorescences and flowers as well as on buds, young fruits and axial parts. B. vulgaris, aquifolum; Mahonia bealei: Puccinia graminis

8 Galls and aecia very similar to those of Puccinia graminis, distinguished only by microscopical characters; mainly occurring on young leaves. Wall of aeciospores of same thickness all around. Sori 2–8 mm across, at first greenish, later on brownish, bulging cushions on leaf underside; spermogonia on deep red discoloured leaf upper side. Occasionally also on leaf midrib, -stalks, or on young axial parts. Spermogonia usually dull orange. Berberis aquifolium, repens; Mahonia japonica: Cumminsiella mirabilissima

gallers on Avenula

Last modified 24.iv.2020

Dichotomous table for gallers on Avenula

(incl. Avenastrum, Avenochloa, Helictochloa, Helictotrichon)

by Hans Roskam

1a On inflorescences or flowers => 8

1b On culms, shoot tips or leaves => 2

2a On leaves or shoot tips => 4

2b On culms => 3

3a Upper internode of culm with one-sided, hard, reddish swelling about 10 mm long and 3 mm wide. Avenula pubescens: Tetramesa sp.

3b The diseased culms develop early, usually over their complete length, because of increased growth above all the basal internodes and have smut patches on their culms ± protruding from the leaf blades on all sides. Spores clustered with 1–2 (4) per ball, enveloped by a layer of many auxiliary cells. Avenula pubescens; Helictochloa versicolor: Urocystis avenastri

4a Malformations caused by animals => 5

4b The shortened, narrowed and often setose leaves on the often rigidly erect, soon stunted shoots with rows of often coalescing, later on erupting smut sori releasing black spores. Spores solitary. Avenula pubescens, Helictochloa pratensis: Ustilago scaura

5a Malformations on ± distinctly stunted shoot tips => 6

5b Leaf blade with less than 10 mm long, often purple, narrow cylindrical swelling. Helictochloa pratensis: Unidentified eelworm

6a Galls caused by larvae of insects; occurring inside => 7

6b Malformations caused by aphids occurring on the outside. The terminal leaf sheaths ± inflated and discoloured. Leaf blade variously twisted, curled or ± rolled inwards. Avenula pubescens, Helictochloa pratensis: Rhopalosiphum padi

7a Tuft-like accumulation of leaves on the upper internodes of the ± thickened shoot tip. Containing a single larva in pith. Avenula pubescens: Tetramesa sp.

7b Development of young shoots stunted while still close to the ground. Stems from their base onwards slightly swollen and excessively shortened towards the tip. The leaves close to one another, but not clustered into a tuft; their bases and sheaths often conspicuously reddened. Avenula pubescens, Helictochloa planiculmis: Chlorops pumilionis

8a Various malformations of spikelets, dependent on the reactive ability during infestation, often associated with leafiness and greening of the spikelets, eventually atrophying of all parts resulting in bleaching. Avenula pubescens, Helictochloa pratensis: Aceria tenuis and/or A. cornuta, Aculodes dubius

8b Ovaries disfigured often in many or all flowers of a panicle, soon destroyed and replaced with a black, dusty spore mass. Avenula pubescens: Ustilago avenae

gallers on Aquilegia

Last modified 24.iv.2020

Dichotomous table for gallers on Aquilegia

by Hans Roskam

1a On above-ground parts => 2

1b Roots with spindle-shaped to lenticular swellings. A. atrata, chrysantha, vulgaris; Meloidogyne hapla

2a On flowers => 7

2b On leaves => 3

3a Malformations caused by animals => 5

3b Malformations caused by fungi => 4

4a Expanded yellow, sometimes violet margined sori on the leaf underside bearing aecia; rotund on leaf blades, oblong-oval on major veins, rachis or stalk. Rust fungi with different host alternation developing similar galls; aecia in May, June:

a Aecia usually on distinctly swollen pads or ± curved bulges. Aquilegia spp.:
Puccinia recondita f. sp. agrostidis

b In similar aecia on A. vulgaris, only slightly cecidogenic: Puccinia actaeae-agropyri

c Usually causing stronger malformations: Puccinia actaeae-elymi

d In similar aecia but differentiated by smaller aeciospores, only known from Aquilegia: Puccinia scarlensis

e Leaflets with swollen blisters which rupture, exposing black powdery spore mass, whole leaf sometimes distorted. A. ottonis subsp. amaliae: Urocystis sorosporioides

4b Leaves or petioles with initially lead-grey translucent, later on rupturing bulges, up to 10 mm long. Containing black dusty spore balls. A. aurea, caerulea, vulgaris: Urocystis aquilegiae

5a Leaf blades arched, curled or curved; caused by aphids or spittlebugs => 6

5b Tips of basal leaves converging. Leaf blade etiolated; margin bent, partially curled to wart-like wrinkled, veins thickened. A. atrata: Unidentified gall mite

6a Parts of leaf blade of younger leaves clustered nest-like, their stalks and rachis shortened and bent. Leaflets curled close to the froth-covered nymph and dark green. Aquilegia spp.: Philaenus spumarius

6b Leaf blade slightly arched, locally often reddened. A. vulgaris: Longicaudus trirhodus

7a Malformations usually confined to single flowers on hardly stunted plants => 8

7b Development of plant often largely stunted, many parts disfigured. Flowers ± distorted; all parts reduced and leafy or, if weakly infected, only the inner parts disfigured. Aquilegia spp.: Cause unknown – ? virus

8a Flowers only slightly stunted and disfigured, not or hardly opened. ± greened. Containing several white to orange- red larvae. A. alpina, vulgaris: Macrolabis aquilegiae

8b Double flowers. A. vulgaris: Inducer unidentified – ? gall mite

gallers on Apium

Last modified 23.iv.2020

Dichotomous table for gallers on Apium

(Incl. Helosciadium)

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodule-shaped swellings, occasionally clustered, ± curved. A. graveolens: Meloidogyne hapla

= Almost coral-like thickenings on roots of etiolated plants are caused by the ectoparasitically living, usually non-cecidogenic, needle eelworm Paralongidorus maximus. Also reported are the dagger eelworm Xiphinema sp.

2a Curl of leaves caused by aphids or cercopids => 7

2b Malformations caused by eelworms or fungi => 3

3a Bulge-like swellings caused by fungi with fructifications on surface => 6

3b Galls without fruiting bodies on surface => 4

4a Galls only a few mm long => 5

4b Mainly base of petioles spongy, swollen. Galls wrinkled. Leaf blades ± yellowing. Upper part of tubers sometimes with ± expanded protrusions, at first wart-like, then penetrating deeper, soon decaying, eelworm-rich infestation sites. A. graveolens: Ditylenchus dipsaci

5a Leaf blade with flat, pin head sized galls, at first white, then yellowish, eventually brown; also on petioles and stems, there occasionally coalescing into ± spindle-shaped bulges; sometimes even on rays of (partial) umbels as well as ovaries. A. nodiflorum: Buerenia inundata

5b In similar small pustules on leaves developing on A. nodiflorum, repens:
Entyloma helosciadii

5c Petiole and leaf veins, and stem with oblong-oval flat bulges, up to 3 mm long, pale green, later on browned. A. inundatum nodiflorum, repens: Physoderma vagans

5d Leaves with small hard pustules, less than 0.5 mm across. Apium spp.: Synchytrium aureum

6a Petiole, rachis, or leaf veins with spindle-shaped, distinctly pad-like arched, yellowish to brownish bulges, usually on underside. Aecia densely placed, cup-shaped, with distinctly protruding, frayed border; spermogonia countersunk. A. graveolens, nodiflorum: Uromyces lineolatus

6b Yellowish, slightly swollen bulging, rotund- to oblong-oval pads, occasionally on the venation, bearing spermogonia as well as aecia on underside. A. graveolens, prostratum: Puccinia apii

7a Large parts of leaf blade ± nest-like deflected; rachis shortened; leaflets close to the froth-covered nymph curled and intensely green. A. graveolens: Philaenus spumarius

7b Leaf blades slightly deflected; rachis shortened; causing complete leaf blade to become compact, ± depressed, with black aphids on underside. A. graveolens: Aphis fabae

gallers on Anthemis

Last modified 23.iv.2020

Dichotomous table for gallers on Anthemis

(incl. Cota, Cotula)

by Hans Roskam

1a On above-ground part => 2

1b Roots with nodule-shaped slender humps, up to 4 mm, with beginnings of lateral roots. Cota tinctoria: Meloidogyne hapla

2a In capitula or fruits => 5

2b Plant partly or completely deformed => 3

3a Malformations by aphids or cercopids => 4

3b Plant bushy by inhibition of the internodes; mostly non-flowering; with pustule-shaped depressions over extensive areas, containing fruiting bodies. A. arvensis: Didymaria matricariae

3c Stem usually close to the ground with up to about 8 (12) mm long, broad spindle-shaped swelling, with a depressed break in the middle concealing a scale insect under a crooked shield. Cota tinctoria: Planchonia arabidis

4a Stems of young shoots locally stunted and curved; leaves closed, with their tips in different ways ± clump-like bent downwards. One froth-covered nymph. A. arvensis: Philaenus spumarius

4b Plant parts bunched together on the ± stunted shoot tips, downwards reflexed and curved; greenish aphids. A. arvensis: Brachycaudus helichrysi

5a Malformation of receptacle and of flower head => 6

5b Ovary or fruit swollen without or together with the lower flower parts. Also the bract may be involved in the gall formation. Containing a single yellow larva. A. arvensis, bornmuelleri, cotula, pseudocotula, rascheyana: Ozirhincus longicollis

5c Similar galls and biology. A. arvensis, bornmuellei, rascheyana, retusa; Cota tinctoria: 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.

6a Receptacle thickened or occupied by independent ± separate galls => 7

6b Capitula deformed in different ways. Marginal flowers partially excessively elongate, ± misshapen and bent; often containing many oospores. Mycelium extended over large parts of flower head, changing into dirty violet-grey layers of branched conidia locally at the surface. A. arvensis, cotula, ruthenica; Cota austriaca: Peronospora radii

7a Complete receptacle swollen and hardened => 8

7b Between the flowers up to 3 mm long, cylindrical-conical achene-like galls, which differ from achenes however by their smooth compact wall. The galls are firmly inserted in the receptacle; the conical top becomes detached at maturity. Containing a single larva. A. arvensis, cotula; Cota austriaca; Cotula triumfettii: Rhopalomyia syngenesiae

8a Malformations caused by maggots of tephritid flies => 10

8b Malformations caused by beetle larvae => 9

9a Receptacle enlarged 2–3 times, globular to ovate; wall thick and tough. Containing a single larva with head capsule. A. arvensis, cotula; Cota tinctoria: Omphalapion laevigatum

9b Recorded from similar galls on A. cotula: Omphalapion hookerorum

9c Slight malformation of capitula. Cota tinctoria: Omphalapion buddebergi

10a Receptacle swollen, malformed, hardened. Larva without distinct head capsule, with black mandibles. A. arvensis, cotula: Eurasimona stigma

10b Similar galls. A. arvensis, cotula: Trupanea stellata

gallers on Isatis

Last modified 22.iv.2020

Dichotomous table for gallers on Isatis

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

1c Root collar with rotund, succulent, up to about 10 mm long swellings. Containing a single larva. I. tinctoria: Ceutorhynchus assimilis

2a Conspicuous, spindle-shaped to cylindrical swellings on main- and side roots. I. glauca, praecox, tinctoria: Plasmodiophora brassicae

2b Outside of roots little changed, temporarily bearing white to brown, poppy seed sized cysts. Giant cells develop inside. Isatis spp.: Heterodera schachtii

3a Malformations on shoot tips or on leaves, partially with conspicuous involvement of midrib; also on flowers => 7

3b Galls on shoot axis or petioles, without or with involvement of leaf blades => 4

4a Galls compact, caused by insects or fungi => 5

4b Galls pale green, spongy; confined to axial parts or only slightly encroaching into the leaf blade. I. tinctoria: Ditylenchus dipsaci

5a Rough-walled galls on stem, petiole or midrib, caused by beetle larvae => 6

5b Bulge-like, spindle-shaped, slight swellings on midrib, at first covered with glossy white, then mealy dusted sori. I. djurjudae, praecox, tinctoria: Albugo candida

5c The entire plant is disfigured. Upper side of the leaves locally bleached and galled; at the corresponding underside a greyish-white fungal bloom consisting of erect, distally strongly branched conidiophores. In the plant tissue locally oospores are formed, and particularly there galling occurs. I. tinctoria: Hyaloperonospora isatidis

6a Shoot axis stunted, with a long expanded swelling, containing several larvae. I. tinctoria: Ceutorhynchus sp.

6b Spindle-shaped, up to 12 mm long, also deep green inside gall; containing a single larva. I. praecox, tinctoria: Ceutorhynchus chalybaeus

7a Malformations on vegetative parts => 8

7b lower buds unopened, slightly swollen. Their peduncle slightly elongated and deflected, causing the galls to be ± hanging. Inside are several white to pale yellow midge larvae. Sometimes the larvae live in young flowering shoots in terminal, dense clusters of distinctly reduced buds between the organs. I. praecox, tinctoria: Contarinia nasturtii

8a Malformations of leaf blades => 10

8b Clustering of disfigured organs on ± stunted shoot tips => 9

9a Shoot axis distinctly shortened terminally, with dense tuft of ± stunted, almost sessile leaves, broadened at base, thickened and more pubescent. Containing several white to pale yellow larvae. I. praecox, tinctoria: Contarinia nasturtii

9b Shoot tips stunted, slightly thickened, organs inserted in dense clusters. Leaves stunted, curved and curled; flower buds reduced, partially ± exhibiting necrotic, greened organs. Infestation of isolated leaves results in the development of ± distinct, pale, ± reddish marbled swellings or folds. I. tinctoria, undulata: Brevicoryne brassicae

10a Leaf blade wrinkled and curled. I. tinctoria: Metaculus rapistri

10b On basal leaves the complete midrib is often ± curved, on larger leaves only the middle part over several cm is stunted and spongy, swollen, the leaf blades close to midrib are abnormally pubescent, bent upwards, strongly lacerated, on upper side bulge-like swollen. Containing several whitish to pale yellow larvae. I. praecox, tinctoria: Contarinia nasturtii

gallers on Helianthemum

Last modified 22.iv.2020

Dichotomous table for gallers on Helianthemum

by Hans Roskam

1a On inflorescences, flowers, capsules or on leaves => 4

1b On shoot tips or axial parts of shoot => 2

2a On shoot tips => 3

2b Shoot axis with ± expanded, sometimes bent, spindle-shaped to bulging swellings, in variable number, each containing the causer in a rimmed small groove. Helianthemum spp.: Planchonia arabidis

2c Swelling of 3 mm across. H. rosmarinifolium: Cistapion cyanescens

3a Tuft- or bud-like clustering of widened, thickened, often densely haired leaves. Containing several orange-yellow larvae. H. canum, nummularium & subsp. grandiflorum + obscurum: Dasineura helianthemi

3b Subglobose terminal gall, 4–5 mm across when young, composed of tightly imbricate, green or pale pink, leaves, shorter and a little wider than normal leaves. Mature gall up to 10 mm long, slender and consists of chestnut-brown, tough, curved scales. Gall one-chambered, rotund, containing a red larva. H. salicifolium: Unidentified gall midge

3c Cluster of whitish pubescent, short, thick leaves terminally on twig. H. croceum: Unidentified gall midge

3d Both terminal leaves of a shoot folded together, developing into a spindle-shaped gall, up to 6 mm long and 2 mm thick. H. canum: Unidentified gall midge

4a On inflorescences, flowers or capsules => 6

4b On leaves => 5

5a Expanded parts of leaves covered with long, 1-celled, browned hairs. H. nummularium: Unidentified gall mite

5b Leaves rolled inwards. Helianthemum spp.: Aphis helianthemi

6a Galls limited to flowers or capsules => 7

6b Complete inflorescence transformed into a dense mass of small, abnormally haired leaves, with ± excessive branching and leafiness. H. canum, nummularium & subsp. obscurum, oelandicum, stipulatum: Aceria rosalia

7a Malformations of flowers => 8

7b Minor swelling of ovary in flowers with stunted perianth. Containing a curved larva. H. nummularium & subsp. obscurum, ovatum: Phrissotrichum rugicolle

7c Minor malformations on capsules. H. nummularium & subsp. obscurum:
Helianthemapion aciculare

8a Flower buds thickened, unopened. H. nummularium: Unidentified gall midge

8b Flower buds slightly disfigured, but with strong abnormal pubescence. H. nummularium: Unidentified gall midge

gallers on Gypsophila

Last modified 21.iv.2020

Dichotomous table for gallers on Gypsophila

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Spindle-shaped swellings on roots, up to 5 mm long and 2 (3) mm thick. G. elegans: Meloidogyne hapla

2b Conspicuous, proliferations on roots, root collar and stem base; 0.5–4.5 mm long; pale coloured, wrinkled-tuberculate at surface. Gypsophila spp.: Pantoea agglomerans pv. gypsophilae

3a On flowers => 9

3b On stems, shoot tips, or lateral leaf buds => 4

4a On shoot tips, buds or leaves => 5

4b Stem with expanded spindle-shaped swellings, the pith containing a caterpillar. G. fastigiata, paniculate: Caryocolum leucomelanella

5a On shoot tips or buds => 8

5b On leaves => 6

6a Malformations caused by animals => 7

6b Leaves sometimes with slightly swollen bulging, compact sori of dark-brown telia. G. elegans, muralis: Puccinia arenariae

7a Leaf blades at any point along length knee-like bent almost at right-angles. Breaking point close to midrib succulent, swollen, usually yellow-green, sometimes reddish. G. fastigiata: Planchonia arabidis

7b Leaves locally clustered, ± deflected and curled, partially deep green. Gypsophila spp.: Philaenus spumarius

8a Shoot tips or lateral buds stunted. Leaves transformed into a hemispherical to onion-shaped, often reddened gall. Occasionally enveloped by a spreading, basally strongly swollen ± fully developed pair of leaves; also may develop ± stunted leaf blades only at the base of galled leaves. Containing a single or several deep orange coloured larvae. G. fastigiata, repens: Bayeriola buhri

8b Leaves ± enlarged at the tip of vegetative shoots, curved inwards, ± converging, discoloured. G. repens: Unidentified aphid

9a Flower buds stunted, globularly inflated; containing dirty-yellow to brown-violet spores. Usually many to all flowers are disfigured on diseased plants. ? G. muralis: Sorosporium gypsophilae

9b Fungus develops in shortened and broadened anthers. Spores red-violet. G. repens: Microbotryum violaceum

gallers on Geum

Last modified 21.iv.2020

Dichotomous table for gallers on Geum

by Hans Roskam

1a On leaves or flowers => 3

1b On shoot tips or stems => 2

2a Weak swelling of petiole or shoot axis below a node. G. urbanum: Unidentified weevil

2b Leaves at shoot tip tuft-like clustered; leaf blades ± folded upwards; main venation ± creased and thickened. Containing white larvae. G. aleppicum, rivale, urbanum: Contarinia gei

3a On flowers => 11

3b On leaves => 4

4a Leaf folds or – curls => 8

4b Leaves with abnormal pubescence, warts, pustule-shaped galls or irregular fleshy swellings => 5

5a Warts or pustules => 7

5b Leaves with fleshy galls or with felt-like pubescence => 6

6a Leaf blade, also its midrib, with fleshy swellings about 0.4–12 mm long, sometimes coalescing, irregular, pale- to yellow-green, on both sides of which an intercellular mycelium develops a cottony covering bearing asci. G. montanum: Taphrina potentillae

6b Leaf blade often severely disfigured, with at first whitish, soon brown-red erineum on underside, often along the veins; corresponding, at first pale green, then ± reddened upward archings on upperside, also erinea on both sides of leaf; erinea occasionally extending onto leaf midrib and petiole, shoot axis, flower peduncles and calyx leaves. Hairs cylindrical. G. aleppicum, molle, montanum, rivale, urbanum: Cecidophyes nudus

7a Small warts on leaf blade, midrib and petiole, up to 1 mm across, sometimes coalescing into expanded crusts, ± golden-yellow translucent. Geum spp.: Synchytrium aureum

7b Leaf blade with rotund pale coloured bordered pustules. G. rivale: ? gall midge

8a Leaf-blade curled, caused by aphids or spittlebugs => 10

8b Leaf blades of basal leaves or leaves on stem folded or rolled at margin, caused by gall midges or sawflies => 9

9a Leaflets, starting at midrib, variously folded upwards. Veins thickened; leaf blade ± twisted. Whitish larvae in folds on upper side. G. aleppicum, rivale, urbanum: Contarinia gei

9b Leaf blades, often of several leaflets as well as entire leaves, loosely clustered upwards, or remaining rolled inwards, beginning at margin, without substantial thickening. At first, hyaline-green caterpillars, bearing many forked setae, develop in the sometimes pale green roll and the wall of the roll is soon eaten away. Each roll containing a single, or several larvae. G. urbanum: Blennocampa sp.

10a Various malformations of leaves, caused by aphids. G. rivale, urbanum:
Macrosiphum gei

10b Often associated with strong downward deflection, ± bumpy, often dark-green curling of leaf. Geum spp.: Philaenus spumarius

11a Flowers contain gall midge larvae. Receptacle slightly swollen, calyx and corolla little changed; between the ± strongly reduced central flower parts are several red midge larvae. G. reptans: Geomyia alpina

11b Various greening of flowers. G. rivale, urbanum: ? gall mite

gallers on Salvia

Last modified 20.iv.2020

Dichotomous table for gallers on Salvia

by Hans Roskam

1a On parts above ground => 2

1b Roots with small whitish swellings, ± cylindrical-spindle-shaped. Salvia spp.: Meloidogyne hapla

1c Conspicuous tuberculate proliferations, mainly on root collar. Salvia spp.: Agrobacterium tumefaciens

2a On flowers or fruits => 9

2b On axial parts or leaves => 3

3a On leaf blades and -stalks, sometimes on stem parts => 4

3b Multilocular swelling of the stem, 10‒45 mm long and 8‒17 mm in diameter. The oval gall chambers are arranged at the outside, ± perpendicular to the wall. The young gall is yellowish green with a felty surface, in the end it is grey and lignified. S. fruticosa, syriaca: Hedickiana levantina

3c Stem distinctly swollen, sometimes distorted; with single or several oval, rimmed, groove-like depressions, in the cavities on underside containing the causer. S. x sylvestris, verticillata: Planchonia arabidis

4a Malformations on leaf blades, -stalks or stems caused by fungi => 7

4b Swellings, folds, curls or abnormal pubescence on leaves caused by animals => 5

5a Malformations caused by aphids => 6

5b Leaf blade with many pubescent ± reddened protrusions of variable size; dense, at first whitish, later on brownish erinea consisting of rigid, simple or branched hairs in the cavities on underside. Sometimes expanded erinea; also on leaf upperside; erineum sometimes encroaching into petiole and stem parts. Salvia spp.: Aceria salviae

6a Leaves folded, sometimes rolled at margin. S. officinalis: Brachycaudus cardui

6b Leaves pale-green spotted, swollen, bladder-like between the veins. S. nemorosa, officinalis, splendens: Aulacorthum solani

7a Swellings with aecia, sometimes associated with other spore forms => 8

7b Leaf blade with small, isolated pads, protruding on underside, sometimes slightly depressed on upperside, ± wart-shaped, bearing exclusively cinnamon- or chestnut-brown telia. S. aethiopis, dumetorum, limbata, nemorosa, nutans: Puccinia stipina

7c Upperside of the leaf with angular, eventually brown leaf spots. Underside with a thin, greyish purple to light brown fungal down of erect conidiophores that apically several times are dichotomously branching, each branch ending in a globular conidium. S. farinacea, officinalis, pratensis, purpurea, verticillata: Peronospora salviae-officinalis

8a Fungus host-specific. Sori often yellowish to reddish bordered, sometimes occurring on the leaf blades, there rotund, on underside ± bladder-like, arched; mainly oblong on veins and stalks, galls in that case variously distorted; with spermogonia and densely arranged, slightly protruding, irregularly opened, at margin lacerate aecia. Outer- and inner wall of peridium cells are thickened. S. judaica, x sylvestris, verticillata & subsp. amasiaca, virgata: Puccinia nigrescens

8b Only aecia with spermogonia on ± expanded, often curved, yellowish bulges on leaf veins and -stalks, occasionally on young axial parts, The cells of the peridium have thin inner walls. Salvia spp.: Puccinia stipina

9a Galls on flowers or flower parts => 10

9b Single or all four mericarps of a flower irregularly swollen, rotund, up to 5 mm long, multi-chambered, ± enveloped by calyx. Each chamber containing a single larva. Salvia spp.: Neaylax salviae

10a Flower galls caused by insects => 11

10b Malformations caused by fungi. Anthers already ± swollen in unopened flowers, globular and soon containing violet spores. Corolla with anthers dropping early. Development of fruit normal. S. pratensis: Microbotryum salviae

11a Galls caused by gall midges => 12

11b Gall caused by gall wasps, at the base of the flower head, rounded, monolocular, thin-walled, 4.0‒6.0 mm in diameter. 2‒3, sometimes more galls are developing. Salvia spp.: Neaylax salviae

12a Flowers remaining unopened. Calyx inflated and discoloured. Containing several flesh-red larvae. S. pratensis, x sylvestris, verticillata: Dasineura salviae

12b Swollen flower buds, contain orange coloured gall midge larvae. S. nemorosa: Asphondylia sp.

gallers on Fragaria

Last modified 20.iv.2020

Dichotomous table for gallers on Fragaria

by Hans Roskam

1a On above-ground plant parts => 2

1b Nodular swellings on roots. Fragaria spp.: Meloidogyne hapla

1c Small solid swellings, often curved and twisted, at the tips of lateral roots; other parts of roots sometimes thickened. Slender and transparent adult eelworms, 1.5–12 mm long, feed on outside of root. Fragaria spp.: Longidorus sp. and/ or Xiphidinema sp.

2a Malformations are restricted to single or several plant parts or, if extending over larger parts are not “cauliflower”-shaped => 3

2b Complete plant ± severely disfigured; shoot stunted, thickened, curved; the many branchings ± fasciated or otherwise coalesced; leaves stunted, inflorescences disfigured; ‘cauliflower disease’ of cultivated strawberries. Fragaria spp.: Putatively combined infestation of: Rhodococcus fascians and/or Aphelenchoides fragariae

3a Flowers disfigured, calyx leaves elongated, corolla distinctly reduced and ± pale green. Flowers mainly sterile, ± clustered because of stunting of stalks. On cultivated strawberries, also on clover. Virus disease: “Flower greening of strawberry”

3b On stems, petioles or leaves => 4

4a Malformations mainly on leaf blade => 6

4b Galls on stems or petioles => 5

5a Oval to spindle-shaped or bulging swellings with single to several rimmed depressions, containing a scale insect. Fragaria spp.: Planchonia arabidis

5b Spongy swelling lacking a gall chamber, mainly at stem base or petiole. Fragaria spp.: Ditylenchus dipsaci

6a Leaf blade variously curved or crumpled => 8

6b Leaf blade with pouch galls or erinea => 7

7a Leaf blade on upperside with nodule-shaped pouch galls up to 1.5 mm long, red, ± pubescent; exit hole on underside. F. moschata, vesca, viridis: Fragariocoptes setiger

7b On leaf underside, spots with erinea of reddish discoloured multicellular, terminally blunt hairs. Fragaria spp.: Phytonemus pallidus subsp. fragariae

8a The inducer lives on the surface of the malformations => 9

8b Various curvings of often short-stalked leaves, mainly on stunted plants. Fragaria spp.: Aphelenchoides fragariae

9a The ± crumpled, locally deep-green leaf blades variously deflected and clustered. Containing a froth-covered nymph on underside. Fragaria spp.: Philaenus spumarius

9b Variously shaped malformations, often associated with curling, sometimes gall-like on yellow-green discoloured, ± vitreous, often severely stunted inner leaves. Caused by tarsonemid mites, living in the folds. Plants stunted. “Curling disease”. Fragaria spp.: Phytonemus pallidus

gallers on Cydonia

Last modified 19.iv.2020

Dichotomous table for gallers on Cydonia oblonga

by Hans Roskam

1a On shoots, thinner twigs or leaves => 4

1b On thicker, woody stems => 2

2a Cancer-like malformation => 3

2b Thicker branches with club- or thick spindle-shaped swellings: Viscum album

3a Bark with ± expanded irregular, cracked proliferations, occupied by white woolly aphids: Eriosoma lanigerum

3b Rotund or flattened oval proliferations on basal stem parts, soon lignified, surface cork-like and granulated. Bacterial cancer: Agrobacterium tumefaciens

4a On leaves and shoots => 5

4b Bark of thin twigs with small nodules, with coarse surfaces: Acalitus phloeocoptes

5a Several leaves at shoot tips irregularly disfigured => 10

5b Leaves with locally defined galls => 6

6a Galls bulge-like or slightly bladder-like, soon covered with fungal sori => 7

6b Leaf blade with many rotund pocks, weakly protruding on both sides; these with narrow exit on underside: Eriophyes pyri

7a Galls bulge-shaped, yellowish, often on leaf veins, occasionally on young stems; cylindrical, tube-shaped, with sori which soon lacerate and rip open from apex downwards => 8

7b Leaf blade often with several weak bladder-like swellings, which display a white-grey cover at maturity consisting of many asci: Taphrina bullata

8a Lateral walls of peridium cells with obliquely or transversely running ridges => 9

8b Lateral walls of peridium cells with rotund tubercles: Gymnosporangium clavariiforme

9a Sori on leaf underside usually only weakly arched. Peridium protruding about 2 mm, later on frayed to its base, its cells 18–24 µm across. Aeciospores 19–26 x 19–22 µm: Gymnosporangium confusum

9b Sori on leaf underside usually distinctly arched. Peridium protruding up to 3 mm, later on frayed to its base, its cells 31–35 µm across; aecia 30–39 x 25–30 µm: Gymnosporangium tremelloides

10a Leaves strongly curled, clumped at the ± stunted shoot tips. Caused by aphids => 11

10b Leaf margin deflected downwards: Cacopsylla mali

10c 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: Podosphaera leucotricha

11a Leaves in spring ± twisted along the midrib, more or less tightly rolled downwards, sometimes developing loose clusters at the shoot tips. Aphid green, with short, thick green siphunculi: Rhopalosiphum oxyacanthae

11b Similar malformations; often clusters more compact. Leaves usually also deflected over the tip. Aphid with rather long black siphunculi: Aphis pomi

11c Leaves are curled and yellowed. Aphids with red body fluids: Dysaphis pyri

gallers on Arrhenatherum

Last modified 19.iv.2020

Dichotomous table for gallers on Arrhenatherum

by Hans Roskam

1a On parts above ground => 2

1b Roots with spindle-shaped, half-screw-shaped bent swellings a few mm long; tissue with cavities. A. elatius: Subanguina radicicola

1c Similar, but compact, malformations sometimes on sagging root tips. A. elatius: Meloidogyne hapla

1d Roots of A. elatius may also become infected with Heterodera avenae

2a Malformations only on inflorescences or flowers => 6

2b On vegetative parts => 3

3a Leaves with long, parallel stripes caused by rusts or smuts => 5

3b Malformations of shoots caused by animal parasites => 4

3c Stems within the leaf sheaths, sometimes also the outside of the sheaths, covered by a dark brown layer of spores. A. elatius: Tranzscheliella hypodytes

4a Shoot conspicuously shortened, swollen at base. Stem only weakly developed, often not protruding from the sheath. Inflorescence with strongly etiolated spikes, sometimes also ± bleached. Contains many eelworms. A. elatius: Ditylenchus dipsaci

4b Shoot axis stunted; panicle stunted, bleached; contains a fly maggot. A. elatius: Unidentified Chloropidae

4c Longitudinally arranged, about 10 (12) mm long saddle-shaped, terminally rimmed depressions, which occur with several under the slightly swollen leaf sheaths above the nodes. Contain blood red midge larvae. A. elatius: Haplodiplosis marginata

4d Lateral swelling of stem, just above the ground, 10–12 mm long and 5–6 mm broad; large chamber contains a single larva. A. elatius: Tetramesa sp.

4e Black aphids under crumpled leaves. A. elatius: Melanaphis pyraria

4f Leaf sheaths of the upper part of stem ± bladder-like swollen; inside are many yellow- to brownish-green aphids, up to about 2 mm long. A. elatius: Laingia psammae

5a Spores solitary, or with 2–3 in balls, enveloped by sterile cells. A. elatius: Urocystis avenae-elatioris

5b Spores solitary, rotund- oblong-oval, densely warty. A. elatius: Ustilago notarisii

5c Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. A. elatius: Puccinia striiformis

6a Inflorescences disfigured by smut fungi => 7

6b Panicle stunted, axial parts wriggled, spikes disfigured, clustered. A. elatius: Unidentified eelworm

6c Inflorescence contains yellow midge larvae. A. elatius: Contarinia arrhenatheri

7a Ovaries and flower peduncle, sometimes also the spikelets, swollen, and soon filled with masses of agglutinated spores. Often all panicles and flowers of a plant with smut, exceptionally only with some apical flowers remaining normal. Unfolding panicles not spreading; spores dispersing at once. A. elatius: Ustilago hordei

7b Malformations similar in all parts; spore masses hardened however, spores not dispersing immediately. A. elatius: Ustilago avenae

gallers on Phalaris

Last modified 18.iv.2020

Dichotomous table for gallers on Phalaris

(incl. Phalaroides)

by Hans Roskam

1a Malformations on or in inflorescence, flowers or fruits => 11

1b Malformations of vegetative parts => 2

2a On leaves and culms => 3

2b Roots with half screw-like or crooked swellings. Phalaroides arundinacea: Subanguina radicicola

3a Complete plant disfigured, or malformations restricted to shoot tips or leaves => 7

3b Galls on culm => 4

4a Larvae between culm and leaf sheath => 5

4b Culm weakly swollen at upper internodes. Larva inside the stem. Phalaroides arundinacea: Tetramesa sp.

5a Midge larvae, lacking black mouth parts => 6

5b Larvae with black mouth parts, usually with several larvae inside the slightly swollen internode at base of an occasionally severely stunted and ± bleached inflorescence. Phalaroides arundinacea: Oscinella trochanterata

6a Culm above the node, underneath the leaf sheath, with several oblong-oval, flat, slightly rimmed depressions, each containing a single orange-yellow larva. Phalaroides arundinacea: Lasioptera calamagrostidis

6b Culm above the node with strong, sometimes almost saddle-like rimmed depressions. Larvae white to golden-yellow. Phalaroides arundinacea: Mayetiola phalaris

7a Complete plant severely stunted or apical leaves distinctly gathered together => 9

7b Malformations of leaf blades and -sheaths => 8

8a Aphid gall. Leaf sheath inflated, ± discoloured, leaf blade twisted, rolled. P. canariensis; Phalaroides arundinacea: Rhopalosiphum padi

8b With similar damage. P. canariensis: Sitobion avenae

8c Long parallel stripes caused by smut, especially on the upper leaves of the ± shortened shoots. Sori also on leaf sheaths, with dusting of blackish olive-brown spores. Panicles reduced, often remaining in sheaths. Phalaroides arundinacea: Ustilago echinata

8d In addition, same host, may occur the rare fungus: Physoderma graminis

8e Leaves curled and wrinkled; culms often severely distorted. Phalaroides arundinacea: Ustilago serpens

9a Malformations without conspicuous accumulation of apical leaves => 10

9b Plant severely stunted. Leaves terminally accumulated. Upper culm containing a single whitish larva. Phalaroides arundinacea: Tetramesa sp.

10a Young shoots often severely stunted in longitudinal growth; swollen at base sometimes slender onion-like. Developing shoots ± strongly shortened, often with many ± distinctly rimmed depressions above the nodes; shoots that continue to grow mostly bleaching. Often with large numbers of larvae per shoot. Phalaroides arundinacea: Mayetiola phalaris

10b Mites are vagrants at the upperside of the leaves and in the leaf sheaths. At higher densities the leaves may become discoloured and rolled. Phalaroides arundinacea: Acaralox arundinaceus

11a Malformations mainly of ovaries, fruits => 12

11b Inflorescence disfigured; flowers stunted, variously disfigured or bleached. Phalaroides arundinacea: Aceria tenuis

12a Ovaries slightly swollen, filled with brown spore masses. Phalaroides arundinacea: Tilletia menieri

12b Spikelets disfigured, ovaries enlarged, ± bottle-shaped. Often found associated with the fungus Dilophospora alopecuri. Phalaroides arundinacea: Anguina agrostis

12c Orange coloured midge larvae feed solitarily on developing ovaries. P. minor; Phalaroides arundinacea: Sitodiplosis phalaridis

12d Yellow gall midge larvae prevent the formation of seeds. Phalaroides arundinacea: Coniophora graminicola

gallers on Onobrychis

Last modified 18.iv.2020

Dichotomous table for gallers on Onobrychis

by Hans Roskam

1a On parts above ground => 3

1b On roots => 2

2a Nodular swellings of the root. O. viciifolia: Meloidogyne arenaria

2b Cylindrical nodules, up to 8 mm long, apically usually flattened or partitioned, which are laterally inserted into main- or secondary roots. O. viciifolia:
Rhizobium leguminosarum

3a On vegetative organs => 5

3b Malformations of flowers or immature fruits => 4

4a Ovaries of young flowers swollen. Perianth shortened. Corolla ± spreading; calyx conspicuously widened and especially bulging on one side. Containing a curved larva. O. viciifolia: Holotrichapion pisi

4b Flowers swollen, unopened. Larvae gregarious, lemon-yellow, jumping. O. arenaria, montana, viciifolia: Contarinia onobrychidis

4c In flower galls of Onobrychis sp. also non-jumping larvae of Dasineura floralis

5a Galls on single or many leaflets => 9

5b Galls on stem, petiole or midrib => 6

6a The inducers live inside the galls => 7

6b Petioles or midrib with single spindle-shaped swelling, also several broad swellings. Infestation strongly widened in the middle, bent, with a rimmed depression containing the inducer. The galls often develop gregariously on stems, with curved bulges containing several depressions. O. arenaria: Planchonia arabidis

7a Galls with tough wall => 8

7b Spongy, pale green, ± wrinkled swellings of variable expansion on stems and leaf axis of young plants. O. viciifolia: Ditylenchus dipsaci

8a Shoot axis with compact, multi-chambered swelling, up to 30 mm long. Larval chambers in several rows, each chamber containing a single white larva. O. arenaria, viciifolia: Aylax onobrychidis

8b About 5–8 mm long, spindle-shaped swellings in shortened inflorescence axis, often hidden by the clustered flowers. Galls each containing a single larva. O. arenaria, montana, viciifolia: Hemitrichapion reflexum

9a Leaf galls caused by gall midges => 10

9b Galls contain mites. Leaflets folded, irregularly bent, not fleshly thickened. Malformation usually on all leaflets of many leaves. O. arenaria, montana, viciifolia: Aculus longifilis

10a Leaflets folded together upwards, pod-like, fleshy thickened. On young leaves usually all, on older, often only several leaflets infected. Larvae gregarious, yellow-white. O. aequidentata, montana, viciifolia: Bremiola onobrychidis

10b Leaf galls. Onobrychis sp.: Janetiella foliicola

gallers on Moehringia

Last modified 17.iv.2020

Dichotomous table for gallers on Moehringia

by Hans Roskam

1a On parts above ground => 2

1b Root with lentil-size swellings. M. trinervia: Meloidogyne hapla

2a On inflorescences or flowers => 11

2b On vegetative parts => 3

3a Several leaves with nearly similar malformations at shoot tips or all over the plant => 5

3b Locally restricted galls on leaves or stems => 4

4a Many yellow translucent multi-cellular warts, less than 1 mm long, on basal leaves and stem parts. M. trinervia: Synchytrium aureum

4b Rotund, sometimes depressed on upperside, yellowish to brown-yellow, on underside, pad-like swellings on leaves, or, elongate in direction of organ development, sometimes distorted bulges on axial parts up to 6 mm long. M. diversifolia, muscosa, tenuifolia, trinervia: Puccinia arenariae

5a Animal causers => 7

5b Caused by fungi fruiting at surface => 6

6a Systemically infected shoots longer and lanky; rigidly erect; leaves often longer stalked; small, pale, sometimes deflected at margin, with a dirty-white to grey down of branched conidiophores on underside. M. ciliata, trinervia: Peronospora arenariae

6b Similar malformations, usually on many shoots of a plant; on all green parts, especially on leaf underside, with many loosely arranged yellow sori. M. trinervia: Melampsorella caryophyllacearum

7a Caused by aphids or spittlebugs => 9

7b Caused by gall mites => 8

8a Leaves clustered at main- and side shoots, disfigured; flowers greened or double, also developing further. M. ciliata, lateriflora: Aceria moehringiae

8b Leaves wrinkled, clustered ball-like at shoot tip; development stunted; development of flowers suppressed; normal flowers exceptional. M. trinervia: Cause unknown – ? gall mite

9a Caused by aphids => 10

9b Shoot axis stunted, with local, sometimes almost facultative, nest-like clustered, deflected, ± curled, partially deep green leaves. M. trinervia: Philaenus spumarius

10a Leaves pod-like folded upwards, violet-marbled, inside weakly pubescent. M. trinervia: Brachycolus stellariae

10b Leaves terminally accumulated, reduced, sometimes discoloured, undulate curled, bent upwards, also deflected, sometimes slightly more pubescent. Aphid reddish to dark brown. M. trinervia: Myzus certus

11a Often largely leafy flowers associated with excessive branching. M. ciliata, lateriflora: Aceria moehringiae

11b In outwardly normal flowers the anthers are stunted, swollen and soon filled with a dusty violet spore mass. M. lateriflora: Microbotryum violaceum

gallers on Echium

Last modified 17.iv.2020

Dichotomous table for gallers on Echium

by Hans Roskam

1a On inflorescences, flowers or fruits => 6

1b On vegetative parts => 2

2a On shoot tips, lateral buds, stems or leaves => 3

2b Complete plant stunted, leaves clustered and like flowers ± etiolated. E. vulgare: Brachycaudus helichrysi

3a On leaves, buds or stems => 4

3b Shoot tip stunted close to ground, transformed into an oblong-egg-shaped blotch with large central chamber, not enclosed by unfolding leaves. E. italicum, vulgare: Cynaeda dentalis

3c Gall on root head. E. vulgare: Pachycerus segnis

4a On leaves or buds => 5

4b Stem locally stunted and swollen, with several rimmed depressions containing a nymph. E. vulgare: Planchonia arabidis

5a Lateral buds transformed into an unopened egg-shaped gall, not dropping in autumn. Contains a single yellow larva. E. arenarium, vulgare: Asphondylia echii

5b Leaf blade with conspicuous, rotund, yellow or reddish pads, ± depressed on upper side, arched on underside or similar, elongated spindle-shaped bulges on venation. E. plantagineum, vulgare: Puccinia recondita f. sp. echii-agropyrina

6a On inflorescences, flowers => 7

6b One of the mericarps enlarged; the remaining ones aborted. Containing a single larva. E. vulgare: ? gall midge, ? gall wasp

7a Expanded parts of inflorescence disfigured => 9

7b Malformations of single or several flowers => 8

8a Corolla unopened, not or hardly surpassing calyx teeth; lower half swollen, thickened, white; upper half acuminate, thickened and reddish. Stamens and ovary thickened. Larvae glossy, lemon-yellow, jumping. E. vulgare: Contarinia echii

8b Flower swollen, unopened, gall rotund-oval. Stamens and pistil aborted. Inner wall lined with mycelium. Containing a single larva. E. arenarium, vulgare: Asphondylia echii

9a Many flowers disfigured, their parts variously leafy, abnormally pubescent. E. vulgare: Aceria echii

9b Inflorescences shortened. Flowers distorted. E. vulgare: Dictyla echii

9b Axis of inflorescence stunted and clustering of flowers of E. vulgare caused by froth-covered nymphs of Philaenus spumarius

gallers on Aegopodium

Last modified 16.iv.2020

Dichotomous table for gallers on Aegopodium

by Hans Roskam

1a On inflorescences, flowers or fruits => 9

1b On stems and leaves => 2

2a Leaf blades folded, curled, rolled inwards or with flat, ± bumpy swellings => 5

2b Leaves or stems with wart- to bulge-shaped galls => 3

3a Bulges over 1 mm long => 4

3b Galls wart-shaped, multi-cellular, less than 1 mm long, yellowish translucent; usually many on the underside of leaf blades, on petioles and basal stem parts; sometimes ridge- or crust-shaped coalescing: Synchytrium aureum

3c In similar galls: Physoderma pulposum

4a Spindle-shaped, compact, vitreous, pale green, later on ± browned bulges, often many on petioles, leaf veins and stems. Spores inside close to vascular bundle: Protomyces macrosporus

4b Leaves especially on underside, particularly on veins and stalks, with thickened, at first yellowish pads or bulges, on which develop 2-celled telia in black-brown sori, soon coalescing: Puccinia aegopodii

5a Leaf blades folded or flat to ± swollen, bulge-shaped => 7

5b Leaf blades rolled inwards or curled, caused by aphids or cercopids => 6

6a Leaf blades strongly converged downwards, almost claw-like; conspicuously curled and deeper green, especially close to the froth-covered nymph. Infected inflorescences stunted, compact: Philaenus spumarius

6b Tips of leaves usually transversely ± narrow to claw-like deflected downwards, irregularly shaped at surface on upper side by smaller or larger, often yellowish discoloured proliferations. Black aphids on underside: Aphis podagrariae

6c Aphid straw-pale to greenish: Aulacorthum aegopodii

7a Leaf blades with expanded swellings => 8

7b Tips of developing leaves folded upwards; ± curled and clumped. Main- and lower parts of lateral veins thickened. White larvae between folds: Macrolabis podagrariae

8a Often several upward protrusions of the leaf blade up to 6 mm long, hardly discoloured, sometimes violet marbled; corresponding depressions on opposite side; each groove contains an egg or larva: Trioza flavipennis

8b Leaves on underside with expanded white, loose covers of branched conidiophores. Infestation sites on upper side discoloured yellow-green, fast growing leaves sometimes slightly arched: Plasmopara crustosa

9a Galls only on flowers or fruits => 11

9b Umbel largely disfigured => 10

10a Development of umbel stunted, partial umbels accumulated because of shortened stalks. Flowers ± greened to leafy, often discoloured reddish: Unidentified gall mite

10b Partial umbels disfigured, clustered, stalks shortened, bearing green aphids: Cavariella aegopodii

11a lowers swollen, globular, not opening. Containing a single larva: Unidentified gall midge

11b Fruit distinctly swollen, bladder-like, protruding above the partial umbel. Containing an orange-red larva: Kiefferia pericarpiicola

gallers on Aconitum

Last modified 16.iv.2020

Dichotomous table for gallers on Aconitum

by Hans Roskam

1a On vegetative plant parts => 2

1b Flowers not opening, conspicuously swollen, ± rotund, yellowish-, then bluish-green. Containing several whitish larvae. A. lycoctonum & subsp. vulparia, napellus, variegatum: Contarinia aconitifloris

2a Malformations ± bulging, caused by smut- and rust fungi => 7

2b Malformations caused by animal inducers => 3

3a Malformations caused by aphids or spittlebugs => 4

3b Stem just below the still undeveloped inflorescence ± spindle-shaped, or irregularly barrel-shaped, swollen over a length of 20–35 mm. The increasingly developed, also outside the gall irregularly eaten, pith contains a single or several larvae. A. lycoctonum subsp. vulparia, napellus subsp. lusitanicum: Ranunculiphilus lycoctoni

4a Malformations caused by aphids => 5

4b Large parts of leaf blade strongly deflected, strongly curled, especially close to the froth-covered nymph; dark green. Aconitum spp.: Philaenus spumarius

5a Leaves ± distinctly deflected. Aphids 3–4 mm long => 6

5b Shoot axis stunted. Leaves or flowers apically clustered, ± bent or disfigured. A. x cammarum, lycoctonum & subsp. vulparia, napellus, plicatum, variegatum:
Brachycaudus napelli

6a On A. lycoctonum & ssp. vulparia. Leaves broad and curved downwards, bell-like yellowish spotted: Delphiniobium lycoctoni

6b On blue-flowering species. Leaves only slightly rolled downwards and bent. Aconitum spp.: Delphiniobium junackianum

7a Malformations contain sori of rust fungi => 8

7b Stem, petioles or often leaf undersides often with curved bulges caused by smuts; initially closed, lead-grey translucent; rupturing later on and then with black dusting. Aconitum spp.: Urocystis irregularis

8a Bulges with aecia, accompanied by pycnidia. Fungus host-alternating => 10

8b Swellings with aecia, with or without pycnidia. Fungus not host-alternating => 9

9a Aecia predominantly in larger groups on swellings of sometimes curved leaf veins, -stalks and stems. Peridium dentate at margin, rather large. A. lycoctonum, vulparia: Uromyces dactylidis

9b Aecia in rotund-oval, ± arched sori usually on underside of leaf blades, broad disc-like, with deflected, soon withering and therefore rarely well-developed margin. Spermogonia on both leaf sides. A. lycoctonum & sspp. septentrionale + vulparia, orientale: Uromyces lycoctoni

10a Aecia on Aconitum spp. Underside of leaves with large, rotund, yellow-brown pads; leaf veins, -stalks or stems with distinctly bent or curved bulges, up to 30–40 mm long. Puccinia actaeae-elymi

10b Malformations and aecia like those of Puccinia actaeae-elymi; only occurring on blue-flowering species. A. x cammarum, degenii, napellus, tauricum, variegatum: Puccinia aconiti-rubrae

10c Aecia similar, morphologically not positively distinguishable from previous rust; predominantly on underside of leaf blade in usually rotund, sometimes slightly swollen, discoloured sori. A. x cammarum, lycoctonum & ssp. vulparia, napellus, tauricum, variegatum: Puccinia actaeae-agropyri

gallers on Knautia

Last modified 17.iv.2020

Dichotomous table for gallers on Knautia

by Hans Roskam

1a On inflorescences or flowers => 10

1b On vegetative parts => 2

2a Locally restricted malformations => 3

2b Complete plants ± stunted, organs variously disfigured. K. arvensis, dinarica, dipsacifolia, drymeia, longifolia: Aphis confusa

3a Malformations terminally on main- and side shoots or on leaves Malformations terminally on main- and side shoots or on leaves => 5

3b Galls only on axial parts of shoot => 4

4a Shoot axis often thickened below inflorescence and densely haired. K. arvensis: Ditylenchus dipsaci

4b Usually basal part of stem with conspicuous, spindle-shaped or irregularly bulging and ± buckled swellings, with single or several rimmed depressions; containing the causative froth-covered nymph under a bulging scale. K. arvensis:
Planchonia arabidis

4c Gall-like malformations on shoots of K. longifolia: unknown galler

5a Galls on leaves => 8

5b Galls terminally on shoots => 6

6a Galls restricted to shoot tips => 7

6b Variously shortened internodes on shoot tips, often predominantly one-sided, causing the leaves to cluster on ± curved stem; leaf blades stunted, ± deflected and curled, deep green close to the froth-covered nymph. K. arvensis, drymeia: Philaenus spumarius

7a Terminal leaves folded together, haired. Containing several white larvae. K. arvensis, dipsacifolia, drymeia, transalpine: Jaapiella knautiae

7b Terminal pair of leaves ± unfolding, completely thickened or only at base, folded together upwards, pouch-like; densely pubescent with rigid hairs. Containing a single yellow midge larva. K. arvensis, collina, drymeia: Unidentified gall midge

8a Galls only in leaf blade of basal leaves => 9

8b Petiole and midrib with pale yellow-green, spongy swellings, variously encroaching onto ± disfigured leaf blade. K. arvensis: Ditylenchus dipsaci

9a Very weak protrusions on underside in vein axils, hardly visible on upper side. K. drymeia, longifolia: Trioza munda

9b Up to 5 mm long, yellow, slightly protruding, often many pustules on leaf blades. Containing a single lemon-yellow larva. K. arvensis: Unidentified gall midge

10a Malformations caused by fungi => 12

10b Malformations caused by animals => 11

11a Malformations of flowers caused by jumping, whitish- to orange-yellow midge larvae. K. arvensis, drymeia: Contarinia dipsacearum

11b Capitula ± disfigured and weakly swollen. Containing a single caterpillar. K. arvensis: Stenoptilia bipunctidactyla

12a nfected flowers often of different colour, partially strange-looking. Several petals enlarged and disfigured; number enlarged by ± largely transformed stamens. anthers and ovaries mostly aborted. K. arvensis, dipsacifolia, drymeia, kitaibelii: Peronospora violacea

12b Diseased capitula almost half-globular. Involucral bracts normal; young flowers unopened for a relatively long time, often distinguished by early discolouration of all capitula of diseased plants. K. arvensis, dipsacifolia, drymeia, longifolia, pancicii: Microbotryum scabiosae

12c The anthers are transformed into a purplish-brown powdery mass of spores. K. arvensis, dipsacifolia: Microbotryum flosculorum

gallers on Symphytum

Last modified 14.iv.2020

Dichotomous table for gallers on Syphytum

by Hans Roskam

1a On flowers or fruits => 9

1b On leaves, sometimes on stems => 2

2a Malformations caused by animals living on surface of host => 7

2b Malformations caused by fungi, fruiting inside or on surface of host => 3

3a Malformations conspicuous, bearing yellowish sori => 6

3b Galls small, up to 1.5 mm across. Spores originate inside nutritive cells => 4

4a Galls on leaf blades => 5

4b Galls only on hairs of leaves and stem. Hairs distinctly shortened and swollen, often with short, immediately narrowed, acutely bent tip. Inside are single or several rotund summer- or perennial sporangia up to about 50 µm large. S. officinale: Synchytrium trichophilum

5a Leaves with several wart-shaped protruding, small, multi-cellular galls, which develop in a centrally situated strongly enlarged nutritive cell yellow perennial sori. S. officinale: Synchytrium jaapianum

5b Expanded parts of leaf blade with many, densely arranged, but usually solitary, rotund to oblong-oval reddish- to dark brown, flat bulges. S. officinale: Physoderma speciosum

6a Tubercular bulges rotund on underside of leaf blade, on main veins, petioles and stems oblong-oval spindle-shaped, up to 15 (25) mm long, orange-coloured ± reticulate. Symphytum spp.: Puccinia recondita

6b Diseased plants or leaves lanky, paler. Large parts of leaf blade bearing small reddish- to brownish-yellow uredinia on underside. Symphytum spp.: Melampsorella symphyti

7a Malformations caused by aphids, spittlebugs or thrips => 8

7b Leaf blade curled, yellowish discoloured. Many white larvae on underside. S. asperum, officinale: Dasineura foliumcrispans

8a Leaf blade arched deflected, ± converging and curled. Symphytum spp.: Philaenus spumarius

8b Leaf blade rolled upwards, ± bent, sickle-shaped. S. cordatum, officinale: Aphis symphyti

9a On inflorescences or fruits => 10

9b On fruits. Development of several mericarps stunted, the remainder enlarged and white pubescent. Corolla disfigured, only opened a little and remaining unopened. Fruit containing several white larvae. S. officinale: Unidentified gall midge

10a Malformations of single or several flowers without conspicuous stunting of inflorescence => 11

10b Malformation and stunting of inflorescence as well as neighbouring leaves. Flowers distorted and disfigured; leaves rolled and curled. S. officinale: Dictyla humuli

11a lowers unopened, variously greatly swollen, especially base discoloured. Calyx sometimes with white-felt-like pubescence. Corolla distorted. Stamens and ovaries shortened and thickened. Often many white to yellowish, non-jumping larvae inside flowers. S. asperum, officinale: Dasineura symphyti

11b Flowers unopened, only slightly swollen at base. Larvae jumping. S. officinale: Contarinia symphyti

11c Flowers strongly swollen, especially in basal part. Calyx often conspicuously enlarged; corolla thickened, ± greened. Receptacle and ovary strongly swollen; containing several white beetle larvae. S. officinale: Ceutorhynchus sp.

gallers on Stachys

Last modified 13.iv.2020

Dichotomous table for gallers on Stachys

by Hans Roskam

1a On parts above ground => 2

1b Roots with small nodular or spindle-shaped swellings. S. sylvatica: Meloidogyne hapla

2a On inflorescences or flowers => 18

2b On vegetative plant parts => 3

3a Locally ± defined galls of stems or on leaves => 12

3b Malformations of shoot tips, on several leaves, or on expanded parts of leaf blades, often simultaneously on stems and other organs => 4

4a Malformations caused by animals => 6

4b Malformations caused by fungi with fruiting bodies at their surface => 5

5a The diseased basal- or more rarely stem leaves are paler and longer stalked than the healthy ones. On underside completely or extensively with scattered small brown sori, sometimes coalesced. S. officinalis & subsp. serotina, pradica: Puccinia betonicae

5b Similar, sometimes almost witches’ broom-like malformations on S. annua, recta: Puccinia vossii

5c Fungal down on the abnormally small, discoloured corolla. It consists of erect conidiophores that apically are branching dichotomously several times, each branch ending in a lemon-shaped conidium. S. palustris, recta: Peronospora jagei

6a Malformation of several leaves terminally on shoots => 7

6b Basal young shoots markedly stunted, conspicuously spongy, pale-green; leaf pairs densely clustered; leaf blades necrotic, similarly disfigured. S. arvensis, palustris, setifera: Ditylenchus dipsaci

7a Malformations caused by aphids and spittlebugs => 10

7b Malformations caused by gall mites or gall midge larvae => 8

8a Leaves clustered, bud- or rosette-like on main- or side shoots, also in leaf axils; galls lacking additional pubescence. Midge galls => 9

8b Stem terminally variously stunted, thickened and distorted; partially with ± excessive branching and leafiness; unfolding of leaves ± largely stunted; sometimes white-felt-like pubescent. Inflorescences and flowers, if present, severely disfigured. S. alpina, annua, officinalis & subsp. serotina, pradica, recta: Aceria solida

9a Inner leaves of end- or lateral buds severely stunted, not unfolding, often ± boat -shaped, bent and shrivelled; developing into a 15–35 mm long, pale, erect, irregular gall. Leaf blades of ± spreading leaves with cartilaginous, green-yellow roll of leaf margin. Larvae living also in disfigured inflorescences; dirty pale yellow to orange-coloured. S. alpina, palustris, recta, sylvatica: Wachtliella stachydis

9b Tip of main- and side shoots or axillary bud transformed into oval, converging loose leaf rosette. Containing several white larvae. S. alpina, palustris, recta, sylvatica: Wachtliella stachydis

10a Aphid galls => 11

10b Single or several terminal internodes usually stunted on one side, thickened and distorted. Stachys spp.: Philaenus spumarius

11a Leaves rolled inwards. Aphid 1.3–1.7 mm long, pale green. Siphunculi whitish with black tip. S. arvensis, cretica & subsp. salviifolia, officinalis, recta, sylvatica: Aphis stachydis

11b Leaves terminally clustered, rugose; transversely rolled downwards. Aphid about 1.5 (2.0) mm long, dark-green to dirty-yellow; siphunculi black. S. arvensis: Aphis gossypii

12a Galls on leaves => 15

12b Stem galls or galls exclusively on petioles => 13

13a Inducers inside malformations => 14

13b Stems, also basal parts of petioles ± bulging over a length of 20 (50) mm. S. officinalis, recta: Planchonia arabidis

14a Stem terminally almost globular; shoot tips atrophied and withering. Containing several larvae. S. alpina, officinalis, pradica, sylvatica: Thamnurgus kaltenbachii

14b Stem with several small pustules (procecidia: oviposition scars, not true galls) which wither after emergence of larvae. S. recta: Unidentified sawfly

15a Localised galls on leaf blades and sometimes additionally on stalks => 16

15b Petiole and leaf blade broadened at base, thickened, abnormally pubescent. S. officinalis: Unidentified gall midge

16a Bulge- or wart-shaped galls on leaf blade or on venation and stalks => 17

16b Leaf margin over ± large extent rolled upwards, irregular cartilaginous, pale-green. Containing orange larvae. S. alpina, palustris, recta, sylvatica: Wachtliella stachydis

17a Galls wart-like, less than 1 mm long, ± golden-yellow; many on underside of basal leaves, petioles and basal stem parts. S. officinalis: Synchytrium aureum

17b Small, weakly protruding, oblong-oval sori on main venation, petioles and young stems, bearing brown uredinia. S. annua, recta, sylvatica: Puccinia stachydis

18a Malformations limited to single or several flowers; axis of inflorescence usually not infected => 20

18b Malformation of complete or large parts of inflorescence => 19

19a Midrib ± stunted, thickened, distorted. Inflorescence compact, transformed into a rotund to oblong-oval ball. Calyx lobes often elongated. All infected green parts ± with white-felt-like pubescence. S. alpina, annua, officinalis & subsp. serotina, pradica, recta: Aceria solida

19b Flower buds ± clustered; unopened; only calyx swollen and enlarged. Corolla, stamens, pistil necrotic. Containing several orange-coloured larvae. S. alpina, palustris, recta, sylvatica: Wachtliella stachydis

20a Flower buds ± swollen, unopened. Midge galls => 21

20b Flowers outwardly hardly changed. Anthers at first swollen, soon destroyed by dark-violet, reticulate, later on dusting spores. S. alopecuros, maritima, officinalis, recta: Microbotryum betonicae

21a Galls thin-walled; internal mycelium absent => 22

21b Galls about 5–6 mm across. Inner wall with at first whitish, later on dirty grey, thick cotton-wool-like mycelium coating. Containing a single larva. S. recta: Asphondylia sp.

22a On S. officinalis. Buds distinctly swollen, unopened: Unidentified gall midge

22b On S. sylvatica. Larvae white, jumping: Ametrodiplosis crassinerva

gallers on Secale

Last modified 14.iv.2020

Dichotomous table for gallers on Secale

by Hans Roskam

1a On above-ground parts => 4

1b On roots => 2

2a Roots with distinctly protruding galls => 3

2b Roots externally not noticeably changed. Later on often with many cysts, about poppy-seed size, at first white, then dark brown. Roots with giant cells inside. S. cereale: Heterodera avenae

3a Roots with many small, ± spindle-shaped swellings, about 1–6 mm long and 0.5–5 mm broad, crooked or screw-shaped, bent. S. cereale: Subanguina radicicola

3b Galls spindle-shaped, of similar size, but not screw-like, curved. S. cereale: Meloidogyne hapla

4a On spikes, florets or fruits => 15

4b On vegetative parts => 5

5a On leaves or culms of already ± developed shoots => 10

5b On young plants or on plants that are severely stunted by the infestation => 6

6a Central leaves of ± swollen shoots diseased and easily pulled out before dying off. On winter grain after a cold winter, often not before early spring, conspicuous infestation is distinguished by its excessive leafiness, which later develops further if not also infected. Pattern of damage of various inducers rather similar => 7

6b Basal parts of shoots strongly thickened, with elongate onion-like swelling. Plants excessively leafy; almost cushion-like shape; new shoots almost similarly infected. Leaf blades, especially of the inner leaves, ± ruffled and spirally twisted; at first dark green, then prematurely yellowing. S. cereale: Ditylenchus dipsaci

7 Malformations caused by ± cylindrical fly maggots with buccal hooks, which are at least 4 mm long when fully grown. Central leaves soon yellowing; at base ± disintegrated => 8

7b Young shoots of winter- and summer grain at base with several larvae of puparia; sometimes, if many present, slightly swollen. Leaf sheaths closely gathered together. Leaf blades often erect, often dark green, shorter and broader, as in healthy plants. Inner leaves later on withering, without conspicuous yellowing. Shoots developing further above the lower node sometimes slightly swollen and cracked. Spikes etiolated, sessile. Underneath the sheaths are several yellowish-white larvae, about 3 mm long, lacking buccal hooks, but with bifid sternal spatula; terminally conically narrowed, also with two narrowing papillae. Puparia brown, flax seed-like. S. cereale: Mayetiola destructor

8a Damage on summer as well as on winter cereals => 9

8b Damage on winter cereals only. Inner shoots in spring soft, with brown puparium at feeding site. Delia coarctata

9a Infected shoots severely stunted and ± swollen. Mature larvae about 4 mm long, yellowish-white; at the narrowed terminal part with 2 wart-like, flattened appendages, with a shallow indentation in between. S. cereale: Oscinella frit

9b With similar biology, also on rye, is the closely related Oscinella pusilla

9c Similar malformations. Mature larvae about 7 mm long, yellowish-white. Anal segment almost hemispherical to rotund-oval with 2 flattened appendages, leaving a flat, wide depression in between. S. cereale: Chlorops pumilionis

10a Malformations on leaf sheaths or culms caused by aphids or fungi => 14

10b Galls caused by apodous larvae developing inside culms or between culm and leaf sheath => 11

11a Larvae lacking sclerotised mouthparts, living on shoots between culm and leaf sheath => 12

11b Larvae in a furrow situated below the spike, in shortened and swollen internodes, protruding into younger culm parts. Spikes ± etiolated, often remaining in the occasionally partially spreading sheath of the upper leaf. Containing a single maggot up to 7 (9) mm long, with buccal hooks. S. cereale: Chlorops pumilionis

12a Culm slightly swollen at infestation site or with ± distinct depression. Larvae 3–4 mm long, yellowish-white or orange-coloured => 13

12b Leaf sheath above the upper internode, more rarely the penultimate internode, slightly inflated; several, elongated, rimmed, saddle-shaped depressions on culm, up to 10 mm long, each containing a single 3–5 mm brick red larva. S. cereale: Haplodiplosis marginata

13a Culm above the first, more rarely the second node, with one or two expanded, black-walled, oblong, slight depressions, each containing a single orange-yellow to brick red larva. S. cereale: Hybolasioptera fasciata

13b Culm stunted; sometimes, if many larvae or puparia present, slightly swollen inside the sometimes weakly swollen leaf sheath immediately above the first or second node. Containing one to several yellowish-white larvae or flax seed-like puparia. S. cereale: Mayetiola destructor

14a Upper leaves disfigured; sheath sometimes slightly swollen; leaf blade ± twisted. The only partially developing spikes are variously disfigured. S. cereale: Sitobion avenae

14b Occasionally causing similar malformations. S. cereale: Rhopalosiphum padi

14c Leaves, sheaths and culms with long, 1–1.5 mm broad stripes of smut, slightly protruding, at first lead-grey, then breaking open and releasing black-brown spores. S. cereale, montanum, strictum: Urocystis occulta

15a Malformations mainly of ovaries or fruits, parasites develop inside => 16

15b Malformations of various floral parts or complete spikes caused by animal parasites living on the host. Inducer unknown

16a The soon disfigured ovaries are filled with compact masses of dark smut spores => 17

16b Spikelets not spreading; diseased grains much smaller than normal ones ± rotund- to oblong-oval, 2–5 mm long, 1–2.5 mm broad, dark coloured, thick-walled, pale coloured inside and filled with many eelworms. Galls dropping off prematurely. S. cereale: Anguina tritici

17a Diseased plants not conspicuously shortened => 18

17b Infected plants grow only to half the normal length. Infestation often of all florets, with shortened ovaries usually developing into ± oval variable smut bodies and containing many reticulate spores, often enveloped by slime. S. cereale: Tilletia controversa

18a Smut grains much smaller than normal, egg-shaped to cylindrical, foul-smelling when fresh, usually all florets of a spike infected. Containing brown-black spores that later form a dusty powder. S. cereale: Tilletia secalis

18b Spikes often only partially infected, usually the lower or middle part. Glumes not spreading. Brown-black, later on dusty smut sori in the ovaries that are destroyed early in development, also in the lower part of glumes. S. cereale: Ustilago nuda f. sp. tritici

gallers on Scabiosa

Last modified 12.iv.2020

Dichotomous table for gallers on Scabiosa

by Hans Roskam

1a On parts above ground => 2

1b Roots with small cylindrical-spindle-shaped swellings, 3–4 mm long, and considerable formation of side roots: Meloidogyne hapla

2a Malformations of inflorescences or flowers => 11

2b Malformations on vegetative parts => 3

3a On leaves, shoot tips or stems => 4

3b Many buds on root collar develop into short, laterally and variously growing, ± clustered stump-like, succulent shoots: Aphelenchoides fragariae and/or Rhodococcus fascians

4a Malformations on leaves, with or without inclusion of tips or axial parts of shoots => 7

4b Galls on axial parts of shoots => 5

5a Inducers inside galls => 6

5b Stem locally stunted, with irregular spindle- or bulge-shaped swellings and often strongly distorted or irregularly bent, up to a right-angle; often with several rimmed depressions which contain scale insects below scales. S. ochroleuca: Planchonia arabidis

6a Shoot axis, especially at base, with nodular, succulent, dark red-brown swelling. Containing a caterpillar. S. atropurprurea, canescens, columbaria, ochroleuca, triandra: Alucita grammodactyla

6b Axial parts of flowering shoots with oblong-oval swelling, up to 4 mm long, often ± crimson-red. Containing a pale-yellow caterpillar with yellow-brown head. S. atropurprurea, canescens, columbaria, ochroleuca, triandra: Alucita grammodactyla

7a Galls with abnormal, ± white pubescence => 10

7b Malformations lacking conspicuous pubescence => 8

8a Malformations caused by aphids => 9

8b Leaves terminally on vegetative shoots ± distinctly clustered. Leaf blades narrowed and ± with protuberances. Scabiosa spp.: Aceria squalida

9a Shoot axis variously stunted. Leaves curved and curled. S. columbaria, ochroleuca, triandra: Aphis thomasi

9b Similar malformations. S. atropurpurea, columbaria, ochroleuca, triandra: Aphis confusa

10a Leaves sometimes densely clustered on tips of non-flowering sometimes stunted main and side shoots; leaf blades narrowed, rolled upwards, ± weaved and tuberculate, especially stunted basally and over often larger expansion ± densely white felt-like pubescent. In strongly infected plants also white erinea also locally on sometimes strongly swollen leaf- or stem parts. Also inflorescences may be severely stunted and white felt-like over large expansion. Scabiosa spp.: Aceria squalida

10b Inside leaf rosette two or more leaves remain erect. Their base is stunted, and severely stunted leaf blades are swollen, mussel-like, thickened and at least the basal part on both sides densely covered with long, white hairs, resulting in a compact gall. Sometimes with similar galls on lateral buds or tips of severely stunted shoots. Containing several white, later on ± reddened larvae. S. columbaria: Jaapiella scabiosae

11a Malformations lacking conspicuous additional pubescence => 12

11b All parts of still young, ± stalked capitula severely stunted and often densely pubescent. Exceptionally also further developed inflorescences affected, of which almost only the involucral bracts are ± disfigured and densely haired. Scabiosa spp.: Aceria squalida

12a Malformations caused by animals => 14

12b Malformations caused by fungi => 13

13a Anthers, sometimes also filaments, ± shortened and swollen, soon filled with dirty straw-coloured spore masses. S. columbaria & subsp. balcanica, lucida, ochroleuca, triandra: Microbotryum intermedium

13b Flowers variously stunted or distorted; sometimes with ± petal-like transformed anthers. Diseased parts soon covered with a loose, dark down of branched conidiophores. S. columbaria, lucida, ochroleuca: Peronospora violacea

14a Malformations of almost entire flower head => 15

14b On ± fully developed capitule, single to many involucral bracts are distinctly elongated, thread-like, rolled upwards, not additionally pubescent and often bumpy and curved. Also some greened receptacular bracts and even sexual organs may be similarly galled. Scabiosa spp.: Aceria squalida

15a Malformation of complete flower head. Flowers greened, ± stalked, and developing new shoots (phyllanthy). Scabiosa spp.: Aceria squalida

15b Flowers unopened, swollen. Containing several jumping midge larvae. S. columbaria: Contarinia scabiosae

gallers on Saxifraga

Last modified 12.iv.2020

Dichotomous table for gallers on Saxifraga

by Hans Roskam

1a In inflorescences, on flowers or their parts => 10

1b On stems and leaves => 2

2a Extensive or limited malformations on leaves, or localised swellings on stems => 4

2b Malformations involve extended parts of shoots => 3

3a Shoot tip disfigured, shortened, ± abnormally haired. Inflorescences, if present, with disfigured, leafy flowers. Excessive branching and leafiness. S. aizoides, mutata: Aculus kochi

3b Internodes shortened. Leaves on shoot tips clustered. Infected inflorescences disfigured. Flowers leafy. Mites free-living on organs. S. oppositifolia: Aceria saxifragae

4a Localised wart- or bulge-shaped galls caused by fungi => 7

4b Extensive malformations on leaves, sometimes on stems => 5

5a Malformations caused by animals => 6

5b Diseased leaf blades smaller, narrower, and paler than the healthy ones, and slightly thickened; on underside large areas are covered with loosely arranged, yellow sori. Buds, stem parts or inflorescence stalks, infected during development ± stunted and slightly swollen. S. cespitosa, granulata: Melampsora vernalis

6a Petiole of several rosette leaves shortened and spongy; leaf blade stunted and especially lower half, especially the veins, wrinkled, pale green. S. umbrosa: Ditylenchus dipsaci

6b Curling of basal leaves. S. granulata: Unidentified aphid

7a Galls pad- or spindle-shaped, several mm in size => 9

7b Galls wart-shaped, less than 1 mm long; sometimes ± coalescing => 8

8a Warts very small, punctiform, 1-celled, crimson-red. The nutritive cell protrudes only a little from the leaf surface, merely extending inside the host tissue. S. granulata: Synchytrium rubrocinctum

8b Nutritive cells enlarged, including neighbouring cells. Galls ± yellowish. S. aizoides, androsacea, bryoides, moschata, stellaris: Synchytrium saxifragae

9a Sori ± whitish- to greenish-yellow, visible on both leaf surfaces. Only exceptionally slightly swollen. Chlamydospores inside leaf, conidia developing on surface. S. ? aizoides, rocheliana, rotundifolia: Entyloma schinzianum

9b Similar infestations on S. paniculata, aspera, bryoides, oppositifolia: Arcticomyces warmingii

9c Sori dark brown, powdery or nodular, mainly prominent on underside, bulge-shaped swellings on leaf blade, leaf veins, -stalks; on stems in ± bulging sori causing distortions and bends. Teliospores striate. Saxifraga spp.: Puccinia saxifragae

10a Galls on flowers or ovaries => 11

10b Inflorescence ± shortened, spirally rolled inwards. S. paniculata: Unidentified lepidopteran

11a Malformations of ovary, containing a single midge larva => 13

11b Flowers ± leafy or swollen and unopened => 12

12a Flowers leafy, transformed into small rosettes. S. biflora, oppositifolia: Aceria saxifragae

12b Flower buds ± strongly swollen; broad egg-shaped, ± reddened, unopened. Containing several sulphur-yellow larvae. S. granulata: Dasineura saxifragae

13a Ovary greatly enlarged, thick-walled. Style stunted. Containing single pale red larva. S. aizoides: Unidentified gall midge

13b Ovary weakly swollen; infected flower shorter and more compact than the normal ones. Containing yellow-red larva. S. granulata: Unidentified gall midge

gallers on Primula

Last modified 10.iv.2020

Dichotomous table for gallers on Primula

by Hans Roskam

1a On parts above ground => 2

1b On roots or root collar => 3

2a Roots with ± elongated, nodular swellings. P. auricula, carniolica: Meloidogyne hapla

2b Short, strongly thickened and banded shoots on root collar. P. juliae: Rhodococcus fascians

3a On inflorescences or flowers => 9

3b On leaves => 4

3c Whole plant disfigured, covered by a down of branched conidiophores. P. acaulis, auricula, elatior, veris: Peronospora oerteliana

4a Leaf blades strongly curled, margin rolled, warts, pads, bulges or spongy, swollen galls on leaves and stems => 8

4b Malformation usually of several rosette leaves caused by the perennial mycelium of monoecious rust fungi. Leaves paler and slightly longer stalked than healthy ones, rigidly erect, soon covered with sori. Primula spp.: Uromyces primulae-integrifoliae

5a Warts, pads or bulges caused by fungi => 8

5b More or less expanded parts with spongy swellings; also curling of leaf blades or rolling of leaf margin => 6

6a Leaf blades curved, curled or margins rolled => 7

6b Whole plant ± stunted. Leaves shortened, especially swollen at base and at veins. Often with various swellings also on inflorescence. Flowers variously swollen and leafy. Primula spp.: Ditylenchus dipsaci

7a Leaf margin narrowly rolled upwards. P. auricula: Unidentified gall mite

7b Leaf blades to large extent often obliquely rolled downwards over the tip, hunched up and arched, dark green close to infestation. A single or several froth-covered nymphs on underside. Primula spp.: Philaenus spumarius

8a Basal leaf parts and venation with many solitary or variously joined, multicellular golden-yellow warts, less than 1 mm long. P. elatior, veris: Synchytrium aureum

8b Leaf underside with rotund aecia bearing pads, on veins ± elongated, yellow, sometimes weakly swollen. Aecia cup-shaped with deflected, lacerate border. P. acaulis, elatior, grandiflora, veris: Puccinia primulae

9a Ovary moderately to belly-like swollen. Seed primordia swollen => 11

9b Malformation of almost all flower parts => 10

10a Flowers variously disfigured. Corolla often greened; also anthers and pistil variously greened; leafiness. These malformations also on plants which bear spongy bulgings on other parts. P. denticulata & var. cashmeriana, florindae, rosea, veris: Ditylenchus dipsaci

10b Calyx tube-shaped elongate, sometimes inflated. Corolla calyx-like transformed, green. Ovary swollen, protruding from flower; seed primordia transformed into minute leaf-like structures. P. florindae: Subanguina klebahni

11a Seed primordia at first hypertrophied, later on filled with masses of blackish, irregular rotund to oblong spore balls. Ovary slightly swollen. Infestation of flowers inconspicuous from the outside. P. acaulis, elatior & subsp. intricata, veris & subspp. canescens + columnae + macrocalyx, vulgaris: Urocystis primulae

11b With similar biology on P. farinosa, stricta, veris & subsp. columnae: Urocystis primulicola

gallers on Pisum

Last modified 10.iv.2020

Dichotomous table for gallers on Pisum

by Hans Roskam

1a On root collar or on above ground organ => 4

1b On roots => 2

2a Roots with nodules => 3

2b Root system and shoot parts ± atrophied; roots unchanged on the outside, giant cells inside; later on bearing poppy-seed sized, lemon-shaped, whitish to brownish egg capsules. Pisum spp.: Heterodera goettingiana

= Also recorded on Pisum species is the clover cyst eelworm H. trifolii. More strongly infected plants often lacking nodules

3a Roots slender or nodular swellings bearing side roots. Pisum spp.: Meloidogyne hapla

3b Oval or cylindrical nodules, often terminally broadened and ± forked or lobed, hand-shaped or coralline-like subdivided, at maturity inside ± flesh-red, up to about 8 mm long, occasionally clustered; laterally inserted on main- and side roots. Pisum spp.: Rhizobium leguminosarum

4a On flowers or fruits => 11

4b On vegetative parts => 5

5a On aerial organs => 7

5b On root collar => 6

6a Proliferations conspicuous, closed, at surface not subdivided. “oot cancer”. P. sativum: Agrobacterium tumefaciens

6b Witches’ broom-like malformation. Accumulation of severely stunted or fleshly thickened, lobed, pale, aerially greening shoots. “Leafy gall”. P. sativum: Rhodococcus fascians

7a Older plants ± severely stunted, leaves and, when present, flowers variously disfigured, or malformations of shoot tips => 8

7b Stems of young plants severely stunted, often conspicuously spongy thickened and ± distorted. Lateral organs stunted, ± bent and curled at base, also swollen; growth dwarfed. Pisum spp.: Ditylenchus dipsaci

7c Shoot distorted, often with proliferation of buds and russeting of leaves. Pisum spp.: Peronospora viciae

8a Plant completely or largely disfigured => 9

8b Shoot tips stunted to variable degree, leaves including, if present, disfigured flower buds, rosette-like or bushy accumulations, containing many white jumping larvae. P. sativum: Contarinia pisi

9a Malformations caused by aphids => 10

9b Leaves on the ± atrophied shoot tip curled, rolled upwards; leaves and flowers, if present, clustered. If strongly infected, the plant remains small and bushy; larvae very slender, many, up to about 1.5 mm long. Pisum spp.: Thrips angusticeps

10a Several leaves of variously disfigured shoot tips; the leaf blades ± curled and deflected, partially discoloured; containing black aphids Pisum spp.: Aphis fabae

10b Similar malformations caused by green aphids. P. sativum: Acyrthosiphon pisum

11a On flowers => 12

11b Young pods disfigured, sometimes with nodular, discoloured swellings. Usually containing many white, jumping larvae. P. sativum: Contarinia pisi

12a Flower buds disfigured and clustered on often severely stunted stalks, especially swollen at base, corolla stunted and strongly curled, unopened; containing many white, jumping larvae. P. sativum: Contarinia pisi

12b Flowers developing into short shoots with scale-like, green leaflets. P. sativum: Unidentified gall mite or virus

gallers on Pinus

Last modified 2.viii.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 (I), 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 twigs => 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 Rhyacionia 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 (cult.) 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

13a 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 Picris

Last modified 9.iv.2020

Dichotomous table for gallers on Picris

(incl. Helminthotheca)

by Hans Roskam

1a On above-ground parts => 2

1b Roots with nodule-shaped swellings. P. hieracioides: Meloidogyne hapla

2a On vegetative parts => 3

2b On inflorescences => 15

3a On leaves => 9

3b On stems, shoot tips or buds => 4

3c All parts of shoot with white crusty blisters, very variable in size; shoot often distorted; P. echioides, hieracioides: Pustula obtusata

4a Galls on stems, on upper shoot tips or lateral buds => 5

4b Shoot formation in the leaf rosette deformed to a conical, 5 mm long, 9 mm wide gall, with several markedly shortened leaves. Containing one maggot. P. hieracioides: Napomyza lateralis

5a Malformations on stems, sometimes encroaching upon neighbouring buds or lateral shoots => 6

5b Tip of the main- or lateral shoot, also the axillary bud, deformed into rotund or oblong, galls up to 15 mm long, consisting of several strongly pubescent, short imbricated covered leaves. Containing several whitish, non-jumping larvae. Sometimes neighbouring stem parts galled. P. hieracioides: Jaapiella picridis

5c These galls may also contain jumping larvae of Contarinia picridis

6a The gall causers develop outside the galls in pit-like depressions or in erinea => 8

6b The gall causers develop inside the galls => 7

7a Galls of spongy nature; distinct from the outside. Early infected stems often mostly stunted in their longitudinal growth markedly swollen over substantial length, ± bent. Later infection results in ± curved localised swellings of different types, sometimes even including the often irregularly swollen receptacle. P. hieracioides: Ditylenchus dipsaci

7b Longitudinal growth of stem not – or rarely stunted, the outside hardly deformed. In the locally thickened pith are many separated elliptical chambers, about 1–2 mm long each with one larva. P. hieracioides: Unidentified gall wasp

7c Similar galls, but with larger chambers, 2.5–3 mm long each with a white larva, on P. echioides, hieracioides: Phanacis caulicola

8a Especially the basal stem part over various length ± bulging swollen, with one or several depressions containing the gall causer. P. hieracioides: Planchonia arabidis

8b Any part of stem with ± extended, dense, initially white or reddish, later brownish erinea. Sometimes the buds are involved, in which case they are to a large extent stunted. P. hieracioides: Aceria picridis

9a Galls predominantly on leaves, on the mid- and lateral main veins extended in various ways into the leaf blades or malformations exclusively on the petioles => 10

9b Leaves stunted in their development, in various ways curled, with loose, abnormal, pubescence. Between the narrow folds are yellowish, jumping larvae. P. hieracioides & subsp. spinulosa: Contarinia picridis

9c Basal leaves disfigured and curled. P. hieracioides: Protaphis terricola

10a Malformations without conspicuous pubescence => 11

10b Leaves with dense, initially whitish, later reddish, finally brownish erinea of multicellular, twisted hairs often on curved petioles and midribs. Pubescence of varied coverage on the under- or, more often, upperside, of the often curled, or even bulging leaf blade and even protruding onto the neighbouring mostly stunted axillary buds. P. hieracioides: Aceria picridis

11a Swellings spindle-shaped, usually less than 1 cm long, caused by fungi which fruit either inside the gall or on its surface => 13

11b Galls usually more expanded, caused by animal parasites, living inside the galls => 12

12a Galls spongy, usually pale green, sometimes reddened with ± wrinkled surface; in various ways protruding from the petiole or main vein into the ± distorted leaf blade. P. hieracioides: Ditylenchus dipsaci

12b Petiole, along with the basal parts of the main vein, distinctly swollen, predominantly on the underside. Gall glabrous, gradually narrowed towards leaf tip. One larva. P. hieracioides: Phytomyza picridocecis

13a The fruiting bodies of the fungus develop inside the galls => 14

13b Midrib on the leaf underside often with several weak swellings, about 2–5 mm long, sometimes coalescing, often yellow-bordered, occasionally resulting in a distortion of the stems, on the underside soon occupied by brown sori. Pycnidia yellowish and on the upperside. P. hieracioides: Puccinia hieracii

14a alls on the main-, and the lateral leaf veins. Veins particularly swollen on ± irregularly bordered, often yellowish, sometimes reddish discoloured, leaf blade areas on the leaf underside, appearing as a distinctly protruding relief. Spores develop within and close to the vascular bundle. P. hieracioides: Protomyces picridis

14b Small, prominent, closed swellings on the main veins, up to 3 (5) mm long, mostly yellow-bordered, whitish to brownish. P. hieracioides: Entyloma picridis

15a Receptacle transformed into an irregular, multi-chambered woody swelling, nut-size. Sometimes the peduncle of the flower head is inflated. Larval chambers spherical, scattered. Helminthotheca aculeata: Timaspis helminthiae

15b Receptacle transformed into a hard, multilocular mass, 8-‒17 x 14‒20 mm, like the rest of the plant covered with a coarse bristly hair cover. Gall chambers 3‒10. Helminthotheca comosa & subsp. lusitanica: Phanacis comosae

15c On flower heads. Helminthotheca echioides; Picris hieracioides: Tephritis divisa

gallers on Hypericum

Last modified 8.iv.2020

Dichotomous table for gallers on Hypericum

by Hans Roskam

1a On above-ground parts => 3

1b On subterranean parts => 2

2a Subterranean buds unopened, egg-shaped, consisting of succulent, yellowish, ± lanceolate scales. Containing 2–5 larvae per gall. H. maculatum, perforatum, pulchrum: Geocrypta braueri

2b oots with nodular to spindle-shaped swellings. H. calycinum: Meloidogyne hapla

3a Terminally on vegetative shoots, on leaves, inflorescences or flowers => 4

3b Axial part of shoot with irregular swellings, bearing single or several rimmed depressions and each containing a flat froth-covered nymph. H. perforatum, pulchrum: Planchonia arabidis

4a On inflorescences or flowers => 14

4b On vegetative parts => 5

5a On leaves => 11

5b Terminally on shoots => 6

6a Galls of ± definite shape on terminal buds of side- and main shoots => 8

6b Expanded malformations of undefined shape terminally on shoots => 7

7a Complete plant ± stunted, sometimes dwarfed with excessive branching; leaves narrower, more acute and densely arranged, pale; glands ± disfigured. H. perforatum: Cause unknown – ? gall mite

7b Shoot axis variously stunted, locally ± buckled, partially intensive green. Hypericum spp.: Philaenus spumarius

8a Galls tuft-like or acuminated,-cylindrical => 9

8b Galls ± globose, usually reddish, consisting of the terminal, distinctly shortened and widened, completely galled pair of leaves. Containing several reddish-yellow to red larvae. Hypericum spp.: Zeuxidiplosis giardi

9a Caused by gall midges => 10

9b Small tufts of leaves, caused by aphids; accompanied by excessive leafiness and distortion of stem. Hypericum spp.: Aphis chloris

10a Several terminal leaves imbricated clustered, tuft- or bud-like. Gall rotund in outline, leaves erect, keel-shaped, basally ± strongly thickened, sometimes yellowish or reddish; apical part often hardly changed. Containing several, at first white, later on pale to darker red coloured larvae. Hypericum spp.: Dasineura hyperici

10b Both terminal leaf pairs remain closed together and form a pointed-cylindrical gall, ± bilaterally symmetrical in cross-section, often reddened, hollow inside. Containing several white to yellowish larvae. Hypericum spp.: Dasineura serotina

11a Malformations of complete leaf blade caused by animals => 12

11b Leaf blade with ± many, yellow translucent many-celled warts, less than 1 mm long, variously joined; also on stem parts. H. perforatum: Synchytrium aureum

12a The additionally variously disfigured leaves are rolled at margin => 13

12b Veins of the discoloured and disfigured leaf are thickened and undulating. H. perforatum: Unidentified gall mite

13a Leaves curled, upwardly rolled; containing a single white midge larva. H. maculatum, perforatum: Unidentified gall midge

13b Leaf blade strongly wrinkled and ± folded, with downward roll of leaf margin. H. hirsutum, maculatum, montanum, perforatum: Aculus hyperici

13c Tight downward roll of leaf margin; roll more pubescent than the rest of the leaf blade, containing several white larvae. H. hirsutum, perforatum: Macrolabis marteli

14a Galls on single flowers => 15

14b Flowers clustered, ±, greened; bracts irregularly curled and rolled inwards; small leafy shoots are often clustered and bushy. H. maculatum, perforatum: Unidentified gall mite

15a Flower buds unopened. Galls rotund; caused by gall midges => 16

15b Corolla leaves unopened, developing into an acuminate gall, in longitudinal direction ± flattened, later on brown striate. Containing a single caterpillar. H. hirsutum, perforatum: Lathronympha strigana

16a Buds swollen, reddened; containing several white larvae. Hypericum spp.: Dasineura serotina

16b Buds especially swollen at base; from wide base short acuminate; ± striate and reddened. Containing white, jumping larvae. H. maculatum, perforatum: Contarinia hyperici

gallers on Corylus

Last modified 8.iv.2020

Dichotomous table for gallers on Corylus

by Hans Roskam

1a On above-ground parts => 2

1b Nodules on roots. Corylus spp.: Subanguina radicicola

2a On catkins or fruits => 13

2b On vegetative organs => 3

3a On leaves => 9

3b On buds, young shoots or older branches => 4

4a On buds and young shoots => 7

4b On woody parts => 5

5a Cancers or witches’ brooms => 6

5b Thicker branches or stems with ± distinct nodular to club-shaped swellings. Corylus cornuta: Viscum album

6a Bark of woody parts with cancer-like proliferations. C. avellana: Neonectria ditissima

6b Small witches’ broom-like malformations. C. avellana: Cause unknown – ? gall mite

7a On young shoots => 8

7b Buds swollen, rotund, up to 10 mm long. Scales enlarged, thickened like the outer leaf primordia and inside with tubercular proliferations. C. americana, avellana, colurna, maxima: Phytoptus avellanae

7c Enlarged globular bud. Contains caterpillar in a large central cavity. C. avellana: Unidentified lepidopteran

8a Young shoots stunted. Usually leaves of several buds per twig are disfigured; their leaf blades curled, folded, partially rolled and more densely pubescent. C. avellana: Cecidophyopsis vermiformis

8b Young shoot with local, pustule-shaped swellings; apical part of shoot ring-barked, withering and soon breaking off. C. avellana, colurna: Oberea linearis

9a Leaves folded or curled => 11

9b Leaf blades with flat, rotund archings => 10

10a Flat upward proliferations, surrounded by a 6 mm long, slightly discoloured and thickened area; the underside cavity contains a single vitreous to whitish larva. C. avellana, maxima: Mikomya coryli

10b Leaf blade with parenchyma galls about 3–5 mm wide, weakly protruding on both sides, initially hardly discoloured. Containing a single larva. C. avellana, colurna, maxima: ? Arnoldiola tympanifex

11a Leaf blade curled => 12

11b Leaf blade folded and crumpled; at base, with white, jumping larvae. C. avellana: Contarinia cybelae

12a Younger leaves, if heavily infected, folded and curled. With green, rarely reddish, ca. 2.5 mm long aphids on the underside. C. avellana, colurna, maxima: Corylobium avellanae

12b Younger leaves, if heavily infested, with discoloured bulges. With pale yellow to yellowish-white, ± 2 mm long aphids on underside. C. avellana, colurna, heterophylla, maxima: Myzocallis coryli

12c Leaf blades loosely contracted together, curled. C. avellana: Philaenus spumarius

13a Malformations of the catkins => 14

13b Gall-like malformations in the developing fruits, from the outside inconspicuously changed. C. avellana: Curculio nucum

14a Catkins completely or only partially swollen => 15

14b Catkins sprouting. C. avellana: Unidentified gall mite

15a Catkins locally or completely pear- or barrel-shaped, swollen. Scales enlarged, glabrous; stamens ± stunted, larvae white, glossy, jumping. C. avellana, maxima Contarinia coryli

15b In similar galls. Larvae white, dull, non-jumping. Inquilines of the previous species: Dasineura corylina

15c Catkins locally swollen, often at their base. Scales ± irregular, sometimes elongated, lacerate, ± pubescent, slightly thickened, spreading at top. Stamens enlarged. C. avellana: Phyllocoptruta coryli

15d Male catkins distorted, often twisted screw-like. Containing one to several caterpillars. C. avellana, ? colurna: Unidentified lepidopteran

gallers on Cornus

Last modified 7.iv.2020

Dichotomous table for gallers on Cornus

by Hans Roskam

1a On leaves => 3

1b On stems => 2

1c lowers slightly swollen and remaining closed, containing a whitish to light orange larva. On C. sanguinea: Unknown gall midge

2a Small, ± rotund-oval, rimmed depressions on bark of ± swollen twig parts. Cornus spp.: Chionaspis salicis

2b Thick branches with ± spindle-shaped, mistletoe bearing swellings. Cornus spp.: Viscum album

3a Malformations of undefined expansion, caused by aphids or free-living mites => 5

3b Galls of ± defined shape, small, wart-, or pustule-like, or conspicuous, ± blunt-conical => 4

4a Galls larger than 1 mm. Leaves on midrib, mainly on lower side veins, usually with several, 3–5 mm broad, often many-chambered, tough-walled, greenish or ± reddened galls; basally blunt-conical, top surrounded by 2–5 or more lobes; protruding on upper side as a ± hemispherical bump. Each chamber containing a single orange-yellow to -reddish larva. C. mas, sanguinea & subsp. australis: Craneiobia corni

4b Hardly 1 mm long, yellow translucent small warts, usually many on basal green organs. C. sanguinea: Synchytrium aureum

5a Malformations caused by aphids => 7

5b Malformations caused by mites => 6

6a Leaf blade with upward protrusions, usually in vein axils, rarely in other areas. C. mas, sanguinea: Cenopalpus spinosus

6b Leaf blade disfigured, distorted, discoloured; margin ± undulate, almost crenate, rolled upwards. C. sanguinea: Phyllocoptes depressus

6c On underside of usually hardly disfigured, soon ± browned leaves. C. mas, sanguinea: Anthocoptes platynotus and/or Tegonotus acutilobus

7a Aphids yellowish, greenish to red-brownish => 8

7b Aphids black. Terminal leaves ± rolled inwards, slightly curled. C. sanguinea: Aphis fabae

8a Aphid powdered, long haired, on midrib of leaf underside usually arranged in rows. Terminal leaves loosely clustered, nest-like. C. alba, sanguinea, sericea:
Aphis salicariae

8b Aphid not powdered, up to 2.5 mm long. Antennae half the body length. Siphunculi pore-shaped. Leaves, if strongly infected, stunted, curled, rolled, sometimes keel-shaped, deflected. C. alba, glabrata, mas, sanguinea: Anoecia corni

8c Very similar aphid. Causing similar malformations facultatively on C. sanguinea: Anoecia vagans

gallers on Carum

Last modified 6.iv.2020

Dichotomous table for gallers on Carum

(inc. Bunium)

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. C. carvi: Meloidogyne hapla

2a On inflorescences, flowers or fruits => 12

2b On vegetative parts => 3

3a Galls bulging, bearing aecia on surface => 11

3b Aecia absent, differently shaped => 4

4a Galls caused by animal inducers or by fungi, fruiting inside => 5

4b Basal leaves variously disfigured. Leaf blades ± arched, soon with expanded areas of grey-white asci. C. carvi: Taphridium umbelliferarum

5a Malformations extended over large parts of leaves => 9

5b Malformations of various expansions on leaf-axis or leaf veins, hardly 1 mm across, wart-shaped => 6

6a Swelling of axis, usually ± exceeding 2 mm => 8

6b Galls ± hemispherical, wart-shaped, usually on leaf underside, on midrib and stalk; sometimes coalesced into smaller ridges or crusts. Perennial spores only in a central strongly swollen nutritive cell surrounded by enlarged auxiliary cells => 7

7a Galls distinctly golden-yellow translucent. C. carvi: Synchytrium aureum

7b Warts very similar, glass clear, later on dark coloured, bead-like; also observed close to umbel. C. carvi: Physoderma hemisphaericum

8a Compact, glabrous, pale green, vitreous, spindle-shaped bulges, about 2–15 mm long on leaf veins and midrib, -stalk and young stem. Many spores close to vascular bundle. C. carvi: Protomyces macrosporus

8b Stalk and midrib ± severely stunted and spongy, swollen. Galls yellow-green, soft, wrinkled at surface, usually over large expansion at lower stem parts and basal leaves; sometimes also as localised bulge on leaf midrib as well as on stem. C. carvi, verticillatum: Ditylenchus dipsaci

9a Leaf blade curled, caused by aphids or cercopids => 10

9b Tip of leaf broadened, thickened, shortened and deflected or enlarged and lacerate; sometimes clustered bush-like due to stunting of midrib. C. carvi: Aceria carvi

10a Leaves converging downwards ± nest-like; curled and deep green close to the froth-covered nymph. Carum spp.: Philaenus spumarius

10b Leaves slightly curled and discoloured, often initially etiolated. Aphid pale green, with bifid cauda. C. carvi: Cavariella aegopodii

11a Leaf veins, -midrib, -stalk or also stem with bulges bearing yellowish spermogonia and aecia. Aecia pustule-shaped, with round exit hole. C. carvi: Puccinia bistortae

11b Only aecia formed, these cup-shaped, with frayed, whitish border. C. carvi: Puccinia polygoni-alpini

12a On inflorescences or flowers => 13

12b Fruit bladder-like swollen, often ± reddened, protruding above the umbel. Containing 1 (‒3) orange-red larvae. C. carvi, verticillatum: Kiefferia pericarpiicola

13a Malformations on expanded parts of umbel => 14

13b Stalks at centre or close to (partial) umbel ± swollen club-shaped or globular. Galls one-, also multi-chambered. Inner wall with mycelium. Each chamber contains a single larva. C. carvi, verticillatum: Lasioptera carophila

14a Inflorescence variously stunted and tangled, flowers stunted => 15

14b Inflorescence severely disfigured. Many parts of flowers leafy, corolla sometimes greened, also discoloured whitish-green or reddish. C. carvi: Aceria carvi

15a Stalks of young inflorescence variously stunted, also distorted. (Partial) umbels ± tangled. Flowers stunted and disfigured. Contain froth-covered nymph. Carum spp.: Philaenus spumarius

15b Similar malformations on young inflorescence caused by many aphids. C. carvi: Hyadaphis foeniculi

gallers on Carpinus

Last modified 5.iv.2020

Dichotomous table for gallers on Carpinus

by Hans Roskam

1a On above-ground parts => 2

1b Root with nodule-shaped swellings. C. betulus: Meloidogyne hapla

2a On leaves or buds, also on fruit wings => 5

2b On stems or branches => 3

3a Conspicuously protruding from the bark => 4

3b Bark initially with closed, irregular crooked proliferations, bursting open later on, displaying the woody part surrounded by variously shaped cancers. “Nectria-cancer”. C. betulus: Neonectria ditissima

4a Localised thickenings and sometimes distortion of branches or stems. C. betulus: Viscum album

4b Heavier branches or stems with bushy, up to 1 m large witches’ brooms, with thickened and densely foliate branched axial parts. Leaf blades curled; asci on the undersides June-August. C. betulus, orientalis: Taphrina carpini

5a On leaves and occasionally on the envelope of the fruit => 7

5b On buds => 6

6a Buds swollen, not opening; spherical or egg-shaped, partially pea-size swollen. Scales grey-white pubescent. C. betulus: Unidentified gall mite

6b Buds swollen, enlarged, not developing. Contain yellow larvae. C. betulus: Contarinia trotteri

7a Galls on the leaf blades or in the vein axils of unfolded leaves => 11

7b Swelling of the veins or leaf blade heavily folded or curled => 8

7c Leaves browning. C. betulus: Aculus betuli

8a Venation involved in the malformations => 9

8b Leaf blade between two side veins with a somewhat thickened, pod-like, ± yellowish or usually red upward fold; on the underside a furrow which opens at maturity. Contains several white larvae. C. betulus, orientalis: Contarinia carpini

8c Occasionally also observed in galls of Contarinia carpini are the yellow larvae of Aschistonyx carpinicolus

9a Venation with conspicuous thickenings => 10

9b Side veins and the neighbouring, upward folded parts of the leaf blade conspicuously ± zigzag-like bent in- and outwards. Heavily infected leaf blades ± rolled upwards. C. betulus, orientalis: Aculops macrotrichus

10a Leaves folded upward over the uniform, only slightly thickened midrib. Infestation often extending into the base of the also slightly thickened side veins, sometimes only locally, the neighbouring leaf blade parts fold subsequently. Midrib of early affected leaves usually bent downwards. On the upper side, especially on the midrib, a single- or several yellowish larvae. C. betulus, orientalis: Aschistonyx carpinicolus

10b Midrib and the adjacent parts of the side veins on the leaf underside with conspicuous, interrupted or continuous, in that case bumpy swellings. Leaf blade sometimes over the midrib ± bent upwards. Galls with a double row of chambers on both sides of the midrib. In each chamber, situated between two side veins, a single yellowish-white larva. C. betulus: Zygiobia carpini

11a Malformations without particular connection with the venation => 12

11b Leaf blade in the vein axils at the upper side weakly arched, sometimes discoloured ± purple-red; with corresponding depressions, at their margin conspicuous very long twisted hairs, on the underside. C. betulus, orientalis: Aceria tenella

= Putative inquiline: Phyllocoptes compressus

12a Leaf blade with small, rotund, hardly arched, pale green or yellowish parenchyma galls, up to 4 mm wide. Containing one single yellow larva. C. betulus: Dasineura ruebsaameni

12b Underside of leaf blade with erinea. C. betulus, orientalis: Cecidophyopsis vermiformis

gallers on Alopecurus

Last modified 5.iv.2020

Dichotomous table for gallers on Alopecurus

by Hans Roskam

1a On above-ground parts => 2

1b Roots with spindle-, screw-shaped or crooked galls, only a few mm long. A. geniculatus, pratensis: Subanguina radicicola

1c Roots with aphids. Alopecurus spp.: Tetraneura caerulescens

2a On inflorescences or fruits => 9

2b Complete host disfigured or malformations on stems or leaves => 3

3a Leaves or sheaths with localised or expanded malformations or with long stripes caused by smuts => 6

3b Main shoot of host stunted and disfigured => 4

4a Malformations caused by fly- or midge larvae => 5

4b Plant growth stunted. Inflorescence remains hidden in the swollen leaf sheaths, pale. A. pratensis: Limothrips denticornis

= Stem gall above internode on A. pratensis is caused by the eurytomid Tetramesa fumipennis

5a Stem shortened with weak swelling below the emerging inflorescence. A. myosuroides, pratensis: Oscinella frit

= On the same hosts the closely related Oscinella alopecuri and O. ventricosi have been described

5a Leaf sheaths usually inflated above the upper node. On stem above the nodes one or several saddle-shaped margined galls, which contain in each depression an intensely red larva. A. myosuroides: Haplodiplosis marginata

5c Yellow midge larvae develop under leaf sheaths at stem base. A. pratensis: Mayetiola alopecuri

6a Leaf blades and sheaths with smut patches => 8

6b Malformations caused by animal parasites => 7

7a Leaf sheaths inflated, bladder-like, sometimes discoloured violet and locally slightly thickened. A. geniculatus, pratensis: Rhopalosiphum padi

7b Leaf blade at base with narrow, elongate-cylindrical swellings. A. geniculatus: Unidentified eelworm

7c Upper leaf swollen, bladder-like, discoloured. Aphid up to 2 mm long, slim. A. geniculatus, pratensis: Laingia psammae

8a Elongate patches, at first lead grey, then dusty, on leaves, rarely on stems. Spores usually 2–3, in balls enveloped by sterile cells. A. aequalis, arundinaceus, geniculatus, myosuroides, pratensis: Urocystis alopecuri

8b Smut patches in black stripes, later on completely shredded leaves, on sheaths and stems. Spores solitary, globular, densely covered with small blunt warts. A. arundinaceus, geniculatus: Ustilago striiformis

8c From A. gerardii has been described: Tilletia sleumeri

9a Inflorescences disfigured over extensive areas => 11

9b Malformations predominantly restricted to ovaries and neighbouring glumes => 10

10a Infected ovaries transformed into a compact smut body, sometimes larger than a normal seed. A. myosuroides: Tilletia controversa

10b Ovaries swollen, tube-shaped elongated, inside with spongy tissues or with expanded cavities. Glumes ± conspicuously enlarged. A. alpinus: ? Anguina sp.

10c Seeds destroyed on account of the puncturing of the ovary by the larva. A. agrestis, pratensis: Dasineura alopecuri

10d Midge larvae live gregariously in inflorescences. A. pratensis: Contarinia merceri

10e Ditto, A. arundinaceus, geniculatus, myosuroides, pratensis: Stenodiplosis geniculati

11a Spikelets variously completely or partially disfigured by aphids. A. arundinaceus, pratensis: Sitobion avenae

11b Similar malformations. A. arundinaeus, pratensis: Sitobion fragariae

11c Spikes leafy, over expanded parts ± greened or, in case of strong infestation, bleached. A. pratensis: Aceria tenuis

gallers on Chaerophyllum

Last modified 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

Last modified 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

Last modified 16.vii.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

Last modified 2.vii.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

7c Midrib of leaf over a length of 8–15 mm swollen, blister-like and slightly bent; on the underside with dense rows of aecia and pycnidia, which may also appear scattered on the upper side. L. alpina, aurea, macrophylla: Puccinia mulgedii

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

Last modified 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

Last modified 26.v.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.: Heterotrioza 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

Last modified 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

Last modified 30.iv.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 Asphondylia 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

Last modified 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

Last modified 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

Last modified 11.iv.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

Last modified 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

Last modified 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

Last modified 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 Inula

Last modified 7.vii.2020

Dichotomous table for gallers on Inula

(incl. Dittrichia, Limbarda)

by Hans Roskam

1a On above-ground or subterranean shoot parts => 2

1b Roots with many small tuberous swellings. I. brittannica: Meloidogyne hapla

1c Unilocular, round, lignified gall, up to 3 mm in diameter. The young gall is green, later it turns yellow to brown. Pupation, after hibernation, in the gall. I. hirta: Isocolus brunneus

2a On capitula => 15

2b On vegetative plant parts => 3

3a On single, or several, usually disfigured terminal leaves => 12

3b On stems, shoot tips; malformations sometimes extending into isolated leaves => 4

4a On shoot tips or lateral buds => 5

4b Smooth soft-walled globular gall, about 5 mm across, yellow-green to red, on various places on stem, leaf buds and flower heads; sometimes several clustered together or connate. One chamber with one larva. Dittrichia viscosa; Inula britannica, conyzae, ensifolia, oculus-christi, salicina: Acodiplosis inulae

4c Spindle-shaped green gall (20 x 10 mm), sometimes spherical; large cavity containing a milk-white larva. Adults emerge in end May. Limbarda crithmoides: Euarestella megacephala

4d Spindle-shaped galls on stem base and in stems, contain frass: Unidentified lepidopteran

4e Unilocular, round, lignified gall, up to 3 mm in diameter. The young gall is green, later it turns yellow to brown. Pupation, after hibernation, in the gall. I. hirta: Isocolus brunneus

5a Malformations of above-ground buds or shoot tips => 6

5b The subterranean buds, and, sometimes also basal above-ground buds on root collar transformed to one-chambered solitary or clustered galls, up to 5 mm long, tough-walled, fleshy; the outside with dense, long, initially white, later grey-brown felt-like hairs. One reddish larva. I. britannica, ensifolia, germanica, hirta, hybrida, salicina: Inulomyia subterranea

6a Terminal- or lateral artichoke-like buds, malformations remaining closed => 7

6b Terminal buds or buds on stems, sometimes involving the neighbouring leaves, transformed into a one-chambered dry-fleshy closed gall about 5 mm across. Containing a single larva. Dittrichia viscosa; Inula britannica, conyzae, ensifolia, oculus-christi, salicina: Acodiplosis inulae

7a Rosette-like malformations => 11

7b More or less bud-like malformations => 8

8a Galls not exceeding 10 mm => 9

8b Partly open bud or young leaves, usually of basal rosette, are largely stunted and densely haired over an extensive area; containing yellow-orange larvae. I. conyzae: Neomikiella beckiana

9a Glabrous or pubescent galls caused by midge larvae => 10

9b Leaves at the shoot tip stunted, curled. In the middle bud-like converging; the following leaves slightly increasing in size and ± rosette-like spreading. I. salicina: Unidentified gall mite

10a Galls conspicuously pubescent => 11

10b Galls inconspicuously pubescent. Young leaves terminally ± severely stunted, at least the basal parts pale and rolled together composing a slender, erect artichoke, enclosing the youngest parts. Containing whitish to yellow larvae. I. britannica, hirta, salicina: Contarinia inulicola

= In galls on terminal shoots, or lateral buds, of various Inula species from dry habitats live gall midges belonging to a second species group, which may differ from the species on I. britannica.

11a Gall about 4–10 mm long, sometimes enclosed by a few shortened leaves, basally thickened and widened, with their leaf blade ± spreading => 13

11b Gall ± distinctly bud-like, about 8–18 (20) mm long; the exterior leaves decreasingly stunted, the base conspicuously enlarged and variously disfigured, strongly white pubescent over large areas. Larva yellowish-red. I. conyzae: Neomikiella beckiana

12a Malformations caused by aphids or cercopids, always lacking dense pubescence => 13

12b Leaves on the shoot tip ± tightly rolled or folded together, densely pubescent and partially stunted. I. salicina, Dittrichia viscosa: Eriophyes cupulariae

13a Aphid galls => 14

13b Leaf blades downward arched and strongly curled, dark green close to the froth-covered nymph. I. britannica, helenium: Philaenus spumarius

14a Leaf blade disfigured, deflected, yellow-spotted, with disfigured venation. Dittrichia viscosa, I. conyzae, helenium: Brachycaudus helichrysi

14b Leaf blade with loose upward marginal roll, sometimes narrowly pod-like malformation on young leaf blades. I. ensifolia, hirta, salicina: Brachycaudus salicinae

15a Larvae rotund-cylindrical usually living, in the soon ± hardened, upwardly arched receptacle. Tephritid gall causers => 16

15b More or less expanded parts of the receptacle of younger, strongly transformed capitula almost semiglobular. Galls about 4–5 mm long with soft fleshy wall containing an elongate midge larva. Dittrichia viscosa; Inula britannica, conyzae, ensifolia, oculus-christi, salicina: Acodiplosis inulae

15c Midge larvae develop in flower heads. I. salicina: Jaapiella inulicola

15d Unilocular, round, lignified gall, up to 3 mm in diameter. The young gall is green, later it turns yellow to brown. Pupation, after hibernation, in the gall. I. hirta: Isocolus brunneus

16a Separate galls with tough, later woody wall; mostly with several in a flower head and bulging out from the receptacle => 17

16b Receptacle sometimes thickened on one side. Galls tough-walled when mature, but not woody. I. britannica, ensifolia, hirta, oculus-christi: Inuromaesa maura

16c Inducer of hardened receptacle galls on I. britannica, conyzae: Trupanea stellata

17a Receptacle inside the flower head strongly swollen, bulge-like to conical disfiguration, apically eventually having an emergence hole. One larva per chamber. I. ensifolia hirta, hybrida, salicina, Limbarda crithmoides: Myopites eximia and/or M. longirostris

17b Similar galls on I. britannica: Myopites tenellus and/or Inuromaesa maura

17c On Dittrichia viscosa. Receptacle swollen, transformed into a woody multilocular gall, red-brown, rotund or elongated, glabrous, measuring 4–8 mm with apically 2–4 (5–6) paler coloured appendages representing the achenes. Each larval chamber containing a white-yellowish larva: Myopites limbardae and/or M. olivieri

17d On Dittrichia viscosa. The receptaculum is transformed into a smooth sphere; a few galled achenes, crowned by pappus hairs emerge as narrow cones from the gall; the other achenes are aborted and are arranged around the gall: Myopites stylatus

= Myopites inulaedysentericae, occasionally recorded from Inula species

= Furthermore from flower heads have been recorded the tephritid flies Ictericodes zelleri from I. conyzae, and Acinia biflexa from I. brittanica

gallers on Capsella

Last modified 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

Last modified 18.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