Dichotomous table for gallers on Vicia

by Hans Roskam

1a On parts above ground => 5

1b On roots or root collar => 2

2a On roots => 3

2b Conspicuous proliferations on root collar or stems. V. faba, villosa, etc.: Agrobacterium tumefaciens

= The bacterium Rhodococcus fascians may cause “leafy galls” on V. faba

3a Roots with nodular swellings or laterally inserted nodules => 4

3b Roots on the outside not distinctly changed; temporarily bearing poppy-seed sized, lemon-shaped, white, soon brown cysts. Giant cells develop inside. Vicia spp.: Heterodera goettingiana and/ or Heterodera trifolii

4a Roots with nodular- or slender spindle-shaped to cylindrical swellings, up to about 6 mm long, bearing some lateral roots. Vicia spp.: Meloidogyne hapla

4b Rotund or cylindrical, about 2–7 mm long or compact, apically broadened, also forked or comb-like to coralloid subdivided nodules, which are inserted with narrowed base into main- and adventitious roots. Vicia spp.: Rhizobium leguminosarum

5a On inflorescences, flowers or fruits => 38

5b On vegetative parts => 6

6a Stem with localised swellings, spindle- to bulge-like or young plants at base conspicuously stunted and spongy, thickened => 32

6b Malformation of many organs terminally on shoots, or galls on leaves => 7

7a Expanded parts of shoots etiolated; internodes elongated; leaves ± reduced in size, usually paler, or internodes and leaf axis ± shortened, slightly thickened; leaf blades reduced. Malformations soon bearing fruiting sori at surface => 27

7b Malformations on single or many, normally inserted or ± clustered leaves; caused by animals => 8

8a Galls on separate leaves or on ± largely unfolded leaf blades => 9

8b Leaf completely disfigured; midrib hypertrophied; leaflets folded, pod-like Containing several orange-coloured larvae. V. angustifolia: Dasineura vicicola

8c Shoot tip distinctly stunted; the very young, hardly developed vegetative or generative organs largely stunted, swollen. Marginal leaves sessile, all basal parts strongly swollen, the peripheral leaflets increasingly developing, leaf blades rolled over their complete length or with unfolded tips only. Larvae white, non-jumping. V. sepium: cf. Dasineura viciae

8d Folded hypertrophied discoloured leaflets; contain yellow, 3 mm long midge larva. Vicia lutea: Anabremia trotteri

9a On petioles, midrib or on midrib of unfolded leaflets => 26

9b On leaflet leaf blades => 10

10a Galled leaflets conspicuously fleshly thickened. In early infestations usually all leaflets of several, clustered leaves disfigured. On older leaves only a few leaflets are galled => 23

10b Leaves not fleshly swollen; curled, curved, folded or rolled inwards => 11

11a Leaf curls or -rolls caused by aphids or spittlebugs => 19

11b Leaf folds, -rolls, curvings caused by midge larvae, thrips or mites => 12

12a Folds or rolls caused by midge larvae => 16

12b Malformations caused by gall mites or thrips => 13

13a Mite galls => 14

13b Plant largely atrophied and distorted; leaflets smaller, irregularly constricted and curved, locally discoloured or browned; ± upwardly folded or -rolled. Plant largely atrophied and distorted; leaflets smaller, irregularly constricted and curved, locally discoloured or browned; ± upwardly folded or -rolled. V. cracca, hirsuta, pannonica, sativa, sparsiflora, tenuifolia, tetrasperma, etc.: Firmothrips firmus

= Stunting of various parts is occasionally caused by the black-brown “pea thrips”: Kakothrips robustus

14a Malformations on species with tendrils => 15

14b On V. cassubica, sepium. Leaflets upwardly folded, bent, petiole ± twisted. Unidentified gall mite

15a Leaf blade of leaflet, mainly of apical leaves, rolled upwards from margin up to midrib, ± curved and deflected. V. angustifolia, cracca, sylvatica, tenuifolia, villosa: Aculus retiolatus

15b Similar malformations on V. hirsuta, tetrasperma: Aceria trifolii

16a Leaf blades of single or all leaflets folded, pod-like, over the midrib or occasionally rolled inwards; not conspicuously thickened. On glabrous Euvicia species => 18

16b Similar galls on ± pubescent species. V. villosa, cracca, hirsuta => 17

17a On V. cracca, villosa, incl. subsp. varia. Fold only slightly thickened. Larva pale flesh-coloured: Anabremia massalongoi

17b Single leaflets of mostly unfolded leaves rolled upwards over the midrib on both sides. Leaf blades not shortened. Gall wall hardly thickened, at first usually not discoloured-, later on often yellowish to brownish. Larvae pale yellow to pale orange-yellow. V. cracca: Tricholaba viciarum and/ or Tricholaba similis

17c On V. hirsuta. Leaf blade folded together upwards with only its midrib thickened. Unidentified gall midge

18a Single to several leaflets per leaf loosely bent upwards. Leaf blades almost normally developed, hardly thickened and discoloured. Larvae white to dull yellow. V. sylvatica: Lathyromyza sp.

18b On V. cassubica, dumetorum, pisiformis. Single or several leaflets of younger leaves folded upwards, only the midrib thicker and discoloured. Galled parts drying after departure of the larvae, causing the unaffected leaf blade parts to be distorted ± sickle-shaped. Unidentified gall midge

19a Malformations caused by aphids => 20

19b Leaf blades usually with several deflected, ± clustered nest-like on the stunted, also curved axis; locally strongly curled and discoloured deep-green. Vicia spp.: Philaenus spumarius

20a Aphid black => 21

20b Aphid dark-green; of considerable size; siphunculi club-like, black, like cauda and legs. V. sativa, sepium, etc., occasionally on V. faba: Megoura viciae

21a On narrow-leafed Vicia species => 22

21b On V. faba; especially at shoot tips, often occurring in large colonies; causing only stunting, no gall-like malformations. Aphid up to about 2.5 mm long, dull-, rarely brown-black: Aphis fabae

= Bulging of leaves may also be caused by Vicia-virus 1.

22a Aphid up to about 2.75 mm long, black, appearing bluish translucent through white powdering; antennae longer than half the body length; siphunculi and the about equally long oblong cauda black. V. cassubica, cracca, Paederota lutea, Vicia pannonica, tenuifolia, tetrasperma, villosa: Aphis craccae

22b Aphid variating in size; black. Froth-covered nymphs only slightly frosted. Apterous adults with glossy back. Siphunculi longer than cauda, black. V. cracca, faba, sepium, etc.: Aphis craccivora

23a Galls on V. sylvatia, cassubica => 25

23b Galls on other vetches => 24

24a Leaflets folded upwards, pod-like. Wall succulent thickened, ± discoloured, also reddened. Often on severely stunted, terminal- or lateral shoot tips already the youngest leaves become galled and clustered into conspicuous balls, up to even 30 and more mm long; in other cases unfolding leaves have been attacked and several to all, usually distinctly shortened, leaflets have sometimes been transformed into clustered, thick-walled pod-like galls. Containing several white, later on proximally ± pink-coloured larvae. Mainly on V. sativa, sepium and other related Euvicia species: Dasineura viciae

= Also Anabremia bellevoyei has been reported as causer of disfigured leaflets, but this species is inquilinous like all other Anabremia species

24b Galls similar. Larvae pale-red. V. cracca, hirsuta, tenuifolia, tetrasperma, villosa, etc.: Dasineura loewiana

24c Similar galls on various Vicia species; containing whitish-yellow larvae: Dasineura spadicea

= Inquiline of D. viciae, loewiana and spadicea: Macrolabis vicicola

25a On V. sylvatica. Unfolding young to almost full grown leaves all or only several leaflets are transformed into strongly cartilage-like thickened, pod-like galls, in cross section almost rotund, usually pale-green. Containing a single or several larvae white to yellow at maturity: Tricholaba viciobia

= Inquiline gall midge: unidentified Macrolabis sp.

25b On V. cassubica. All leaflets of one or more youngest, already isolated or unfolding leaves folded upwards, pod-like. Complete gall wall conspicuously thickened, ± discoloured or reddened. Containing several milk-white, non-jumping larvae. Unidentified gall midge

26a Up to 10 (15) mm long, spindle-shaped, thin-walled swelling with oblong larval chamber on petioles or midrib. Containing a single larva. V. cracca, ? villosa, incl. subsp. varia, dumetorum, sylvatica: Cyanapion gyllenhalii

26b Midrib weakly swollen. V. sepium: Apion sp. s. lat.

27a Infected parts, especially on leaf underside, with expanded, ± grey-white patches of branched conidiophores. Malformations almost only caused by systemic infection, partially etiolated, partially associated with shortening of diseased organs => 29

27b Malformations caused by rust fungi => 28

28a Aecia and spermogonia loosely distributed over underside of leaf; mycelium often completely pervading the ± disfigured plant; leaves conspicuously smaller and shorter, pale-green. V. onobrychioides: Uromyces valesiacus

28b Fungus repeatedly developing aecia. Spermogonia only occurring together with primary aecia. Secondary aecia cup-shaped with slightly bent margin; in small groups with 2–5 on sometimes weakly galled pads on stems or scattered on expanded, usually not disfigured parts on undersides of leaves. V. hirsuta, more rarely V. tetrasperma: Uromyces ervi

29a On several Euvicia species => 30

29b On V. hirsuta, lathyroides, tetrasperma: Peronospora ervi

30a On V. cracca and forms, resp., on V. sepium => 31

30b On V. angustifolia, sativa, villosa: Peronospora viciae

31a On V. cracca: Peronospora mayorii

31b On V. sepium: Peronospora viciae

32a Stem with tough-walled or spongy swellings, containing gall causers => 33

32b Stem on any area, mainly close to ground, with broad spindle-shaped to bulging swellings, which bear single, or several rimmed depressions on the surface, containing froth-covered nymphs. Vicia spp.: Planchonia arabidis

33a Stem, also inflorescence stalks and -midrib, sometimes also leaf axis, with slender spindle-shaped, thin-walled, often at first pale-green coloured, large-chambered swellings; containing beetle larvae => 34

33b Seedlings severely stunted. Internodes stunted, sometimes twisted, often distinctly swollen. Gall tissue spongy, necrotic. Similar infestation ± encroaching into petioles and midrib; leaflets disfigured. Swellings often one-sided, curved, wrinkled, bulging, yellowish or reddish, irregularly arranged over the internodes. V. cracca, faba, hirsuta, pannonica, sativa, tetrasperma, villosa: Ditylenchus dipsaci

34a Swellings elongate spindle-shaped, usually slightly protruding => 36

34b Galls distinct, middle parts about twice as thick as the normal organ; elongate at the internodes, more compact on nodes; about 7–10 mm long. Containing a larva with a small head capsule => 35

34c Internodes with expanded, slender swellings, about 15–25 (35) mm long, reaching twice the organ diameter. The pith, which is excavated over a length, containing a compact white maggot with black gullet: cf. Agromyza erythrocephala

35a On V. cracca, dumetorum, hirsuta, sepium, sylvatica, tenuifolia, tetrasperma, etc.: Cyanapion gyllenhalii

35b Similar galls on V. cracca: Catapion seniculus

36a Galls usually differing from the previous ones by their small size, however, not positively distinguishable without rearing of adults. V. pyrenaica, sativa subsp. nigra => 37

36b V. angustifolia, lathyroides, sativa, sepium, tenuifolia, parviflora, villosa: Apion sp. s. lat.

37a V. sativa subsp. nigra: Holotrichapion pullum subsp. aestimatum

37b V. pyrenaica, ? V. sativa, sepium. Swelling of node, about 2 mm broad, 7 mm long; inconspicuous: Holotrichapion aethiops

38a On fruits => 44

38b On inflorescences or flowers => 39

39a Malformation of the complete inflorescence or localised galls on its stem parts only => 40

39b Unopened flowers contain several white, eventually orange-coloured jumping midge larvae. V. cracca, cassubica, tenuifolia, villosa, incl. subsp. varia, etc.: Contarinia craccae

= White larvae of Ametrodiplosis viciae, living on V. cracca, belong to an inquiline of Contarinia craccae

= White larvae of Jaapiella sp. are developing together with Contarinia craccae in flower heads of V. cracca

= Orange-yellow larvae of Anabremia viciae, recorded from flower buds, are inquilines of an unidentified gall midge

40a Malformations extending over inflorescence => 41

40b Spindle-shaped, up to 15 mm long, usually yellowish-green swelling on inflorescence stalks or rachis. Containing a single larva. V. cracca, hirsuta, sylvatica: Cyanapion gyllenhalii

41a Inflorescence and flowers stunted, ± clustered, ball-like => 42

41b ll flowers of a raceme ± greened and leafy. V. hirsuta, tetrasperma: Aceria trifolii

= On V. cracca and especially V. villosa inflorescences occasionally with all flowers, usually on many racemes, variously disfigured and partially greened by viruses

42a Gall midge larvae occur between organs on stunted shoot tips => 43

42b Inflorescences and shoot tips clustered into balls of flowers, or leaves. Aphids almost black, appearing bluish because of the white powdering; also encroaching onto stems. V. cracca: Aphis craccae

43a hoot tips distinctly shortened. All inserted organs clustered into conspicuous, ± dense balls. Flower primordia, situated between young leaves with pod-like disfigured leaflets, largely stunted, variously swollen and unopened. Only exceptionally normally coloured. Within and between organs are many white larvae. V. angustifolia, sativa, sepium: Dasineura viciae

43b Axial parts of inflorescence distinctly stunted. Buds clustered into rotund, more pubescent balls; unopened or only slightly opened. Yellow larvae present between buds and rachis. V. sepium: Unidentified gall midge

44a Pods disfigured by midge larvae => 45

44b Locally variously distinctly swollen pods containing a larva with narrow head capsule. V. cracca: Apion sp. s. lat.

46a Galls on Vicia species developing tendrils => 47

46b Galls on erect Vicia species => 46

46a Pods often completely or slightly disfigured, at their surface bumpy to sometimes undulately, curved. Containing several jumping, white larvae. V faba, ? angustifolia, ? sativa: Contarinia sp.

46b Pods disfigured; locally more swollen and with mycelium inside. Containing a larva at first pale-yellow, later on orange-coloured. V. sepium: Asphondylia lathyri

47a Pod of V. hirsuta, sylvatica etc. locally distinctly swollen. Inner wall of gall with mycelium. Containing a pale- to yolk-yellow larva: Asphondylia ervi

47b Ditto on V. cracca. Containing white larvae: Asphondylia sp.

mod 6.xii.2019