Plant Parasites of Europe

leafminers, galls and fungi

gallers on Astragalus

Dichotomous table for gallers on Astragalus

by Hans Roskam

1a On parts above ground => 2

1b Side roots with smaller egg-shaped nodules, about 7 mm long, cylindrical or terminally broadened and branched to coralloid: Rhizobium leguminosarum

2a On inflorescences, flowers or fruits => 17

2b On vegetative organs => 3

3a Malformations caused by mycelium of rust fungus bearing aecia and telia => 16

3b Malformations by animal causers => 4

4a On leaves => 11

4b On buds, shoots, stems or thorns => 5

5a Galls on stems or thorns => 8

5b Galls on shoot tips or lateral buds => 6

6a Malformations with ± conspicuous abnormal pubescence; on small-leafed Astragalus species => 7

6b Tip of main shoot or of ± stalked side shoots severely stunted. The still unfolded vegetative or also generative parts restricted in further development and completely stunted, ± thickened. The marginal leaves in all basal parts swollen, towards the exterior increasingly unfolding, the free part partially towards midrib rolled inwards or also folded and strongly narrowly curled. In the middle of the malformation are several white larvae. A. glycyphyllos: Contarinia sp.

7a Shoot tip or lateral bud as result of ± expanded thickening of stipules, petioles and leaflets transformed into a whitish densely pubescent, rotund, tuft-like mass. A. arenarius: Unidentified gall midge

7b Top of main- and side shoots severely stunted; younger organs clustered into a rotund to egg-shaped ± closed gall. The marginal leaves ± stunted, all parts close to gall thickened, pale green and more pubescent, at their tips sometimes almost normal. The centre of the gall contains a single orange-yellow larva. A. danicus: Dasineura rossi

8a Single galls ± spindle-shaped, sometimes clustered into conspicuous irregular nodular structures => 9

8b Galls globular or barrel-shaped, acuminate, about 3–5 mm across, with thick, compact, glabrous wall. Containing a single or several larvae. Inducer unidentified – ? gall midge, ? eulophid chalcid

9a All-sided spindle-shaped galls on stems => 10

9b Galls usually one-sided on internodes, spindle-shaped to oblong-oval, about 4–6 mm long and 2 mm wide, bulging, pale green or browned; chambers in woody part, each contains a single larva. Galls usually with several per internode, sometimes closely alongside or behind one another and coalescing. Close to nodes usually densely clustered, conspicuous, ± oblong, sometimes consisting of almost all-sided brown-tubercular gall complexes, measuring 10–25 mm in length and 10–15 mm in width. A. arenarius, cicer, glycyphyllos: Inducer unidentified – ? gall midge, ? eulophid chalcid

9c Stem galls of various size on A. glycyphyllos, up to even finger size, as well as about cherry-sized axillary galls on A. arenarius which on this host contained several yellow midge larvae in a large central cavity: Dasineura astragalorum

9d Large galls on stems. A. lagopoides: Asphondylia anatolica

10a Stem with all sided swelling, regular, wide spindle-shaped, tough- and thin-walled. A large chamber in pith containing several white chalcid larvae. A. danicus: Inducer unidentified – ? gall midge, ? eulophid chalcid

10b Stem close below the top swollen bottle-shaped; inside a cavity contains several white larvae. A. alpinus: Inducer unidentified – ? gall midge, ? eulophid chalcid

11a Malformations on leaflets or without conspicuous malformation of axial parts => 13

11b Galls mainly on petioles or midrib => 12

12a Petioles mainly at base often with several, usually separated, hard, spindle-shaped to oblong-oval one-chambered swellings, about 3–4 mm long. Containing a single larva. A. exscapus. Inducer unidentified – ? gall midge, ? eulophid chalcid

12b Leaf midrib stunted; leaflets clustered, along midrib and base thickened. A. alpinus: Dasineura cf. viciae

13a Leaflets folded upwards pod-like => 14

13b Leaf blades of leaflets rolled downwards. A. alpinus, arenarius, glycyphyllos: Aceria astragali

14a On A. danicus, exscapus, frigidus => 15

14b On many other Astragalus species. The leaflets of younger leaves are completely galled, strongly thickened and ± pale green, also reddish. In older leaves sometimes only some leaflets are distorted, in large-leafed species with only locally pod-like swellings, remaining with a ± broad margin of normally developed leaf blade; the leaflets may also be rolled upwards and thickened at margin. Older leaves brownish-yellow. A. cicer, glycyphyllos, monspessulanus: Dasineura glyciphylli

14c Inflated, yellowish green leaflets or terminal swellings on young stems. A. alpinus: Dasineura berti

14d Pod-like folded leaflets on A. lusitanicus: Dasineura mariae

15a Single or all leaflets of larger leaves pod-like, rolled upwards, strongly thickened, pale green or reddened. Each gall contains an orange-yellow larva. A. danicus, onobrychis: Dasineura rossi

15b Pod-like folded leaflets on A. lusitanicus: Dasineura mariae

15c Inflated, yellowish green leaflets or terminal swellings on young stems. A. alpinus: Dasineura berti

16a Mycelium perennial; leaves of infected shoots disfigured, shorter and tougher than the healthy ones. Often completely covered with telia on underside. A. frigidus: Uromyces phacae-frigidae

16b Shoots completely infected with mycelium, made conspicuous by its pale colour, all parts ± etiolated. Aecia mainly on underside, often completely affecting all leaf blades; III often also on leaf midrib and -stalks. A. alpinus, australis, frigidus; also on Oxytropis: Uromyces lapponicus

16c Similar malformations on A. leontinus, norvegicus. Spermogonia absent: Uromyces splendens

17a On inflorescences or on single flowers (for spindle-shaped galls on stalk => 18

17b Fruit hardly swollen, shortened, disfigured. Containing a single larva. A. asper. Asphondylia sp.

18a Single or several flowers disfigured => 19

18b Developing young inflorescences severely stunted; their stalks ± thickened. Flower buds variously swollen, globular, arranged in ± dense balls. A. glycyphyllos: Contarinia sp.

18c Usually all flowers of several inflorescences are already disfigured in bud stage and slightly swollen. Ovules at first swollen, later on filled with masses of red-brown spore balls: Thecaphora affinis

19a Flowers swollen, unopened; with midge larvae inside => 20

19b Flowers disfigured, containing a larva with head capsule. A. arenarius, austriacus, cicer, danicus, glycyphyllos, onobrychis, sempervirens: Mesotrichapion punctirostre

19c Similar malformations on A. glyciphyllos, varius, virgatus contain larvae of Pseudoprotapion astragali

20a Calyx strongly swollen, almost enveloping all organs. Corolla shortened, thickened, greened. Stamens and ovaries mostly moribund. Containing several orange-yellow larvae. A. arenarius, austriacus: Contarinia sp.

20b Similar galls, but with a dense layer of mycelium inside. A. glycyphyllos: Asphondylia sp.

Last modified 24.viii.2020