Plant Parasites of Europe

leafminers, galls and fungi

gallers on Berberis

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

Last modified 24.iv.2020