Plant Parasites of Europe

leafminers, galls and fungi

gallers on Chondrilla

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

Last modified 3.vi.2020