Plant Parasites of Europe

leafminers, galls and fungi

gallers on Erucastrum

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

Last modified 14.v.2020