Plant Parasites of Europe

leafminers, galls and fungi

gallers on Leymus

Dichotomous table for gallers on Leymus arenarius

by Hans Roskam

1a On above-ground parts => 2

1b Roots with many nodular or elongated spindle-shaped swellings, about 0.5–5 mm long and 3–5 mm broad, ± obliquely bent, crooked; containing eelworms inside the ± spongy tissue. Subanguina radicicola

2a On vegetative parts => 3

2b Inflorescence variously disfigured and bleached. Aceria tenuis

3a Malformation with black fungus sori => 5

3b Galls in culm, caused by animals => 4

4a Culm locally weakly swollen; containing a single larva. Tetramesa brischkei

4b Culm stunted in development. Upper internode sometimes appearing thickened. Inflorescence aborted, stuck in the sheaths, disfigured and ± dishevelled. Containing a yellowish-white, up to 4 mm long larva. Oscinella pusilla

5a Diseased shoots at first showing enhanced development; number of internodes and leaves increased. Organs weaker and usually paler than healthy ones. Leaves rigid, erect; plant looking weak; exceptionally with primordia of usually crippled and curved inflorescences. Internodes below the leaf sheaths, rarely also the sheaths, with expanded smut sori developing, on their surface. Tranzscheliella hypodytes

5b Smut patches on the leaves or sheaths. Ustilago striiformis

Last modified 27.v.2020