COLONIZATION OF GRASS GERMPLASM NURSERIES BY DIURAPHIS-NOXIA (MORDVILKO) (HOMOPTERA, APHIDIDAE)

Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), colonized gras s germplasm nurseries maintained by the Western Regional Plant Introdu ction Station (WRPIS) in southeastern Washington. Although most access ions exhibited little or no RWA-induced damage, 22 accessions in the g enera Agropyron, Elytrigia, Leymus, Rostraria, Stipa, and Heterantheli um required an application of a foliar insecticide (dimethoate) to sup press damaging RWA populations. This study demonstrated that seed-rege neration protocol at WRPIS should include routine surveys of grass nur series to detect germplasm at risk to colonization and damage by RWA.