DIFFERENTIAL DAMAGE TO RANGE GRASS SEEDLINGS BY RUSSIAN WHEAT APHID (HOMOPTERA, APHIDIDAE)

Resistance to feeding damage by the Russian wheat aphid, Diuraphis noxia (Mordvilko), was studied in the greenhouse on seedlings of nine range grass species: Elytrigia dasystachya (Hook.) A. Love & D. Love, Elytrigia intermedia (Host) Nevski subsp. intermedia, Elytrigia repens (L.) Nevski, Elytrigia spicata (Pursh) D. R. Dewey, Elytrigia stipifolia (Czern. ex Nevski) Nevski, Elymus trachycaulus (Link) Gould ex Shinn, Elymus cinereus Scribner & Merr., Elymus junceus Fischer, and Leymus karelinii (Turcz.) Tzvelev, and two hybrids between Elytrigia repens and Elytrigia spicata and Elytrigia repens and Elytrigia stipifolia. Based on the amount of feeding damage, plant introductions (PI 440065 and PI 440066) of Elytrigia repens and the hybrids between Elytrigia repens and Elytrigia spicata (RS and RS1) and Elytrigia repens and Elytrigia stipifolia were resistant. All other entries were susceptible. It may be possible to use Elytrigia repens entries with Russian wheat aphid resistance to make interspecific crosses to a broad range of grasses for the purpose of developing Russian wheat aphid-resistant grass hybrids.