2011 Annual Report 1a.Objectives (from AD-416) Collaborative project investigating the biotypic diversity in Russian wheat aphid in the western United States. 1b.Approach (from AD-416) Russian wheat aphid (RWA) samples (n=20-30/state) will be collected from 8 western states (OK, TX, CO, NM, KS, WY, ID, UT) in 2011. Colonies will be maintained at Stillwater and screened against key sources of resistance in wheat and barley in order to determine their biotype classification. Plants to be screened will include Dn7 resistance that is currently being transferred to wheat for resistance against the new RWA biotype, RWA2. Three to four sites will be selected to study RWA biotype diversity within fields in 2013. These aphid samples will be screened against resistance sources in 2014 in order to determine their biotypic status. 3.Progress Report During FY 2011 we conducted surveys of Russian wheat aphid populations throughout the southern Great Plains, including portions of Colorado, New Mexico, Utah, and Wyoming. Colonies of all sampled populations were established and phenotyped. The ADODR monitored activities via periodic phone calls, e-mails, and brief written reports from the collaborator.