Transmission of Bean Common Mosaic Virus by Cereal Aphids (Homoptera: Aphididae). SUSAN E. HALBERT, University of Idaho, Aberdeen Research and Extension Center, P.O. Box AA, Aberdeen 83210. GAYLORD I. MINK, Washington State University, Irrigated Agriculture Research and Extension Center, Rt. 2, Box 2953-A, Prosser 99350; MATT J. SILBERNAGEL, USDA-ARS, Irrigated Agriculture Research and Extension Center, Rt. 2, Box 2953-A, Prosser, WA 99350; and THOMAS M. MOWRY, University of Idaho, Parma Research and Extension Center, 29603 U of I Lane, Parma 83660. Plant Dis. 78:983-985. Accepted for publication 26 July 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0983.

Bean common mosaic potyvirus (BCMV) is aphid-transmitted in a nonpersistent manner. BCMV can be subdivided into two serotypes, A and B. BCMV serotype A has been identified in Idaho as the cause of seed lot rejections and occasional crop failures in recent years. We suspected that cereal aphids could be important vectors of BCMV because they comprise a large proportion of airborne alate aphids in Idaho as measured by the Idaho suction trap survey system. Five species of cereal aphids Diuraphis noxia, Metopolophium dirhodum, Rhopalosiphum padi, Schizaphis graminum, and Silobion avenae—were tested along with Myzuspersicae for efficiency of transmission of BCMV using timed acquisition probes. D. noxia, Metopolophium dirhodum, and M. persicae were tested in mass inoculation experiments, and winged I), noxia and M. persicae were tested further in an arena setting. All aphid species tested transmitted the virus in all three experiments except D. noxia, which appears to be a nonvector. Transmission efficiencies and average suction trap collections in bean production areas were combined to produce a potential vector index (PVI). Trap collection data for 1989 1992 showed a high correlation between the PVI and the number of hectares of seed beans rejected because of virus infection (r2 = 0.96, P = 0.018). Prior to that (1985-1988), the correlation was poor in that Tar fewer hectares were rejected than predicted by the PVI.