The project is a comprehensive and integrated approach to managing aphid vectored viruses of cool season food legumes grown in southeastern Washington State and adjoining Idaho. For decades, unpredictable episodic outbreaks of aphids and the diseases caused by viruses they vector have severely reduced yields of pea and lentil crops in this region. Adapted dry pea and lentil varieties lack resistance to the two most prevalent viruses, Pea enation mosaic virus (PEMV) and Bean leaf roll virus (BLRV), each vectored by the pea aphid Acyrthosiphon pisum. Growers, therefore, typically either prophylactically apply the organophosphate insecticide dimethoate to suppress aphids even when the realized risk of virus infection is low, or they avoid spraying and instead leave the crop open to catastrophic loss when infection risk is high. We address this problem with three integrated research and extension outreach components. The first develops IPM decision tools for producers. These include deriving a virus risk assessment system for pea and lentil based on monitoring immigrating aphids for virus (using reverse transcriptase polymerase chain reaction based detection of viral RNA) and incorporating meteorological data to predict the intensity and timing of aphid flight activity. This first component also develops economic injury levels for direct aphid injury as well as indirect injury caused by the aphid-vectored viruses, and tests alternatives to dimethoate for reduction of indirect injury when indicated. The second component accelerates ongoing efforts to breed resistance to BLRV and PEMV in adapted pea and lentil varieties. These varieties will reduce the need to treat aphids for one or both viruses. The third component educates producers about the IPM tools developed and engages these producers in project activities and product development. The principal investigators include virologists, breeders, entomologists and extension educators from two universities in Idaho and Washington and the USDA-ARS. Results and IPM recommendations will be disseminated via the world wide web, grower newsletters and listserves and workshops. The virus management decision support system will be maintained with industry funds under the guidance of the PD after the project's completion. The project addresses issues covered in the Pest Management Strategic Plan for Pulse Crops. The project also directly addresses RAMP program goals to enhance the development and implementation of innovative IPM strategies for multi-crop food and fiber production systems on an area-wide or landscape scale.