2012 Annual Report 1a.Objectives (from AD-416): Develop integrated pest management for insects vectoring diseases in Pacific Northwest potato crops. 1b.Approach (from AD-416): Determine susceptibility of different potato plant growth stages to BLTVA phytoplasma under field conditions using leafhopper exclusion and exposure studies. Determine susceptibility of different potato plant growth stages to BLTVA phytoplasma under field conditions by timing applications of selected insecticides targeted against the beet leafhopper. Assess the impact of the timing of BLTVA infection on the potato yield, tuber processing quality, and phytoplasma transmission rate in daughter tubers. Develop treatment (action) thresholds for the beet leafhopper to reduce incidence of purple top disease in Columbia Basin potatoes. 3.Progress Report: Several insects, including aphids and beet leafhopper, are serious pests of potato in the Pacific Northwest and the objective of this project is to develop integrated pest management program for these potato pests. For a third year, field research conducted on the beet leafhopper and its associated pathogen BLTVA phytoplasma confirmed that as few as one BLTVA-infective beet leafhopper per potato plant is enough to cause potato purple top disease, leading to significant yield loss. In addition, a study on the identification of sources of beet leafhopper populations colonizing potato fields in WA, using light traps and marking the leafhoppers with protein markers, was initiated. Information from this research will help growers in developing tools and strategies to better manage beet leafhopper and reduce incidence of purple top disease in Pacific Northwest potatoes. The work reported here addresses objectives 2 and 3 of the parent project plan.