Surveying aphid vectors and alternative hosts of Potato virus Y in Oregon and Washington

The Pacific Northwest accounts for over 53% of United States potato production. Oregon and Washington combined produce $830 million in potatoes annually. Potato virus Y (PVY) is a widespread and persistent disease of potatoes in the Unites States and worldwide. In Oregon and Washington, the virus reduces yields, damages tubers, and contaminates seed potatoes. There are multiple strains of PVY: PVY^O, PVY^N, and PVY^NO. The necrotic strain, PVY^N, causes necrotic lesions in the tubers. While PVY^N is currently found at low levels in the Pacific Northwest, the incidence of the N-strain has been increasing. In contrast, PVY^N is the dominant strain in Europe where it has been detected in multiple weed hosts. Many of these weed hosts have not been investigated in the United States. The same weeds serve as hosts for aphid species that are frequent pests or migrants in potatoes. Multiple aphid species in Oregon and Washington are potential vectors of PVY, including green peach aphids (Myzus persicae Sultzer), potato aphids (Macrosiphum euphorbiae Thomas), and bird cherry-oat aphids (Rhopalosiphum padi L.). A survey was conducted on potential weed hosts of PVY in the Columbia Basin of Oregon and Washington and Klamath Basin in Oregon. Weeds were monitored for aphids and sampled for PVY during the potato growing season. The weed species surveyed included: Solanum dulcamara L., Chenopodium album L., Erodium cicutarium L., Sisymbrium altissimum L., and Lactuca serriola L. The results from the first year of the survey will be presented and discussed.