Seasonal flight dynamics of aphid species in occurrence with potato virus Y infection in commercial potato fields of Wisconsin

Potato virus Y (PVY), once managed effectively by strict seed certification practices, has re-emerged as a serious disease problem in the seed potato crop. New variants of PVY that cause tuber necrosis further threaten tuber quality. Managing levels of PVY in seed and eliminating the tuber necrotic strains will require an adjustment of seed certification practices and a more aggressive use of on-farm management strategies by potato growers. The goal of this project has been to document the seasonal phenology of aphid vector species and their relationship to PVY incidence in the field.  Replicated field plots were set up in Wisconsin using green tile pan traps and sentinel potato plants for two growing seasons. Sentinel plants were left in the field for a week, then held in an aphid-proof greenhouse for PVY disease development and detection. Membrane ELISA was used to test for the presence of PVY and the strain of PVY infecting the plant was determined. Over a matching sample interval, aphids were collected from pan traps and identified to species.  Flight patterns of aphids in potatoes can be well documented. Using statistical techniques such as non-metric multidimensional scaling, aphid movement can be correlated with PVY disease progress in different regions of Wisconsin and can help to define the relative importance of specific aphid vectors in driving recent PVY disease cycles.  Moreover, we hope to define the periods of greatest risk for PVY transmission and the necessity for deployment of targeted, best management practices to limit PVY spread.