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

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 in many areas of the United States and Canada. New variants of PVY that cause tuber necrosis further threaten tuber quality in both seed and commercial crops. 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 both seed and commercial 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 over two growing seasons, 2010 - 2011. Replicate sets of sentinel plants were exposed at weekly intervals in the field and later held in an aphid-proof greenhouse for PVY disease development and pathogen detection. Membrane ELISA was initially used to screen for the presence of PVY. Samples were later subjected to RT-PCR and products sequenced to determine the strain of PVY. Over a similar sample interval, aphids were collected from green tile pan traps and identified to species. Correlating aphid movement with PVY disease progress will help to define the relative importance of specific aphid vectors in 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.