Associate Professor University of Kentucky Lexington, Kentucky
Spotted Wing Drosophila (SWD) is an invasive pest of many fruit crops. In many regions where SWD is found, there is considerable variation in environmental conditions and food availability across the year, but the seasonal biology of this species is not well understood. In previous work we observed that SWD can persist year-round in Kentucky and survive some of the harshest temperature conditions experienced in the state. Further, flies that are provided food had increased survival in both the coldest and the warmest conditions tested. However, the food sources SWD relies on in its natural winter habitats are unknown. To determine the suitability of different food sources available in winter, we tested the extent to which winter-morphs of SWD can survive long-term at 10 °C on four different winter berries (buckthorn, honeysuckle, privet, and coralberry) that are widely available in Kentucky during the winter months. We also investigated whether winter-morphs would oviposit on the berries when kept at 10 °C, and if those eggs would be viable when moved to 25 °C. Finally, we tested the thermal tolerance of SWD after being kept on different berries to see if certain diets were more beneficial for surviving extreme temperatures. Experiments are still ongoing, and results from this study will help us understand how SWD are surviving through the winters and may lead to possible cultural control solutions by limiting their food sources.