Spotted-wing drosophila, Drosophila suzukii (Matsumura), an economically damaging invasive species of numerous fruit crops, was first detected in Minnesota in 2012. High fecundity, and short generation times facilitated a rapid rise in the global pest status of D. suzukii, particularly in North America and Europe. To date, the majority of crop injury research has focused on fruit crops such as blueberries, raspberries, and cherries. However, little is known regarding the impact of D. suzukii on the wine grape industry in the upper Midwest region of the United States. Field trials were conducted in Minnesota during the summers of 2017-2018 to examine season-long phenology of D. suzukii in wine grape vineyards and wineries, and to assess the efficacy of exclusion netting for control of D. suzukii. Four treatments were evaluated, 1) open plot check (control), 2) open plot treated with an insecticide, 3) exclusion netting, and 4) exclusion netting, with artificial infestations of D. suzukii adults. Exclusion netting was applied at véraison and removed at harvest. On each sample date, 20 berries (10 intact and 10 injured) were collected from each plot for dissection. The number of larvae and adults were recorded for each berry to determine infestation levels. As shown by mean larval infestations and injured berries across treatments, exclusion netting provided a significant reduction in the level of D. suzukii infested berries when compared with the untreated check. These results indicate that exclusion netting could provide an effective alternative management strategy for D. suzukii in wine grapes.
Bibliographical noteFunding Information:
We thank Suzanne Wold-Burkness, Adam Toninato, Emily Fleissner, Anh Tran, Sarah Holle, Walter Rich III, and Izzy Bur (UMN Fruit & Vegetable lab) for assistance with trapping, data collection, and treatment applications. A special thanks to Dr. Matthew Clark (University of Minnesota), and John and Jenny Thull (UMN Horticultural Research Center, HRC), for sharing their knowledge and expertise in wine grapes and assisting with the application of exclusion netting. We also thank the Minnesota vineyards and winery’s that allowed us to conduct research on their property, Parley Lake Winery, St. Croix Vineyards, Alexis Bailly Vineyard, and the UMN HRC. This research was supported by the Minnesota Agricultural Experiment Station, the University of Minnesota Rapid Agricultural Response Fund, and the UMN Extension Integrated Pest Management Program (NIFA Project 2017-70006-27278).
We thank Suzanne Wold-Burkness, Adam Toninato, Emily Fleissner, Anh Tran, Sarah Holle, Walter Rich III, and Izzy Bur (UMN Fruit and Vegetable lab) for assistance with trapping, data collection, and treatment applications.
© 2019 The Author(s). Published by Oxford University Press on behalf of Entomological Society of America.
- Drosophila suzukii
- berry injury
- integrated pest management
- invasive insect pest