Determining Patterns of Drosophila suzukii Movement and Attraction to Fermentation-Based Baits in Commercial Blackberry Fields in North Carolina

Monitoring programs for Drosophila suzukii that predict infestation risk for growers are not currently available. Non-crop habitat such as wooded edges may serve as a source of infesting populations and provide D. suzukii with refuge from management treatments. We hypothesized that there may be diurnal or seasonal patterns associated with D. suzukii movement between non-crop habitat and crop fields and diurnal activity patterns associated with D. suzukii attraction to fermentation-based baits. To test these hypotheses, we deployed 2-headed Malaise traps between crop fields and wooded edges and standard D. suzukii traps baited with yeast/sugar/water solution between crop fields and wooded edges and within crop rows. Traps were deployed weekly in June-August 2013 at two commercial blackberry fields in Cleveland County, NC, and were checked hourly for 24 hours, except during darkness. Most D. suzukii were caught in traps during the evening and early morning hours. Later in the season, yeast/sugar traps placed between crop fields and wooded edges caught more D. suzukii than traps placed within crop rows. Understanding D. suzukii movement and diurnal activity patterns will help growers effectively time insecticide applications and is essential for the development of future management strategies, including attract and kill and mass trapping.