Monitoring, trapping, and behavioral studies of the spotted wing drosophila, Drosophila suzukii (Matsumura), a new pest threatening Florida blueberries

Spotted wing drosophila (SWD) Drosophila suzukii (Matsumura) is a serious threat to Florida’s blueberry industry.  Unlike most vinegar flies that prefer damaged or decaying fruit, the female SWD has a serrated ovipositor that allows her to lay eggs in healthy, ripening fruit.  Damage from SWD causes depressed skin scars and rapid degradation from larval development, rendering fruit unmarketable.  Effective monitoring and knowledge of SWD oviposition behavior are essential for a successful integrated pest management program to control SWD and prevent yield losses.  A trapping study was conducted on two farms to test the effectiveness of different trap designs baited with apple cider vinegar (ACV).  Experiments were randomized complete block design with 5 treatments and 4 replicates.  Among the treatments, 4 included a plastic cup and 1 a yellow sticky card.  Amidst the 4 cup treatments, 2 had yellow visual stimulants, one of which had detergent added to the ACV.  The last two cup treatments included one with a yellow sticky card hanging inside and a standard transparent cup (control).  Results showed the treatments with the yellow sticky card caught fewer flies than other treatments.  No significant differences in cup trap captures indicated that neither the yellow stimulus nor the soap affected SWD captures.  Oviposition behavior was also observed on different ripening stages of Southern Highbush blueberries in laboratory bioassays.  Spotted wing drosophila preferred dark blue berries, although some oviposition occurred on green and pink berries.