Optimizing Spotted Wing Drosophila Management Programs in Blueberries

Spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an insect pest of Asian origin and has expanded its range worldwide over the past 4-5 years.  It has recently emerged as a major pest of small and stone fruits in the United States causing significant crop losses as high as 100%. Management is achieved primarily through preventative insecticide applications. Growers make as many as twice weekly applications to protect berries from SWD infestation, however,  which may not be possible without achieving complete coverage of all surfaces of the berries. Blueberry growers employ a wide range of technologies to apply insecticides but the level of coverage achieved by those specific technologies has yet to be evaluated. In order to optimize effectiveness of insecticide applications against SWD, it is extremely important to understand the level of coverage achieved by those technologies and whether or not it is sufficient to protect fruit from SWD infestation. We conducted studies to compare spray coverage achieved by sprayers most commonly used by blueberry growers, residue deposition in the fruit, and effectiveness of the spray residues against SWD. The results of those studies will be discussed.