Methyl benzoate as oviposition deterrent & repellent against spotted wing drosophila in California cherry orchards

Drosophila suzukii (Spotted Wing Drosophila, SWD) is a significant pest of California cherries. SWD females possess a serrated ovipositor, allowing them to deposit eggs in healthy fruits. SWD has become a challenging pest for cherry growers to manage due to the pesticide resistance found in recent years  in addition to its broad host range, high fecundity, and multiple generations per season. There is a need for alternatives to manage this pest in an integrated fashion. Methyl Benzoate (MB) is a non-toxic and naturally occurring volatile compound derived from plants and widely used as a flavoring agent in food. It has proven effective as a repellent against a variety of pests, including SWD, in other states and crops. This study incorporates laboratory and field experiments to evaluate the viability of MB as a repellent against SWD oviposition. For field study, MB dispensers were applied in early May, accompanied by control trees and separated by a buffer. Fruits gathered through harvest from treated and controlled trees were inspected at the lab for SWD damage. Two 24hr no choice style lab trials were conducted using store bought cherries and UCCE Stanislaus lab-reared SWD—treated vs. control and dose response. Statistical analysis of the oviposition per fruit in both field and lab trials shows that significant reduction can be achieved using MB. The findings of this research are critical for ongoing funding of the project so that we can develop optimum application methods for cherry growers.