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

Drosophila suzukii (Spotted Wing Drosophila, SWD) is an invasive species and significant pest of California cherries. Unlike other Drosophila species, SWD females are equipped with a serrated ovipositor, allowing them to deposit eggs in healthy, ripening fruits. The larvae feed on the fruit causing damage and rendering it unmarketable. 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 year. 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 and larval damage in cherries. For field study, MB dispensers and traps were applied in early May, accompanied by control trees with only traps separated by a buffer. Fruits gathered through harvest from treated and controlled trees are inspected at the lab for SWD damage. Supplemental lab trials will be conducted using treated and control cherries with no previous SWD damage, exposed to UCCE Stanislaus lab-reared SWD. Results will be disseminated to California cherry growers and pest management professionals, thereby adding to their toolboxes and improving IPM practices.