D3395: Ovipositional deterrent/repellent capabilities of naturally existing methyl benzoate and its analogs to manage Drosophila suzukii

Spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), is a major pest of many small fruit crops globally. SWD was first discovered in California in 2008 and it quickly spread throughout much of the United States. Major crop losses can occur due to lack of detection of the larvae pre-harvest as they develop inside what appear to be healthy, ripening fruit. Management plans to control SWD behaviorally could include both oviposition deterrent and/or repellent compounds as well as attractive odors. We explored the use of methyl benzoate and some of its analogs as potential SWD oviposition deterrents/repellents. These compounds exist naturally as floral fragrance and can be found in fermented apple juice. Oviposition and olfactory choice experiments were conducted under laboratory conditions that tested methyl benzoate and nine analogs. Comparisons were also made to geosmin, a compound known to decrease egg-laying and act as an SWD repellent in both laboratory and field cage experiments. Of the analogs tested, methyl 2-methoxybenzoate decreased egg-laying at levels similar to that observed with geosmin in both laboratory and semi-field conditions. In olfactory tests, methyl 2-methoxybenzoate also repelled SWD at levels comparable to geosmin. The methyl benzoate analog methyl 2-methoxybenzoate has potential for use as an ovipositional deterrent/repellent. In conjunction with an attractant, methyl 2-methoxybenzoate could be used in a push-pull management system to control SWD in small fruit crops.