Oviposition deterrent as a component of a push-pull management approach for Drosophila suzukii

Authors: MOVVA, VIJAYA - University Of Hawaii; SHRESTHA, BINITA - Cornell University; HESLER, STEVE - Cornell University; Sun, Xiuxiu; Zhu, Junwei; LOEB, GREGORY - Cornell University; TAY, JIA-WEI - University Of Hawaii; Cha, Dong

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2025
Publication Date: 6/18/2025
Citation: Movva, V., Shrestha, B., Hesler, S.P., Sun, X.N., Zhu, J.J., Loeb, G.M., Tay, J., Cha, D.H. 2025. Oviposition deterrent as a component of a push-pull management approach for Drosophila suzukii. Environmental Entomology. Article nvaf057. https://doi.org/10.1093/ee/nvaf057.
DOI: https://doi.org/10.1093/ee/nvaf057

Interpretive Summary: Spotted wing drosophila (SWD) is a serious invasive pest that attacks berries and cherries worldwide. Traditionally, calendar-based insecticide spraying has been the primary strategy for managing SWD infestations. However, insecticide resistance has become a growing concern. In response, researchers from USDA-ARS in Hilo, Hawaii, USDA-ARS in Lincoln, Nebraska, the University of Hawaii, and Cornell University are developing a push-pull management system for SWD. Our research has identified a novel two-component oviposition deterrent, comprised of caprylic acid and capric acid, as a promising generally regarded as safe (GRAS) "push" component in this system. Field trials on raspberries demonstrated that spraying this deterrent significantly reduced SWD infestations, indicating its potential as an effective tool in the push-pull approach to SWD management.

Technical Abstract: Drosophila suzukii, spotted-wing drosophila (SWD), is a major pest of berries and cherries worldwide that attacks fruits at the ripening stage shortly before harvest. Recently, a mixture of caprylic acid and capric acid was developed as a 2-component oviposition deterrent (2c) as an alternative to traditional insecticides to protect fruit from SWD infestation. In this study, we evaluated the efficacy of the 2c as a ‘push’ component in a SWD push-pull, in combination with a previously identified 4-component SWD attractant (4c) as the ‘pull’, comparing the effect of push (2c), pull (4c), push-pull (2c + 4c), and control on SWD oviposition in the laboratory and field. In both laboratory choice and no-choice bioassays using raspberry agar as an oviposition substrate, the pull treatment alone (4c) did not result in oviposition reduction. In contrast, both 2c and 2c + 4c resulted in a similar level of reduction in SWD oviposition compared to control, indicting ineffectiveness of the 4c as a pull as tested in this study. Similar results were also observed in the field, where fewer SWD pupae emerged from raspberries from the 2c or 2c + 4c treated raspberries compared to untreated control, for both previously bagged natural raspberries and store-bought sentinel raspberries. No significant difference in SWD infestation was observed between control and 4c treatment. Given that 2c components are generally regarded as safe food additives, 2c has a potential use as a push component in SWD push-pull.