Does habituation affect the efficacy of semiochemical oviposition repellents developed against Drosophila suzukii?

Authors: Stockton, Dara; Cha, Dong; LOEB, GREGORY - Cornell University

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2021
Publication Date: 9/17/2021
Citation: Stockton, D.G., Cha, D.H., Loeb, G.M. 2021. Does habituation affect the efficacy of semiochemical oviposition repellents developed against Drosophila suzukii? Environmental Entomology. 50(6):1322-1331. https://doi.org/10.1093/ee/nvab099.
DOI: https://doi.org/10.1093/ee/nvab099

Interpretive Summary: Ongoing research to develop an olfactory repellent against spotted-wing drosophila (SWD), Drosophila suzukii, has identified 3 potential volatiles that may be useful in future commercial applications. In this study we investigated whether the deterrent response to these volatiles (octenol, geosmin, and 2-pentylfuran) remained intact despite long-term pre-exposure during both adult and larval SWD life stages. Our results showed that the deterrent response was preserved despite pre-exposure to octenol and 2 pentylfuran. However, mortality decreased following larval pre exposure to octenol. Geosmin was not found to be repellent in any of our trials, indicating that this compound may not be suitable for future field research as its effects were inconsistent from previous short term exposure reports. Future research may focus on 2-pentylfuran as the most promising candidate for repellent-based behavioral management of SWD.

Technical Abstract: BACKGROUND: The long-term application of feeding and oviposition repellents is limited to arthropod systems in which habituation, or sensory adaptation, do not occur. Although several compounds appear to reduce Drosophila suzukii oviposition in berries, previous studies have yet to address whether habituation is a significant risk following pre-exposure. We tested the response of adult female D. suzukii to 3 previously identified volatile oviposition repellents, 1-octen-3-ol (octenol), ±-geosmin, and 2-n pentylfuran (2-PF), following adult and larval pre-exposure. RESULTS: We did not find evidence of habituation to octenol or 2 PF in adult flies. In contrast with previous investigations, we did not observe repellent effects in response to geosmin for reasons that remain unclear. When exposed to each of repellents as larvae, D. suzukii showed similar deterrence as those exposed as adults alone. However, mortality did decrease in F1 octenol treated flies. CONCLUSIONS: Our results suggest that long-term developmental exposure does not inhibit the effectiveness of the octenol and 2 PF. However, greater survivorship on octenol treated baits in F1 flies, combined with apparent neurotoxic effects of this compound,indicate that it may not function as behavioral deterrent. For this reason, 2-PF appears to be the most likely candidate for field applications going forward.