Coconut oil derived five-component synthetic oviposition deterrent for oriental fruit fly, Bactrocera dorsalis

Authors: ROH, GWANG HYUN - Oak Ridge Institute For Science And Education (ORISE); Kendra, Paul; Zhu, Junwei - Jerry; RODA, AMY - Animal And Plant Health Inspection Service (APHIS); LOEB, GREGORY - Cornell University; TAY, JIA-WEI - University Of Hawaii; Cha, Dong

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2023
Publication Date: 5/26/2023
Citation: Roh, G., Kendra, P.E., Zhu, J.J., Roda, A., Loeb, G.M., Tay, J., Cha, D.H. 2023. Coconut oil derived five-component synthetic oviposition deterrent for oriental fruit fly, Bactrocera dorsalis. Pest Management Science. https://doi.org/10.1002/ps.7584.
DOI: https://doi.org/10.1002/ps.7584

Interpretive Summary: Oriental fruit fly (OFF) is one of most destructive invasive pests of fruits and vegetables worldwide. Although bait sprays can effectively control OFF damage, resistance development has been a concern. Researchers at USDA-ARS, APHIS-PPQ, Cornell University, and University of Hawaii have identified a mixture of five coconut-oil derived fatty acids as novel oviposition deterrent for OFF. In a series of bioassays, when directly applied on surface, the 5-comonent mixture significantly reduced OFF oviposition in artificial oviposition substrate and real fruit. These compounds are generally regarded as safe and has great potential as a novel management tool to control OFF damage in susceptible crops, providing OFF management programs an alternative means to protect fruit and prepare for the undesirable event of establishment of these flies that can constitute serious trade-barrier.

Technical Abstract: BACKGROUND: Bactrocera dorsalis, oriental fruit fly (OFF), is one of the most destructive agricultural pests. Although bait sprays can effectively control OFF, resistance development has been a concern. We evaluated the oviposition deterrent activity of coconut free fatty acids (CFFA), a mixture of eight coconut oil-derived fatty acids known to repel hematophagous insects and deter their feeding and oviposition, against OFF females. RESULTS: In laboratory 72-hr two-choice assays using guava-juice infused-agar as an oviposition substrate, CFFA deterred OFF oviposition in a dose-dependent manner with the greatest reduction of 87% at 20 mg dose compared to control. Among the eight CFFA components, when tested individually, four compounds (caprylic, capric, oleic, and linoleic acids) significantly reduced OFF oviposition (“negative-compounds”), two (lauric and myristic acids) had no effect (“neutral-compounds”), and two (palmitic and stearic acids) stimulated OFF oviposition (“positive-compounds”). In two-choice tests, the “negative-compounds” blend failed to elicit the same level of oviposition reduction as CFFA at equivalent concentrations found in CFFA. Adding the two “neutral-compounds” recovered the oviposition deterrence similar to CFFA. Subsequent subtraction tests showed that four “negative-compounds” plus lauric acid was as effective as CFFA in reducing OFF oviposition in guava-juice agar. This five-component key-deterrent blend also reduced OFF oviposition by 95 and 72% on papaya and tomato fruit, respectively. CONCLUSION: CFFA acts as an oviposition deterrent for OFF. Given that CFFA compounds are generally regarded as safe for humans and the environment, CFFA and its bioactive components have potential use in behavioral control strategies against OFF.