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ARS Home » Plains Area » Lincoln, Nebraska » Agroecosystem Management Research » Research » Publications at this Location » Publication #395155
Research Project: Management of Stable Flies to Improve Livestock Production

Location: Agroecosystem Management Research

Title: Efficacy evaluation of medium-chain fatty acids as skin and spatial repellents against Aedes aegypti (Diptera:Culicidae) mosquitoes

Author
item FAROOQ, MUHAMMAD - Anastasia Mosquito Control District
item QUALLS, WHITNEY - Anastasia Mosquito Control District
item BANGONAN, LEA - Anastasia Mosquito Control District
item XUE, RUI-DE - Anastasia Mosquito Control District
item PEPER, STEVEN - Anastasia Mosquito Control District
item ARYAPREMA, VINDHYA - Anastasia Mosquito Control District
item BENZ, KIM - Onederings
item Zhu, Junwei - Jerry

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2022
Publication Date: 12/23/2022
Citation: Farooq, M., Qualls, W.A., Bangonan, L., Xue, R., Peper, S.T., Aryaprema, V.S., Benz, K., Zhu, J.J. 2022. Efficacy evaluation of medium-chain fatty acids as skin and spatial repellents against Aedes aegypti (Diptera:Culicidae) mosquitoes. Journal of Medical Entomology. 60(2):333-338. https://doi.org/10.1093/jme/tjac184.
DOI: https://doi.org/10.1093/jme/tjac184

Interpretive Summary: Medium-chain length fatty acids, including caprylic acid, decanoic acid and lauric acid from natural sources have been shown to exhibit repellent activity against various biting arthropods (Zhu et al. 2018). Repellency by these fatty acids against ticks, bed bugs, and biting flies was further demonstrated to be stronger than DEET while providing a longer residual effect. Recently, Qualls et al. (2021) evaluated thirteen natural repellent compounds and found that 7% coconut fatty acids provided strong repellency against mosquitoes up to three hours which was equivalent to the DEET control. Thus, possible adoption of the fatty acids from natural sources as additional effective and long-lasting repellents, merits further research.

Technical Abstract: This study consisted of an olfactometer evaluation of new formulations containing medium-chain fatty acids for spatial repellency and in laboratory arm-in cage study for contact repellency against Aedes aegypti L. mosquitoes. Six formulations each of decanoic acid (C10) and lauric acid (C12) were evaluated for spatial repellency. These formulations contained 0.28%-10% of either C10 or C12 as the active ingredients in a consumer friendly skin care formulation Base formula without fatty acids was evaluated as control in spatial repellency evaluation. For the arm-in cage evaluations, six formulations of C10, one base formulation and a 7% DEET product were tested for contact repellency. For contact repellency, United States Department of Agriculture (USDA) standard repellent test cages were used to determine the complete protection time (CPT) of the different formulated repellents. Among all decanoic acid formulations tested, the concentration of 2.25 %(wt) indicated the best level of spatial repellency, but not significantly different from other concentrations. None of the lauric acid concentrations showed any level of spatial repellency. In the arm-in-cage evaluations, the highest contact repellency resulted from 4.5% decanoic acid, which was significantly higher than 7% DEET and base formula.