New biting fly repellent from a coconut oil source

Authors: Cermak, Steven - Steve; Kenar, James - Jim; Zhu, Junwei - Jerry

Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/27/2018
Publication Date: 9/24/2018
Citation: Cermak, S.C., Kenar, J.A., Zhu, J.J. 2018. New biting fly repellent from a coconut oil source [abstract]. Association for the Advancement of Industrial Crops Annual Conference, September 23-26, 2018, London, Ontario, Canada.

Interpretive Summary:

Technical Abstract: Many blood-sucking insects are capable of transmitting human and animal pathogens worldwide. Repellents are a primary tool for reducing the impact of biting insects on humans and animals. A new inexpensive derivative from coconut oil (fatty acids) was found to be an excellent insect repellent. N,N-Diethyl-meta-toluamide (DEET), developed by Samuel Gertler of the U.S. States Department of Agriculture in 1944, is considered to be the standard insect repellent and these new materials have comparable repellency. Although DEET has claimed to be the most extensively used personal arthropod repellent for six decades, it has been frequently associated with human health issues, particularly for infants and pregnant women. Plant derivatives acting as insect repellents or insecticides are nothing new. The first successful plant-based insect repellent was citronella oil that contains the active ingredient citronella, but with a limit to its effectiveness. These new coconut based compounds are active against a broad array of blood-feeding arthropods. The medium-chain, C8 to C12 fatty acids were found to be the dominant repellent compounds and they are also listed as GRAS (generally recognized as safe) substances. The fatty acid composition of hydrolyzed coconut oil shows it to contain a series of C8 to C12 medium-chain fatty acids that represent >65% of total fatty acids present. In laboratory bioassays, these compounds repelled biting flies for two weeks after application. Repellency was stronger and with longer residual activity than that of DEET, the most effective and long-lasting repellent currently available commercially. In conclusion the fatty acids derived from coconut oil displayed better repellency against several blood-sucking insects, compared to the most commonly used repellent, DEET. Cattle treated with the coconut oil fatty acid formulation had significant protection against biting flies which may be the longest lasting repellent reported to date. The cost of applying a coconut fatty acid repellent to cattle is estimated to be extremely cost effective, less than 0.1 U.S. dollars for animals of 800 to 1000 pounds in size. Such an economically sound practical tool could be easily adopted for livestock animal producers as well as other public health applications for preventative measures (repellent barriers).