Biorational compounds as effective arthropod repellents against mosquitoes and ticks

Two species of ticks (Dermacentor variabilis and Ixodes scapularis) and one mosquito species (Culex pipiens) were examined for the degree to which they were repelled by several natural and biorational molecules. These were compared to the active ingredients of several commercial arthropod repellents including N,N-diethyl-3-methylbenzamide. The repellent molecules were applied to a surface and either tested immediately or after drying for 5 hours to model extended use of the ingredient. Ethyl perillyl carbonate was the best-ranked repellent and is a biorational molecule not currently on the market for this purpose. The best long-term arthropod repellents were often the same for both the ticks and mosquitoes. I. scapularis ticks were more sensitive to most repellents than the D. variabilis ticks.