Evaluation of commercial insect repellents on human skin against Aedes aegypti (Diptera: Culicidae)

An olfactometer was used to evaluate the efficacy of selected commercial insect repellent products against Aedes aegypti (L.). A comparison of 12 commercial repellent products was made on human skin. The products tested included 2 natural oil insect repellent formulations (Buzz Away and Green Ban) containing plant extracts, 2 proprietary products (Skin-So-Soft lotion and bath oil), and 8 commercial deet preparations in various concentrations and forms of spray aerosol, stick, cream, and lotion. Behavioral responses and time to probe were determined in triplicate using 10 female mosquito challenges per replicate for each product. Generally products with higher concentrations of deet were found to have longer repellence times. OFF spray and Muskol lotion offered the longest repellence times. However, there was no significant difference in time for mosquitoes to probe among the formulations. Skin-So-Soft lotion and bath oil were not as effective as deet in repelling Ae. aegypti. Natural oil insect repellent formulations offered essentially no repellency against As. aegypti. This is a simple and reproducible method to evaluate the efficacy of insect repellents and is recommended for preliminary screening of new insect repellents or formulations.