Submitted to: Journal of Medical Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/12/2005
Publication Date: 5/1/2005
Citation: Bernier, U.R., Furman, K.H., Kline, D.L., Allan, S.A., Barnard, D.R. 2005. Comparison of contact and spatial repellency of catnip oil (nepetea) and n,n-diethyl-3-methylbenzamide (deet) against female mosquitoes. Journal of Medical Entomology. 42(3):306-311. Interpretive Summary: Mosquitoes play a significant role in spreading diseases such as malaria, encephalitis and West Nile fever. In recent years, an emphasis has been placed upon the development of natural repellents to replace synthetic repellents as a means to protect people and animals from mosquito bites. Catnip oil was recently reported to be a more effective repellent than the synthetic repellent deet, which is found in many commercial mosquito repellents. However, a true test of its ability to protect people was not available. Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, USDA, ARS, Gainesville, Florida examined catnip oil as a candidate repellent for protection from mosquitoes. Comparison of this oil to the well known repellent deet showed that catnip oil is a slightly less effective topical repellent than deet. However, these studies showed that catnip oil masks human odor from mosquitoes better than deet can and this property can be used in novel strategies to prevent mosquito bites. The use of natural repellents, such as catnip oil, will reduce our dependence upon synthetic repellents as personal protectants from mosquitoes.
Technical Abstract: Nepetalactone, the primary component of catnip oil, has been reported recently to repel the Yellow-Fever mosquito, Aedes aegypti (L.). In this study, commercially available catnip oil was compared to the standard repellent N,N-diethyl-3-methylbenzamide (deet) for its ability to affect the host-seeking ability of Ae. aegypti. A triple cage olfactometer was used to bioassay each substance and to assess their attraction-inhibition (spatial repellent) capabilities when combined with the following attractants: carbon dioxide, L-lactic acid and acetone, and human odors. Repellent tests were conducted with each substance against female Ae. aegypti, Anopheles albimanus Weidemann, and An. quadrimaculatus Say. Catnip oil and deet are both weakly attractive to Ae. aegypti, catnip oil was the better spatial repellent, while deet was a more effective contact repellent in tests with all three species of mosquitoes.