Submitted to: Journal of Medical Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/1/2004
Publication Date: 5/1/2004
Citation: Klun, J.A., Strickman, D., Rowton, E., Williams, J., Roberts, D., Debboun, M. 2004. The resistance of anopheles albimanus to deet and 2-methylpiperidinyl-3-cyclohexen-1-carboxamide in laboratory human-volunteer repellent assays.. Journal of Medical Entomology. 41(3):418-422. Interpretive Summary: Anopheles albimanus is a mosquito that occurs in Middle America and is capable of transmiting malaria to humans. It was not known for certain if Deet could be used to effectively repel the mosquito from biting humans because there were conflicting laboratory and field test reports concerning the effectiveness of Deet against this mosquito. We determined that the mosquito was not easily repelled by Deet nor the newly discovered repellent, SS220, at usual skin doses used against other mosquitoes. However, we found that a reasonable level of protection against malaria can probably be attained by using higher than usual doses of these repellent. This is important information for DOD and the public should they travel to Middle America.
Technical Abstract: The insect repellents N,N-diethyl-3-methylbenzamide (Deet) and the racemate and 1S, 2S stereoisomer of 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220), were tested against Anopheles albimanus Wiedemann and Aedes aegypti (L.) in laboratory human-volunteer assays. Estimated skin doses of Deet or racemic AI3-37220 required to reduce biting by 95% in A. aegypti were 0.023 and 0.035 micro mol/cm2 skin, respectively, while estimated doses for 95% bite reduction of A. albimanus in an approximately 40 year-old laboratory colony established from El Salvador were five times higher at 0.12 micro mol Deet/cm2 skin and greater than 0.20 micro mol /cm2 skin for AI3-37220. In tests with the 1S, 2S stereoisomer of AI3-37220 newly colonized A. albimanus from Belize bit less aggressively than El Salvador A. albimanus. However, the Belize-derived mosquitoes were as resistant as the old El Salvador colony to repellent effects of the compound. Earlier workers surmised that usual skin doses of Deet would offer only limited protection against A. albimanus in the field. Our findings support this speculation, but they also indicate that Deet doses higher than those needed for protection against A. aegypti might offer reasonable protection against A. albimanus. Results indicate that neither racemate nor 1S, 2S stereoisomer of 2-methylpiperidinyl-3-cyclohexene-1-carboxamide offer as much protection as Deet against A. albimanus despite being highly effective against A.aegypti.