Submitted to: Journal of the Mosquito Control Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2002
Publication Date: 4/16/2002
Citation: BERNIER, U.R., KLINE, D.L., SCHRECK, C.E., YOST, R.A., BARNARD, D.R. CHEMICAL ANALYSIS OF HUMAN SKIN EMANATIONS: COMPARISON OF VOLATILES FROM HUMANS THAT DIFFER IN ATTRACTION OF AEDES AEGYPTI (DIPTERA: CULICIDAE). JOURNAL OF THE MOSQUITO CONTROL ASSOCIATION. 2002.v.18.p.186-195. Interpretive Summary: Scientists at the USDA, Agricultural Research Service, in collaboration with scientists from the University of Florida, in Gainesville, Florida, have compared chemicals from the skin of human beings to understand better why mosquitoes are attracted to us. A mass spectrometer equipped with a gas chromatograph was used to examine the differences in compounds and compound abundances between people who are normally at the extremes of attraction. A second study was performed to examine the day-to-day differences in compound abundances for the same human subject. The analysis of a single volunteer allowed for minimization of larger variations in emanations that are observed when examining two different people. Some of the compounds produced by humans were weak attractants for the yellow fever mosquito. This work will be of greatest use to scientists concerned with the attraction of mosquitoes to a host and may lead to environmentally-safe methods of mosquito control. The methodology will be useful to scientists examining other insects which feed upon blood from human and livestock hosts.
Technical Abstract: Host odors are believed to play a major role in the location of bloodmeals by female mosquitoes. Prior work has shown that female Aedes aegypti (L.) are attracted to a residuum of skin emanations deposited on glass. The attraction of mosquitoes to handled or rubbed glass varies from person to person and from day to day. This variation indicates that mosquito behavior varies over time and that there is a relative difference in the ability of people over time to attract mosquitoes. Volatiles desorbed from glass handled by two human subjects that differ markedly in their attraction of Ae. aegypti were examined for differences in compound abundances. It is known that the attractive emanations, once deposited onto glass, have a finite lifetime; therefore, compounds that decreased substantially during aging of handled glass were also noted. A study was conducted on the variations in compounds present with a single subject were erecorded over a 5 day period. Emanations from the subject were transferre to glass, then thermally desorbed from the glass and compounds present were compared on the two consecutive days that showed the largest difference in attraction. Some of the candidate attractants identified by these studies were screened in an olfactomer. A few of these compounds were found to be weak attractants for Ae. aegypti.