|Mcelfresh, Steven - UNIV. CALIF - ENTOMOL DPT|
|Millar, Jocelyn - UNIV OF CALIF-ENTOMOL DPT|
|Carde, Ring - UNIV. CALIF-ENTOMOL DPT|
Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 13, 2008
Publication Date: N/A
Interpretive Summary: The Mosquito and Fly Unit at CMAVE is involved in research aimed at improving mosquito control, personal protection, ecology, and surveillance. Some of the diseases transmitted by Culex mosquitoes are West Nile virus, Saint Louis encephalitis, Japanese encephalitis, western equine encephalitis, eastern equine encephalitis, and avian malaria. Birds are important reservoirs for these diseases, and important hosts for Culex mosquitoes. Trapping for surveillance and even control of Culex mosquitoes could be greatly enhanced with better knowledge of their host odors. This study examines the chemical ecology of Culex quinquefasciatus, specifically odors attractive to host-seeking females. What is unique about this study is that it demonstrates attraction of these mosquitoes to odors from bird feces without added carbon dioxide, and demonstrates that odors isolated from the feces elicit antennal responses. This presents a new avenue for research on host odor sources for ornithophagous mosquitoes.
Technical Abstract: Odors from fresh chicken feces in water elicited upwind flight of host-seeking female Culex quinquefasciatus mosquitoes in a dual-choice olfactometer. Acidification of the slurry of chicken feces and water resulted in increased attraction, whereas alkaline slurries of chicken feces and water controls did not attract female mosquitoes. This is the first reported example of avian fecal odor eliciting upwind flight of female mosquitoes. Headspace odors from acidified slurries were sampled using solid phase micro-extraction (SPME) coated fibers. Eight volatile aldehydes [(E)-2-decenal, undecanal, dodecanal, tetradecanal, pentadecanal, hexadecanal, heptadecanal, and octadecanal] identified in the headspace of acidified chicken feces elicited electroantennogram responses from antennae of Cx. quinquefasciatus females. The improved electroantennogram technique in which four antennae were used in parallel for monitoring the GC effluent is described in this manuscript.