Can you smell me? Identifying the semiochemicals associated with the Western Mosquitofish, Gambusia affinis, and their effect on the oviposition behavior of the Western Encephalitis mosquito, Culex tarsalis.

The Western encephalitis mosquito, Culex tarsalis, has been shown to respond to the presence of fish-associated semiochemicals in oviposition sites by decreasing the number of egg rafts laid, in both laboratory and field bioassays.  A decrease in oviposition rate on water that contained fish semiochemicals, has been attributed to the presence of different classes of chemical compounds which cause the mosquitoes to alter their oviposition behavior.  Whether or not the compounds present act solely as attractants, repellents or deterrents has not been determined. Using chemical ecology techniques we have identified three compounds of interest to date.  Using wind tunnel and choice bioassays, we evaluated the resulting behavioral sequences of female C. tarsalis to chemicals associated with the Western mosquitofish, Gambusia affinis, and evaluated their potential role in mosquito oviposition behavior.