Culex pipiens (Culicidae) is attracted to humans in southern Ontario, but will it serve as a bridge vector of West Nile virus?

Abstract

AbstractWe tested whether the known bird-biting mosquito, Culex pipiens Linnaeus (Diptera: Culicidae), is attracted to human hosts by placing humans at ground level (∼1.5 m) or in the forest canopy (∼5 m) in a Niagara woodlot. Modified Centers for Disease Control (CDC) miniature light traps (no light, no CO2) were placed next to the human hosts to capture the attracted mosquitoes. The human-baited traps were compared with control traps (standard CDC miniature light traps with CO2, but no light). As expected from previous research, there were more C. pipiens captured at the higher elevation than at ground level. Generally, they were attracted to control traps more than to human-baited traps at 5 m, whereas at 1.5 m there was no difference between the two trap types. As a comparison, most Aedes vexans (Meigen) mosquitoes were captured at the 1.5 m elevation but there were significantly more captured in the control traps than the human-baited traps during all periods. Because C. pipiens is attracted to humans throughout the entire season at the 1.5 m height (where they might encounter humans), it is likely that C. pipiens can serve as a bridge vector of West Nile virus (WNV).