Phenology of Coquillettidia perturbans and Culiseta melanura (Diptera: Culicidae) in East-Central Georgia, USA: Implications for the Ecology of Eastern Equine Encephalitis Virus

摘要

We sampled mosquito larvae and adult females in east-central Georgia (Screven County), where two species of mosquitoes, Coquillettidia perturbans (Walker) and Culiseta melanura (Coquillett), believed to be important in the epidemiology of eastern equine encephalitis virus (EEEv) were common. The study site, being a wildlife management area, supported large numbers of birds and snakes that are believed to harbor EEEv, and EEEv had been historically reported from wild birds from Screven County. Thus, the location was conducive to studying aspects of the sylvatic cycle of EEEv. Adult traps (CO2 baited) indicated that Cs. melanura adult females were only common in midsummer. In contrast, Cq. perturbans adult females were common for almost the entire summer, and this combined with larval sampling in local wetlands suggested that Cq. perturbans was bivoltine in east-central Georgia, which is much farther north than previously suspected. We did not detect EEEv in any mosquito samples, but the phenology of Cq. perturbans suggests that only the second generation of these mosquitoes would play an important role as bridge vectors of EEEv to humans and horses in eastern Georgia.