Bloodfeeding patterns of Culex, Aedes and Anopheles mosquitoes in an oak woodland in Lake County, California

Determining the bloodfeeding patterns of mosquito vectors is a crucial component in understanding the transmission dynamics of the pathogens they carry. Although the feeding patterns of prominent West Nile virus (WNV) vectors, Culex tarsalis and the Culex pipiens complex, have been reasonably well categorized in California, much less is known about host selection in other vector species. To compare seasonal feeding patterns of these and other potentially important vectors, including Culex stigmatosoma, Aedes sierrensis, Anopheles freeborni and Anopheles franciscanus, blood-engorged females were collected over 3 years from an oak woodland in Lake County, CA. Avian and mammalian host abundance was routinely surveyed, and bloodmeals were identified by DNA sequencing of the mitochondrial gene, cytochrome c oxidase I (COI). As expected Ae. sierrensis and the Anopheles species fed almost exclusively on mammalian hosts, primarily mule deer and black-tailed jackrabbit. Interesting, as a reputed vector of dog heartworm, no dog bloodmeals were identified from Ae. sierrensis, though dogs were available as a host. Cx. stigmatosoma fed exclusively avian hosts, despite the fact that mammalian hosts were available and fed upon by concurrently collected Cx. tarsalis. By feeding on WNV-competent avian hosts, Cx. stigmatosoma may play a role in the maintenance and amplification of WNV, but it is unlikely to serve as a bridge vector to mammals. While this focal study did not provide a robust overview of the bloodfeeding in these species, it provided a unique opportunity to compare differences in selection among several vector species presented with the same array of available hosts.