Encephalitis
Guides
Culex tarsalis
Western Encephalitis Mosquito
Culex tarsalis is a mosquito species distributed across North America, with particular importance in the western United States as a vector of multiple arboviruses. The species is distinguished by black and white banding on the legs. It serves as the primary vector for West Nile virus in agricultural areas of California and transmits Saint Louis encephalitis virus, Western equine encephalitis virus, and avian malaria parasites. Some populations exhibit autogeny, the ability to produce eggs without blood feeding. The species has been the subject of extensive genetic research, with a reference genome published in 2020.
Ochlerotatus triseriatus
eastern treehole mosquito, treehole mosquito
Ochlerotatus triseriatus, the eastern treehole mosquito, is a container-breeding mosquito native to North America. It is the primary enzootic vector of La Crosse virus, the leading cause of arboviral encephalitis in children in the United States. Larvae develop in natural tree holes and artificial water-holding containers, feeding on microbial communities associated with decaying organic matter. The species exhibits strong density-dependent survival, with larval crowding significantly reducing per-capita survival rates—a trait that has important implications for mosquito control strategies.