Culex pipiens (Northern House Mosquito)
Present year-round. Breeds in foul or polluted water. Feeds on birds and mammals, including humans. Readily enters buildings and bites indoors. Can transmit West Nile virus, Western Equine Encephalitis, and St. Louis Encephalitis.
Culex tarsalis (Western Encephalitis Mosquito)
Present primarily spring through fall. Breeds in a wide range of habitats. Prefers birds, but often feeds on humans at night. This mosquito is the primary vector of West Nile virus, Western Equine Encephalitis, and St. Louis Encephalitis.