When it comes to mosquito’s in Washington State, Culex Tarsus and Culez pipiens are two species that are vectors of the West Nile Virus. Winter mosquito is present pretty much everywhere. The Southern House Mosquito is a subtropical species that is generally found Virginia across to Southern California and South. The cattail mosquito is generally found all over the U.S. There are actually at least 40 species of mosquito’s in Washington state, according to Washington State University.