Associated with a parasite that causes malaria, a rare disease in North America, Anopheles mosquitoes are present in the tropics and subtropics.

The genus Aedes conveys dengue fever, one of the most rapidly expanding diseases in the world with a small but significant risk in the U.S., and yellow fever, which occurs in Africa and South America.

Mosquitoes of the genus Culex include the only ordinary house mosquito and species associated with St. Louis Encephalitis and dog heartworm.