Mosquitoes and the diseases they vector have wreaked havoc in Florida's history. The literature describes conditions that prevailed well into the twentieth century, thusly…"each summer yellow fever, malaria and dengue would sweep through the villages like a forest fire". Not until the discovery of the role of the mosquito as a vector of these pathogens did things change. Such knowledge and relentless mosquito control programs resulted in the demise of yellow fever in 1910, of dengue in 1932 and malaria in 1948. Encephalitis. on the other hand, is an annually recurring event and the threat of the historically prevalent diseases still abounds with pressure from the tropics. The control of pest mosquitoes is an ongoing necessity. To cope with the mosquito menace, Florida supports 50 organized local mosquito control districts in 48 counties. Combined state and local budgets exceed 26 million dollars annually. The state leads the nation in expenditures for mosquito control and continues to be a pioneer in the field.