Mosquitoes of the family Culicidae possess aquatic larval stages. Mosquito larvae, or wrigglers, occur in a variety of aquatic situations, depending on the species. The larvae of most species feed on algae and organic debris, and they principally breathe at the surface, usually using a breathing tube at the posterior end of the body. Anopheles larvae lack this tube and breathe through a pair of spiracular plates at the posterior end instead.
The larvae feed on a variety of aquatic microorganisms and pass through four larval instars. With the exception of species of Mansonia and Coquillettidia, they have to come to the water surface to breathe. When disturbed, they swim up and down.
In tropical climates the larval period can be as short as 7-10 days. In cooler climates it may take weeks to months, and several species even overwinter in this stage.