Eggs of permanent-water breeders are deposited on the water surface and may hatch in 1 to 3 days depending on temperature. Floodwater species deposit their eggs on moist soil or another wet subtrate and display a wide variation in incubation periods from several days to a year or more depending on the species and the season. The larvae of all mosquitos live in water and have 4 developmental periods or instars. At the end of each instar, the larva sheds its skin by a process called molting. The mouthparts on the underside of the head include a series of brushes which vibrate rapidly to sweep small organisms on which the larvae feeds.
Most larval species possess an elongated siphon or an air tube.
There are other mosquito larvae that possess no air tube. Pupa Unlike most other insects, the mosquito pupa is very active and like the larva, lives in water. It differs greatly form the larva in both shape and appearance. The pupa has a comma-shaped body divisible into two distinct regions. The front region consists of the head and thorax and is greatly enlarged.