File:Culex mosquito - Philip Henry Gosse - 809 1997 48.jpg

This chalk drawing is by PH Gosse. Culex is a genus of mosquito whose individuals are important disease vectors. It shows the imago (adult), ova, pupa and larval developmental stages.�Drawings illustrating the life history of a Gnat (Culex). The eggs are laid in batches on the surface of the water where they float like little rafts, as shown at B. The larvae (D) hatched from these eggs are worm like and, when undisturbed, hang head downwards in the water, breathing through the forked tail, the tip of which just protects above the surface. After a series of moults, the worm like larva changes into a pupa (C) able to jerk itself through the water by forcibly bending and straightening the body, and breathing through two small trumpet-shaped tubes placed just behind the head. Eventually, the adult gnat (A) emerges from this pupa-case, using it as a raft upon which to rest until the wings have expanded and it is able to fly.