Locomotion through use of the mouth brushes in the larva of Culex pipiens (Diptera: Culicidae).

The larva of the mosquito Culex pipiens is a filter-feeder and is able to use the feeding current generated by its mouth brushes to glide slowly through the water. The hydrodynamics of the mouth brushes, and of gliding, were investigated by visualizing the feeding current using dyes. Unlike the mouth brushes of a sessile filter-feeder such as the blackfly larva, those of C. pipiens function more like 'paddles' than 'rakes', a beneficial adaptation to life in still as opposed to running water. Technically, the Froude efficiency of gliding is very low (0.23) because the design of the feeding brushes favours delivery of water into the wake rather than forward momentum to the body. The wider implications of these findings to foraging strategy and other aspects of the behaviour of mosquito larvae are discussed.