..........Mosquitos Stages in the life cycle of some mosquitos from the Seattle, WA area. There are several genera of mosquitos, and in the United States there are about 160 species. The mosquitos shown here are probably of the genus Culex, but I am uncertain of that. These pictures are typical of mosquitos but do not represent all species. In addition there are many aquatic insects which are NOT mosquitos but which appear somewhat similar.

Egg Rafts The female mosquito lays her eggs directly on the water. The eggs are layed one at a time and stick together to form what we call rafts, which remain floating on the surface with the ends of the eggs in contact with the water. The compostion of the water seems to play an important role and the female mosquito is attracted to water which gives off the odor of decaying material which will serve as food for her offspring. On the right is shown an egg raft floating in water over a dime for size comparison. Click on the photo for an enlargement of the egg raft.

At left is an egg raft from which larvae have hatched. The eggs may hatch in as little as 24 hours depending on the temperature and provided they are kept on the water. One raft will consist of 100 to 400 eggs.

Larvae

The larval stage of the mosquito feeds on micro-organisms and decaying organic material. They can swim short distances by flapping their tail section. A breathing tube on the tail, visible on the larva in the photograph on the left, enables them to get oxygen from the surface. This allows them to live and feed where the oxygen content of the water is low due to crowding or decay. Some species of mosquito lack this tube and must lay parallel to the surface to get oxygen. The larvae retreat to below the surface when startled and for short periods while feeding. Larger photos of larva

Pupae Mosquito larvae become pupae as they prepare for their transformation into adults. Pupae are still mobile and are fast swimmers with a strange tumbling motion that relies on a lot of tail-flapping. They are not feeding at this stage however and spend more time at the surface, where their increased boyancy means that greater effort is required to move any deeper.

This is the pupa stage. This particular mosquito pupa is close to metamorphosing into an adult.

Useful Mosquito links: http://www.mosquitoes.org/Mosquitoes/LifeCycle.html Mosquito life cycle. www.west-nile-virus-prevention.com, Mosquito species http://westnilevirus.nbii.gov/mosquitoes.html West Nile Virus related information http://www.rci.rutgers.edu/~insects/poswn.htm Species of Mosquitos www-rci.rutgers.edu/~insects/njmos.htm Mosquito biology info and good links http://www.wa.gov/wdfw/factshts/westnilevirus.htm Washington Fish and Widlife on West Nile Virus. http://212.187.155.84/wnv/List_WPMod_Cont/westnile/List_WNV_Mosq.htm List of Mosquitos.

 
 

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