Mosquitoes are small, long-legged, two-winged insects belonging to the order Diptera.  Worldwide, there are over 2,600 known species.  In Indiana, fifty-three species have been identified.  In Allen County, forty species of mosquitoes have been identified.

Mosquitoes have four distinct stages of development:  egg, larvae, pupae, and adult.  Eggs must be in water in order to hatch.  Larvae and pupae are aquatic; adults are active, free-flying insects.

• Illustration of Mosquito Life Cycle

Male mosquitoes emerge from the pupal stage about twenty-four hours before the females.  Mating occurs within forty-eight hours, so the majority of females in any population are always fertile.  Both females and males utilize nectar and other plant juices as energy sources; only females take a blood meal, utilizing the protein to produce eggs.

Mosquitoes can be placed into two categories.  One category consists of mosquito species that lay their eggs on the surface of water, while the other category is mosquitoes that lay their eggs on a moist surface next to or above water.  Mosquitoes in the second category can be labeled "floodwater" mosquitoes.  They will hatch when the water covers the eggs and the conditions are correct.  An example is eggs are layed on wet leaves next to a low area in the middle of the woods.  A heavy rain fills up the low area and the eggs are covered.  If the temperature is warm enough, the eggs hatch.  If there is no rain, the eggs are protected by a hard cover and may survive up to ten years.  The majority of nuisance mosquitoes are floodwater species, such as Aedes vexans and Psorophora ciliata.  Aedes triseriatus, a vector of LaCrosse Encephalitis, lays her eggs along the insides of treeholes and artificial containers.

Surface egg-laying mosquitoes deposit their eggs singly or in rafts that may hold 100 to 200 eggs.  Culex species lay egg rafts on water in clogged gutters, tires, birdbaths, dried-up ditches, and un-maintained swimming pools.  Anopheles species lay several single eggs on open bodies of water. 

Mosquitoes also differ in the time of day when biting occurs.  Some species bite during the day, while others only bite at night.  Aedes triseriatus is a day-time biter, while Culex pipiens is a dusk to dawn biter.

Mosquito Hygiene