Larvae feed on microscopic organisms in the water. The larval stage may last a week or longer, but the pupal stage usually lasts only two or three days before the adult mosquito emerges. Pupae tumble by rotating the head and tail region as they move to the safety of deeper water. Adult mosquitoes mate as they fly in swarms. Fertilized females seek a blood meal which is needed for egg maturation.
Most species feed on either warm or cold-blooded animals and birds are often the host.
Birds also may be a reservoir for some of the encephalitis and avian malarial disease agents. Male mosquitoes feed on nectar. Mosquitoes probably live only about two weeks. In Nebraska some species will develop several generations per year while others may have only one. In Nebraska, A. vexans , A. dorsalis , A. nigromaculis , Culex tarsalis , and Culiseta inornata are the most numerous mosquitoes.