All About Mosquitoes

Asian Tiger Mosquito biting, Spain
Roger Eritja/Oxford Scientific/Getty Images

Mosquitoes are not only a great annoyance and irritant during outdoor activities in the spring and summer, they can be vectors of serious disease, including encephalitis, West Nile virus, and yellow fever.

Mosquitoes are:

  • 1/4 - 3/8 inch long
  • pale brown in color with narrow, oval bodies
  • winged
  • found in all regions of the U.S.

Mosquito Facts

  • Females are usually larger than males and are the only ones that "bite" humans.
  • The female sucks the blood of humans or animals to enable the production of eggs.
  • Different species have different host preferences, with some preferring humans while others prefer bird, frogs, deer. They will also feed on the blood of dogs and cats, subjecting them to disease in the same way as humans.
  • Mosquitoes also feed on the algae and bacteria in water ("pond scum") as well as the nectar of plants, other juices, and decaying matter.
  • Mosquitoes are most active in the evening until dawn. They can also be active in cool, shaded areas during the day.
  • Mosquitoes have poor vision, using receptors on their antennae to sense the presence of a blood meal.
  • Mosquitoes breed in and near standing or slow-moving waters. The female deposits the egg on the water, which then hatch into larvae (sometimes called "wigglers," then pupae (or "tumbler"), then adult.
  • Mosquitoes can develop from egg to adult in 10 to 14 days. They will mate soon after becoming an adult.
  • Bats, birds, and spiders are natural predators of adult mosquitoes, while fish and aquatic insects feed on the water-borne larvae and pupae.
  • Most mosquitoes survive the cold by overwintering in the egg stage. When waters thaw and warm in the spring, the eggs hatch to become biting, reproducing adults within two weeks.
  • Many communities have mosquito-abatement programs, but these vary widely based on factors such as regional species, population size, potential larval development sites, and state or local regulation.

Disease Transmission

There are more than 3,000 species of mosquitoes worldwide, and 170 in North America. However, three species are responsible for the greatest problems of mosquito-born disease, which causes millions of deaths each year.

  • Anopheles mosquitoes carry malaria and transmit filariasis (also called elephantiasis) and encephalitis. This mosquito is primarily seen in the eastern U.S., with the greatest predominance in the Southeast.
  • Culex mosquitoes carry encephalitis, filariasis, and West Nile virus. This mosquito is most common in the Northeast U.S.
  • Aedes mosquitoes carry yellow fever, dengue, and encephalitis. This mosquito is believed to be established in 26 states in the continental U.S. as well as Hawaii. It was only discovered in America when it was identified in Texas in 1985.

Control and Protection from Mosquitoes

Mosquito control or protection can be achieved through:

  • Repellents - During the warm months, most retailers have shelves filled with sprays and lotions designed to be applied directly to the body and clothing to repel mosquitoes and prevent bites. When products with effective active ingredients are used correctly, this can be the best means of protection. Read more about repellents.
  • Devices - A vast array of devices are marketed as attracting, repelling, trapping or killing mosquitoes, but what are they and do they work? Read more about Devices.
  • Environmental Modification - Reducing moisture – including flooded areas, standing water, and untreated, stagnant ponds – around your home can make a significant difference in mosquito populations. Read more about this and other environmental modifications for control.