Midges Flies and Mosquitoes: Diptera

Physical characteristics: This small mosquito measures 0.1 to 0.15 inches (3 to 4 millimeters) long. It is black with a u-shaped patch of white scales on the back of the thorax and white rings on the legs. The wings are clear with scales along the edges. The white eggs soon turn black after they are laid.

Geographic range: This species is originally from Africa but is now established in all tropical and subtropical regions of the world.

Habitat: Yellow fever mosquitoes live in hot, humid habitats and often breed near human dwellings, especially in towns and cities. Females search for blood meals early in the morning or late afternoon. They prefer human hosts and generally bite around the ankles. They rest in poorly lit cabinets, closets, and cupboards. The eggs are laid singly along the water's edge. The larvae develop in standing water.

Diet: Both males and females depend on plant juices for their own nutrition. Only the females need a blood meal so that their eggs will develop. The larvae strain tiny bits of floating plant material from the water.

A female yellow fever mosquito is shown feeding on a human arm. The mosquito normally conceals her slender stylets, which can be seen here inserted in the skin as she removes blood from her victim. (©Martin Dohrn/Photo Researchers, Inc. Reproduced by permission.)

Behavior and reproduction: When resting, the back legs are curled up. They often clean these legs by rubbing them against one another. They also raise and lower their back legs, as well as cross and uncross them.

Yellow fever mosquitoes and people: This species is the most important transmitter of viruses that cause human dengue fever and urban yellow fever. It also spreads chikungunya virus in Asia.

Conservation status: This species is not considered endangered or threatened. ∎