Midges Flies and Mosquitoes: Diptera

Many species gather in mating swarms, usually around a large, stationary object such as a shrub, tree, boulder, or house. Others use open, well-lit areas such as a sunny patch in the forest or along a road. March flies, also known as lovebugs, form large mating swarms along roads in Central and South America, as well as in parts of the southeastern United States.

Many species of hover flies, bee flies, fruit flies, and robber flies mimic the distinctive colors and shapes of ants, bees, and wasps. These flies not only look like stinging insects, but they act like them too. Resembling harmful insects allows mimics to fool potential predators and live longer so they can mate and reproduce.

Before mating, many flies engage in courtship behaviors that include leg and body movements or wing flapping. In some dance flies, males offer females a dead insect as food. Mating usually starts with the couple facing the same direction but ends with the male and female facing opposite directions. A few species reproduce by parthenogenesis (PAR-thuh-no-JEH-nuh-sihs), a process where the larvae develop from eggs that have not been fertilized.

The life cycles of flies include four very distinct stages: egg, larva, pupa, and adult. Females lay their eggs on or near the right kind of food for the larvae. Fruit fly females use their long needle-like ovipositor, or egg-laying tube, to pierce the skin of fruit and lay their eggs inside. Parasitic species lay their eggs in, on, or near their hosts. Flies with aquatic larvae lay their eggs in the water or on nearby rocks and vegetation. Mosquitoes lay their eggs singly or in groups that form floating rafts on the surface of the water. The eggs usually hatch in a few days or weeks. The larvae molt, or shed their exoskeletons, four to nine times before reaching the pupal stage. The larvae may take just a few weeks to up to two years to reach maturity. The adults may live for several weeks or more.