Why Do Flies Have 4 Wings?
WouterThe fruit fly, Drosophila melanogaster, has three segments: the first segment, or forewing, is where the large wings sprout, and the second segment, or hindwings, is where the smaller, bulbous hindwings are located. These segments help to balance the fly during flight, and they help it fly in a straight line. Interestingly, a gene called Hox is found in the third segment, which transforms the insect into a near-identical copy of the second segment.
True flies are a part of the Order Diptera, which includes many commonly found insects, including mosquitoes, midges, sand flies, blowflies, and the house fly. In addition to four wings, dipterans have club-like structures called halteres, which are used as balance.
Dickinson reports that the sensory cells in the haltere detect changes in haltere position and send signals to the wing muscles to alter the angle of flight. This mechanism is crucial for the flight of flies. It enables them to change direction within 30 milliseconds.
Houseflies have one pair of flight wings on the thorax and one pair of secondary wings in the rear. They evolved from flies that had two wings. Houseflies’ halteres are used to balance in the air. Houseflies have five segments of legs and a hard exoskeleton, and their hairs serve as taste and smell organs.
