Fruit Fly

Fruit Fly, common name for two families of true (two-winged) flies, the larvae of which feed on fresh or decaying vegetable matter. True fruit flies, such as the house fly-sized apple maggot, have intricate, often colorful wing patterns by which females recognize males of their species. They are sometimes called peacock flies because of the way they wave and display their wings in courtship. The term fruit fly is also applied to the much smaller vinegar flies.

Among the true fruit flies, adults of the apple maggot are found in orchards throughout the summer months. The female punctures the apple skins with its sharp ovipositor and lays one or more eggs in each apple. The maggots bore through the pulp and grow to about 6 mm (about 0.25 in) in length. After the apple has fallen, the larvae burrow about 3 cm (about 1 in) underground, where they spend the winter and spring as pupae. The cherry maggots, the currant fruit fly, the melon fly, and the olive fruit fly have similar life cycles. The Mediterranean fruit fly spoils fruits grown in Mediterranean climates. Brought under control in Florida in 1930, it reappeared in other countries in 1956, causing worldwide quarantines on imported fruit; it recurred in California in the 1980s.

Vinegar flies proliferate on yeast produced from rotting fruit and similar fermenting substances. The most important vinegar fly is the red-eyed pomace fly. It has exceptionally large chromosomes in the salivary gland and can produce a large new generation in only two weeks. In the early half of the 20th century, American geneticist Thomas Hunt Morgan exploited these characteristics in experiments that revealed many of the basic principles of genetics. In early 2000, research involving the red-eyed pomace fly once again advanced understanding of modern genetics when scientists sequenced the fly’s entire genetic makeup, or genome. Scientists expect that the techniques used to unravel the fly genome will help in efforts to decode the human genome.

Scientific classification: Fruit flies belong to the order Diptera. True fruit flies constitute the family Tephritidae. Vinegar flies constitute the family Drosophilidae. The apple maggot is classified as Rhagoletis pomonella, cherry maggots as Rhagoletis cingulata and Rhagoletis fausta, the currant fruit fly as Epochra canadensis, the melon fly as Dacus cucurbitae, the olive fruit fly as Dacus oleae, and the Mediterranean fruit fly as Ceratitis capitata. The red-eyed pomace fly is classified as Drosophila melanogaster.