Fruit Fly

Fruit Fly, common name for two families of true (two-winged) flies. True fruit flies, such as the housefly-sized apple maggot, have intricate, often colourful 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.

Larvae of the true fruit flies develop in living plant material, especially fruits and other seed-bearing organs. For example, the apple maggot is found in North American 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 (‚ in) in length. When the apple has fallen, the larvae burrow about 3 cm (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. Originally from South and East Africa, the Mediterranean fruit fly spoils fruits grown in Mediterranean climates. Brought under control in Florida in 1930, it recurred in California in the 1980s.

Vinegar flies, the study of which has provided much of the current information on heredity, 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 new generation in only two weeks, making it an ideal subject for genetic experiments. Studying fruit flies also enables scientists to examine basic brain processes alongside genetic differences. In 1999 it was demonstrated that these insects sleep. More recent research has shown that fruit flies can learn to avoid unpleasant stimuli, have short-, medium-, and long-term memory, and display “salience” (basic attention), despite their brains only having 250,000 neurons compared to 100 billion in human brains.

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 Bactrocera cucurbitae, the olive fruit fly as Bactrocera oleae, and the Mediterranean fruit fly as Ceratitis capitata. The red-eyed pomace fly is classified as Drosophila melanogaster.