family: drosophilidae
species: drosophila melanogaster
common names: pomace flies; small fruit flies
specialties: short life cycle. giant salivary chromosomes.
hosts:
notes: May be pest in supermarkets, canneries, wineries, where may be soft or decaying fruit. Larvae feed on the yeast growing on the fruits rather than directly on the fruit.

Agriculture and Agri-Food Canada Insect Identification Sheet No. 100 1986

Vinegar Flies

Drosophilidae

Vinegar or pomace flies, also known as drosophilids or small fruit flies, exist almost everywhere. A well-known member of this family is the subject of extensive genetic studies.

Injury:

Numerous adults often cause annoyance in food processing plants and homes, especially during the fruit processing season. Eggs and larvae found on tomatoes and other fruits frequently create a problem in food processing plants.

Life History, Appearance and Habits:

Adults are small yellowish or brownish-grey bristly flies, usually 2-3 mm long. One species, D. busckii Coq., has longitudinal dark stripes on the thorax; many species have red eyes. Normally, the flies are found around all kinds of overripe, fermenting and decaying fruits and vegetables, on which they lay eggs. The eggs have two to four slender filaments near one end. Larvae are scavengers that feed chiefly on yeast and bacteria living in the food source. They are attracted to various esters produced by
fermentation and to acetic acid (vinegar), but the yeast and other microorganisms associated with the decaying pulp (pomace) are the most important constituents of their diet. At 25 degrees the larval stage lasts about 6 days and the pupal stage about 4 days. Thus the life cycle can be completed in 10-14 days, giving many overlapping generations.

Control:

Do not leave cut or spoiling fruit or vegetables, fruit salads, fruit juices, jams, jellies or pickles exposed. For best control, find the breeding source and eliminate it. Dispose promptly of fermenting fruits and vegetables. Do not keep whole raw fruit exposed to infestations. Whenever possible, keep susceptible foods in cold storage.

If adults appear, check vegetables such as potatoes, carrots, and onions that are frequently stored in large quantities. One rotten vegetable can support a sizable infestation. The same is true for stored flower bulbs or tubers.

Name: Gilkeson, Linda A.
Title: Integrated Pest Management Coordinator
Company: Ministry of Water, Land and Air Protection
Reference Text: HOUSEHOLD PESTS

Fruit flies are tiny, harmless flies with reddish eyes. They are usually a nuisance in the summer, which is when their eggs are often brought into the house on fresh fruit. In warm weather it takes only a few days for the immature stages to develop into adults and, since every female can lay hundreds of eggs, an infestation can develop very quickly in a small amount of fermenting fruit or other food. Removing their breeding sites immediately remedies the problem. Keep fruit in the refrigerator and take any kitchen garbage containing food scraps out of the house several arial a week. If you compost kitchen waste, it is a good idea to bury it in the compost pile every day or two in warm weather.

The following is from G.J.L.Ramel@exeter.ac.uk

Fruit-flies (Drosophilidae)

These are the small flies with light red eyes that you find in the kitchen in Summer whenever some fruit has become over-ripe; once you get some in your house they tend to fall into your drinks, especially beer, wines, cordials and fruit juices. The genus Drosophila contains more than 1,000 species some of which have a two week life cycle and are commonly found in Universities and Colleges around the world where they are used for experiments in the study of genetics and in Pet Shops where they are sold as food for baby spiders and preying mantis.