Dump Flies
Black garbage fly, Ophyra leucostoma (Wiedemann), Ophyra aenescens and other species,
Muscidae, DIPTERA

DESCRIPTION

Distribution -- Dump flies are practically cosmopolitan. In North America, they inhabit garbage disposal areas of urban communities from British Columbia to Newfoundland and south through Arizona and Florida.

Feeding Habits -- Dump flies do not bite animals or people but feed on a wide range of liquid substances. Larvae, on the other hand, breed in garbage, fowl excrement, livestock manure, and other decaying organic matter. They are predaceous and frequently prey on other types of fly larvae.

Damage -- In some areas, these disease-carrying flies are second in importance only to house flies. By walking on or otherwise contaminating food, it is possible that dump flies can transmit polio, typhoid fever, dysentery, and food poisoning. Fortunately, their occurrence in houses is uncommon.

Life History -- The biology of dump flies is not well known but is presumably similar to that of other muscoid flies. It is not known whether the eggs are laid on fresh or decomposed garbage; however, adult flies and advanced stages of fly larvae are seldom found in garbage which is less than 2 or 3 days old.

Adult dump flies dislike shade and are particularly active in sunshine. Huge numbers of these flies may be active at dumps on warm, sunny days but seem to be absent in cool, cloudy weather. On warm days, males sometimes hover in the air much like little house flies.

CONTROL

Dump flies can be controlled by sanitary garbage disposal practices. Burning, burying or covering garbage eliminates flies' access to their favored breeding sites and thereby prevents development. In poultry houses, manure should be managed to keep it relatively dry until the manure can be properly disposed of. Disposing of swine and cattle manure in open lagoons reduces dump fly populations (but may increase mosquito populations). Chemical control of dump flies is rarely necessary.