Biology:

The phorid fly breeds primarily in and feeds on moist decaying organic matter. Because it frequents unsanitary areas (with the ability to spread disease causing bacteria onto food products) this fly is of particular concern to hospitals, health care facilities and restaurants. The reproductive potential of these flies is tremendous and very large numbers of them may appear in a short time. Adult flies are strong fliers, having been known to travel as far as 6 miles within a 24 hour period. Phorid flies are found throughout the world and are a serious pest when found in food producing, food handling or food serving facilities. Health care facilities are another favorite target of this fly. Phorid fly larvae have been found in the open wounds of patients in nursing homes and hospitals. Fermenting materials such as fruit, dirty garbage containers, rotten vegetables or slime in drains are just a few of their favorite breeding and feeding places.
Phorid flies develop by egg, larva, pupa and adult. The female will lay about 20 eggs at a time and will lay about 40 eggs in a 12 hour period. Each adult female phorid will lay approximately 500 eggs. The tiny eggs are deposited on or near the surface of decaying organic matter. Larvae emerge in 24 hours and feed for 8 to 16 days. The Phorid fly larvae then crawl to a drier spot to pupate. The life cycle from egg to adult can be completed in as little as 14 days (under ideal conditions) but may take as long as 37 days to complete their cycle.

Control:

Sanitation and habitat elimination are keys to managing this group of flies.

It may be difficult to locate the source of infestation since the flies can be well concealed in and around plumbing and areas where moisture may collect.