Facts, Identification & Control
Length: Very small — 0.5 to 5.5 mm. To the naked eye, phorid flies resemble common fruit flies in appearance.
Color: Most are black or dull brown, but some are yellowish in color.
Thorax: The arched thorax of the adult gives them a humpbacked appearance. It is for this reason that phorid flies are often called “humpbacked flies.”
These insects feed on rotting food, so they also spread bacteria and disease. In addition, a phorid humpbacked fly infestation may indicate the presence of a dead animal inside a wall or crawl space or a plumbing leak located under the home’s slab.
Costly Repairs
Phorid humpbacked flies breed and develop deep within plumbing, which makes them hard to remove from a home without help. Not only will they potentially infect food and food surfaces with disease microorganisms, but resolving a phorid fly problem may require expensive repairs if they are developing from a plumbing leak.
These flies are difficult for homeowners to completely control with any pesticides and often rarely works as the only solution. The situation has to be assessed and the source of the infestation determined (is the source a clogged drain, broken pipe or sewer line?). In many cases the floor must be removed and the pipe repaired. The soil around the break must also be removed.
Another solution to this problem is to first physically clean the drains — remove as much of the organic material as possible and then use a biological drain cleaner on a regular basis (every two weeks).
These pests display characteristically short and erratic flight. Adults have a peculiar habit of rapidly running across windows, TV screens, tables, walls, and plant foliage. They are frequently mistaken for “gnats.”
What Do They Eat?
Some foods that phorid flies eat includes:
- Moist organic material that gathers in drains or other plumbing
- Decomposing flour on the floor and under equipment in bakeries and kitchens
- Decomposing vegetables such as potatoes and onions
- Fungi
- Insects