Native to North America, and a member of a large family of flies that otherwise are not of any pest significance.
This species of fly is often found in structures where the larvae may breed in decaying vegetable or animal materials. They also feed on abandoned bee hives, feeding on the honeycomb and other materials. The larvae then leave the food material prior to pupation, and mature larvae or the large pupae may be found well away from likely sources for them. Dumpsters are a common source of larvae of these flies.
The adult fly is a very large fly, up to an inch in length and somewhat narrow bodied. It is shiny black, with a flattened abdomen and with a pair of large, light, clear looking patches at the base of the abdomen. The wings are held flat and crossed over the abdomen when at rest.
The larvae also may be an inch long, and they are flattened and brown, and with distinct segmentation along the body. The head end is distinctly narrowed and pointed. The pupa look very much like the late stage larvae, and may be dark brown to almost black in color.
Characteristicts Important to Control:
The presence of the larvae, the pupae, or many adult flies indoors indicates breeding within the structure is likely. Unsanitary garbage containers should be a primary suspect, but alternatives such as abandoned bee hives considered as well. Removal of these sources and proper sanitation are the keys to control.