The Cluster Fly

The cluster fly, or Pollenia rudis, is a fly often mistaken for the common house fly, Musca domestica. It is actually more closely related to the blow fly. This fly is slightly larger then the house fly, and a dull grey color with black markings. The most striking feature of the fly are golden-yellow hairs on its thorax which gives it a golden sheen. Cluster flies do not hang around garbage or refuse like so-called “filth” flies. The adults actually feed on flowers during the spring and summer months. It is also a parasite of the earthworm, using it as a food source when in the larval stage. When you see a lot of cluster flies, it is a good indication that you also have a lot of earthworms. The cluster flies breed in the spring and summer, producing up to four generations in one year.

This fly seems to appear in a home suddenly during the fall or winter, because they get into the attic or crawlspaces of a home trying to keep warm. They will be seen clustered usually on the upper south or west side of a building, where they will crawl into any cracks or crevices in an attempt to get warmers. Then a group of these flies will mistakenly crawl into the house when they are trying to escape, and will buzz at the windows. They are very sluggish and are easy to capture or kill.

They carry no diseases that affect humans, and so are not a concern in that way, and they do not feed or reproduce inside of buildings. They are simply a pest because of their numbers and presence.

The best way to prevent the flies from getting into your house, is to seal as much of the exterior as possible. Fill in all cracks or seams on the outside of the building. Then, do the same thing inside in any room that the flies are appearing in. Watch to see where they are coming in, and fill in any cracks around the perimeter of the room, such as around the baseboards, ceiling fans, or trim. The best time to start prevention is in the summer to fall, before they start clustering. Stopping them after they have entered the house is more difficult, it means using pesticides where the flies come in and are clustered, which is hazardous to the inhabitants. Residual sprays are suggested if necessary.

Visit HSD online if you would like a product to control cluster flies
Article Source