Cluster Flies—Pollenia spp.
These insects, sometimes called "attic flies," often become pests in homes. They usually appear in late fall or early winter and again on warm, sunny days in early spring. They buzz around the home and gather in large numbers at windows, often in rooms that are not regularly used.
The cluster fly is a little larger than the common housefly and moves sluggishly. It can be recognized by the short, golden colored hairs on its thorax, the part of the body to which the legs and wings are attached. The larvae, or maggots, of cluster flies develop as parasites in the bodies of earthworms.
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Identification and Control Information
- Fact Sheet: Cluster Flies—University of Maine Cooperative Extension
- Fact Sheet: Cluster Flies—University of New Hampshire Cooperative Extension
[Photos, left to right: Whitney Cranshaw, Colorado State University, Bugwood.org]