CLUSTER FLY

Identification, Facts, & Control

Latin Name

Pollenia rudis

Appearance

Fat, Slow, and has no stripes

The cluster fly basically looks very much like the house fly. However, its body structure is more robust (fatter) in appearance and also, the cluster fly has no stripes on its thorax and is a slower moving fly.

Cluster flies get their name from their annoying habit of entering homes in the fall and gathering in clusters in secluded areas such as attics and wall voids. An offensive, sweetish odor may be given off from these gatherings. During the warm days of winter and in the spring, cluster flies become pests because they will become active and crawl about over walls and windowsills in the living space of the house. Although this fly is obviously a nuisance, cluster flies do not fly around inside the house in a noisy fashion as do some other related flies (e. g., green and blue bottle flies).

Cluster flies mate in the spring and lay their eggs in cracks and crevices in the soil. These eggs hatch in about three days and the larvae burrow into the bodies of earthworms where they develop. The entire life cycle takes about twenty-seven to thirty—nine days. Because the larvae of cluster flies do not utilize excrement or other filth as food, they are thought to be less of a mechanical carrier of disease organisms than the house fly.

Click on a species of flies below to learn further information.

House Flies