Cluster Flies

flyCommon Name: Cluster fly
Scientific Name:Pollenia Rudis

Introduction: Cluster flies are very similar to house flies only a little larger. Cluster flies are about 5/16 of an inch long and are a dull shade of gray. A cluster fly has a very distinctive odor when crushed and the tips of their wings overlap when resting, unlike house flies whose wings do not.

Biology: Female flies lay their egg in the soil near earthworms in the early spring. Once the egg hatches the larva will burrow into the nearby earthworm to feed. It normally takes up to a month to complete the life cycle from larva to adult. There are four generations per season. The flies of the last generation are very noticeable in the fall while looking for a place to hibernate, thus becoming a major nuisance for homeowners during time this frame.

Habits: Cluster flies will go dormant over the winter usually in the attic of the structure close to a pasture or field near animals. Cluster flies will enter the structure from under overhangs, or voids in the siding and pulleys for windows. Cluster flies will become active whenever the temperature is over 54 degrees and can normally be found in windows on the sun side of the house. Cluster flies do not mate inside the structure, but will return outside to mate.