Winchester Pest Control
Winchester Pest Control

Winchester Pest Control

 Integrated Pest Management

 Telephone - 781-729-1893

Cluster Fly
The common name reflects this fly's habit of developing in compact clusters. They are prevalent throughout New England wherever the earthworm is found, usually in well drained soil with grass cover. The adults are about 3/8" long and dark gray in color.

With warming springtime temperatures, cluster flies emerge from under the soil to mate. Eggs are laid in soil cracks & hatch in about 3 days. The larvae attach themselves and develop to adult on their host the earthworm. This process is typically completed in about 30 days, with usually 4 generations per year.

As autumn days shorten & weather cools, cluster flies will enter buildings to overwinter particularly in wall voids or attics that receive the most sunlight. They do not multiply in structures; however they can be a nuisance problem in autumn when they enter to hibernate or become active on warm sunny days of winter and again in the spring when they attempt to leave the structure. Once stimulated, they seek light and can be seen around windows or room lighting. Their movements are slower or sluggish when compared to house flies.