Cluster Flies

Pollenia rudis

Cluster flies are also known as attic flies. They’re related to blow flies, such as the blue bottle flies, green bottle flies, etc. They are sometimes mistaken for the common housefly, but are bigger and move more slowly. Cluster flies also overlap their wings at rest whereas houseflies keep their wings separate. Some say that cluster flies give off an odor that smells like buckwheat honey.

Color	Dull-gray with black markings but has golden-yellow hairs on the thorax, which can give the appearance of a golden sheen.
Legs	6
Shape
Size	Length of 8-10 mm (0.3-0.4 inch)
Antennae	True

Where Do Cluster Flies Come From?

Cluster fly larvae develop inside earthworms living in the ground outside of homes and develop into cocoons before hatching into adult flies. One thing to note is that cluster flies don’t breed indoors. Adults are attracted to the sunny side of homes in the fall, trying to find ways to get inside before winter begins. If you find cluster flies in your house, they’ve chosen your home as a warm place to overwinter before returning outdoors in the spring.

How Long Do Cluster Flies Live?

Cluster flies live one to three months, from egg to death. Adult cluster flies lay eggs in cracks in the soil when they emerge in spring. Their eggs hatch within about three to four days and the hatched larvae feed on earthworms for two to three weeks. The larvae will pupate in the soil for 11-14 days before becoming adult flies. They are typically around three to four generations of cluster flies each spring/summer.

What Do Cluster Flies Eat?

Cluster fly larva burrows into the soil and feeds on earthworms. Adult cluster flies feed on flower nectar, plant sap, fruit, flowers, and other types of organic matter.

How Can I Get Rid of Cluster Flies?

There are several cluster fly control methods. To remove cluster flies, use a hand vacuum to capture the flies and remove them from your home. You can also use a light trap or flypaper trap. For prevention, make sure all windows that open have screens. Seal cracks behind baseboards and electrical outlets, and around windows and nearby door trim. Cluster flies can be a nuisance, but they won’t reproduce indoors and do not carry any diseases. If your cluster fly infestation continues, contact Arrow Exterminators for a professional pest control plan.