Cluster Flies

Cluster Fly (Pollenia rudis)

Biology & Habits

Length – Body 10 mm, Wingspan up to 20 mm

Colour – Thorax is a dark grey and olive colour, Abdomen has a chequered or lined pattern

Cluster Flies normally inhabit loft spaces over the winter and are often confused for House Flies. The female cluster fly will lay her eggs in soil close to the runs of earthworms. When the earthworms hatch into larvae, they will seek out and enter the body of the worm to seek and develop inside the worm. The larvae will leave the worm to pupate. After pupation the adult fly will emerge.

Autumn, early winter, adult flies seek harbourage to over winter and usually hibernate in many hundreds in warm loft spaces. It is common for the cluster flies to return to the same harbourage year after year. The flies do not feed over winter


Sapphire Pest Management can offer 2 options for treatment:
  • Space treatment of void or loft using a knock down insecticide, early winter and repeated early spring
  • The use of electric fly control units (if the environment allows for the safe use of electric fly control units)

Cluster Fly