Pest Index

Cluster Fly

Fly (Cluster Fly)

Binomial Name: Pollenia rudisClusterFlies

Identification:

  • Overall Length: Adult is 3-6mm
  • Colour: Adult is dark grey
  • Other Features:  Wings overlap when at rest

Life Cycle: The adult fly lays its eggs in the soil.  After hatching in 3-4 days the larvae penetrate earthworms on which they feed.

BehaviourThey derive their name from their habit of entering a house from August to September and “clustering” over winter.  They gather in wall voids, attics, window frame voids and other secluded areas to rest over winter.

Signs of Infestation: With the arrival of Spring, Cluster flies emerge by the hundreds on warm days to bask in the sun on outside walls or on the inside of windows.