Description: The adult is a large fly up to 10mm in length with a wingspan of up to 20mm. The thorax has a distinctive dark greyish/olive colour and is covered in golden hairs. The abdomen has a chequered pattern. The wings are held at rest folded tightly on top of the abdomen.

Little is known about the life cycle. The female fly lays eggs at the entry of worm burrows. The larvae hatch and find the earth worm. They enter the body of the worm and develop within it. They leave the earthworm to pupate and after pupation, the adult flies emerge.

Cluster flies are found in Northern Europe, North America and Canada.

How to control cluster flies: Voids harbouring the flies can be treated with dust / mist application of insecticide. ULV treatment and dichlorvos strips can also be effective used in the right circumstances.