Common Name: Cluster Fly, Attic Fly Latin Name:
Pollenia sp.
(P.
Beuk, det.)
Length: 6 to 8 mm
Range: Throughout Alberta
Habitat:
Various
Time of year seen: Spring
to fall.
Larval Diet: Earthworms
Other: Cluster flies can be found in and on most buildings and
other structures. In the spring and fall flies cluster on the warm,
sunny sides of buildings with light colored siding or that are near grassy
areas with earthworms. As the weather becomes cooler, they move into
protected places (i.e. buildings) to hibernate. Reproductive activity
occurs outside after the flies leave their refuges in the spring. The
female fly lays her eggs in soil that has earthworms. The eggs hatch
in three days and the larvae burrow into an earthworm and begin to consume
it. This stage takes from 13 to 22 days at which point the larva pupates for
11 to 14 days before emerging as an adult fly. There are usually four
generations per year. Adult flies are non-metallic grey with lighter
and darker grey patches on the abdomen, the thorax has crinkly hairs and is
not distinctly striped and the wing tips are overlapped when the fly is at
rest. (http://ohioline.osu.edu/hyg-fact/2000/2110.html) |