Cluster flies may not get as much attention as other pests, but they can cause serious problems in your house when they take hold, especially if they hibernate for a season, gain a foothold and attract other pests.

Droppings can stain curtains and walls and wreak havoc.

Cluster Fly Removal in Peterborough and Kawartha Lakes

Call Dave’s Quality Pest Control now to deal with cluster flies and other pests that invade your home.

These flies are commonly referred to as cluster flies and can be abundant in houses with large lawns or those backing onto open parks. The name "cluster fly" is derived from their habit of entering a house in the fall and gathering in clusters that may emit a sickly, sweetish odour if disturbed.

Cluster flies hibernate in secluded areas of houses, such as in wall voids, attics, closets and empty rooms. They are a particular nuisance as they leave stains on the walls and curtains. If the flies die in the wall voids they may attract larder beetles, which will feed on the dead flies and then migrate to other areas of the house. In the spring, the sluggish cluster flies will migrate from their hibernating areas to living spaces and gather on windows as they are attracted to light.

Cluster flies (Pollenia rudis) belong to the same order as fruit flies, houseflies and mosquitoes (Diptera). Adult cluster flies are approximately eight to 10 millimetres long. They are dark grey with black and silver (non-metallic) checkered abdomens, with many golden hairs on their thorax (these may or may not be present on older flies). Their wings overlap when they are at rest.
Cluster flies are parasites on our friendly earthworms. The eggs are deposited singly into cracks in the soil of lawns or open areas in late summer or early fall. The eggs hatch in approximately three to seven days and the larvae then enter the body cavities of earthworms to overwinter until spring when feeding activity resumes. The larvae feed for up to 19 days; they then moult and begin the final larval stage. The larvae finish feeding on what is left of the earthworm hosts and then enter the soil where they pupate for approximately 10 weeks. In mid-summer, adults emerge from the soil. These adults and the cluster flies that hibernated in households will mate and lay eggs in late summer or fall, repeating the cycle. Adult cluster flies can often be seen sunning themselves on stumps of trees and sides of houses in autumn before they hibernate in Fall in your home.
Although many do not consider them a serious health danger, cluster flies can hibernate in large numbers, then produce large swarms when they come back to life in the spring season. Another danger occurs when hibernating cluster flies are triggered by unpredictable warm winter spells. During an unexpected spike in temperature, sleeping cluster flies wake up and are drawn towards the light from windows in swarms. Cluster flies also act as hazardous parasites on otherwise harmless creatures like earthworms.
Cluster flies have a similar appearance to house flies. They are dark gray in colour and about 1 cm long, with gold or yellow hair. They are larger and darker in colour than house flies and slower and more sluggish in comparison.
Cluster flies are seasonal creatures that seek a safe place to hibernate when autumn temperatures drop. Dwellings with plentiful sun and open lawns attract cluster flies. Cluster flies seek out dark hidden places to hibernate. If there are openings in your wall, they will find it. If there are damaged screens or cracks in doors or window frames or uncovered vents cluster flies will burrow in.
Cluster flies often return to the same property every year and live long lives, sometimes two years or more although most other species live less than 3 months. Especially when hibernating, cluster flies can still stain curtains and walls. Larder beetles sometimes feed on those that die during winter, then remain and can live for years. Therefore, it is critical to stop the infestation.