Flies

The facts

That allowing any type of insect or rodent within your premises or home will obviously be a nuisance and in some cases serious illness, loss of business and in extreme circumstances, legal and civil prosecution. The Cluster Fly is 6mm long with a wingspan of 10mm, a largish fly with a distinctive bristly yellowish and black marked abdomen, the thorax is covered with yellow-gold hairs, large reddish compound eyes.. Cluster flies are found throughout the UK and their common name refers to their habit of forming clusters when “hibernating” - in often large numbers - in buildings. Whilst there is a specific species of common cluster fly (Pollenia rudis), there are other species of cluster fly and swarming flies which have a similar hibernating nature and these may also be involved in forming mixed populations of flies inside suitable buildings. The life cycle of the Cluster Fly is very much dependent on the prevailing weather conditions, and in this country, two generations a year are usual but in hot summers, up to four generations per year are possible. Cluster flies are “field” flies and in summer and early autumn they are of no consequence. However, as the weather becomes cooler, they seek out shelter in nooks and crannies in houses and other buildings. As the weather becomes colder, they search for more protection from the elements and may be seen in large numbers, particularly in roof spaces, lofts, etc, sometimes with several thousand flies clustered together.

Where do Flies live?

South west and mainly South facing buildings are favoured, the flies will invade cladded buildings and silos, and will enter roof spaces and voids via small gaps and crevices in the fabric They will cluster on the exterior of buildings in huge numbers prior to crawling into the harbourages, in the spring the warmth revivers them and they start to leave buildings in numbers. Eggs laid loosely on damp soil and in leaf litter, larvae hatch after a week and seek out earthworms, they bore through the wall of the victim's body. After it has grown to full size it bores its way out of the worm and pupates in the soil. Depending on the weather two generations are normal but up to four are possible, flies hatch from the pupae and live outdoors, they start to enter buidlings in large numbers in late September onwards into November when the temperature begins to fall.

Why keep Flies under control?

The cluster flies are the genus Pollenia in the blowfly family Calliphoridae. Unlike more familiar blowflies such as the bluebottle genus Phormia, they do not present a health hazard because they do not lay eggs in human food. They are strictly parasitic on earthworms; the females lay their eggs near earthworm burrows, and the larvae then infest the worms. However, the flies are a nuisance because when the adults emerge in the late summer or autumn they enter houses to hibernate, often in large numbers; they are difficult to eradicate because they favour inaccessible spaces such as roof and wall cavities. They are often seen on windows of little-used rooms. They are also sometimes known as attic flies.

Prevention & Control

Control methods for cluster and swarming flies are often ineffective or incomplete. It is often impossible to keep flies from entering premises. Indeed, it is likely that in many premises used by cluster flies the areas or voids used are difficult, if not impossible, to locate. The best method of control is to prevent them entering the building in the first place, especially by blocking any access into cavity walls, e.g. replacing missing bricks, filling in other holes, etc. Although proofing is seldom 100% successful, sealing around window and door frames and other obvious entry points can also assist in controlling their presence. Cluster flies do not breed indoors and once they are inside a property, control can be relatively easily achieved with a range of insecticides and fly strips.

Treatment

Contact Paramite Pest Solutions if you suspect you may have a problem and we can advise you on the best course of action. A visit by our pest control officer can be arranged. He will carry out a survey. Paramite Pest Solutions will take all possible precautions. Revisits will be made until the problem is cleared.