Cluster Flies

The Cluster Fly is often mistaken for the common house fly but they are more sluggish and often appear to fly very slowly. They can overwinter in vast numbers in lofts, cellars and dark voids. These flies are of no particular harm but can be alarming because of their great numbers. Generally noticed on the first warm days of spring when they congregate on the inside of windows. Frequently found in window frames, particularly sash windows. Interesting life cycle - lay eggs in damp earth and resulting larvae migrate into the bodies of earthworms where they develop into maggots which then bore out of the worm to pupate. Easily controlled with spray, fumer or electronic device.

Best Methods for Controlling your Pest

DIY or The Professionals?

If you can get access to the flies hibernating voids, and are comfortable with using insecticidal fumers, then they are easy to control.
If the flies hibernating area is extensive and you would rather not use insecticides, you may be better to get a pest control company to come in and use a non-toxic spray likw Oa2ki.

Cluster Flies are not easy to kill without insecticides because of the difficulty of accessing all their hibernating places.

Electronic Fly Killers: These need to be plugged into a live mains socket as they emit an attractant light which draws the flies towards an electrified stainless steel grid which kills the flies and the dead bodies are collected in a removeable tray beneath. The unit should be located at the opposite end of the room to any existing source of light in order to attract the flies to the electronic lights rather than the window lights. Extra deep collection trays are available for cluster fles.

Glue-Board Light Traps: These operate in the same manner as electronic units except that the flies are traped on glue boards. These glue boards can fill very rapidly and so may not be suitable for large infestations unless you are able to change the glue pads regularly.

Insecticide Fumer: These fumers contain Permethrin and are lit using a match, they then give off a pall of smoke which gets into all cracks and crevices coating all surfaces with a very thin layer of permethrin insecticide. The flies - and other insects - are killed upon contact with the permethrin dust.

For safety, place each unit on an old saucer or tin lid before lighting.

Make quite sure there are no bats or bees in you loft as they will also be killed and that is illegal. Also, it may be a good plan to inform the Fire Brigade in case a helpful neighbour sees smoke coming from your loft and phones the Fire Brigade! Remember, if you need to use several fumers because of the size of your loft, light the furthest away first to enable you to get back out.

Do not use fumers if you are asthmatic.

Insecticidal Dusts: can be puffed onto surfaces used by the flies and into difficult to reach voids. The dust settles on surfaces and insects subsequently come into contact with the dust and so are killed.

Non-Chemical Dusts: these dusts do not contain chemical insecticides but work by rubbing off the protective waxes covering the insects body causing it to dy from dehydration.

Insecticidal Sprays: are a means of dispensing the active ingredient onto surfaces via water rather than smoke or powder. The result is the same but without the active ingredient hanging around in the air as it does with powder, dust or smoke.

Use pesticides safely and always read and understand the label.