Flies - more information

General information on flies

Use of insecticides and pesticides

Insecticides can be purchased from garden centres/shops, hardware/ironmongers shops, DIY stores, etc.



Common house fly (Musca domestica)

Adults are 6-8mm long, with a wingspan of 13-15mm; the thorax is grey with four longitudinal dark stripes; the sides of the abdomen are yellowish and may be transparent; the larva is a typical maggot - it undergoes larval moults, gradually increasing in size and changing colour from white to cream; pupa is about 6mm long and may be yellow, brown or black. Houseflies are potential vectors of a wide range of diseases such as dysentery, gastroenteritis and tuberculosis and can also transmit intestinal worms. These flies move from filth to food indiscriminately and may therefore move pathogens from dirty to clean areas. Fly spotting is produced when feeding and defecating.

Lesser house flyLesser house fly (Fannia canicularis)

Adults are 5-6mm long, with a wingspan of 10-12mm and with a grey thorax, which has three indistinct longitudinal stripes on it; the abdomen has an extensive area of yellow at its base. Potential vectors of a wide range of diseases, such as dysentery, gastroenteritis and tuberculosis, and can also transmit intestinal worms. They move from filth to food indiscriminately and may therefore move pathogens from dirty to clean areas. Fly spotting is produced when feeding and defecating.

BlowflyBlowflies (Calliphora spp)

Adults are 9-13mm long with a wingspan of 18-20mm; adults are large robust flies with a stout abdomen; the thorax and abdomen are black/blue and dusky in colour. Blowflies are attracted to rotting animal remains on which they lay their eggs. In their search, they can mistake stored meat as a suitable host. The possibility of disease spread is similar to the housefly.

Cluster flyCluster fly (Pollenia rudis)

Adults are 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 checkered pattern. The female fly lays eggs in soil or leaf litter. When the larvae hatch they seek out an earthworm. They enter the body of the earthworm and develop within it until leaving to pupate. The adults are known to over-winter in buildings in large numbers, often thousands.

Fruit flyFruit flies (Drosophila spp)

Adult fruit flies are small, yellowish/brown with a darkly striped abdomen; they have prominent compound eyes that are generally red in colour, although darker variants occur; the wings have two clear notches in the front border, which can clearly be seen with a hand lens. Fruit flies are commonly associated with human food preparation and storage areas. They are a source of annoyance in many kitchens, restaurants, etc. They are attracted to alcohol and waste fruit and can build up to very large numbers when these food/breeding materials are present.

Prevention and Control

Most flies can be controlled by the use of flypapers, insect traps of various kinds and aerosol insecticides.

Control methods for cluster flies are often ineffective or incomplete and it is often impossible to keep flies from entering premises. Sealing around windows and door frames and other obvious entry points, however, can reduce infestations. Flies and other insects can be discouraged from entering buildings by using fly screens and fly strips on windows and doors. House flies and blow flies breed in dirt and organic waste, and if the flies are present in large numbers breeding sites should be investigated. Refuse bins should have close-fitting lids and food should not be left out uncovered. Cluster flies do not breed indoors and their presence does not indicate poor hygiene. Strangely they sometimes target a single property in a group. Roof spaces are often used to over-winter and on warm days cluster flies can emerge from hibernation and get into inhabited rooms. Control measures are as for other flies, but don't forget the loft!