Ministry of Agriculture

Control of Insect and Related Pests of Livestock and Poultry in British Columbia

House Fly

Host: Livestock and People

Description of Injurious Stages and Damage


House flies are dark grey in colour, about 6 millimetres long with four longitudinal black stripes behind the head. Although house flies do not bite they are very annoying to animals and people. They are particularly undesirable around dairy barns because of possible contamination of milk and milking equipment. Because of their feeding and breeding habits, flies are also a threat as carriers of some human and livestock diseases.

Summary of Life History

Eggs are laid and maggots develop in bedding straw, spoiled grain, or other rotting organic matter. A few overwinter in barns as larvae or pupae in manure or rotting bedding. A life cycle may be completed in 2 to 4 weeks in the summer, with several generations per year. House flies are most abundant outdoors in August and early September, but can be a year round problem in hog and poultry barns.

Control Recommendations

Elimination of breeding sites is essential for effective season-long control of house flies in and around farm buildings and pens. Parasitic wasps that kill fly pupae can be purchased and released to aid in reduction of house flies. Automatic misters, fly paper, electrocuting and baited traps can be used in milk rooms and other areas of low fly numbers. Residual wall sprays (0.5%-1% diazinon, 1% dimethoate, 1-2% malathion or 0.1% permethrin) can be applied where flies congregate (be sure to alternate between kinds of insecticides to prevent resistance development); scatter baits containing methomyl, propoxur, naled or dichlorvos are also available.

Black Flies | Bot Flies | Cattle Grubs | Face Fly | Hog Mange Mite | Horn Fly
Horse & Deer Flies | House Fly | Lice | Mosquitoes | Poultry Lice
Chicken Mite & Northern Fowl Mite | Sheep Bot Fly | Sheep Ked | Stable Fly | Ticks