How To Control Flies

It is rarely possible to entirely eliminate flies and flying pests from homes and offices but the numbers can be kept to minimum.

• Flies inside – It is best practice to keep flies from entering buildings with the use of mesh screens on windows and doors or keeping doors and windows closed. If flies gain entry; aerosol fly sprays can knock down flies in a room but only work for a short time, i.e. they are non-residual. Be sure to remove or cover fish tanks and follow all precautions stated on the can. Stay out of the area after spraying an aerosol as any people or pets in the room would be inhaling insecticide.Automatic dispensers that regularly puff insecticide (natural pyrethrum plus synergistic enhancer) into a room can be useful for deterring and controlling flies but they should always be sited away from food and food preparation areas.

• Surface treatment using residual type sprays containing insecticides such as deltamethrin or permethrin will give long term control of flies. Flies are killed after they land on the treated surfaces and insecticide will not be inhaled by people or pets using the rooms. Spray the surfaces that you see flies landing on; these are often the edges of doorways and window frames, light fittings, ceilings, tops of walls and wall corners.

• Note: Pyrethroids are broken down by UV light and have a shorter life in bright sunlight. They are also slower to work in higher temperatures; so on warm days the flies may take several hours die after contact.

• Some flies don’t ‘like’ variable airflows. An oscillating fan can help to make a room unattractive to flies.
• Flies outside – It is more difficult to deal with flies outside as it may not be possible to treat areas not within your control and there can be no way to proof against flies. However, there are ways to minimise the nuisance. Search for possible breeding sites of flies. Remove or treat with insecticide any decaying animal or vegetable matter that might provide food for maggots (fly larvae). Check and clear drains.

• Spray exterior walls, window frames, door frames, pergolas and other fly alighting surfaces using residual surface spray.
• Baits are being developed for the control of flies. These may be useful in areas such as chicken coops, animal houses etc. In such areas spraying can be less effective because of dust the presence of a great deal of decaying matter to attract the flies.

• Citronella candles and other repellents can reduce fly numbers in limited areas such as decks and around barbecues. However, windy days will dissipate the repellents rapidly.

• Personal insect repellent can be useful in preventing flies as well as mosquitoes and sandflies coming close to us.