What are biting flies?

Black flies, Biting midges (No-see-ums), Horse flies, Deer flies and Stable flies are all biting flies. Many of these species require a blood meal in order to lay eggs. In most species only the female takes blood meals. Some biting flies have piercing mouthparts to pierce the skin, inject an anticoagulant containing saliva and get a blood meal, while some have scissor-like mouthparts to cut into the skin causing a blood flow that they will feed on. Biting flies locate victims by sensing certain substances, including carbon dioxide and moisture in exhaled breath, dark colors, movement, warmth and perspiration.

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Black fly

What do black flies look like and where do they live?

Black flies are small, dark colored and about 2-4mm in length with a humpbacked appearance. They develop in moisture environments and running water. Adults can fly considerable distances in search of blood. These flies are most common in spring and early summer.

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Biting midge

What do biting midges look like and where do they live?

Biting midges are tiny bloodsucking flies that resemble tiny mosquitoes. Biting midges range in size form 1-3mm in length. Their small size allows them to penetrate window and door screens. They are numerous along seashores or along the shores of rivers and lakes. Unlike black flies, the biting midges do not travel very from the water.

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Horse fly

What do horse flies look like and where do they live?

Horse flies are large flies that are usually solid black and range in size from 20-30mm in length. They may be striped like a wasp and occasionally have metallic eyes. These flies are able to take large chunks of flesh from their victims. Horse flies have a flight range of several kilometers.

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Deer fly

What do deer flies look like and where do they live?

Deer flies are similar to horse flies but smaller in size ranging from 12-25mm in length. Deer flies are black with yellow-green markings on the thorax and abdomen. Their eyes are bright green or gold with patterns and their wings have a distinctive brownish-black pattern. The bite is much like that of the horse fly.

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Stable fly

What do stable flies look like and where do they live?

Stable flies are very similar to houseflies in appearance but both sexes bite. Stable flies range in size from 4-7mm. They develop in piles of decaying straw, manure, grass clippings or other piles of rotting vegetation. There are several generations per year; therefore the stable fly can be present in high numbers, especially in livestock.

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How can I control biting flies using cultural/non-chemical control?

Flies are best controlled by eliminating favorable development sites, however since most flies develop in water this can be very difficult. Stable flies can be controlled by simply eliminating any decaying straw piles or by spreading out wet straw to dry. Avoid areas of high biting fly concentrations when the adults are active. Wear light coloured, loose fitting clothing - most biting flies are attracted to dark colours.

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How can I control biting flies using chemical control?

Use approved repellents; those containing deet are most effective. As most flies develop in water, applying a chemical is not advisable unless spraying is done at the community level by a commercial applicator. Stable flies can be controlled by treating fly resting surfaces or host animals with a residual spray, which is usually required in livestock operations.

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How can I control biting flies using biological control?

There is a parasitic wasp currently being studied for control of the stable fly. Any biological insecticide available for black fly control would still have to be applied by a commercial applicator.

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