Ministry of Agriculture
Control of Insect and Related Pests of Livestock and Poultry in British Columbia
Horse and Deer FliesHost: Cattle, Hogs, Horses, People
Description of Injurious Stages and DamageAdults are medium to large flies sometimes referred to as "bull-dogs." Adult females pierce the skin and suck blood, causing great annoyance to animals, interrupting grazing, with loss of weight gain in beef cattle and reduction of milk yields from dairy cattle. Cattle and horses will often seek shelter in dense bush or in buildings to avoid horse and deer fly attack.
|Horse Fly||Deer Fly|
Summary of Life HistoryLife histories of our various species of horse and deer flies are not well known. Eggs are laid on stems and leaves of aquatic plants. Larvae live in the mud close to water, perhaps for a year or two, before pupating and emerging as adults. Adults are most active on warm sunny days.
Control RecommendationsNo satisfactory protective sprays are available. Temporary relief may be obtained from repellent sprays. Darkened shelters or areas of deep shade into which animals can escape from the flies should be made available.
Black Flies |
Bot Flies |
Cattle Grubs |
Face Fly |
Hog Mange Mite |
Horse & Deer Flies | House Fly | Lice | Mosquitoes | Poultry Lice
Chicken Mite & Northern Fowl Mite | Sheep Bot Fly | Sheep Ked | Stable Fly | Ticks