Deer fly

Deer flies are blood-feeding flies in the family Tabanidae, commonly placed in the subfamily Chrysopsinae and often referred to as tabanid flies.

Deer flies are blood-feeding flies in the family Tabanidae, commonly placed in the subfamily Chrysopsinae and often referred to as tabanid flies. They are known for painful bites on humans and other mammals, especially near wet habitats where their larvae develop. Deer flies are present in Canada, particularly in humid, wooded, and wetland areas, where they can be bothersome to people, pets, and livestock during warm months.

Classification

Deer flies are commonly treated as members of the subfamily Chrysopsinae within the family Tabanidae. They belong to the order Diptera, the true flies.

Appearance and behaviour

Deer flies are usually small to medium-sized flies with patterned wings and distinctive eyes. They are strong fliers and are known for persistent biting behaviour.

Life cycle and habitat

Their larvae develop in moist or aquatic environments such as wetlands, muddy edges of water, and damp soils. Adults are commonly found in warm, sunny areas near water and vegetation.

Biting and importance

Only female deer flies bite, using mouthparts that cut the skin and draw blood. Their bites are often painful and may cause itching, swelling, and irritation; they are also notable pests of livestock and humans.