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Nature

Deer Fly

What is deer fly?

· Emily Grant

Key facts

Common name Deer fly[1]
Family Tabanidae[1]
Genus Chrysops[1]
Order Diptera[2]
Feeding Females bite for blood[2]
Other hosts Humans, cattle, horses, dogs[2]

Deer flies are blood-feeding flies in the family Tabanidae, genus Chrysops, known for their painful bites on humans and animals. They are closely related to horse flies and often confused with them. Deer flies are serious pests of livestock and people.

Context

Deer flies are blood-feeding insects in the family Tabanidae, genus Chrysops, and are common pests of humans and livestock [1]. They are closely related to horse flies and often confused with them [2]. Females bite to obtain blood, using cutting mouthparts to lacerate skin and lap up the blood [2]. Their bites can be painful and cause swelling due to the bite and saliva [2].

Documented claims

  • Deer flies are bloodsucking insects and can be serious pests of cattle, horses, and humans. [2]
  • Deer fly females use cutting mouthparts to lacerate skin and lap up blood. [2]
  • Deer flies are closely related to horse flies and are very similar to them. [2]
  • Deer fly bite pain and swelling are caused by the bite and saliva. [2]

Questions and answers

Are deer flies painful?

Yes, deer fly bites are painful and cause swelling due to the bite and saliva [2].

What's the difference between a horsefly and a deer fly?

Deer flies are closely related to horse flies and are very similar, but they are in the genus Chrysops while horse flies are in Tabanus [2].

Are there deer flies in Canada?

Deer flies are found in Canada, as they are common pests of humans and livestock in the region [2].

Sources

  1. Deer Flies - Home and Garden IPM from Cooperative ... — extension.umaine.edu (retrieved August 3, 2026)
  2. Deer Fly - Veseris Canada — veseris.ca (retrieved August 3, 2026)

Sources last checked August 3, 2026. · More in Nature