Horse Flies

Tabanus spp.
iStock_000045227998Large - Horse Fly.jpg

Horse flies likely received their common name because they are notorious pests of horses and other mammals. They are commonly found in both suburban and rural areas near bodies of water, which serve as breeding sites, and where mammal hosts are most abundant.

Pest Stats


Gray or blackish body, wings usually lacking dark areas but some species with entirely dark wings; eyes often large and green or purple with horizontal stripes




Stout-bodied and without bristles


About 3/8 - 1 and 1/8” (10-30 mm) long




Found throughout North America



Adult horse flies are fast, strong fliers and capable of flying for more than 30 miles, though they generally do not disperse widely. They most often attack moving and dark objects. Horse flies often rest on paths and roads, especially in wooded areas, where they wait for potential hosts. Horse flies are attracted to light and will sometimes congregate at windows.


Horse flies are typically woodland or forest dwellers. Species usually feed during full daylight and are most evident on windless, hot, sunny days. In general, larvae develop in wet soil close to bodies of water.


Adult horse flies typically feed on nectar, but females require a blood meal before they are able to reproduce effectively. Female horse fly bites, especially in large specimens, can be quite painful because their mouthparts are used for tearing and lapping, as opposed to mosquitoes, which simply pierce the skin and suck blood. Female horse flies are also persistent and will generally continue biting a host until they either succeed in procuring their blood meal or are killed. They are even known to chase their intended targets for short periods of time. Some species are vectors of disease organisms but in the U.S. most horse fly-vectored diseases only involve livestock.

If you notice horse flies or experience their bites, contact a professional immediately to discuss how to get rid of the infestation through a proper course of pest control.