body length to at least 20 mm. Teskey gives range 19-25 mm.
eyes uniformly dark, dull, bare; antennae dark; wings translucent, blackish along heavy raised veins; thorax gray with reddish tint above, light gray and hairy below; abdomen very dark reddish with middorsal line of small but distinct white triangles
(dark antennae and reddish abdomen with small white triangles are diagnostic in Ontario)
[TT notes: wing membrane may be lightly infuscated but heavier along veins]
includes eastern United States and southeastern Canada (Internet records from Georgia, Maine, Michigan, Minnesota, and BugGuide photos from Ontario).
Burger (1995) gives range as Minnesota to Nova Scotia, south to North Carolina. Thus the Georgia record below (Berry College) may be based on an incorrect determination. Dr. Burger is THE North American authority on Tabanidae.
Teskey, H.J. 1990. The insects and arachnids of Canada. Part 16. The horse flies and deer flies of Canada and Alaska: Diptera: Tabanidae. Research Branch Agriculture Canada Publication 1838: 1-381.
Burger, J.F. 1995. Catalog of Tabanidae (Diptera) of North America north of Mexico. Contributions on Entomology, International. Vol 1, Number 1. Associated Publishers. 100 pages.
Pechuman, L.L., H.J. Teskey and D.M. Davies. 1961. The Tabanidae (Diptera) of Ontario. Proc. ent. Soc. Ont. 91:77-121