General Aspects



The family Tabanidae includes approximately 4300 to 4500 species and subspecies worldwide. Of these, 335 species in 25 genera are found in the Nearctic Region (Burger, 1995). The family Tabanidae is divided into three accepted subfamilies: Chrysopinae, Tabaninae and Pangoniinae (Fairchild, 1969; Mackerras, 1954). The former two of these subfamilies contain most of the economically important tabanids. Tabanids in the subfamily Chrysopinae are called deer flies, with nearly all being members of the genus Chrysops. The subfamily Tabaninae includes horse flies, represented by the genera Tabanus and Hybomitra.


Table 1: Morphological characteristics used to differentiate adult horse and deer flies (Mullens, 2002)


Horse flies (e.g., Tabanus)

Deer flies (e.g., Chrysops)

Body length

10-30 mm

6-11 mm


Short, base of flagellum greatly enlarged

Long, base of flagellum not greatly enlarged


Vestigial or lacking



Clear, uniformly cloudy or spotted

Distinctly banded

Apical spurs on hind tibiae



Further information

  • Burger JF: Catalogue of Tabanidae (Diptera) of North America north of Mexico. Contrib Entomol Int. 1995, 1, 1-100
  • Fairchild GB: Climate and the phylogeny and distribution of Tabanidae. Bull Entomol Soc Am. 1969, 15, 7-11
  • Mackerras IM: The classification and distribution of Tabanidae (Diptera). I. General review. Aust J Zool. 1954, 2, 431-54
  • Mullens BA: Horse flies and deer flies (Tabanidae). In: Mullen G, Durden L (eds.): Medical and Veterinary Entomology. 2002, Academic Press, London, pp 263-77

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