Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

BugGuide is a National Moth Week Partner. How to add your National Moth Week 2021 photos. July 17-25.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

National Moth Week 2020 photos of insects and people.

Photos of insects and people from the 2019 BugGuide Gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Previous events


Family Tabanidae - Horse and Deer Flies

Night visitor - Chlorotabanus crepuscularis - male Horse Fly - Tabanus lineola - male Horse Fly - Tabanus subsimilis Horse Fly - Tabanus lineola - male Tabanus sp? - Hybomitra large horse fly deer fly - Chrysops - male Horsefly 7-2-19
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon (Orthorrhapha)
Infraorder Tabanomorpha
Family Tabanidae (Horse and Deer Flies)
Other Common Names
Bulldog Flies, Clegs, Yellow Flies of the Dismal Swamp, Greenheads, Gad Flies, Copper Heads
Explanation of Names
Tabanidae Latreille 1802
350 spp. in 31 genera in our area(1)(2), 145 spp. in Canada and Alaska; almost 4,500 in ~160 genera worldwide(3)
8-25 mm
Regional keys: n. NA(3), e. Canada(4)(5), CA(6), ID(7), ME(8), MI(9), OH(10), TX(11)
Medium to large flies, females take blood, and some are pests. The notched posterior margin of tergite 1 on the abdomen is unique. Typical characteristics:
stoutly built flies with large squamae (scales above the halteres, also called calypters);
feet with 3 pads (as opposed to 2);
3rd antennal segment elongated, clearly made up of several fused parts;
3rd antennal segment with a prominent tooth at base in some groups
wing veins R4 and R5 fork to form a large 'Y' across the wing tip.
3rd antennomere
wing venation
tarsal pads
Worldwide and throughout NA; detailed analysis of distribution in NA in(3)
Adults wide ranging
larvae mostly in wet soil in marshes/bogs and at margins of streams & ponds; a few spp. in sand/gravel in fast-flowing streams; others also in drier soils(12)
Year round in FL, summer further north
adult females feed on vertebrate blood, usually of warm-blooded animals; males (also females in a few spp. in all 3 subfamilies) visit flowers
larvae mainly carnivorous, a few eat detritus
Life Cycle
larval stage up to 2 or more years, esp. in the north(12)
The bite is effected by stabbing with the mouthparts and slicing the skin with scissor-like movements of the finely serrate, knife-like mandibles and smaller maxillae. After capillaries are ruptured, anti-coagulant saliva is pumped out through the hypopharynx, and the blood is lapped up using the labella. See detailed mouthparts images in Hine (1903) and Thomas (2012).
Some tabanids have very striking color patterns on their eyes; Kn├╝ttel & Lunau (1995, 1997) suggest these colours filter light to improve contrast detected by the eye pigments themselves, and play a role in sexual signalling. --Francis Gilbert
Internet References
Taxon profile (Squitier 2011)[Cite:185010]
Works Cited
1.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
2.Catalog of Tabanidae (Diptera) of North America north of Mexico
Burger J.F. 1995. International Contributions on Entomology 1(1): 100pp.
3.The horse flies and deer flies of Canada and Alaska (Diptera: Tabanidae)
Teskey H.J. 1990. The insects and arachnids of Canada, Pt. 16. Ottawa: Agriculture Canada. 381 pp.
4.Tabanidae of Canada, east of the Rocky Mountains 1: a photographic key to the species of Chrysopsinae and Pangoniinae
Thomas A.W., Marshall S.A. 2009. Canadian Journal of Arthropod Identification No. 8.
5.Tabanidae of Canada, east of the Rocky Mountains 2: a photographic key to the genera and species of Tabaninae...
Thomas A.W. 2011. Canadian Journal of Arthropod Identification No.13.
6.Adult and immature Tabanidae (Diptera) of California
Middlekauff, W. W. and R. S. Lane. 1980. University of California Press.
7.The horse flies and deer flies of Idaho
Nowierski, R. M. and A. R. Gittins. 1976. Research Bulletin, Agricultural Experiment Station, University of Idaho College of-Agriculture. 96, 1-48.
8.The horse flies and deer flies of Maine (Diptera, Tabanidae)
Pechuman L.L., Dearborn R. 1996. Maine Agric. & Forest Exp. Sta. Technical bulletin 160, iv+24 pp.
9.A synopsis of the Tabanidae (Diptera) of Michigan
Hays, K.L. 1956. 1956. University of Michigan, Museum of Zoology.
10.Tabanidae of Ohio with a catalogue and bibliography of the species from America north of Mexico
James Stewart Hine. 1903. Columbus: Press of Spahr and Glenn.
11.The horse and deer flies (Diptera: Tabanidae) of Texas
Goodwin and Drees. 1996. 1996. Southwestern Entomological Society.
12.Manual of Nearctic Diptera Volume 1
Varies for each chapter; edited by J.F. McAlpine, B.V. Petersen, G.E. Shewell, H.J. Teskey, J.R. Vockeroth, D.M. Wood. 1981. Research Branch Agriculture Canada.