Horse Flies and deer flies Insect The 3-spot horsefly, Tabanus trimaculatus, is found in the United States and feeds on deer, moose, and domestic livestock. It can also attack humans. Body length 0.5-0.6 inches (13-15 mm). The “blinder deerfly, Chrysops caecutiens, is from Europe. It is called the “blinder because it bites its host’s eyelids, causing them to swell up and reduce the animal’s ability to see. Body length 0.5-0.6 inches (13-15 mm).
Common name: Horseflies, deerflies (elephant flies, clegs)
class subphylum: Insecta Hexapoda
Number of species: Around 3,000 (350 U.S.)
Size: From 0.2 in (5 mm) to 1 in (2.5 cm)
Key features: Eyes large, usually with brightly colored patterns; body stout wings often with darker patterning; biting proboscis; eyes of male nearly touching on top of head
Habits: Tend to be active on sunny days, usually avoid shade when biting; stealthy flight when approaching hosts to feed
Breeding: Males either form individual territories and mate with passing females or gather in swarms
Diet: Males feed only at flowers; females take nectar and blood; larvae mainly predaceous, while others feed on decaying vegetable matter
Habitat: Wherever the mammals they feed on are found; larvae in water or damp soil
Distribution: Worldwide-tropics, temperate zones, and the arctic.
Horse fly Insect HD Photos Collection: