Black Horse Fly (Tabanus atratus)
Detailing the identifying qualities of the Black Horse Fly, including physical features and territorial reach.
Updated: 2/5/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
Large Black Horse Flies are notorious biters of horses and all things smaller, including humans, leaving behind painful sores on its victims.
Black Horse Flies are about an inch long, making them highly visible and somewhat intriguing to watch. They are fast fliers despite their hefty size. Females feed on blood, and they are not averse to taking it from anything that has it. Their mouth parts cut open flesh, allowing blood to ooze out. They use a proboscis to sponge up the blood, leaving behind an open wound. These wounds can become infected, which poses a threat to livestock health. They are also very painful bites for humans. Males do not bite and do not drink blood. Males actually drink flower nectar and spend their days looking for females to mate with.
Males and females are both completely black, but males have huge eyes that touch each other at the center of the face; the eyes of females are separated. It's the size of the eyes that strikes curiosity in most people that see them. The color of the eyes may vary depending on the lighting. Facets comprising each eye reflect light, so sometimes their eyes appear black, sometimes silver (see photo gallery) and sometimes shades of their surroundings.
This species is found in the eastern part of the continent. Females lay fertilized eggs on or near water sources. Maggots (larvae) feed on other aquatic insects and worms. Chemicals, home remedies, and special collars exist as methods used to deter the presence of Horse Flies, especially in stables.