Yellow-Fly (Diachlorus ferrugatus)
Detailing the physical features, habits, territorial reach and other identifying qualities of the Yellow-Fly.
Updated: 8/28/2014; Authored By Staff Writer; Content ©www.InsectIdentification.org
The bites of the female Yellow Fly are both annoying and painful. They attack at will and usually with friends.
Sometimes mistaken for a Deer Fly, Yellow Flies are just as unwelcome by both humans and animals. The female attacks exposed flesh for a quick blood meal. Males do not bite. Heads and ears are easy targets on humans. Faces, backs and legs are often targets on animals such as horses and livestock. They will use their tails to swat and kill the Yellow Fly since repeat attacks are the norm. The bites are painful, becoming red and irritated over the next day or two, often ending in an allergic reaction that leads to painful blisters. Humans can use insect repellents with DEET to deter them. Fly traps in stables and barns are said to reduce their numbers in those areas.
Both genders will drink flower nectar and eat pollen, but females add to their diet by consuming blood from animals. She will lay 50 or so fertilized eggs in a muddy area, near a lake, creek, pond or stream. Larvae (maggots) hatch and will molt several times before taking on a winged adult form. They feed on decaying matter and spend some time feeding on debris in water before migrating to land.
The most active months for biting attacks are May and June in the south. They are most active between afternoon and dusk. Large congregations live near water, which is necessary for part of the larval life stage. They can be found bothering people and animals in backyards, open fields, parks, farms and forest edges near water.