The bites of the female Yellow Fly are both annoying and painful, especially since they attack at random and usually have their friends with them.
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. These large animals use their tails to swat and kill the Yellow Fly since repeated attempts to bite are normal. The fly bite is painful, becoming red and irritated over the next day or two, often ending in an allergic reaction that can lead 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, sparing livestock.
Both male and female Yellow Flies drink flower nectar and eat pollen, but females add to their diet by consuming blood from animals. She can lay 50 or so fertilized eggs in a muddy area, near a lake, creek, pond, or stream. Larvae (maggots) hatch and 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 are May and June in the southern states. The fly is most active between afternoon and dusk. Large congregations of them typically live near water, which is necessary for part of the larval life stage. They are often found bothering people and animals in backyards, open fields, parks, farms, and forest edges near water.
Scientific Name: Diachlorus ferrugatus
Fly or Mosquito
Size (Adult; Length): 8mm to 10mm (0.31in to 0.39in)
Colors: yellow, black, brown, green, blue, purple
Descriptors: flying, biting, eye bands, green eyes, clusters,
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