Order and Family:
Calliphoridae, Blow Flies
1/2″ (13 mm). Head gray with large red eyes, black sides, and reddish beard. Thorax dark gray. Abdomen metallic blue. Legs dark gray to black, bristly. Wings clear.
Female feeds on wounds and rotting meat. Larva eats juice from decaying flesh.
Eggs require 90 percent relative humidity to hatch; if enough moisture is present, hatching occurs almost immediately. Larvae grow rapidly and often crawl many feet to pupate in drier places, either in soil or in crevices of buildings. Adults emerge in 2-3 weeks. Many generations a year.
Pastures and barnyards, near decaying meat, exposed flesh wounds, and dung.
Greenland south along the Atlantic Coast to Virginia, southwest to Mexico, north to Alaska.
Females are attracted to meat and often enter open houses. They buzz loudly when they can’t find an exit. When feeding in wounds, larvae keep flesh essentially sterile but retard healing. On live animals the infestation is known as myiasis. The related Red-headed Blow Fly (C. erythrocephala), same size, is very similar in appearance and behavior but has orange sides to its head and a black beard.