Housefly Facts

The house fly musca domestica is a common pest that enters homes during the summer months. Although these insects do not bite, they can cause diseases by spreading harmful organisms. You can control house flies and house fly maggots with a combination of good sanitation practices, exclusion methods and chemical controls.

Identification

Adult house flies range in size from .25 to .312 inches long. They are usually dark or light gray, and most have four long dark gray or black stripes that run lengthwise down the thorax, which is the area directly behind the head. Sticky, bristly hairs cover their clawed legs, enabling the insects to land on and adhere to smooth surfaces. Their larvae, which range in size from .38 to .75 inches, have pale worm-like bodies.

Life Cycle

House flies often breed in areas where people live. They lay their eggs in garbage cans, near rotting produce or animal excrement, or in other decaying organic matter. The larvae, which hatch in as little as a day, are important to the ecosystem because they break down organic material during the feeding process. They molt twice before pupating and becoming adults. The maturation process can take as few as three days or as many as 26, depending on the weather and environment.

Diet and Disease

House flies have sponging mouthparts and they mostly feed on liquids, but they are also able to digest solid food by ingesting it, regurgitating it and then ingesting it again as a liquid. Since they often breed in decaying plant and animal matter, they carry organisms such as bacteria and viruses on their bodies and transmit them from place to place as they feed, or expel them in their saliva. These pathogens can contaminate foods and cause food poisoning or other harmful diseases.

Control

You can control house fly populations by pouring boiling water into infested garbage cans to kill the maggots inside, and by keeping garbage cans covered so that flies cannot breed inside. Clean up and discard animal waste or other organic material that may attract flies. Caulk your screens and seal up cracks or openings so that insect pests cannot enter your home. Kill flies with fly swatters or with fly paper, or spot-treat infested areas with aerosol insecticides.

References

• Colorado State University Extension: Flies in the Home; W.S. Cranshaw and F.B. Peairs; February 2009
• Virginia Cooperative Extension: House Fly Maggot; Eric Day
• University of California Davis Vet PDA: Musca domestica
• Texas A&M University: House Fly
• University of Kentucky College of Agriculture: House Flies; Blake Newton; May 2004