Left to right: house fly, black fly, blow fly, and flesh fly.
Left to right: deer fly, canyon fly, and horse fly.
Flies are members of the Insect Order “Diptera” (meaning “two-wings”).
The adults can be identified by having only one pair of wings; however these fly species may be quite diverse in appearance. Nuisance flies are found throughout California and cause a variety of problems. The immature (larval) stages of these flies are found in a range of habitats, including water and semi-aquatic sites. Fly larvae found in decaying organic matter are sometimes called maggots.
What is the public health importance of nuisance flies?
The close association of many of these insects with dead animals, feces, or garbage and their attraction to humans, animals, and our food allows flies to potentially pick up and spread a variety of bacteria and parasites that may cause disease. Others are capable of delivering painful bites and can spread diseases to humans and animals. Some nuisance flies reproduce rapidly and become annoying simply because of their sheer numbers, but are not medically important.
How are nuisance flies controlled?
The term nuisance flies covers many species so there is no one method of control. Suggested steps include the following:
Identify the problem fly, if possible, by using online resources, pictorial guides or by contacting local environmental health departments, vector control agencies or university extension services.
Eliminate items that attract flies such as rotting organic material (meat, leaves or grass clippings, household garbage) or animal feces.
Ensure that windows and doors close properly and that screens are in good repair.
Use insect repellents containing the active ingredient DEET, picaridin, oil of lemon eucalyptus or IR3535. Wear long sleeve shirts and long pants to provide an effective barrier to biting flies.
Turn off or limit the use of lights at night.
Cover food and pet food when flies are present.
Various traps, baits and insecticidal sprays are available for fly control. Read the product labels or consult a pest control professional to determine which products are available to control the specific nuisance fly problem.
Common nuisance flies (.pdf)
Information on most common flies around us.
Keep Pests and Pesticides Out of Your Office!
Effective ways to prevent fly pest indoors than spraying pesticides.