Welcome to the State of California 
BLACK FLY     © 2009 Erik Blosser
BLOW FLY     © 2006 Gayle and Jeanell Strickland
CANYON FLY     Photo by Alec Gerry, UC Riverside
DEER FLY     © 2005 Bruce Marlin
FLESH FLY     © 2008 Ted Kropiewnicki
HORSE FLY     http://PaulDavidsonPhotography.com
HOUSE FLY    © 2005 Robin McLeod
MIDGE     Copyright © 2009 Steve Nanz
NO-SEE-UM     © 2005 Kerry S. Matz

Nuisance Flies 

Nuisance flies are insects that are annoying or can spread diseases to people and domestic animals by biting or carrying pathogens.  All nuisance 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.

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.


Educational Materials

  •  Nuisance Flies Fact Sheet (PDF)   
  • Resources

  • Vector-Borne Disease Section

    Last modified on: 8/30/2012 7:09 AM