WSU Extension


Brown marmorated stink bug
Clover mites
Cluster flies
Fruit flies
Fungus gnats
Giant house spider
Hobo spider
House centipede
House dust mites
House flies
Little house flies
Mice and rats
Moth flies (drain flies)
Multi-colored Asian lady beetle
Odorous house ants
Pavement ants
Root weevils
Seed bugs
Sowbugs and pillbugs
Spiders (non-biting)
Thatching ants
Western boxelder bug

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Caption: The complete lifecycle (eggs, larvae, pupae, adults) of the house fly.
Photo by: Ken Gray
House flies
(revision date: 7/14/2015)

Use Integrated Pest Management (IPM) for successful pest management.

The house fly is one of the most cosmopolitan insects and has been considered a pest for centuries. The house fly measures 3/16 to 1/4 inch long and can be distinguished from other flies by the 4 dark stripes on the thorax and the yellowish abdomen with dark markings. House flies can develop from egg to adult in as little as a week if conditions are right and can build up to huge numbers quite quickly if food is abundant. They breed in animal dung, carrion and decaying plant material. They overwinter in our area as pupae. The house fly can transmit dozens of diseases, including diarrhea, polio, and Salmonella. Disease transmission usually occurs when the house fly comes into contact with the pathogen and then passively moves this pathogen to humans.
Management Options

Non-Chemical Management
  • Do not provide good breeding sites.
  • Do not place or compost vegetation waste near doorways or entries.
  • Do not allow pet manure to accumulate in the yard.
  • Fly traps (available commercially) can assist in keeping numbers down, particularly if you can’t control nearby breeding sites.
  • Do not use electric zapper traps outdoors since they kill more beneficial insects than pest insects. However, these traps can be very useful indoors.
  • Maintain tight-fitting window and door screens.
  • Invest in a good old-fashioned fly swatter.
Select non-chemical management options as your first choice!

Chemical Management

None recommended.


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Caption: The complete lifecycle (eggs, larvae, pupae, adults) of the house fly.
Photo by: Ken Gray