The house fly goes through complete metamorphosis meaning there are four stages to its life cycle: egg, larva (maggot), pupa and adult fly. A female fly can lay several batches of 75-150 eggs each over her lifetime. Eggs are laid in moist organic material like garbage, lawn clippings, and animal feces, so the larvae will have a food source. Eggs hatch approximately 12 hours after they are laid and will complete the life cycle in roughly 10 days. However, higher temperatures will speed up the life cycle process while cooler temperatures will slow it down. Adult flies have four dark lines on the back of their middle body region and can't bite. In the summer, adult usually live three weeks.
It seems house flies are always around in the summer months, so what can we do to manage these pests? Why use Integrated Pest Management (IPM) of course! The first line of defense against house flies is sanitation. By removing their breeding area and food sources, house flies cannot complete their life cycle. The second line of defense is exclusion. Keep them from entering the building. If house flies are still a problem, look to non-chemical measures. Here are some specific things you can do to deal with house flies.
- Don't allow organic matter to accumulate. Inspect the grounds for areas where this might occur.
- Keep trash in sealed containers such as trash bags or cans with tight-fitting lids.
- Remove trash at least once a week and rinse out the trash container.
- Close the lids and doors to dumpsters and keep them as clean as possible. Locate dumpsters as far away from building doors as possible.
- Inspect all doors, windows and other openings leading into the building.
- All windows should have screens that fit tightly. Repair or replace any screens with holes.
- Seal or plug openings around doors, windows and pipes to prevent flies from entering.
- Use screening on ventilation openings.
- A fly swatter or rolled up newspaper or magazine is an effective, economical way to address the occasional flies that are inside a room or building.
- Sticky fly strips, or flypaper, can be used in confined areas where there is little air movement. These are useful for a small number of flies, not a heavy infestation.
- Traps with food attractants can be used in outside areas if there aren't any other competing food sources (i.e. garbage, decaying organic material, etc). Keep in mind these types of traps can be quite smelly so they should be used away from buildings.
Check out Penn State Extension's fact sheet for more information on house flies.
If after practicing good sanitation and exclusion techniques you still have a large house fly population, talk with your licensed pest control provider about additional suggestions and options for house fly management. Make sure the flies that are causing the problem are properly identified as house flies. See the attached fact sheet for more information about the house fly.