Phorid (Humpbacked) Flies


phorid fly

Phorid fly adults (Whitney Cranshaw, Colorado State University,

phorid fly

Phorid fly adult (USDA ARS, Wikimedia Commons)

phorid fly

Adult phorid fly (Charles Lewallen, Wikimedia Commons)


  • very small; 1/64 - 1/8 inch long
  • steep arch or humped back behind head
  • eyes not red

Nesting Habits

  • lay eggs on decomposing organic material
  • larvae need moist, organic material to survive
  • floor drains are a common breeding ground
  • trash cans, dumpsters, moist food in floor or kitchen equipment cracks/crevices, soil in potted plants, dirty mopheads and pet cages (on moist feces/food)
  • occasionally found near broken pipes under slabs


  • decomposing organic materials


  • nuisance pest indoors
  • can spread disease through contact

IPM Recommendations

  • Locate breeding susbstrate, if possible, and remove.
  • Regularly clean floor drains.
  • Keep exterior doors closed, install screen doors, or install an automatic door closer, especially on doors leading into the kitchen.
  • Exclude fly entry via caulking, weather stripping, door sweeps, screens, etc.
  • Keep dumpsters at least 50 feet from the building.
  • Close lids on dumpsters and garbage cans.
  • Inspect and clean trash cans, dumpsters and garbage areas.
  • Keep food preparation area floors and equipment very clean.

Additional Resources

IPM for Flies: Integrated Pest Management in Sensitive Environments (University of Nebraska-Lincoln Extension)