Small Fly Development Sites

Small Fly Development Sites and Preventing an Infestation

Small fly populations increase in the summer months. They may enter from the exterior through an open dock door or arrive on incoming shipments like fruits and vegetables. Once indoors, they will seek suitable sites and laden with the right mix of organic material to lay their eggs. All the species listed below feed on organic matter but in different stages of decay. The level of decay will dictate which fly species will develop in that material. Removal of the food source is key to small fly control. There are several species of small flies that will reproduce inside structures. These flies include: Small fruit flies (vinegar flies), Phorid flies and Drain flies.


Fly Species

Development Site

Small Fruit FlyFilth Fly Image

  • Pop and soda dispensers including beverage tray drains and drain lines
  • Over-ripening fruits and vegetables.
  • Food residue underneath trash can liners
  • Damaged or leaking food containers like soda syrup cartons

Phorid Flies and Dark-eyed Fruit FliesPhorid_Fly

  • Floor drains which have not been kept cleaned
  • Deterioration in floors where moist organic material has accumulated
  • Exterior dumpsters
  • Interior and exterior trash receptacles which are not cleaned and maintained
  • Mop sinks which are not properly cleaned
  • Mops and cleaning rags which are not cleaned and stored properly
  • Floor scrubbers which are not properly emptied and cleaned

Drain FliesDrain_Fly

  • Floor drains which are not routinely cleaned, and water trap levels in floor drains not maintained
  • Condensate lines which are not cleaned
  • Condensate and drip trays which are not cleaned

Control Methods for Small Flies

Sanitation and exclusion are critical in reducing small fly problems. To avoid problems with small flies, maintain high levels of sanitation. Cull fruits and vegetables in storage to remove over-ripe product. Use first in, first out rotation of stock and check incoming shipments for signs of flies. Keep doors closed when not in use and report fly sightings to your pest management professional.