This week’s critter communique is the Phorid fly. Read on to discover a few filth fly facts.
Name: Phorid fly (meaning “a cause of that”).
ID: Adults are up to 1/4” long with a 1/3” wingspan. Dark brown, tan in color. From a side view, the thorax appears humpbacked. Leg femur section is pronounced. Three veins reach the wing edge with no cross veins. Female is larger than the male. The male’s compound eyes appear to be touching, while the female’s compound eyes appear to be spaced.
Spotting: While taste-testing, feeding, and defecating. Light-colored spots are saliva, and dark-colored spots are feces. Under PestWest CSI Kit or UVA torch inspection, spotting and shed particles from grooming are evident. Abundance and ratios of spots provide clues to the number of flies and distance to reproductive source(s).
Notable: Adult flies have a characteristic behavior of immediately taking flight when disturbed or scuttling in a fast run (reason for alias “Scuttle fly”).
Flight: ~3.0 mph
Life: Complete metamorphosis or egg, larva (maggot), pupa, and adult stages. Egg to adult in 14 days (under good conditions).
Distribution: Found throughout the US.
Where: Sewer breaches, mausoleums, elevator pits, drain vaults, carrion, wet vegetation, and garbage.
Health: Moves pathogens from filth to food causing food borne illness. Possible cause of myiasis or infection of fly larvae.
Safety: Contaminates food and food preparation surfaces.
Control: Conduct routine camera inspections of roof vents to sewer lines. Repair broken sewer lines and remove contaminated soil. Remove moist, decaying organic matter. Keep dumpsters in good repair, clean, and at maximum distance from the building. Utilize fly screens and other pest-proofing methods. Short-store refuse in well-sealed containers. Caulk or appropriately seal wall and floor cracks. Install air curtains for positive pressure (3.0 m/s-service doors and 9.0 m/s overhead doors). With the use of a UV-AMETER, install numerous insect light traps for monitoring and population reduction. For en masse Phorid fly flushes, the large capture capacity of electronic fly killers (EFK) may be required.