Phorid Fly Identification & Prevention

Also known as the humpbacked fly or coffin fly, phorid flies will infest almost any type of moist, decaying organic material.

Description

Phorid flies are small flies, tan to dark brown in color, up to 1/8 inch in length, and distinguished humpbacked. Any organic material that remains wet can potentially be utilized for food and breeding by this fly. The female deposits 20 eggs at a time and can produce 40 eggs in 12 hours. Larvae emerge within 24 hours and feed for 8 to 16 days before crawling to a dry area to pupate. Under ideal conditions, the lifecycle can be completed in as little as 14 days or take as long as 37 days.

Biology and Behavior

• Because they frequent unsanitary areas, phorid flies are a concern as they can transmit pathogenic bacteria onto food or human tissues.
• Phorid flies can be found in mausoleums and mortuaries and will infest human cadavers.
• Commercial kitchens that 'wet wash' with pressurized water often push moist organic debris into cracks under equipment and gaps under walls where the material ferments and breeds phorid flies.
• The most difficult infestations happen due to sub-slab breaks in drain lines where organic material accumulates. Adult flies or larvae enter the living space through cracks in the slab, gaps around utility penetrations, or unsealed expansion joints.
• You can find sub-slab infestations by boroscopes used to locate broken lines or cutting a core hole in the slab to look for conducive conditions or signs of activity. Replace all infested soil and repair the leaks to solve these problems.
• Phorid fly problems are also common in overwatered house plants and floral displays, as well as pet terrariums.
• Wet mops and brooms that collect moist organic material and are not cleaned and stored properly are good breeding sites.