Moth flies indoors are commonly observed resting with their wings held over their body on bathroom walls and around drain surfaces. Larvae feed in decaying organic matter, commonly within drains on the gelatinous film underneath drain plugs and screens and inside of pipes.
As with all species of flies, the first method of control is through sanitation. Wet organic material on which flies can lay their eggs must be removed, destroyed, therefore eliminating any future breeding sources. Killing adult flies will reduce infestation, but elimination of breeding areas is necessary for good management.
If a drain or trap is found to be a breeding ground, clean the drain thoroughly (scrubbing it , if possible) and use Vector Bio 5 Drain Cleaner to destroy the film harboring the organisms.
You can also apply Gentrol Aerosol to areas of fly breeding. For drains, apply product into and around the downspout and catch basin area. Coat these areas thoroughly as fly larva develop in the scum buildup on the sides of drain pipes. Repeat applications at 2 to 4 week intervals depending upon the severity of infestation.
Archer Insect Growth Regulator may be used to control nuisance flies, by application into moist breeding areas (potted plants, moist debris, or litter) or into areas holding standing water, such as gutters, drains, pools, and fountains.