Broken drainpipes under a house may also supply the conditions needed for a breeding site for moth flies. After repairing the broken pipe, the area should be allowed to dry out, and any soil or gravel that contains large amounts of organic debris should be removed. Residual insecticides are not effective in treating the soil for moth flies. The combination of the excess moisture and high levels of organic matter will usually render the insecticide ineffective. More importantly, there is no insecticide labeled for this use.
Sewers can create an interesting treatment problem.
It will be impossible to remove the organic matter from a sewer, so in this case, periodic ULV treatment of the sewer non-residual insecticide will help in reducing the adult population. PC Mark Yates is a research coordinator in the entomology department at the University of Georgia, Athens, Ga., under Dr. Brian Forschler.