It can be distressing to service professionals and customers when a previously controlled cockroach infestation seems to return with a vengeance. The customer has followed all sanitation and exclusion recommendations — and the service professional has performed a model cockroach integrated pest management (IPM) program — yet large numbers of adult cockroaches suddenly make an appearance.
Such occurrences might mean there are old drains or sewer pipe openings hidden within the construction. Seeing large numbers of cockroaches shortly after a rainstorm is often a good indicator they are emerging from sewer systems.
Use monitoring equipment and sightings to create a “heat map” to help narrow your search. Once found, old drains and sewer openings should be screened or sealed to prevent additional introduction.
Paul Curtis, BCE, is manager of Technical Services for Terminix International.
Wouldn’t sealing the drain openings have been part of the initial control measures? Not the last. Ironically as Itype this I am about to do just that. Deal all abandoned drain openings in a large office building. American cockroaches have been present for 6+ months. Another pmp has been “spraying” monthly to no avail. I was called in by building owner and apon initial inspection numerous abandoned bathrooms were located in the basement. All the p traps in the toilets and sinks are dry. First step is to seal all these openings.