American cockroaches (ACRs) are not native to North America. This is a fact that many of you probably already know. They were introduced from Africa via ship in the 1600s. They most likely found ship-going very easy with food, harborage, and plenty of moisture. However, this article is not about where they literally came from but when we're servicing accounts asking ourselves where are they coming from?
What I want to do in this article is share with you some of the experiences that I have had over the past 30 years in the DMV solving problems involving American cockroaches. It amazes me the number of accounts that I have inspected that are having issues with this species and some of the key areas where harborage was overlooked. Hopefully those of you that are experiencing problems with this species will be able to think creatively about where these cockroaches are harboring and thus be able to solve your customers’ problems.
One of my most memorable accounts dealing with this species was an apartment complex in Maryland that was having a chronic problem with hundreds of ACRs emerging into the apartment. We were unable to immediately identify the harborage and/or points of entry. We explored outdoor areas and other points of entry within the apartment. The only hint was the numerous ACRs we found in one bedroom with an exterior door, and it also backed up to the bathroom. Initially we addressed infestation by baiting and while we were killing a lot of ACRs we weren't solving the problem. The apartment was slab on grade, and we finally explored the tub plumbing access panel. We found the soil under the slab had settled and that the sub slab area was heavily infested. The story didn't end there, we decided a dust application under the slab would correct the problem. During the application of the dust, into the sub slab area we later went out into the living room after we pumped a couple pounds of dust into the sub slab space and discovered that during renovation they left a hole behind the kitchen cabinets. Needless to say, we walked into a dust storm. The good news was that the apartment was vacant and we solved the problem.
Another infestation that we encountered was at a major museum downtown. American cockroaches were crawling across the sidewalks leading to the museum and even in the streets. We identified the source of the activity coming from the nearby sewer. We decided to treat the sewer with a relatively new dust formulation - deltamethrin. We learned a valuable lesson when using this highly effective product. It is also highly repellent. The treatment flushed hundreds of American cockroaches out of the sewer onto the sidewalks leading up to the museum. While the treatment was effective in eliminating the infestation, the public and management panic that occurred as a result of treatment taught us a lesson in product selection or alternatively timing of applications.
We had an office building downtown and for six months we were trying to resolve the appearance of American cockroaches on the 6th floor of this office building. Our inertial search was for open drain lines, dry traps, or other areas that these cockroaches might be coming from. Unfortunately, we could not find any place where ACRs could exit the sewer system into the working space. The exterior of the building where they were occurring was solid brick until the sixth floor where there was a bank of windows. One day coincidentally talking with a parking attendant who asked what we were doing he indicated to us that the exterior wall next to the garage had big gaps along the foundation. He told us we should be out here at night and see the migration of ACRs up the wall. The gap at the foundation was heavily infested. We later found that there were gaps around the windows on the 6th floor that were allowing these cockroaches to enter the building. Once we treated the area the problem was resolved.
One of the most common areas overlooked in high rise buildings are the sewer ejector pits and damp crawlspaces. When these areas are found and directly treated the infestations are often resolved. What warrants further investigation is how did they get into occupied areas of the building. In the areas of activity, the first things to look for are dry drains. Another possibility are open drain lines in the building. These occur during renovation when plumbers forget to seal an abandoned drain line or when rats chew through a rubber boot placed over a drain line. The most efficient way to uncover these openings is a smoke test. You can hire a plumbing company to do this or add on the service to your job (it is not a difficult process). ACRs apparently love to climb, so all levels of the building must be investigated and don’t assume that their appearance on any floor is the source – investigate the bowels of the building.
I recently had a consulting call from someone living in Melbourne, FL near my hometown. She sent me a picture of some adult ACRs that were infesting her house. In Florida they can readily infest the outdoors as well as moist areas in the house such as the kitchen, walls, attics, etc. She was totally freaking out. She hired a company that sprayed in and around the house, and subsequently baited. There was some success, but they kept appearing. I suggested treating the walls with dust, which they did, and the adults ceased to appear. A few weeks later she sent me a photo of nymphs and in her word “baby” roaches and said they were now appearing. I explained to her this can happen because ACRs have egg capsules (ootheca) that were deposited before the females died and can take up to several weeks or longer to hatch. The good news is they were dying and I haven’t heard from her in a couple of months.
When dealing with ACR infestations it is important to keep in mind their biology and habits:
The two most important points to remember, investigate ACR infestations thoroughly and educate your customer.