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American cockroach

The American cockroach (Periplaneta americana) is one of the largest and most prolific cockroach species in the United States. In some areas they are known as “water bugs” or “Bombay canaries,” but in the Southeast they are affectionately called “palmetto bugs.” It’s a fitting name for the largest cockroach in the “Palmetto state” of South Carolina. American cockroaches are built for stealth and speed. These cockroaches easily can scale up a plumbing pipe and squeeze through a tiny crack to make their way indoors. Having a large, speedy insect running past you on the kitchen floor in the middle of the night is scary enough, but these suckers are pretty good fliers too. With wings outstretched, they can easily be mistaken for a small bird.

I remember vividly one day when I visited a small hardware store in Beaufort, S.C., to pick up some supplies. While examining the different types of duct tape on a shelf, something moving caught the corner of my eye. I turned and noticed several feet down the aisle a bird flitting around the hammer section. It didn’t strike me as unusual because you commonly see birds in hardware stores. As I made my way down the aisle, I see the “bird” land on a shelf and realize that it’s an American cockroach. It’s an impressive insect.

Because of their size, having a half-dozen of these fast-running insects lurking inside a residence can be quite unnerving to the people living there. Imagine having several dozen American cockroaches appearing in your home on a consistent basis over several months. This situation was happening to a customer in our area. Charleston is somewhat known for its “palmetto bugs.” When the sun goes down, the American cockroaches emerge from the sewers and storm drains among the cobblestone streets to take in the sites of the city and to nibble on remnants of shrimp and grits and spilled beer.

Their slightly smaller cousins, smokybrown cockroaches (Perplaneta fuliginosa), also called “palmetto bugs” by the locals, emerge in large numbers from their harborages in live oaks and palmetto trees to join in the fun. Native Charlestonians are used to dealing with these large cockroaches and expect to see, and somewhat tolerate, one or two occasionally wandering indoors. Newcomers, however, tend to get a little culture shock when they first move to this beautiful historic city.

IN THE FIELD. The homeowner with the American cockroach issue grew up in Charleston and did have a tolerance for them, but not at the numbers she was seeing. Repeated visits by the local PMP was not yielding the desired results. Plenty of dead cockroaches were being found following treatments, but so were lots of live ones. The PMP was getting frustrated, as well as the customer, so he called me for some assistance. I happily obliged and met him at the account to do some investigation.

We walked through the history of treatments and he had done all of the usual steps that tend to provide good control of peridomestic cockroaches. This includes treating the exterior perimeter of the house with a residual pesticide, treating exterior harborages (leaf litter, under shrubs, under decks, tree holes, woodpiles and other low-lying shady moist areas) with a granular insect bait, and applying dust insecticide in void areas and in the attic (this is a slab home so no crawlspace to treat). On the inside, rooms where cockroaches were frequently seen were treated by applying a residual aerosol insecticide into cracks and crevices, dust applied in voids (wall voids around pipe entrances, cabinet voids and voids around appliances), and granular insect bait applied underneath appliances.

The home and property was very well maintained. The inside of the home was clean and free of clutter and had no known moisture issues. The yard was well maintained with no piles of debris, no mulch or pine straw around the foundation and very little shrubbery. There was a large palm tree and a couple of oak trees near the house but no limbs were touching or extending over the roof. So what were we missing?

After a thorough inspection and questioning the homeowner on the history of the house, we learned there had been multiple additions to the home, and there was a water pipe that ruptured a while ago in the kitchen that had since been repaired. We discovered a couple of inaccessible voids where the additions had been built, and we treated those with a dust insecticide. We also applied a granular bait around nearby drainage ditches and a manhole cover located in the street close to the home. Perhaps these additional treatments is what was missing. I left that day not feeling confident, but hopeful. A little over a week later I received another phone call. We did not make a difference. So, I made another trip back to Charleston.

After removing the customer’s dishwasher from the wall, the author saw a hole in the drywall that had been “patched” with a piece of cardboard. When the cardboard came off, a virtual waterfall of cockroach droppings came pouring out of the hole, along with dozens of American cockroaches of all life stages.

The homeowner, the PMP and I were standing in the kitchen questioning everything again to see if we could figure out what we missed. Most of the cockroaches were being seen in the kitchen, especially coming out from under the dishwasher. As we’re standing there, two adult cockroaches darted out from under the dishwasher. I asked the homeowner where exactly the water leak happened and she said in the wall behind the dishwasher. She wasn’t sure if that could have anything to do with the situation because it had been repaired a long time ago and they had not had any issues with it. The PMP was perplexed because he had treated under and around the dishwasher very thoroughly. Just to make sure that wasn’t the issue we decided to pull out the dishwasher and take a look.

After removing the dishwasher, I noticed the hole in the drywall had been patched with a piece of cardboard taped over it. I pulled the cardboard off and a virtual waterfall of cockroach droppings came pouring out of the hole, along with dozens of American cockroaches of all life stages. Cockroaches were scurrying everywhere, including up everyone’s pants legs. It was like a scene out of an Indiana Jones movie. The customer was screaming, the PMP was knocking down cockroaches with a contact insecticide and stomping on others, and I was laughing maniacally, because we found the cause of the infestation. I tried sucking up cockroaches with a battery powered handheld vacuum, but quickly realized it wasn’t powerful enough to handle the large insects. As soon as I turned it off and set it down, the cockroaches would run back out of it. I asked the customer if we could borrow her vacuum and she quickly ran to get it. I highly encourage the use of vacuums for large insect infestations — what a great tool this is.

After about an hour of killing cockroaches, and sucking up cockroaches and piles of droppings, we got things to settle down. We treated inside the wall voids through the hole and anywhere else we could get access inside the wall and instructed the customer to get the hole fixed properly. She smiled and explained that she had been trying to convince her husband to remodel the kitchen and now will be the perfect opportunity to do so. I definitely felt better after leaving this time. I learned a valuable lesson that day, and that is to make sure to ask plenty of questions when investigating the cause of an infestation and to not always take the customer’s word that repairs were done properly.

The author is technical director at Terminix Service, Columbia, S.C.