By Chris Williams on August 4, 2017.

Is there a big black cockroach that lives outdoors? It doesn’t look like cockroaches I’ve seen inside. These bugs are mostly around the foundation but lately I’ve found a couple inside in our basement storage room. Will the same kind of cockroach sprays work on these guys? Can I use the spray outside? V. B., Lawrence, MA

You are probably talking about the oriental cockroach, but these mostly outdoor roaches are often confused with black ground beetles found around foundations so you should have a professional identify the insect in question.


The oriental cockroach is a fairly common pest outside in cool, dark, damp areas around building foundations, under leaves, wood, or stones, or in ground cover plantings. They are attracted to decaying vegetation like grass clippings, garbage cans, and pet poop or pet food left outdoors. In some regions, they occupy municipal sewer systems.

Oriental cockroaches will move indoors, especially when outside conditions become too wet or too dry, or in the fall as temperatures drop. Oriental cockroaches can survive the winter outside, however, in protected places. They can also survive and reproduce indoors if they find just the right conditions with plenty of moisture.

Oriental cockroach adults are shiny black or blackish-brown. The male is about 1 inch long with short wings, although he doesn’t fly. The female is slightly larger and has only short wing buds. The wingless nymphs look like miniature females but are shiny, reddish-brown.


Trying to control these roaches outside with household cockroach spray will be a waste of your time and money. Because they hide in so many protected places in woodpiles, under debris, under splashblocks or garbage cans, and similar sites, it would be impossible to find and spray all of their hiding places to kill them directly. Most consumer indoor cockroach sprays are not labeled for outdoor use because they simply will not stand up to or last very long in outdoor conditions to provide ongoing control.

There is a better way. At Colonial Pest, we offer a Preventative Maintenance Program that includes two annual barrier treatments around the exterior perimeter of your home. These treatments are designed and timed to kill insects living in these sites and those that are most likely to find their way indoors. With effective outdoor pest management, you should never have to treat for pests indoors. If cockroaches or any other pests, such as ground beetles, do find their way inside, our program includes follow-up indoor treatment at no additional charge. More than 9,000 households in New Hampshire and Massachusetts use this worry-free plan.

For more information on your specific situation, give Colonial Pest a call, and check out these pertinent blogs:

Photo Credit : By Acrocynus – Acrocynus, CC BY-SA 3.0, Link



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