Wood Cockroaches are Temporary Pests
By Chris Williams on June 8, 2011.
Q. I’m so embarrassed…and puzzled. In the last week, I’ve found several cockroaches in my house. I’ve never had cockroaches before and don’t know where they’ve come from. At least they look like cockroaches. They’re about one inch long, and light brown, and they fly!
A. It’s hard to confirm without seeing a specimen, but sounds like you have been invaded by the Pennsylvania wood cockroach. Don’t be embarrassed; it doesn’t mean you’re a bad housekeeper. These roaches are not like the typical German cockroach that lives and breeds indoors. The Pennsylvania wood cockroach is a temporary pest that can move indoors at this time of year. Despite its name, it does occur in our area.
The wood cockroach lives and breeds outdoors. You can find it in wooded areas (duh!) usually under bark, in stumps, or in ground litter or mulch. They sometimes end up closer to us: in firewood, in potted plants, under cedar shake shingles, and in roof gutters. Houses surrounded by woods are the most likely to be invaded by wood cockroaches.
You’re seeing the male cockroach which flies to lights and can accidentally end up inside anytime from May to October. We get most of our calls though in late May and June during the cockroach’s breeding season. The Pennsylvania cockroach male is strongly attracted by pheromones given off by the female and will fly great distances to reach her. The female wood cockroach is smaller, has very short wings and cannot fly. But if a female ends up around your porch light or, heaven forbid, inside your house, you can expect to be besieged by male wood roaches trying to get to the female.
Wood cockroaches enter homes through cracks and crevices around doors or windows or are carried in on firewood during cold weather. They often end up in the bathroom or other rooms where there is a light on at night. The Pennsylvania wood cockroach spends the winter in the nymphal stage, often under bark on firewood. When firewood is brought inside in the winter, the glossy, reddish-brown, wingless nymphs warm up and can become quite active.
Fortunately, this early summer invasion is fairly short-lived. Wood cockroaches are not adapted to indoor living. They don’t breed indoors and they won’t live long in the drier indoor environment. They don’t bite or smell, and they don’t do any damage to indoor furnishings. The presence of wood cockroaches in a home rarely requires the use of pesticides. Never treat firewood with pesticides. The best thing to do is to catch the wood roaches, if you can, and shoo them back outdoors (outdoor cockroaches really are beneficial). Seal any openings around windows and doors that they might be using to enter. And, keep your outside lights off for a week or two to keep from attracting the cockroaches.
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