The most troublesome species of stink bug is not native to America; it traveled to the Northeast in shipping crates from Asia about ten years ago. Since then, that species has proved to be more likely to invade homes than other families of stink bugs, and it is expected to continue to spread. This spells trouble for the South, including Knoxville and other parts of East Tennessee.
Last winter and spring, Russell’s Pest Control received many calls from homeowners who were frantically trying to manage “shield bugs” that were literally coming out of the wood work. That’s because stink bugs (who do resemble a shield) are a lot like ladybugs in their seasonal habits. Much like the Japanese lady beetles, stink bugs are likely to invade homes in the Knoxville area when the weather is first starting to get cool. They sunbathe on the south and west walls of homes and businesses while it’s warm. Then, they move inside at the first frost and overwinter in wall voids and attics until the spring weather causes them to wake up and re-emerge. Sometimes, a sunny winter day will fool some of them into thinking it’s spring, and the stink bugs will start to stir. That’s often when homeowners realize that they have a problem. Soon, all of the bugs wake up and try to head back outside to feed. Those that lack a good sense of direction, however, will get turned around and end up in the house instead.
The refreshing coolness of fall probably sounds far away after the hot summer that we’ve had. However, now is the time to start thinking about keeping those stink bugs out of your house so that your defenses are ready by the time the heat breaks. The best way to avoid a stink bug invasion is through exclusion. Walk around your house and begin to look for openings that a bug could use. You’re looking for cracks around windows and doors, gaps in the siding, and openings around pipes. Inside, look for similar cracks around the doors and windows as well as openings around the exhaust fans in bathrooms and kitchens. A good tube of suitable caulk is your best tool to ward off stink bugs. You might also want to look into screens for your attic ridge vents if yours are damaged.
Closer to the first frost, you can wash the west and south sides of your house with a simple dish soap mixture. The soap keeps the bugs from sunning on the house, but it is also washed away quickly by rain and dissipates in bright sunlight; you may have to re-apply the wash often until the weather gets cold. You can also get a professional pest treatment with a backpack blower that more reliably deters the stink bugs from approaching openings into the house (coincidentally, I know a place where you can contact an exterminator who does those treatments).
Once the stink bugs are inside, it’s too late to use pest control treatments. You’ll have to wait for them to leave in the spring because killing them in the walls will only invite a host of new pest problems. Should you find them inside, a vacuum should be used to remove them, but expect a bit of a bad smell if you are sweeping up several at once (they aren’t called stink bugs for nothing, you know).
Start working on closing those openings now. And, if you decide to get some professional help on the job, don’t wait until the last minute! Leave yourself time so that you know you can get the treatment done before things cool down.