You may have seen them on your window screens or even inside your house — shield-shaped, brown bugs about the size of your little fingernail. These may be the brown marmorated stink bug (BMSB), a recently introduced, invasive insect from Asia that was first detected in the Quad-Cities in 2012.
The insect has joined the boxelder and Asian lady beetles as pests that like to come into homes in the fall.
While they don't bite, get into food or make holes in your clothes, they release a foul odor when they're disturbed or threatened. In the wild, this smell sends predators away. In a home setting, it can be repulsive. And in some areas of the country these bugs are so numerous that they can literally cover the side of a house, according to university extension services.
They also are a big threat to commercial food production. They feed on fruit, lowering its value by roughly 90 percent, making it unfit for the fresh consumption market and destined for processing.
How to keep them out
To keep them out of your house, block all points of entry. If there's a space between your screen door and the threshold, for example, keep the storm door closed. (This is good advice even if you're dealing with a look-alike beetle and not specifically the brown marmorated stink bug.)
You also can apply an insecticide around the perimeter of your home, said Kate Terrell, of Wallace's Garden Center and Greenhouses, Bettendorf. This can block them for several days to a week, she said. Her recommendations are Ortho Home Defense or Bayer Home Pest Control.
• Rub screens with dryer sheets; the more pungent the better. Some homeowners have found this can reduce stink bugs entering a home by up to 80 percent.
• Hang a damp towel over a lawn chair or deck railing overnight. In the morning, stink bugs will blanket the towel. Drown the bugs in a bucket of soapy water.
• Squish a few stink bugs outdoors. The odor warns other stink bugs to flee.
What to do once they get inside
• Don't touch them directly or squish them.
• Stink bugs move slowly enough that you can catch them and deposit them outdoors. Grab them gently with a plastic bag to avoid touching them directly.
• Or, take an empty water bottle and use the lid to flick the bug into the bottle. Tighten the lid to contain the smell, and place the whole thing outdoors.
• If you have quite a few, you can try the Japanese beetle solution of drowning them in a soapy solution of water. Choose a straight-sided ½- or 1-gallon container. Fill it one-fourth full of water mixed with 1 teaspoon of liquid soap or detergent. When disturbed, stink bugs tend to drop downward. Knock them into the bucket from walls, draperies, screens and so forth.
• Vacuum bugs, and empty the bag afterward. Don't suck stink bugs into a bagless vacuum because that will make the vacuum stink.
• In areas of the country where stink bugs are really bad, many homeowners buy wet/dry vacs used solely for gathering stink bugs. Immediately after gathering bugs, they dump the vacuum's contents into a larger garbage bag and seal it tightly.
• Another technique to try is to wrap a knee-high stocking around the outside of the vacuum tube, secure it with a rubber band, and then stuff it into the tube. Stink bugs will be trapped in the stocking and won't enter the vacuum filter. When you turn off the vacuum, careful remove the stocking, holding the end closed. Dump the captured stink bugs into a container of soapy water, as noted above, to kill the bugs.
• Do not apply insecticides indoors to control stink bugs. While insecticidal dust may kill bugs in wall voids, the carcasses can stink and attract other pests, such as carpet beetles, which can damage other things in your home. Applying an interior pesticide along baseboards won't kill stink bugs nor will it keep them from emerging around the baseboards.
• Stink Bug traps (similar to Japanese beetle traps) contain a pheromone that can last four weeks, luring the bugs from up to 50 feet away. Non-toxic and odorless, these traps may be used indoors.