(NEXSTAR) — Fall weather has finally settled in, bringing with it a crisp breeze that may encourage you to open the windows to enjoy.
As delightful as that autumn air may feel, your open windows may also serve as an open door to the invasive brown marmorated stink bug.
There's a fair chance you've already been acquainted with the stink bug, a native of East Asia that often begins looking for ways into your home as the leaves start to change.
These brown marmorated stink bugs have been in the U.S. for decades, spreading to nearly every state except Wyoming, South Dakota, and Alaska. In addition to being a nuisance in our homes, it has caused “severe agricultural and nuisance problems” in about a dozen states.
This time of year, the stink bugs are looking for a place to hunker down for winter, Michael Skvarla, an assistant research professor and head of the Insect Identification Laboratory at Penn State University, tells Nexstar.
If you're hoping to keep the stink bugs out, your options are slightly limited. The best way is physical exclusion, according to PJ Liesch, the director of the UW-Madison Insect Diagnostic Lab who is aptly referred to as "the Wisconsin Bug Guy."
"This simply means making your home and other structure sealed up nice and snug, because these [bugs] are sneaking in through gaps and cracks," Liesch tells Nexstar, explaining that those gaps could be anywhere: around the edges of siding, windows, doors, or soffit areas, or where the siding meets the foundation.
For those areas, Liesch recommends sealing them with whatever seems appropriate, whether it be caulk, expanding foam, backer rod, or new weather stripping.
"The trade-off is that it can be somewhat putsy work to go around the entire outside of your house and spend hours and hours sealing things up so you have that initial time and cost investment of doing that. But in the long run, that can work really well for these and other insects, and it can last a very, very long time," he explains.
Skvarla and Liech also noted that while you can apply insecticide outside your home, it isn't the most effective method. Insecticides don't work well against stink bugs, research has found, and they will also break down due to rain and sunlight. Any home methods, from essential oils to specific spices, will be even less helpful than the insecticides.
How long you'll be seeing the stink bugs this fall will depend on how well you've protected your home, Liesch says. If a big group of the bugs can march their way in, you could be finding them through winter and into spring next year.
As for those brown marmorated stink bugs sunning themselves on the side of your home, you can expect to see them until it is "consistently cold," according to Skvarla. Unlike other bugs, this invasive species isn't killed off by the first frost and may be active again on warm winter days.
On a bigger, more permanent scale, the brown marmorated stink bugs are here to stay, Liesch and Skvarla agree. Their population may decline in your area, but they will likely never go away forever.
There may be hope, though, about reducing their presence. As Skvarla explains, the brown marmorated stink bug's natural enemy, the parasitic samurai wasp, has also found its way to parts of the U.S.
These extremely small wasps — much smaller than the murder hornets that captured everyone's attention during the pandemic — are able to attack stink bug eggs. While the U.S. Department of Agriculture was researching the use of the samurai wasps as a possible weapon against the brown marmorated stink bugs, the species was found in nature.
In the areas where the wasps have been reported, including in the Northeast and along the West Coast, stink bug populations have decreased. While the USDA continues researching the wasps, they cannot be released or moved throughout the country. Skvarla says they can be moved within states where they have been detected — California, Delaware, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Utah, Virginia, West Virginia, Washington, and the District of Columbia — but not across state lines.
For now, experts agree the best you can do is to seal up your home to prevent the stink bugs from coming in, and if they do come in, you may want to avoid squishing them. The brown marmorated stink bug lives up to its name when crushed and, in rare cases, the stink fluid they create can cause irritation to some humans.
