As the days get shorter and the air cools, many of us feel like burrowing in our warm, cozy homes to wait out the cold. We’re not the only ones. The kudzu bug is also looking for a place to spend the winter, and according to calls to The N&O, many are taking up residence in and on Triangle homes.
“The bugs look for a place to pass the winter,” says entomologist Mike Waldvogel, extension associate professor at N.C. State University. The kudzu bug was accidentally imported to the U.S. from China, established itself in Georgia and now has made its way to North Carolina. The bug is especially prevalent near – you guessed it – kudzu, and also soybeans. It’s found in about 90 of the state’s 100 counties.
Waldvogel answered a few questions this week about the stinky bug. This is an edited transcript.
Q. Are the bugs really bad this year?
Since this is a new pest, there’s no history behind it to compare to other years. The problem is that “really bad” is in the eye of the beholder when it comes to what is essentially a nuisance pest. Some houses/areas see more activity. A lot depends on proximity to host plants – kudzu, wisteria, soybeans, etc.
Q. Why are people seeing them now?
They’ve been feeding and “out of sight” to the public. As plants’ leaves turn yellow and drop, temperatures cool, and day length declines, the bugs look for a place to pass the winter. That’s when they move from kudzu and soybean fields and into mulch, the bark crevices of trees and logs, under stones and such. If there are houses nearby, they congregate on homes, cars, etc.
Q. Are they harmful?
To your psyche. Just by the sheer numbers that cover homes and land on people, (they)create a significant nuisance. They’re a type of stink bug, so when they’re disturbed, they release an odor. They can exude a liquid that can irritate the skin. It’s a chemical designed to “discourage” predators.
Q. What attracts them?
At this time of year, they are often drawn to white/light-colored surfaces (but that doesn’t mean they ignore darker-colored buildings). In the spring, they move in search of host plants and quite possibly produce a chemical that attracts other kudzu bugs. So, they can cover a lot of plants that they may not even feed on, but then they move to hosts that will support their offspring.
Q. What can we do about infestations?
Not a lot, actually. Chemical control is still only partially effective and relies primarily on targeting the insects that are currently gathering on surfaces. We don’t recommend “preventive” sprays because a) you really don’t know whether the bugs will gather on your house and where exactly they’ll be on your house (more likely they’ll be spread out over broad areas), and b) trying to treat the entire exterior of your house isn’t economically, logistically or environmentally prudent. Also, the sprays simply won’t be durable enough to last the weeks during which these insects will be actively seeking overwintering sites.
You can’t predict where the insects will show up indoors and so it doesn’t help to spray baseboards or around window interiors or set off insecticidal foggers. Stick with using a vacuum cleaner, but make sure to discard the bag (or clean the vacuum if it’s a bagless unit) because the bugs do emit an odor.