‘Providing a free home inspection’: Annual arrival of box elder and stink bugs is a good reason to button up
Just like colors changing or frost on the pumpkin, a sure sign of fall is the arrival of a pair of pesky invaders.
Neither stink bugs nor box elder bugs pose a threat or carry disease. They’re not feeding or reproducing and don’t bite, experts say. But they can be a nuisance.
“These are what we refer to as household invaders,” said Sharon Yiesla, plant knowledge specialist with Morton Arboretum’s Plant Clinic. “They’re rather flat and they can get in around cracks near doors or windows.”
Here they are popping out from where you least expect, hiking a ride on your dog or basking on a wall outside before disappearing under the siding when the area turns from sun to shade.
This time of year, you also can add the Asian lady beetle to the list of little visitors looking for a warm place to spend the winter. Simple as that.
“They are harmless to humans but can certainly be an annoyance if they are able to get inside,” said Gary Glowacki, manager of conservation ecology for the Lake County Forest Preserve District.
Like other agencies, he said, the district gets calls this time of year regarding stink and box elder bugs. He takes a sensible view.
“However, I like to think of them as providing a free home inspection service where they help residents find all the cracks and gaps that not only allow critters entry but also let all the cold air in,” he added.
Bronze-colored, prehistoric looking, shield-shaped marmorated stink bugs are native to China and debuted in the U.S. in the late 1990s, according to the Illinois Department of Agriculture.
The “stink” is a defense mechanism, explained Scott Schirmer, nursery and northern field office section manager with the agency.
“So don’t smash them and avoid disturbing them too much,” he said.
A nuisance? Perhaps. But they don’t kill indoor plants or harm anything else.
In summer, stink bugs live in and eat fruits and vegetables, according to University of Illinois Extension.
Sprays are not effective in killing them and shouldn't be used inside, the extension advises. Suck them up with a vacuum, drop them in soapy water, or hand pick or sweep them outside is the general advice.
Stink bugs are most concentrated in the mid-Atlantic region and can cause major damage to fruit, vegetable and field crops but are not a significant agricultural pest elsewhere, according to the U.S. Environmental Protection Agency.
Box elders feed on box elder, maple and ash trees but not to the point of causing significant damage, Glowacki said.
They also are mainly a nuisance, although their feces can stain light-colored surfaces and smashing them also can release an unpleasant odor, according to the National Pesticide Information Center.
Once inside, either pest will hunker down and hide most of the winter, Yiesla noted.
“A properly sealed and energy-efficient house should not have any problems with either species,” Glowacki added.