How to make sure that lady beetles, and stink bugs too, never spend winter in your home again

If you spent this past winter finding multicolored Asian lady beetles on your lampshades, brown marmorated stink bugs on your toaster, there’s bad news and good news.

The bad news, CFAES experts say, is that Ohio’s colder than normal winter probably didn’t faze them. When the winds blew, snow flew and temperatures fell below zero, they were mostly snug in your attic or walls, sheltered from the storm. It’s why they sneaked in to begin with.

The good news is, with warm weather arriving, they’ll be leaving your house to return outdoors, and you can take steps to keep them from getting back in.

“Summer is a good time to bug-proof your home,” said Joe Boggs, entomologist and educator with CFAES’s Ohio State University Extension outreach arm.

What you can do

For starters, Boggs said, “I always tell people to go up in their attic with the lights off, so they can look around and see if any light is coming through (from the outside).”

Seeing light coming in where it shouldn’t means there’s a gap, an entry point into your home. Come fall, stink bugs and lady beetles could use that gap to get in. So could western conifer seed bugs and boxelder bugs, among others.

Common places for gaps are window frames, doorjambs, soffits and unscreened attic vents.

Soffits themselves may have small, bug-proof vent holes in them that let in light, and that’s OK, Boggs said, but if you see light streaming in where the soffits meet the wall, “that’s a problem.”

Attic vents let light through, too, but need to be screened against bugs.

“I also tell people to consider walking around the outside of their home and taking a look,” Boggs said. “Even on a 10-year-old home, the caulking can start pulling away from the windows and doors.”

The solution, he said, is to get out your caulk gun and fill in the gaps. It’s less than fun. But it does the trick.

“Who doesn’t love caulking?” he asked with a laugh.

What’s their story?

In Ohio and much of the United States, brown marmorated stink bugs and multicolored Asian lady beetles are common fall home invaders. They seek safe, secure places for spending the winter that are neither too cold nor too hot — an unheated attic, for instance.

There, they chillax, conserving stored fat, in groups of dozens or hundreds. And sometimes, yes, random ones may stumble into your living room.

Neither species is native to Ohio or North America; both are invasive species from Asia.

Neither is venomous.

But both can emit a stink, can stain your carpet or wall if crushed, and often are a nuisance with their pop-in visits.

Outside in summer, brown marmorated stink bugs are crop pests, while multicolored Asian lady beetles eat crop pests, specifically aphids.

‘Marmie’ strong

CFAES scientist Andy Michel says his hunch is that brown marmorated stinky bugs are “really hardy” and “can survive pretty well in cold temperatures.”

Michel, an entomologist, studies the stinkers because of the harm they can do to crops such as soybeans. He said a worst case for “marmies” would be a prolonged warm spell in spring, causing them to go outside, followed by a long cold snap below freezing.

“That would tend to knock back the population a bit, killing the ones that were early emergers and weren’t able to go back into hiding,” he said.

But don’t count on it. If they bugged you last winter, he said, you might want to take Boggs’ advice.

“If you saw one marmie in your living room,” Michel said, “you likely had more in your attic.”

Meet the beetles

Multicolored Asian lady beetles, too, are apparently winter-tough.

While “we don’t understand everything about them,” and their populations have fallen since the explosions of the 1990s, “the outside temperature doesn’t seem important in terms of their overall survival,” Boggs said.

When it comes to cold weather, he said, “we know they can dodge the bullet. They’re even a problem in Minnesota.”

Details

Learn more at go.osu.edu/FallBugs and go.osu.edu/MALB.

Photos: 1, multicolored Asian lady beetle by Kulac (self-published work by Kulac), CC BY-SA 2.5, via Wikimedia Commons; 2, multicolored Asian lady beetles by Pbech (own work), CCO, via Wikimedia Commons; 3, brown marmorated stink bug by Lildobe (own work), CC BY-SA 3.0, via Wikimedia Commons.

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