Why Are There So Many Boxelder Bugs This Season?

Originally published on April 19

MINNEAPOLIS (WCCO) -- There's a particular insect bugging people early this spring, even though it's more known to make an appearance in the late summer.

Several homeowners emailed us wondering: Why are there so many boxelder bugs this season? Will they be as prevalent as last year?

Artwork catches the eye in the window at the Everett & Charlie gallery near Lake Harriet. Yet, it's these pesky pests trying to steal the spotlight, or sunlight rather. Boxelders were crawling across the gallery's front window Tuesday afternoon.

"They like to gather on the southside of my home and sun themselves," said Janine Laird, adding that they've also surprised her inside her home. "Like when they fly by my head."

It was hard to ignore the boxelder bug bonanza late last summer. But their numbers this spring are surprising many.

Connie tweeted: "I sweep up a pile of them every day...I've lived in this house for 40 years and rarely saw a box elder inside until this year."

Marian from St. Paul emailed WCCO saying she'd never seen them in her house in the spring until now.

Should we be seeing boxelder bugs right now in our homes?

"It's normal this time of year to see boxelder bugs and stink bugs and some other critters," said Erin Buchholz, an integrated pest management specialist at the Minnesota Landscape Arboretum. "We had an abundance of box elder bugs last fall, and since we saw those high numbers it would make sense that we're seeing high numbers again this spring."

Box elders seek warmth in our homes over winter and emerge as the temperature outside rises. One problem is they can be directionally challenged.

"Sometimes they get confused and they turn around the wrong way and they actually enter your home when they've been hiding in your siding all season long," Buchholz said.

Weather-stripping cracks near windows and doors can help keep them out of homes later this fall. So too can the proper pesticide.

The question is: Will they even be as much of a problem this year?

"Unless there's something this summer that dampens their reproduction," Laird said.

The drought last summer allowed boxelders to flourish.

"Rainy weather and storms will tend to help us out by suppressing insect populations," Buchholz said.

With a rainy and cold spring so far, it's possible the insect population could be impacted. Buchholz said rarely is there a heavy infestation of boxelders in consecutive years.

The weather in the months ahead should play a key role.