Michigan Stink Bugs: To Squish or Not to Squish?

It was a historical year. The search engine we now know as Google was founded, the FDA approved Viagra, the name Lewinski entered our vocabulary, Apple unveiled the iMac, ANNNNDDDDD stinkbugs made their first appearance in Michigan.

The Invasive Species Arrives in Michigan

The brown marmorated stinkbug, as it's known in scientific circles, arrived in the Mitten State in 2010, and we have been collectively dodging these seemingly clumsy fliers ever since. They hitched a ride from Southeast Asia, more than likely on a piece of cargo that arrived in the United States sometime in the mid-'90s, perhaps in Pennsylvania. 

These lovely little pests are most drawn to homes with ornamental plants, gardens, berry bushes, and fruit trees. They also enjoy hanging out on the side of homes, where there is plenty of sun in the spring and summer.

The Stink Bugs' Impact on Michigan Agriculture

Their most significant impact in Michigan has been on crops. Stink bugs aren't picky eaters either. They'll eat vegetables, fruit, legumes, nuts, cotton, and houseplants. The University of California's Integrated Pest Management program detailed how this invasive species cause crop damage, just by eating it with their straw-like mouths:

Stink bugs damage the crop directly by feeding on fruit. Early season feeding results in dimples or irregularly depressed areas on mature fruit. If the feeding occurs after maturity there is little external evidence other than excrement, which appears as small, brown, tear-shaped drops.

Mid-Atlantic US farmers suffered catastrophic losses in 2010 thanks to the brown marmorated stink bugs' impact on peach and other fruit crops.

If You Squish a Stink Bug, Does It Attract More? Experts Disagree

As a defensive tactic, stink bugs secrete a pungent odor when threatened, especially when squished. Does this attract more stink bugs like some insect Hydra? Opinions vary:

The experts at Rutgers University frequently ask, 'Will killing the brown marmorated stink bug attract more?' Here's their answer:

No. While this is true for some types of insects it does not occur with the brown marmorated stink bug.

Would the fine people at Rutgers lie? Because BobVila.com disagrees:

If you do anything to bother the shield-shaped, dime-size stink bug, you may suddenly find yourself subject to its foul odor, which actually attracts even more stink bugs!

One has to respect a fine institution like Rutgers, but Bob Vila...he had a beard and a plaid shirt. Who do you believe?

What is That Smell?

When it comes to smell, think of stinkbugs as the skunk of bugs: if you upset one, it might spray you (some species of stink bugs can spray chemicals several inches; thanks for that nightmare fuel, Orkin), and if you kill one, it will stink up an entire home.

Get our free mobile app

It turns out that the smell has many of the same chemical elements present in cilantro but is nowhere near as appetizing. If potent enough, it can linger for hours, so it's best not to squish the little pests. It's better to vacuum them up or flush them because the same chemicals that provide that odor also stain floors, carpets, and other surfaces.

When Can You Expect Them To Arrive?

Mosquitos and stink bugs share similar seasons in Michigan, mainly between March and September. In Spring they emerge and start to feed. They need their strength because breeding season is May through August. Brown marmorated stink bugs lay a mass of about 20-30 eggs, which are usually red in color. Good news is they lay there eggs outdoors, usually under a leaf.

Once they hatch, they undergo five molts before reaching full-grown adulthood. Rutgers University says they spend a total of 6 to 8 months on the planet, most of it spent trying to find the warm places they are attracted to. This explains why you see so many in and around light fixtures and other electronics.

• Related:

Once Fall arrives, these pests scramble to find a warm spot to spend any Winter months they may have in their short lives. This explains why the change of season brings stink bugs back into our homes. They are crafty too! They are ridiculously flat and can slip into even the tiniest of crevices. Once a stink bug finds a nice place to hunker down, they are nice enough to release that wonderful scent so that its family and friends all come to cuddle together. This is when they go into diapause, a type of hibernation. Basically, they take a long nap and start the cycle again in the Spring.

How Do I Prevent Them From Coming In?

Seal it up tight! Every nook and cranny. These smelly interlopers can suck it in, flatten out and squeeze through even the tiniest of holes.

The United States Environmental Protection Agency (EPA), who considers the brown marmorated stink bug an invasive pest, recommends the following:

• Caulk windows inside and out.

• Weather strip entry doors and/or install door sweeps if daylight is visible around the perimeter of the door.

• Rake away all debris and edible vegetation from your home’s foundation to keep from attracting pests.

• Inspect for and seal foundation cracks to block a potential point of entry.

• Secure crawlspace entries.

• When insulating exposed plumbing pipes around the foundation or the crawlspace of your home, caulk small gaps and fill larger ones with steel wool.

• If your home has a fireplace, cap or screen the top of the chimney to keep out pests.

• Contact a pest control professional to treat surrounding vegetation near your home’s foundation, which can harbor large populations of stink bugs, with products registered for residential outdoor uses. For more information, see Choosing a Pest Control Company.

Are Stink Bugs Here to Stay?

Experts may not agree on whether or not squishing one will attract more, but most agree they aren't going anywhere anytime soon. In fact the brown marmorated stink bug has even begun to colonize the United Kingdom.