It was the mid-90s. A few enterprising stink bugs in China stowed away on a US-bound cargo ship. At first they flew under the radar, quietly taking up residence in Allentown, Pennsylvania.
But the Queen City soon became ground zero for a nationwide infestation of stink bugs. Flash-forward 20 years, and our stink bug problem is of almost biblical proportions, wreaking havoc in homes and fields across the country. Consider the Maryland scientist who vacuumed 8000 from his attic in a single day, or the mid-Atlantic apple growers who lost more than $35 million in crops in just one year.
To the stink bug’s delight, I’m sure, its natural Asian predators have remained homebound. And while the U.S. has native stink bugs, the brown marmorated stink bug—BMSB for short—has become ubiquitous. For those living in the few remaining states that have yet to spot a BMSB: they’re shield-shaped, smaller than a quarter, and with a marbled coloration (as marmorated implies). They have a loafing, prehistoric aura that ranges from comical to frightening. And once they appear, they appear in droves.
Stink bugs don’t bite, sting, or destroy the foundations of your house, but they can feel like an invading army anyway—especially in the winter when they seek refuge from the cold. Inside, they enter a hibernation-like state, where they don’t mate, lay eggs, or eat.
In theory, anyway. In reality, it seems they fly around all winter like drunken pilots. What is going on?
Eric Day, an entomologist at Virginia Tech, says stink bugs may find warm homes a little too cozy. The cold triggers their hibernation, so when it’s too warm, stink bugs stay active. They use up their energy reserves flying around, often trying to orient themselves towards light. “That’s when you find them belly-up on the window sill,” he said.
Unfortunately, exercising stink bugs to death doesn’t seem to be a reliable way to get rid of them.
A better method: fill cracks and crevices in walls and windows. But since Murphy’s Law dictates that stink bugs will find the one crack you can’t, try this: fill a foil roasting pan with water and a little dish soap, then shine a desk lamp into the pan, leaving the room otherwise dark. The bugs will be drawn to the light—and drown. Why the soap? “It breaks the surface tension,” says Day, “so bugs will sink and drown rather than float around and crawl out of the pan.”
Getting rid of stink bugs in nature is a more complicated and serious issue—especially for farmers whose crops are being destroyed. Broad-spectrum pesticides are an unhappy solution, since they kill useful insects, too.
Day says a predator or parasite is the best way to deal with any invasive species. This is called a biological control. Praying mantises and spiders may eat them for lunch, but it’s not enough to stop the spread. So scientists look to the pest’s native land for the perfect candidate.
Scientists are currently pinning their hopes on a tiny, non-stinging Asian wasp who lays her eggs inside stink bug eggs. In an ironic plot twist, U.S. scientists were studying the wasp under quarantine when one appeared in the wilds of Maryland all on its own—apparently another stowaway.
But before releasing another imported species into the wild, they’ll study it in the lab to make sure it won’t become a problem in its own right.
While there’s no news yet on whether these wasps will be the answer to our prayers, Day is confident a solution is on its way.
In the meantime, humans have swarmed the Internet to ask questions, swap stories, and express general awe. (I read an entire comments section devoted to accidental ingestion horror stories.)
One spirited online debate concerns the stink bug’s trademark smell. Stink bugs release a scent when they’re alarmed, handled, or squashed. It’s their only defense mechanism, and many experts (and people with noses) say that squashing them is an extermination method to avoid. Even vacuuming them up can make the bag reek.
But not everyone agrees. Google “Stink bugs smell like …” and suggestions pop up ranging from “skunk” to “green apple.”
The most frequent report? An “over-the-top cilantro smell,” says Day. This seemed unlikely to me, but a Maryland entomologist reports that one of the compounds in the bug’s secretion is also found in cilantro.
Weird, right? Even weirder, the smell and taste of cilantro is a controversy in its own right, with people getting heated about whether it's delicious or disgusting.
Day suspects stink bug lovers and haters may break along the same lines. This glacial perceptual rift strikes me as a mind-trip akin to the blue/gold dress.
Another niche topic among stink bug enthusiasts is their taste. While one man reported that the stink bug was the “worst bug” he’d ever eaten (how many bugs has he eaten, anyway?), another thought it tasted just as it smelled—that is, like cilantro. Granted, the second guy was eating it in a taco, purposefully made with the bugs.
Yes, stink bugs have even invaded our tacos. Our tacos! They must be stopped. Bring on the wasps.