No, the polar vortex didn’t kill off all the stink bugs

No, the polar vortex didn’t kill off all the stink bugs
Severe winters will indeed kill off more stink bugs than usual, according to Virginia Tech research, but not 95 percent of them. (Source: AP Photo/Matt Rourke, File/AP)

(Gray News) – A year without stink bugs – it’s an enticing prospect. But, unfortunately, it’s not a likely one.

Despite a number of media reports this week suggesting a staggering 95 percent die-off of stink bugs thanks to the polar vortex, which set in across large parts of the country in late January, there’s not really any evidence for such an extreme culling.

Many of the reports were based on a news article posted to the National Pest Management Association site, which outlined how certain invasive insect species are affected by winter cold. According to an association representative, it was originally posted in 2014, and resurfaced last week independent of the association and without properly identifying its date.

As an opening aside, it referenced a Virginia Tech research experiment that estimated 95 percent of stink bugs would have died in the polar vortex.

The issue was that the research experiment wasn’t really so much a controlled experiment.

When original reports citing the 95 percent figure circulated five years ago, The Baltimore Sun talked to the Virginia Tech entomologist who spawned the factoid, Thomas Kuhar. He told the paper the “experiment” was just an observation that a stink bug population kept in a bucket outside his lab had mostly died off in the cold that year.

But, as the paper noted, stink bugs survive winters specifically because they don’t live outside when the cold sets in.

They find shelter in tiny cracks and nooks and crannies around your home, or even under rocks, trees and the like. According to a study published just this month, they can fit through spaces as small as 3-by-7 millimeters.

Then they hang out there until the weather warms up.

“It was an anecdote,” Kuhar told The Sun about his observation.

With the story resurfacing now, a Virginia Tech spokeswoman said in an email that Kuhar told the university that there is “no new research on this topic” and that the confusion was a mix of information from a 2016 study he conducted and misunderstandings in the 2014 media reports.

Of course, bad winters will kill off more of the population than usual. In fact, his 2016 paper found that exposed stink bugs die at temperatures in the low 20s Fahrenheit.

“Severe sub-freezing temperatures will negatively impact winter survival of these stink bugs if they were unable to find suitable shelter such as the inside of houses and sheds,” Kuhar said, according to the Virginia Tech spokeswoman.

His 2016 study classified the bug as “chill-intolerant.”

But, as he told The Sun in 2014, even extreme cold wouldn’t be a threat to wipe out whole populations.

“If you had to pick an insect that could survive a winter like this, it would be the stink bug,” he said.

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