Cold weather may help quash invasive species Asian stink bug

Scientists think the unusually cold weather this winter may be killing off some of the stink bug population.
CBS Baltimore

BALTIMORE -- The invasion of stink bugs from Asia may have finally met its match: the polar vortex.

CBS Baltimore's Alex DeMetrick reports freezing temperatures this winter are stopping at least some of the bugs cold.

The polar vortex that reduced Maryland to a snow globe this winter may have put a big chill on Asian stink bugs.

"Boy, I sure hope so," said Mike Rapp, a University of Maryland entomologist.

Rapp is encouraged by the research of a colleague in Virginia who left a colony of the bugs outside.

"He left it out during the polar vortex, and he saw a kill rate of something like 95 percent," Rapp said.

That's welcome news. Ever since its arrival from China a decade ago, the non-native stink bug has been chewing its way through mid-Atlantic crops.

By 2011, researchers in the field were trapping growing numbers in Maryland, and they were worried.

"This is a very significant pest that's going to have some real ramifications if we can't get it under control," said Bryan Butler of the University of Maryland Extension Service.

Some control did come from heavy rains and a growing taste by native predators for stink bugs.

Now subfreezing temperatures have helped.

"I think we could be cautiously optimistic that some stink bugs in unprotected locations may have really taken it on the chin," Rapp said.

But stink bugs have survived millions of winters in China, and they'll likely pull through this one in Maryland, especially all the ones that have moved indoors with us.

"Our homes, our tool sheds, heated buildings provide an excellent overwintering refuge," Rapp said.

Scientists see signs the extremely cold weather might have overcome a major stink bug defense.

The insect is capable of changing its blood chemistry into something resembling anti-freeze.