A University of Montana professor of forest entomology and pathology says this prolonged and uncomfortable deep freeze probably won't be enough to kill Mountain Pine Beetles.
The rice grain-sized beetles are a native species that mass-attack trees. U-M College of Forestry and Conservation's Dr. Diana Six says hundreds or thousands of the insects can swarm a single tree, leaving it defenseless and essentially doomed.
Mountain Pine Beetle populations surged in recent years and have had devastating impacts, leaving a red swath of dead and dying forests from Canada almost to Mexico.
" It's kind of running its course in a lot of places, but they've already killed a lot of trees. In Montana, along some areas, they're still expanding. So if you go to the Big Hole or the Bitterroot - some of those areas - they're still on the increase in those spots."
The Pine Beetle population has thrived, in part, during several consecutive years of relatively warm winters. It takes very cold temperatures to kill the bugs. It's obviously quite cold right now and expected to get even colder, but Six says it's just not enough.
"If these kind of temperatures had have happened in October they'd have been dead because they wouldn't have had time to prepare. But right now they've produced antifreeze and they can take temperatures to -30. They actually produce sort of a Glycerol - something that keeps the liquids in their bodies from freezing, and so when they get ready for winter they produce this compound and it takes a very cold temperature to actually freeze them."
Six says this cold snap may kill some of the cleverly-engineered insects in various pockets, but she's not expecting a widespread impact.