It's killing invasive insects:
"This winter has been a godsend for the hemlock. Overnight temperatures dipped to minus 15 [Fahrenheit, or -26°C] here in Amherst [Massachusetts], and that’s cold enough to guarantee almost complete adelgid die-off," Joseph Elkington, a professor at the University of Massachusetts, Amherst, told the Worcester Telegram.
Elkington says that in some parts of North Carolina, subzero temperatures have killed 100 percent of the adelgids. In Massachusetts, around 80 percent of the population should die, according to a state official. Gypsy moths and emerald ash borers are similarly vulnerable to extreme cold; the U.S. Forest Service estimates that 80 percent of Minnesota’s emerald ash borers died in January. Other invasive insects, such as the southern pine beetle, which has been ravaging New Jersey, and the Asian stinkbug, may be dying off as well.
In fact, this nearly tops the reasons I like living in a temperate climate. Malaria? Not in Chicago, ever. Kudzu? Nope. Emerald ash borers? Die, you green vermin, die.
There's a problem, though:
The cold may also kill off predator insects that forest officials have been releasing to take out invasive insects. For instance, parasitoid wasps that are supposed to control the emerald ash borer population in Michigan and other states are even more vulnerable to the cold than their prey, whose populations might recover more quickly as a result.
Plus, we've had snow on the ground for 65 days now.
So it's not all perfect. But at least the cold has done something useful for us.