Yale Environment 360: As a frigid winter takes a toll on the U.S. and Canada, invasive insect populations are also taking a hit. The U.S. Forest Service estimates that up to 80 percent of emerald ash borers, which have been decimating ash tree populations, were killed by long stretches of bitter cold in the the upper Midwest this year.
Several other insect pests, many of which have migrated northward because of milder winters in recent years, also are faring poorly this winter, including corn earworms and gypsy moths....