MARQUETTE, MI (AP)-- Crews have begun measuring how much damage a ravaging insect has done to evergreen trees in northern Michigan.
Michigan Department of Natural Resources forest health staffers are mapping the latest outbreak of spruce budworm, which attacks balsam fir and white spruce. They also feed on black spruce, tamarack, pine and hemlock.
Large-scale epidemics happen every 30 to 50 years. Experts say they're part of the natural cycle as trees mature. Budworm caterpillars feed on new shoots, which eventually can kill older and stressed trees.
The DNR says the hardest hit places this year appear to be in the western Upper Peninsula. Also affected are trees in eastern Mackinac and Chippewa counties, as well as the southeastern part of the northern Lower Peninsula.