Tree Bug Threatens State's Hemlocks

The hemlock forests of Massachusetts are under invasion. The culprit? An insect called hemlock woolly adelgid. And this winter is make-or-break time for the scientists trying to save the trees from this infestation.

WBUR's Meghna Chakrabarti recently visited Petersham in the central part of the state to find out more about the insect invaders.