Balsam woolly adelgid was introduced into North America from Europe around 1900. It feeds on true firs, including balsam and Fraser firs. It is currently found in the northeastern U.S., the Canadian Maritimes, British Columbia and the Pacific Northwest.
The N.H. Division of Forests and Lands monitors balsam woolly adelgid and in 2015 they mapped mortality of balsam fir from balsam woolly adelgid on 3,513 acres.
Vermont Forest Health leaflet
pest alert from U.S. Forest Service
Looking for the Balsam Fir by James Frohn, Grafton County Forster