MAINE MONITOR • November 21, 2025
The frontline of Maine’s battle against the invasive hemlock woolly adelgid is concentrated in the Midcoast, where the tiny insect is wreaking havoc on its namesake evergreens. After arriving in Kittery more than two decades ago, the adelgid has traveled up Maine’s coast largely unrestricted and bypassed a state quarantine on moving hemlock saplings designed to prevent the adelgid’s spread. In recent years, a coalition of Midcoast land trusts, private landowners and Maine Forest Service officials have ramped up their efforts to control the hemlock woolly adelgid by recruiting the help of a familiar foe: two species of beetle that prey on the adelgid in Asia and the U.S. Pacific Northwest. It’s a counteroffensive that forest managers hope will knock back the adelgid to both relieve the recently infested hemlocks in the Midcoast and thwart the insect’s inland expansion.