Suppression of the Hemlock Woolly Adelgid

A branch of hemlock covered with hemlock woolly adelgid

The Hemlock Woolly Adelgid (Adelges tsugae) (HWA) is a catastrophic introduced pest of hemlock trees in the eastern United States. Without long-term control of the HWA there may be devastating impacts to southern Appalachian ecosystems as eastern and Carolina hemlocks are lost throughout their native range.

HWA began attacking hemlocks along the east coast in the 1950's and it currently infests about one-half of the area where hemlocks grow in the eastern U.S. It was first detected on the Nantahala and Pisgah National Forests in 1999.

In 2005 the National Forests in North Carolina completed an environmental assessment (EA) that allows for the treatment of HWA through the use of predatory beetles as well as the pesticide imidacloprid to treat individual trees.

In August of 2010, a revised environmental assessment for HWA management was completed that expands the number of areas that can be treated and allows for additional types of treatments, including the use of Safari (dinotefuran) and the use of a native fungus that attacks the adelgids. Link to the 2010 EA.

Follow the link below for more information regarding current management of the HWA.