Bad News for the Hemlock Woolly Adelgid

Over the past decade, the hemlock woolly adelgid, a tiny insect, has ravaged the hemlocks of Southern Appalachia, causing widespread death of the trees that once lined mountain streams throughout the region. Efforts to keep hemlocks alive include releasing insects that feed on the hemlock woolly adelgid, including the Laricobius beetle featured in a recent article on CompassLive.

Now there’s a new biocontrol insect on the scene. On May 11, U.S. Forest Service researchers released Leucopis silver flies on infested eastern hemlocks near Grandview, Tennessee.

In recent years, researchers at Oregon State University and the Forest Service Northern Research Station have been evaluating the potential of two species of silver flies (Leucopis piniperda and Leucopis argenticollis) for biological control of hemlock woolly adelgid.

The May release, conducted under a USDA-APHIS permit, marked the first eastern U.S. release of the predator silver fly. Researchers will monitor the release sites for predator fly establishment and impact on hemlock woolly adelgid.

For more information, email Bud Mayfield at amayfield02@fs.fed.us.

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