Woolly or not, hemlock woolly adelgid could fall victim to this winter’s cold snaps

The hemlock woolly adelgid is an aphid-like insect that attacks eastern and Carolina hemlocks — and can even kill trees in 3-5 years. Adelgids are tiny, but because they live crowded together, their fuzzy white wax coverings make trees look like they’ve been flocked for Christmas.

hemlock woolly adelgid
Hemlock Woolly Adelgid. Photo by Fred Likel.

Adelgids have moved into New York these last few years. But this year, the weather could be fighting back. Researchers in Vermont found that only 14% survived temperatures of 5°F in March. And Dr. Joe Elkinton at the University of Massachusetts reports 81-98% mortality in some parts of Massachusetts this year. So maybe there’s a silver lining to those cold nights we’ve been having.

How can you check adelgids to see if they’re dead? You’ll need a handlens or dissecting microscope and a darning or dissecting needle.  Carefully scrape off the wax and gently poke the insect.  If it wiggles, it’s still alive. Squash it.

For more information, see UMassAmherst’s fact sheet on the hemlock woolly adelgid.

Author: Elizabeth Lamb, Ornamentals IPM Coordinator, NYS IPM