So you have woolly adelgid, now what?

The Penn State Extension office in Pittsburgh has been fielding daily phone calls from residents who discovered woolly adelgid on their native Eastern hemlocks.

“The good news is that hemlock woolly adelgid can be managed fairly easily in the residential landscape,” said Brian Wolyniak, Penn State Extension educator in Pittsburgh.

First, homeowners have to identify the woolly adelgid, which this time of year looks like tiny tufts of cotton running along the underside of hemlock branches.

Hemlocks can also be plagued by elongate hemlock scale, which appears as light-colored spots on the needles. Both are treated differently, Wolyniak said. If in doubt, contact your county Penn State Extension office or a tree care company.

If the tree is small and homeowners can access the tops, they can spray with horticultural oils or soaps. If the tree is larger, a consumer insecticide product with the ingredient imidacloprid can be applied to the soil, Wolyniak said.

If there is a stand of hemlocks or large hemlocks, residents might want to consider a tree care company with a licensed pesticide applicator to treat them, he said.

But the fight won’t be over: Hemlocks that are treated for the adelgid will have to be treated again in the future.

Wolyniak recommends that homeowners know their tree species and what healthy specimens should look like. They should check their trees a few times a year for signs of insects, disease, and changes in appearance or growth.

To learn more about the woolly adelgid visit the following websites:

Western Pennsylvania Conservancy; Penn State Extension, and the state Department of Conservation and Natural Resources.