This Cold Winter Is Too 'Woolly' For Hemlock Pests

Mar 10, 2015

We are finally coming out of the deep freeze that we were in for pretty much all of February. Forty-three days below freezing in some parts of the state, 5-degree averages in Montpelier and Rutland. There will be some casualties of the cold weather – but that's not necessarily a bad thing.

In fact, this winter’s harsh weather is good news – at least temporarily – for those combating a pest that threatens Vermont’s hemlock trees.

The Hemlock Woolly Adelgid is a tiny insect, but a big problem that threatens hemlock trees from Georgia to Maine. The pest is currently found in Southern Vermont.

"Between 97 and 99 percent of the adelgids that were active through the early winter have been killed by this cold that we've had." - Jim Esden, Vermont Fish and Wildlife

Forester Jim Esden of Vermont Department of Forests, Parks and Recreation says the timing, duration and bitterness of this winter’s cold weather has resulted in a very high mortality rate for the insect.

“Between 97 and 99 percent of the adelgids that were active through the early winter have been killed by this cold that we’ve had,” says Esden.

Unfortunately, Esden says, any surviving insects can reproduce quickly, because adelgids are female and their eggs don’t need to be fertilized.

But Esden believes the cold will at least hamper the spread of the pest in coming months.