An Environmental Christmas Tale

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Once upon a time, in Ancient Greece, a respected philosopher named Socrates became a social outcast because he vociferously opposed the political climate.

Eventually jailed, he refused to renounce his principles and was condemned to death.

The executioners of the day forced prisoners to drink a solution made from the poisonous hemlock tree, and Socrates died after consuming this toxic cocktail.

Flash-forward to 1953, when the woolly adelgid—a small black insect covered in white fuzz—is accidently carried from Japan to Virginia.

Over the next decades, it becomes the single greatest threat to hemlock trees in eastern North America—especially in the South, where winters aren’t cold enough to stop the bugs from defoliating entire forests.

Today, Pennsylvania, New York and New England woodlands are under siege from the hemlock woolly adelgid, which has already obliterated trees in Southern Appalachia.

So, why should we care about the fate of hemlocks on this chilly December day?


Because loss of these trees drastically alters their ecosystems.

“Hemlocks have a unique ecology,” explains David Mausel, PhD, a postdoctoral entomology researcher at the University of Massachusetts, Amherst. “They’re one of the few evergreens whose loss affects stream temperatures, for example, so trout and other fish species are lost. When the hardwoods move in, many characteristic birds of the hemlock forest are gone, too. Losing the hemlock has an ecosystem-level impact.”

But Dr. Mausel, dubbed Sherlock Hemlock, may have a solution. He’s been seeding hemlock study plots with thousands of predatory Laricobius nigrinus beetles, which may help stem the adelgid invasion.

While it may take 20+ years to know with certainty whether the beetles will save the eastern forest, Dr. Mausel believes action is required now. Because it’s warmer in the South, infested trees can die in as few as 4 years. In the North, winter slows adelgid population growth, and it may take 15 years for a tree to die.


“In the South, it’s already too late,” says Joseph S. Elkinton, PhD, a UMass entomology professor. “But here, if we can get the beetles established and it turns out they’re helpful, we might be able to bring the adelgid population down to where it’s innocuous.”

He says Dr. Mausel has “by far the most promising” approach to saving the eastern hemlock.

“The sad thing is, there is no alternative right now,” Dr. Elkinton says. “There are other potential predators that can be tried in the future—some from Japan, where the woolly adelgid came from. But no one else is anywhere near being able to test a natural weapon against the adelgid, and the problem is acute for our forests right now.”

While this story may strike you as an odd Christmas tale, it carries several important messages:

  1. Mother Nature deserves our respect.
  2. When we attempt to solve a problem, the most natural way is often the best.
  3. Each of us is a steward of the Earth, and politics should never distract us from our responsibilities.

I hope you have a merry, eco-friendly, safe and organic Christmas!

Photos courtesy of the University of Massachusetts, Amherst

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