Hemlock tree's enemy

State agencies fight to save Ky.’s Hemlocks

By Brad Hicks / Staff Writer

Those who enjoy the scenic greenery of eastern Kentucky forests and parks have an unseen enemy that is threatening to wipe out the vibrant landscape.

The Hemlock Wooly Adelgid, an insect so small its detection is extremely difficult, preys on a target millions of times larger than itself – the Eastern Hemlock trees found throughout eastern Kentucky.

But a new group is trying to stop it.

In February, state agencies, such as the Kentucky Natural Lands Trust and Kentucky State Nature Preserves Commission, along with private citizens, formed the “Save Kentucky’s Hemlocks” organization.

This organization plans to chemically treat the Adelgid before the insect gets out of hand. They also want to educate the public and private landowners on what to look for and how to combat the Adelgid. Merrill Flanary, Pine Mountain Forest Steward, said the task, unlike the miniscule tree munchers, is not small.

“It’s not going to be easy, but it is combatible,” she said. “We’re going to get out of it what we put into it. The quicker we get on this, the better it will be.”

The Hemlock Wooly Adelgid can hardly be seen by the naked eye, but it does give away its presence during the winter and spring months by adorning a white, cotton-like ball that serves as both an egg sack and protective cover. The “wooly” sacks can be seen on the underside of Hemlock branches.

“It’s too small for the naked eye,” Flanary said. “It gets its name because it puts on a wooly mass.”

In vampiric fashion, the Aldegid dig their fangs into the base of the Hemlock branches and drain the tree’s nutrients. As populations grow, the insects spread up the branch of the tree, allowing them to even more quickly drain the life force from the trees.

If the feeding goes uninterrupted, the soft, green Hemlock needles are soon reduced to brittle, brown and dry shells.

Flanary said the Adelgid can lay tens of thousands of eggs each year, with two annual generations.

Though small in stature, the Adelgid’s effect on forest habitats can be great. Besides aesthetic effects, the Aldegid destroys the habitats of many other birds and insects that rely on the Hemlock trees for housing. They also affect wildlife on the ground level. The Blackside Dace, a minnow that can be found in southeastern Kentucky which is on the federal list of threatened species, is also affected. The Hemlocks provide cover and cooler temperatures for the streams the small fish inhabit. As these trees are drained of life and die off, that cover lessens, causing water temperatures to rise and making the conditions unsuitable for the dace.

This tiny killer was first found in Kentucky in 2006. Because of its microscopic size, those studying the bug are unsure of how it may have first arrived here.

“It’s so small, there’s no telling how it got over here,” Flanary said.

What is known is that the bug is an unwanted import from the Land of the Rising Sun. It is believed the Adelgid, which is Japanese in origin, was first introduced to the western United States when it came over on nursery stock in the 1930s. Western Hemlock trees are not susceptible to the Adelgid, so it is believed the bugs moved to find more suitable food.

Eventually, the insect migrated east and was found in Richmond, Va. in 1954. Now, the Adelgid can be found all over the eastern part of the country, from New England to North Carolina. In Kentucky, it has been found in Bell, Harlan, Leslie, Letcher, Pike, Powell, Clay and Whitley counties.

“Pretty much every state in its home range has been affected,” Flanary said.

She also said Kentucky is a veritable feeding ground for the Adelgid, and there is an abundance of Easter Hemlocks in the Commonwealth. However, because the populations are so isolated, the first plan of attack — the introduction of a beetle that would feed on the Adelgid -— was shot down.

“Our populations of Adelgid are isolated and low, so it wouldn’t justify spending hundreds of thousands of dollars on the beetle,” Flanary said.

Because the Adelgid can quickly change lush, green scenery into a graveyard of brown, dead trees within as little as five years of initial infestation, steps are being taken to address the problems.

Those interested in slowing the destruction of the Adelgid are trying to keep history from repeating itself. The country’s American chestnut population was practically destroyed by a parasite introduced accidentally when nursery stock trees were imported from Asia.

“I don’t think it’s an exaggeration to compare the destruction of the Eastern Hemlock to American chestnuts,” Flanary said. “It completely changed forest dynamics throughout the United States.”

The last meeting of the Kentucky Hemlock Project was March 20 in London. To find out about future meetings, contact Alice Mandt with the Kentucky State Native Preserves Commission at 502-573-2886, or contact your local county extension agent.



Brad Hicks can be reached at bhicks@thetimestribune.com

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