Hemlock S.O.S.

[cleeng_content id="469066735" description="Read it now!" price="0.49" t="article"]Program to save ailing trees comes to Panhandle

CHARLES TOWN – Experts from the state Department of Agriculture hope to begin working with local landowners as a program aimed at saving hemlocks from a devastating Asian pest expands into the Eastern Panhandle.

West Virginia’s Hemlock Woolly Adelgid Cooperative Pilot Project is the only one of its type in the nation, according to Buddy Davidson, a spokesman for Agriculture Commissioner Walt Helmick.

“The program is so new, we don’t know what the overall effect might be,” Davidson said. “But we’re trying to save as many of the trees as we can.”

The state’s effort to protect hemlocks from the woolly adelgid is expanding to Jefferson and Berkeley counties.

The state’s effort to protect hemlocks from the woolly adelgid is expanding to Jefferson and Berkeley counties.

Between now and Sept. 30, the agriculture department will accept applications from private landowners in Jefferson, Berkeley and 44 other counties across the state where the hemlock woolly adelgid, an aphid-like insect native to Japan and China, has been found.

Sometimes described as the redwoods of the Appalachians, majestic hemlock trees can grow 75 feet tall or higher and live hundreds of years. They’re considered a “keystone species,” a type of tree that plays a crucial role in how a healthy ecosystem functions.

The bug itself is barely visible to the naked eye, but thanks to a white, waxy wool-like substance that covers the adelgid, infected trees bare telltale cottony tufts at the base of their needles.

By feeding on the hemlock’s sap, the woolly adelgid keeps the tree from sending nutrients to its foliage. Its needles change from a healthy deep green to a sick, grayish green and then fall off – and without needles, the tree starves to death, usually within three to five years of the bug’s arrival.

In Asia, the pest is kept in check by natural predators, but in the United States, the woolly adelgid has been spreading unabated since the early 1950s.

Winds carry the hemlock woolly adelgids into new areas, and migratory birds, deer and other animals, even humans, spread the bug, too.

Because a single woolly adelgid can lay up to 300 eggs at a time and can reproduce asexually twice a year, many fear the beloved hemlocks will be wiped out by the menance.

In West Virginia, a growing number of landowners are eager to rescue their hemlocks, Davidson said. “We’re hearing more interest in our pilot program as word gets out that there’s something landowners can do to keep their trees healthy.”

Davidson said hemlocks in West Virginia’s state parks have been treated with the insecticide, but the rescue program for hemlocks on private land began just in 2011. Initially, that aid was available only in Southern West Virginia, in the area surrounding the New and Gauley rivers.

The program does require landowners to chip in on the cost of the state’s intervention, with the price tag varying according to how many trees are on the property, the size of the trees and whether they’re located near a stream or river.

“Unfortunately, fighting the hemlock woolly adelgid is on the labor-intensive side,” Davidson said. “With the gypsy moth, which lives in the canopies of trees, we can send up a plane and take care of a large swath of land at a time, but the hemlock woolly adelgid plants itself at the base of the tree’s just-formed needles and requires a tree-by-tree approach.”

But chemicals aren’t the only way to fight the hemlock woolly adelgid.

Scott Salom, who leads the hemlock woolly adelgid project at Virginia Tech, has spent nearly two decades pursuing a natural alternative to wiping out the bug plaguing hemlocks: breeding and releasing thousands of beetles that are the pest’s natural predators in Asia.

“The chemical approach is very effective, but it’s also time-consuming and therefore expensive – and not particularly practical for treating forests full of hemlock trees,” said Salom, a professor of entomology at the university’s College of Agriculture and Life Sciences. “The natural biological approach we’ve undertaken is a good, large-scale, long-term way to address what’s happening to hemlocks across the Northeast.”

Salom’s work has involved trips to Osaka, Japan, where DNA studies show the hemlock woolly adelgid originated. It seems this beetle has a sole food source – the hemlock woolly adelgid – and thus will prove a powerful natural enemy.

The latest variety of Asian beetle has a life cycle that closely matches the hemlock woolly adelgid, Salom said. “That makes it that much more effective as a predator,” he said.

WATCH: The state Department of Agriculture has put together a video on the pilot program that can be seen at youtube.com/watch?v=PIZ9kL9Lq6Q

The beetle lays an egg inside the hemlock woolly adelgid’s egg case, which typically holds hundreds of future offspring. When the beetle hatches, it chows down on hundreds of the young adelgids. When that food source is depleted, the beetle then begins to feed on the adults, Salom said.

The bugs and larvae Salom and his colleagues brought back from Japan now are being bred and introduced across Virginia, at Carnifax Ferry in Nicholas County and other spots in West Virginia, and elsewhere.

So far, he said in an interview, the work is going gangbusters. “They’re establishing so well where the hemlock woolly adelgid is present, we’ve been able to harvest the beetles there for introduction elsewhere instead of having to breed all the beetles in the lab.”

Still, the problem has a decades-long head start on Salom’s bugs. “We have a lot more requests for beetles than we have beetles to accommodate,” he said. “We’d like to get to a point where we can release 5,000 beetles at a time instead of 1,000 and release them at more sites.”

The hemlock woolly adelgid has long been present in the western United States, but there – as in Asia – the trees evolved alongside the insect and managed to co-exist, Salom said.

“In the East, it’s akin to when Europeans arrived and exposed the Native Americans to smallpox,” he said. “Hemlocks didn’t have a chance to adapt. Without defenses, they’re very susceptible.”

Salom believes both the West Virginia Department of Agriculture project and his work at Virginia Tech have their place – with the chemical treatments halting the spread of the pest on private property and the beetles killing the bug on larger tracts of public land.

“It may be that they’re quite compatible together,” he said. “This is a challenging insect to try and control. The more ways we work at combating it, the better.”

Tree trouble

 

How the epidemic started: Introduced to the United States from Japan, the hemlock woolly adelgid lacks any native predators in the eastern part of the country. With no defense against the pest, hemlocks have rapidly fallen victim to the adelgid since it was identified in Richmond, Va., in 1951.

How it’s spread: The hemlock woolly adelgid has been found on hemlocks in 46 of West Virginia’s 55 counties, including throughout the Eastern Panhandle.

Infestations have been found in more than half of the geographic range of the eastern hemlock, which extends from New Brunswick south to Alabama and as far west as Minnesota. Without intervention, infected trees typically die within four years.

Why hemlocks matter: Without hemlocks, the unique forest ecosystem declines. Not popular as a timber product, the long-lived evergreens thrive in shady conditions. Hemlocks’ thick foliage helps keep the forest floor moist and cool.

Fish need hemlocks. The trees help cool the mountain streams that heat-sensitive trout and other native fish along with crawfish, salamanders and insects call home.

Birds love hemlocks, too. The trees’ thick boughs provide shelter and places to nest to untold numbers of birds. One survey concluded that 96 percent of all wood thrush’s nests are made in hemlocks and some warblers will nest only in hemlocks.

Humans also are hemlock fans. Hemlocks have long been the draw to West Virginia’s 132-acre Cathedral State Park, located along U.S. 50 in Preston County. The state’s largest remaining tract of virgin timber, the park was deemed a National Natural Landmark in 1965. The park is best known for its Centennial Hemlock, estimated to be 500 years old. The huge hemlock fell victim to lightning strikes in 2004, but visitors can still see its massive stump.

Creating a defense: The state’s Hemlock Woolly Adelgid Cooperative Pilot Project offers three years of protection against the hemlock killer, but does require landowners to pay for each tree’s treatment.

The total fee varies depending on the tree’s diameter at breast height and whether it’s near open water.

Learn more: Get more information from the WVDA’s Forest Entomologist Tim Tomon (ttomon@wvda.us or 304-637-0290). Find the application and a program brochure at wvagriculture.org.

 

 

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