By Melissa Hale-Spencer
RENSSELAERVILLE — Can a Pacific Northwest silverfly save eastern hemlocks in New York State? The Huyck Preserve in Rensselaerville is leading the way in finding out.
It’s called biological control, and it means putting a natural predator near its prey as a way of managing a pest — in the way that lady bugs killing aphids, or deer mice eat gypsy moths.
The Edmund Niles Huyck Preserve, an accredited land trust with over 2,000 acres and a biological research station, is working with the New York Hemlock Initiative at Cornell University to implement biological control of the hemlock woolly adelgid, a destructive pest of eastern hemlock trees from Asia that was introduced in Virginia in the early 1900s. Since that time, adelgid has killed millions of hemlocks from northern Georgia to Nova Scotia.
The Huyck Preserve is a partner in the Capital Region Partnership for Regional Invasive Species Management, a not-for-profit quasi-governmental agency hosted by the Cornell Cooperative Extension of Saratoga County and funded through the state’s Department of Environmental Conservation via the Environmental Protection Fund.
In 2018, the Huyck Preserve began work on its first invasive-species management and monitoring plan, according to a release from the preserve, and Capital Region PRISM (Partnership for Regional Invasive Species Management) became a significant resource for protecting the lands and waters of the preserve from the harmful effects of invasive species, including forest pests like hemlock woolly adelgid.
The Huyck Preserve undertook its first chemical treatment of woolly adelgid in 2020. But the pest has continued to spread across the nearly 350 acres of hemlocks at the Huyck Preserve. This spring, the New York State Hemlock Initiative released two species of silverflies, Leucopis argenticollis and Leucopis piniperda. These tiny flies are native to the Pacific Northwest of the United States and are specialist predators of the woolly adelgid.
In other words, they feed only on the adelgid and are at very low risk of causing ecological problems. The silverflies feed on adelgid eggs as larvae and are some of their most numerous predators on the western hemlocks of the Pacific Northwest.
This year’s release is part of a long-term study coordinated by the three organizations, and future monitoring will determine the success of establishment of silverfly and control of the adelgid. Only time will tell if the release of a small number of silverflies (compared to the vast infestation of the hemlock wooly adelgid at the preserve) is successful.
By Terry Belke
Of the almost 750 million acres of forest in the U.S., only about 3.5 million acres (or 6-percent), are considered old growth.
COOKSBURG PA — Old growth forests in North America are very rare. It’s estimated that of the almost 750 million acres of forest in the U.S., only about 3.5 million acres are considered old growth forests, and scientists have been debating for years on how to define them.
Cook Forest Environmental Education Specialist Dale Luthringer explains, “I think the best definition that I’ve seen so far is you’re trying to get a certain number of trees in the forest that pre-date the lumber history for that area.”
Cook Forest in Northwest P.A. was founded in 1927, and Luthringer says it’s considered one of the finest stands of old growth White Pine and Hemlock in the United States.
“By far, the ancient White Pine and the Hemlock is really what sets Cook Forest apart,” he says. “In terms of tall White Pine, we’ve got three White Pine that are in the hundred and seventy foot class. Our tallest Hemlock is just shy of a hundred and fifty feet, it’s about a hundred and forty eight feet tall.”
But this forest is not special only for the immense height of it’s trees. These towering sentries are truly ancient.
“Our oldest Hemlocks and Pines are around three hundred and fifty years old,” says Luthringer. “We have White Oak and Chestnut Oak that are approaching that, that we’ve got actual ring data, three thirty plus. The oldest known tree in the woods is actually a Cucumber Tree […] it’s on the ground now, but it’s the oldest known Cucumber Tree to science. That tree was about four hundred and forty years old.”
When the park was founded it was an effort to protect this unique environment from the ravages of the timber industry. Now almost a century later, park management must defend the Hemlocks from a new destructive force.
The invasive insect Hemlock Wooly Adelgid was discovered in Cook Forest in 2013. The tiny insect can kill trees within four to 10 years of infestation, and is ravaging forests across North America. Fortunately for the Cook Forest Hemlocks, the park was prepared for the invaders, and have been successful in protecting the cherished trees.
Source: Beetles making difference in woolly adelgid fight at Nay Aug Park – The Times-Tribune, 2017-04-15
By David Singleton
A beetle is winning the battle against the hemlock woolly adelgid at Nay Aug Gorge.
Almost 20 years after the woolly adelgid arrived at Nay Aug Park and started threatening the hemlocks in and around the gorge, officials believe they’ve finally gained the upper hand against the invasive, tree-killing pest, thanks in large part to a predatory beetle called S. tsugae.
“I think we caught it in time, and we have turned the corner. There is no doubt about it,” city forester Tony Santoli said. “I have seen great improvement.”
Since it started working with Santoli in 2011, Tree-Savers, a private company with offices in Waymart that specializes in saving endangered hemlocks, has released about 10,000 S. tsugae beetles at Nay Aug as part of an effort to eradicate the woolly adelgid and restore the park’s weakened hemlocks to health.
Like the woolly adelgid, the beetle — its full scientific name is Sasajiscymnus tsugae — is native to Japan. It is the woolly adelgid’s natural enemy, feeding on the tiny insect’s eggs.
A beetle is winning the battle against the hemlock woolly adelgid at Nay Aug Gorge.
An insect infestation that is killing hemlock trees in New England forests is having a significant impact on the water resources of forested ecosystems that provide essential water supplies to one of the nation’s most populous regions, according to research by Indiana University geographers and colleagues at three universities in Massachusetts.
The study is the first to show an increase in water yield—the amount of water reaching streams and rivers—resulting from forest damage caused by an insect pest called the hemlock woolly adelgid. Insect-damaged trees use less rainfall and allow more water to reach the ground and run off into waterways. With less foliage, the trees return less moisture to the atmosphere via transpiration and evaporation.
“We observed a 15 percent increase in annual water yield,” said Taehee Hwang, an assistant professor in the Department of Geography in the IU Bloomington College of Arts and Sciences. “But there are a lot of issues involved with this subject. Water quality may suffer as rainfall runs off more quickly from forested areas and carries higher concentrations of nutrients. The long-term picture may change as hemlocks are replaced with broad-leaved trees that have a different impact on water resources.”
By Rowena Lindsay
Hemlock woolly adelgids aren’t native to North America, but droves of them have settled into American forests where they threaten entire ecosystems.
A tiny bug, no bigger than a grain of pepper, is wreaking big-time havoc in US forests, and forest managers are scrambling to keep up.
Hemlock woolly adelgids aren’t native to North America, but droves of them have taken up residence in hemlock forests, from New England to the West Coast, thanks to increased trade and travel. Nestled under the needles of hemlock trees, the invasive insects cut off nutrients to the tree and can eventually take down trees that have stood for 300 years.
If left unchecked, the hemlock woolly adelgid and other pests are projected to put 63 percent of the nation’s forests at risk by 2027, according to a study published this year in the journal Ecological Applications. The tiny invaders could put several species of hemlock at risk for extinction, threatening the biodiversity and stability of ecosystems across the country and cutting a carbon sink for mitigating greenhouse gas emissions.
Globalization has opened the door for hundreds of invasive pests, from the Asian longhorned beetle to the emerald ash borer. And climate change, it seems, will make it even more difficult to evict them.