Crews move quickly to save hemlocks
LAKE GEORGE — The Nature Conservancy next week will begin treating a number of trees on Dome Island infested with hemlock woolly adelgid, an invasive species that threatens around 80% of the trees in the Lake George basin.
The insect was first identified on a handful of trees on the protected island’s south end during an Oct. 8 survey led by Mark Whitmore, an entomologist with Cornell University’s New York State Hemlock Initiative.
After consulting with a number of regional partners, including the Adirondack Park Invasive Plant Program and the Lake George Land Conservancy, the Nature Conservancy decided to begin treating the infected trees in order to preserve the character of the island and prevent the invasive insect from spreading further.
“The Nature Conservancy is moving quickly on Dome Island to act before spring, when birds most often carry hemlock woolly adelgid crawlers and could further spread this infestation around the lake,” Peg Olsen, director of the Nature Conservancy in the Adirondacks, said in a statement.
An infestation of woolly adelgid was spotted by a camper at a campsite in the Glen Island Campground on the eastern shore of Lake George in August.
About 60% of trees located on the 15-acre island, which sits just south of The Sagamore resort in Bolton, are eastern hemlocks. A total of 80% of trees in the Lake George basin are also hemlocks, according to the state’s Department of Environmental Conservation.
Native to Japan, hemlock woolly adelgid attaches itself to the branches of hemlock trees, cutting off water supply and killing any emerging buds. The insect, named for the white, wool-like texture it forms during the colder months, can kill a tree between four and 10 years, making early treatment crucial.
The Adirondack Park Invasive Plant Program will administer the treatment protocol to the infected trees on Dome Island, which consists of applying two different pesticides, dinotefuran and imidacloprid, to the bark of trees. Trees located on the island’s shoreline will not be treated.
The Nature Conservancy will continue to monitor the health of the tress and determine if a second round of treatment will need to be administered in the future.
The same treatment that will be applied to the trees on Dome Island has been administered in other parts of the Lake George basin, including Paradise Bay, a popular site for camping that sits on the eastern shoreline of the basin north of Dome Island.
“It’s very intensive,” said Justin Perry, chief of the Bureau of Invasive Species and Ecosystem Health on Oct. 22 while working with a pesticide application crew at Paradise Bay.
Perry explained that the two pesticides applied to the trees protect and shield in different ways.
“The dinotefuran is a quick-absorbing, quick-acting chemical that moves through the tree and knocks the existing population back,” he said. “The imidacloprid is more of your shield, it will protect the hemlock for up to seven years.”
There are other obstacles, Perry noted.
“The issue is we can’t treat every tree within an acre because we are limited to the amount of chemical we can put down in a given year,” he said.
Perry said that a separate crew comes before the application team to tag the infected hemlock trees. Once trees are tagged, the information is mapped out in “real-time” to help direct the crews spraying pesticide.
“This is the fabulous thing with technology,” Perry said.
After the trees are identified, it’s a race against time.
Pesticide sprayers gear up in Tyvek suits and put on respirators to protect from the chemicals.
“Based on the size of the tree, they will spray a specific amount that’s calculated all the way down to timing,” Perry said.
He noted that once the chemicals are sprayed at the base of the tree, it gets absorbed through the bark and then distributed throughout.
“That’s why we’re under pressure this fall because eventually these trees will go to sleep in the winter,” Perry said. He also noted that once the trees shut down, their treatment is done for the year.
“We know our window of time is limited,” Perry said.
Whitmore, meanwhile, has spent months surveying the Lake George basin for woolly adelgid since the infestation was first identified this summer.
Subsequent surveys have since identified infestation on trees throughout a 250-acre swath of land on the eastern portion of the lake’s shoreline between Dresden and Fort Ann. It’s unclear how the insects have been able to spread, though birds and wind are likely culprits.
The trees are being treated as they are identified.
Meanwhile, the DEC has been working to treat the infected trees throughout the Lake George basin by applying the same treatment to those trees on Dome Island.
In September, the department announced a five-year partnership with the New York State Invasive Species Institute and Cornell University to develop projects aimed at stopping the spread of the invasive throughout the state.
The partnership will be supported by $3.5 million from the state’s Environmental Protection Fund.
“The unfortunate discovery of hemlock woolly adelgid on Dome Island has reinforced the importance of research to study how it spreads. Our tree canopy sampling will generate a snapshot of HWA distribution now and in subsequent years to allow us to carefully evaluate treatment efficacy,” Whitmore said in a statement.