Beetle unleashed to fight invasive bug in Lake George basin

A state Department of Environmental Conservation technician sprays a hemlock tree with pesticide at Paradise Bay on the eastern shore of Lake George on Oct. 22. (Provided photo — Jackson Gerker, The Post-Star)

LAKE GEORGE — A new weapon has been deployed in the fight against hemlock woolly adelgid in the Lake George basin: a predatory beetle that feeds on the invasive insects.

Mark Whitmore, an entomologist with Cornell University’s New York State Hemlock Initiative, released 620 laricobius nigrinus beetles last month near Paradise Bay in the hopes of curtailing the spread of woolly adelgid.

The beetles are native to the Pacific Northwest and feed on hemlock woolly adelgid, which threatens the life of thousands of eastern hemlock trees found throughout the Lake George basin. The Adirondack Explorer magazine first reported the beetles’ release.

“In my mind, it’s a long-term solution for managing adelgid populations,” Whitmore said. “It’s not going to wipe them out, but hopefully it will keep the populations to a level at which they will not damage the trees.”

The beetles are a form of biological control and for years have been vetted by federal researchers and private scientists, like Whitmore, to ensure they would not disrupt the ecosystem before being released.

Whitmore breeds the beetles in his lab and has released thousands throughout the state where hemlock woolly adelgid have been found, including parts of the Hudson Valley and western New York.

The bugs will simply die off once there is no more hemlock woolly adelgid left to feed on, Whitmore said. He noted, however, that’s not likely to happen anytime soon.

Hemlock woolly adelgid reproduce asexually, which means it takes just one insect to start a new colony.

“The predators will never be able to eat them all,” Whitmore said.

Whitmore plans to release two more biological controls in the spring. The additional controls are both flies and also come from the Pacific Northwest.

An infestation of hemlock woolly adelgid was discovered earlier this year at the Glen Island Campground on the eastern shore of Lake George back in August, but has since been found throughout the basin, including on the protected Dome Island.

It’s unclear how the insects have been able to spread, though birds and wind are likely culprits.

Hemlock woolly adelgid is native to Japan and can kill a tree between four and 10 years by attaching itself to the branches of hemlocks and cutting off the water supply, killing emerging buds.

Since being discovered in Lake George, the state Department of Environmental Conservation has been quick to deploy surveillance teams to identify infestations and deploy crews to spray a regiment of pesticides that will kill the woolly adelgid and preserve the damaged trees.

Infected trees have so far been discovered in a 250-acre swath of land between Fort Ann and Dresden on the eastern side of the lake.

Most recently, a small infestation of woolly adelgid was discovered in the Pilot Knob area, according to the DEC.

“So far, that infestation looks small. Surveys to further determine the size of the hemlock woolly adelgid infestation near Pilot Knot will be scheduled for this winter and spring,” the DEC said in statement.

Whitmore said the fight against hemlock woolly adelgid is far from over, even with biological controls in place.

Surveying will continue to identify more infected trees and the DEC will continue to deploy resources and monitor the progress in the years ahead, he said.

“This is a collaborative effort,” Whitmore said.

To learn more about hemlock woolly adelgid, you can visit the New York State Hemlock Initiative’s website at nyshemlockinitiative.info.


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