An invasive pest known for killing eastern hemlock trees is creeping ever deeper into the Adirondacks, according to a new report from the New York State Department of Environmental Conservation.
Concerned residents and volunteers last month reported seeing the pest, hemlock wooly adelgid, on eastern hemlocks growing on the western shore of Lake Champlain in the Port Douglas area, Essex County, as well as the north end of Great Sacandaga Lake at Conklingville Dam, Saratoga County.
DEC verified the detections and made follow-up visits to the sites which revealed visible signs of HWA.
HWA was first confirmed in the Adirondack Park in 2017, and has since become established in the Lake George watershed. But the insect has never been detected this far north.
HWA is native to Japan and likely came to the U.S. on nursery stock. It has been present in NY since the 1980s.
Hemlocks play a vital role in NY’s forest ecosystem, providing unique environmental conditions under cool, dense canopies that protect wildlife, fishery habitat, water quality, and prevent soil erosion, DEC Commissioner Amanda Lefton said.
HWA gets its name comes from the white, woolly sacs it makes at the base of hemlock needles in winter and early spring.
After hatching in spring, the tiny bug feeds on hemlock twigs in the same manner aphids attack garden plants. An HWA infestation can kill a healthy tree within 10 years.
Unlike many conifers, eastern hemlocks tolerate shade. They grow slowly, taking 250 to 300 years to reach maturity, and may live for 800 years or more.
“While this new infestation is concerning, it also demonstrates the value of public awareness and timely reporting,” Adirondack Park Invasive Plant Program Director Brian Greene said. “Each report helps us to better understand the spread of this invasive insect and contributes to the larger effort to protect hemlock forests.”
Early detection of HWA is essential because infestations can easily go unnoticed while significant damage accumulates.
DEC encourages landowners, land managers, and outdoor enthusiasts to learn how to identify HWA and to report suspected sightings using the iMapInvasives app.
Identification guides, reporting tools, and support are available on both the New York State Hemlock Initiative and AIPP websites.