HWA Management Update, November 2020

The Lake George Land Conservancy has made the invasive hemlock woolly adelgid (HWA) a priority for several years. Since 2016 we have monitored our own lands looking for signs of this tiny insect, hosted a number of training events to educate the public, and developed the knowledge and skills to rapidly respond to any infestation.

The LGLC has been especially busy this fall, working in the field with partners following several confirmed infestations of HWA within the watershed.

Glen Island Update:

close-up of hemlock needles

Magnified view of the bottom of hemlock needles. Note the double white lines.

In August, a camper identified and reported HWA at the Glen Island Campground in Dresden, Washington County. Shortly after the infestation was reported, staff from the New York State Department of Environmental Conservation (DEC), Cornell University’s New York State Hemlock Initiative, the Adirondack Park Invasive Plant Program (APIPP), and the LGLC were on the ground to survey hemlock trees in the area, determine the extent of the infestation, and prepare for treatment.

To date, the LGLC and our partners surveyed over 250-acres and spent approximately 100 working days finding and tagging infested trees to prepare for treatment.

DEC began treating high priority infested hemlock trees in October, and have to-date treated approximately 2,500 infested hemlock trees within a 138-acre area. The DEC and its partners will return to the site in coming years for additional treatments to manage this infestation.

In addition to treating the infested trees, our partners at the NYS Hemlock Initiative, led by Dr. Mark Whitmore, released over 600 Laricobius beetles. These beetles feed exclusively on HWA, and in the long-term will play a vital role in controlling the spread of HWA. (Click to learn more about these beetles and Dr. Whitmore’s research.)

Dome Island Update:

Dr. Mark Whitmore studies hemlock samples

Mark Whitmore from the NYSHI recording data for a study of HWA on Dome Island in Lake George. Photo courtesy of NYS DEC.

In October, LGLC staff, Dr. Mark Whitmore and members of the NYS Hemlock Initiative traveled to Dome Island to survey for the presence of HWA.  HWA was identified on a number of trees, concentrated to the southern end of the island.

The LGLC and our partners at The Nature Conservancy (TNC), NYS Hemlock Initiative, and APIPP, once again sprung quickly into action. A field crew returned right away to Dome Island to survey and mark infested trees for treatment, then carefully treated infested hemlocks in early November. Treating the currently infested trees will reduce the spread of HWA to non-infested trees, and hopefully will reduce the amount of resources to be used on the island. We will return to Dome Island next year to continue treatments and see if HWA has spread.

Dome Island is an iconic and historic property with more old growth trees than many other areas of the watershed, and has seen very little human impact as a protected island. Because of its unique ecosystem, the spread of HWA on Dome Island and the effectiveness from treatments will be studied by partners at NYS Hemlock Initiative.

Behind the scenes:

Even when we are not out in the woods checking hemlock health, HWA is always a priority in the work that we do. This year we strengthened our relationships with partners and together developed a plan to quickly identify and manage future HWA infestations.

In addition to contributing staff time in the field, the LGLC provided $25,000 to fund a field crew from Adirondack Research. This field crew worked in the woods for four weeks and searched an additional 300 sites throughout the watershed, looking for additional infestations. Thankfully, this group did not find any other infestations. In addition, LGLC is contributing $3,000 to a project led by APIPP, the FUND for Lake George, and others to undertake remote sensing to study the health of the hemlock stands to search for HWA.

Surveying and treatments on partner lands have ended for the year, but the LGLC will be hard at work all winter, looking for HWA on our preserves and hosting several online training events.

Upcoming Training Events:

February 25, 2021: Take Action Against HWA – Impacts, ID and Citizen Science
Online via Zoom, presented by APIPP and NYSHI  >  Register