News

Hemlock Tree Treatment Update

GENEVA, N.Y. – Slow and steady progress continues in our efforts to treat hemlock trees affected by the Hemlock Woolly Adelgid. While state agencies are working to protect hemlocks on public lands and in state parks, Seneca Lake Pure Waters Association (Pure Waters) is focused on hemlocks located on private property—particularly those flanking cold-water streams that continuously feed Seneca Lake.

The Hemlock Woolly Adelgid is a small, aphid-like invasive insect from Asia that was introduced to the eastern United States in 1951 and has caused widespread mortality of hemlock trees throughout the southern and eastern states.

Our assessment phase was completed in 2025, identifying priority areas where hemlocks are most critical to stream health and water quality. We are now in the treatment phase, which requires detailed documentation of tree locations, verification of soil temperatures near 40 degrees, and applications conducted only on days with little to no wind or rain. Hemlock trees located within 15 feet of a stream are treated using an injection process, which allows for precise delivery of the insecticide and further control over application near waterways.

In November, licensed pesticide professionals from CC Environment and Planning LLC treated a total of 121 hemlock trees within the Seneca Lake watershed. Many more trees remain in need of treatment. During the winter season, we are actively pursuing additional funding to continue this important work to protect and preserve hemlock forests and the cold-water streams they support.

How You Can Help
In addition to ongoing treatment efforts, volunteers play a key role in tracking the spread of the Hemlock Woolly Adelgid across New York State. From February 1 through March 15, 2025, community members can participate in the HWA Winter Mapping Challenge by surveying hemlock trees and reporting findings through iMapInvasives. Volunteer monitoring helps inform treatment priorities and strengthens statewide efforts to protect hemlock forests and the cold-water streams they support. Learn more and get involved!

Learn more about Pure Waters

To learn more about donating: https://senecalake.org/giving/
To learn more about volunteering: https://senecalake.org/volunteer-opportunities/

Seneca Lake Pure Waters Association is a 501(c)3 organization committed to preserving, protecting, and promoting the abundant resources of the largest Finger Lake. Seneca Lake is a source of drinking water, recreation, and economic opportunity for the greater community and its visitors. Our programs and partnerships make it possible to monitor water quality, educate the public, and evaluate threats to ensure the a healthy future for Seneca Lake and those who depend on it.