Hemlock Protection

Primary funding for Hemlock Protection is provided by donations to the SLA. Donate today!


“If we lose the hemlocks, we lose the lake” – Dr. Robert Werner, SLA visionary.

Hemlocks are essential for a healthy Skaneateles Lake and are a valuable asset in preventing harmful algal blooms (HABs). Hemlocks are one of the best steep bank and ravine sediment control strategies available which can reduce the amount of phosphorus that flows into the lake and feeds HABs. Additionally, the tree cover they provide keeps streams cool (and thus lower lake temperatures) which is another way to defend against HABs.


The Concern:

Native to Asia, the hemlock woolly adelgid (HWA) is an invasive, aphid-like insect that attacks North American hemlocks. HWA are very small (1.5 mm) and often hard to see, but they can be easily identified by the white woolly masses they form on the underside of branches at the base of the needles. Their feeding severely damages the canopy of the host tree by disrupting the flow of nutrients to its twigs and needles. Tree health declines, and mortality usually occurs within four to 10 years.


Hemlock wooly adelgid underneath a hemlock branch

Our Program:

The Skaneateles Lake Association has designated $50,000 from the SLA Legacy Fund to fund HWA management efforts. Currently, our efforts employ Zeb Strickland, a licensed pesticide applicator with extensive experience in treating HWA, to treat designated areas within the watershed. The pesticide treatment of HWA is a bridge to the future biological treatment of using silver flies to combat HWA. Cornell University is assessing the use of releasing silver flies into areas infected with HWA as these flies actually eat the woolly adelgid. Neither pesticide treatment nor silver flies will completely eliminate HWA, but both are tools in our pocket to help these ecosystems.

The effort to combat and control HWA is being carried out by both Onondaga County Soil and Water Conservation District (OCSWCD) and the Skaneateles Lake Association.

Please contact the SLA if you need help identifying possible HWA infection and we can refer you to a licensed pesticide applicator.

Other resources:

How to Identify Eastern Hemlock Trees – YouTube Video

imap invasives site to look up where HWA is present on Skaneateles Lake

NYS Hemlock Initiative