Through collaboration with our partners, hemlock woolly adelgid biocontrol agent- Laricobius nigrinus, has been released in the SLELO region for the first time.

On October 13th, 2022 approximately 2,000 L. nigrinus from the Pacific Northwest were released at Mexico Point State Park . Beetles were provided by Cornell University’s NYS Hemlock Initiative, and partners with the NYS Office of Parks Recreation and Historic Preservation along with SLELO staff joined the release effort.  These beetles will feed on hemlock woolly adelgid over the winter, and over time they will become established and dispersed to help manage HWA populations in the SLELO region and beyond. 

Hemlock woolly adelgid is an invasive insect that threatens hemlock trees- genus Tsuga.  Feeding on tree sap, HWA injects their specialized mouthparts into the base of hemlock needles. This triggers a defense in host trees to “wall off” these incisions (similar to a scab growing over a cut) and over time, the feeding of HWA  weakens the host tree and leads to tree mortality. Infested trees will display signs of distress such as needle loss and discoloration, lack of regrowth in the spring, and limb damage or loss. Hemlocks that experience environmental stresses, such as drought, are more susceptible to an HWA infestation. In general, untreated hemlock infestations will cause host trees to die off within four to ten years, depending on infestation density and the overall health of the host tree prior to infestation. You can help protect hemlock trees by joining our invasive species Volunteer Surveillance Network (VSN) to receive training on how to recognize and report HWA using iMapInvasives.org.