On Earth Day, April 22nd, 2026, the Harrisville Conservation Commission presented a public look at an important conservation effort underway in the Monadnock Region: The Harrisville Hemlock Initiative.
Our hemlock forests—vital to wildlife habitat, watershed stability, and year‑round ecological balance—are increasingly threatened by the invasive Hemlock Woolly Adelgid (HWA), an aphid-like insect. For the past two years, the Harrisville Conservation Commission has launched a biological control program to restore balance in our forests. With generous support from local donors and landowners, we’ve released more than 7,500 Laricobius nigrinus beetles—a natural predator of HWA—across Harrisville and neighboring towns including Dublin, Peterborough, and Hancock.
These beetles are already showing strong results in states from New York to North Carolina. We are introducing the same program here in the Monadnock Region.
Dr. Richard McDonald, Entomologist and project consultant of Symbiont Biological Pest Control, has been leading a weeklong monitoring effort in Harrisville from April 19th to 23rd. This video presents our findings to the public. His early research into the potential for this project has resulted in successful biocontrol programs in western North Carolina over the past 20 years. His efforts have supported additional release programs in New York State, New Jersey and other states in between. He is a national leader in establishing this method of biocontrol along the East Coast.
Harry Wolhandler, Harrisville Conservation Commission Chair and Project Director, introduced the background and goals of the Monadnock program.
Ralph Zingaro, a research horticulturalist, consulting arborist and Pest Control Advisor with 35 years of biocontrol and Integrated Pest Management experience, has been leading the Harrisville field assessment and release efforts. Ralph detailed our local efforts and provides insight into the critical value of this project’s future impacts.
Whether you’re a nature enthusiast, land steward, conservation commissioner, or simply curious about biological control, this event offers a rare opportunity to learn directly from the scientists and organizers guiding this work.
This video includes question-and-answer from the 55 members of the public and members of local Conservation Commissioners. For more information contact Harry Wolhandler, ConCom@HarrisvilleNH.org.