Harrisville Conservation News

How Are Our Lakes and Ponds Doing?

Harrisville’s fourth annual Town‑Wide Lakes Meeting will be held on Tuesday, June 2 at 7:00 PM via Zoom (zoom link).

Representatives from our lake associations will share updates on boating activity, water‑quality monitoring, and ongoing efforts to prevent invasive aquatic plants and bacteria. With town support, our Lake Associations sponsor both Lake Host inspections and Weed Watcher programs on Silver Lake, Skatutakee Lake, and Harrisville Pond.

All interested residents are welcome to join the conversation.

Restoring Native Vegetation Harrisville is continuing its effort to remove invasive Japanese Knotweed and Phragmites along roadsides and, with permission, on private land. Knotweed spreads aggressively through its roots, so targeted fall herbicide treatment is the most effective control.

Vegetation Control Services will revisit the 70 sites treated last year and identify any patches needing follow‑up. To protect pollinators, all spraying occurs in late September–early October.

Landowners can report Knotweed and grant removal permission by emailing ConCom@HarrisvilleNH.org. A coordinated, town‑wide effort helps protect Harrisville’s native plants.

Saving Our Hemlocks Hemlock Woolly Adelgid (HWA), an invasive insect weakening hemlocks across our region, is spreading quickly. Hemlocks make up about 25% of our local forests and provide critical winter habitat, stream shading, and drought resilience.

The Harrisville Conservation Commission is working to slow HWA by releasing Laricobius nigrinus, a natural predator beetle used successfully in the Pacific Northwest. Over the past two years, the Con Com has raised funds to import and release these beetles locally, aiming to establish self‑sustaining populations that can spread 1–2 miles per year.

To learn more, watch the Con Com’s Earth Day presentation Saving Our Hemlocks on YouTube (https://www.youtube.com/watch?v=mUBkO5FXRdo) .

Protecting Our Hemlocks: The Harrisville Hemlock Initiative

A public presentation on the Harrisville Conservation Commissions efforts to save our local forests from an invasive predator, the Hemlock Wooly Adelgid. Click here to view this presentation on YouTube.

On Earth Day, April 22nd, 2026, the Harrisville Conservation Commission offered a public look at The Harrisville Hemlock Initiative, an important conservation effort underway in the Monadnock Region.

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, 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.

More about the Harrisville Hemlock Initiative:

Growing Regional Momentum

Launched in 2024, the Harrisville Hemlock Initiative has rapidly expanded into a coordinated regional response to HWA. In just 18 months, the program has:

• Raised $76,900 in community support from concerned landowners
• Released more than 6,800 Laricobius nigrinus beetles across 15 sites
• Launched two potential insectaries in Harrisville and Dublin
• Built partnerships with universities and conservation organizations, with guidance from the NH Forest Health Bureau

HWA, once limited by cold winters, is spreading across southern New Hampshire. Hemlocks make up 25% of our local forests and serve as a keystone species—providing winter habitat, stabilizing stream temperatures, and supporting diverse plant and animal life.

While pesticides can protect individual trees, they are costly and temporary. Biological control offers a long‑term, self‑sustaining solution capable of protecting forests at a landscape scale.

Why Laricobius nigrinus?

This specialized beetle feeds exclusively on adelgids at every life stage, with a strong preference for HWA. In the Pacific Northwest—where HWA is native—Laricobius beetles are a winter predator that helps keep populations in check, preventing the widespread hemlock mortality seen in states along the Eastern seaboard.

Research shows that Lari beetles can dramatically reduce HWA densities and allow hemlock stands to recover. Once established, Lari’s can naturally spread one to two miles per year, helping inoculate forests across the region.

Strengthening Scientific Capacity

• Dr. Richard McDonald, consultant entomologist to the Harrisville Conservation Commission, acquired a USDA APHIS permit in April 2025 to collect Laricobius beetles from established populations in the mountains of North Carolina and other states for direct shipment to the Harrisville Conservation Commission.
• Dr. McDonald will be in Harrisville from April 19^th – 23^rd, 2026 to aid the Conservation Commission in launching a local monitoring program. Volunteers are invited to participate and will be trained (email ConCom@HarrisvilleNH.org).
• Dr. McDonald and Ralph Zingaro, Conservation Commission project lead for field releases and monitoring, will review Lari beetles gathered in field monitoring efforts and examine HWA egg sacs for signs of Lari reproduction (Lari eggs inside the disrupted egg sacs). Each Lari larvae consumes 100–200 HWA eggs before dropping into the forest floor to aestivate over the summer and return as a mature Laricobious Nigrinus beetle in late fall.
• On Earth Day at 7 PM, Dr. McDonald and Ralph Zingaro will present the results of the monitoring effort. The NH Association of Conservation Commissions has agreed to webcast the presentation to Con Com members in Cheshire County. The recording will be posted on YouTube – search for Harrisville Conservation Commission.
• This March Ralph Zingaro went to Cornell University and created connections to staff of the New York State Hemlock Initiative, strengthening regional scientific exchange and potential future supply options from their successful program. Over 20 years, the NYSHI has released Lari’s in over 80 state locations and reports that 18 of these are sufficiently established to support wild beetle collection for redistribution.

Community Support Is Expanding

With donors stepping forward in Dublin, Peterborough, and Hancock, the initiative is growing into a regional defense effort. A new Citizen Science mapping project, developed with support from the Harris Center for Conservation Education, will help identify HWA hotspots and guide future releases.

“The goal is to inoculate our forests with a defensive line of established Laricobius beetle colonies across the region,” said project director Harry Wolhandler. “Acting now, in the early stages of HWA infestation, we can protect our hemlock forests and our native ecology for future generations. There are few environmental opportunities that are more than holding actions or remediation. This is a rare opportunity to contribute to one permanent, self‑sustaining environmental solution.”

Let’s protect our forests—together.

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For more information email ConCom@HarrisvilleNH.org

Harry Wolhandler, Chair
Harrisville Conservation Commission
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Annual Report of Activities, 2025

2025 has been a very active year for the Harrisville Conservation Commission. Thanks to a unique set of talents on the Con Com, we’ve turned attention towards dealing with invasive species on three fronts: removing invasive Japanese Knotweed from town roadsides and private lands, halting the spread of Hemlock Woolly Adelgids to protect our Hemlock trees, and continuing support to prevent aquatic invasives from invading our most used lakes and ponds.

Last October, a program was launched to restore native vegetation along town roadsides by eliminating patches of Japanese knotweed. First brought to HCC attention in 2014 as small roadside patches roughly 5 to 8 feet wide, last year these patches had grown to 30 and 50 feet wide, eliminating parts of our ecology supported by native plants. With the support and understanding of Harrisville citizens, we began spraying patches with a systemic herbicide that kills the plants down to their roots. This is expected to be a 5-year effort involving annual inspections and major spraying efforts for two years, tapering off as needed for the toughest patches in year 3, and maintenance operations to eliminate new sprouts in later years. In 2026, HCC will invite private landowners to report infestations on their land and permit removal at no cost to them. This project is supported by the Harrisville Conservation Fund with no impact on local taxes.

For the second year in a row, Harrisville Conservation Commission is working to establish biological controls to protect our hemlock forests from the fast-spreading Hemlock Woolly Adelgid (HWA). With a federal USDA permit, we’ve been releasing Laricobius nigrinus beetles—natural HWA predators—sourced from North Carolina and other regions. The NH Forest Health Bureau continues to support and coordinate with our efforts. Hemlocks are a keystone species supporting more than 150 kinds of wildlife and plant life. Dozens of bird species rely on hemlock stands for nesting and winter cover. Mammals such as deer, moose, fisher, porcupine, and flying squirrels depend on hemlock shelter. Hundreds of insect species thrive in the cool, moist forest floor beneath hemlocks. Along streams, hemlock shade keeps water cold for brook trout and the aquatic insects they feed on. This effort was first launched with seed money from the Conservation Fund. Private donations from concerned landowners with the vision to support a long-term effort to prevent the loss of our forest wildlife and the welfare of our forests.

HCC continues to support our three major lakes and ponds with subsidies to pay for Lake Host programs on Silver Lake, Harrisville Pond, and Lake Skatutakee, funded by an invasive species line item in our annual budget. Each June, HCC hosts a townwide Zoom for lake-interested residents and Lake Associations to share information about the health of their water bodies and tips on ways to protect our waters.

As chair, I am deeply grateful to the members of HCC who bring a unique and broad set of talents to the table and allow us to continue to protect our wonderful town and its environment. We also greatly appreciate the widespread support of our townsfolk who love and appreciate the natural bounty that we all share!

Harry Wolhandler, Chair (Biology & Environmental Management)
Don Scott, Vice Chair (Environmental Mitigation & Landscape Architecture)
Ralph Zingaro (Research Horticulturalist & Plant Doctor)
John Sandri (Arbiculture [Tree Care] & Landscaper)
Jordan Long (Zoology and Media Communication)
Tom McGregor (Outdoorsman, Hunter & Fisherman)
Kathy Scott, Selectboard Representative (Recycling & Town Government)
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Conservation Commission Projects 2024 – ongoing:

* Restoring Native Vegetation along Town Roadsides
The Harrisville Conservation Commission launched two important projects in 2024-25 to help restore the balance of nature in Harrisville.

The first is a long-discussed initiative to restore native vegetation along Town Roadsides by removing invasive plants that have been crowding it out. Invasives are plants that spread quickly and out-compete native vegetation for resources.

The second is an effort to reduce populations of an insect that is threatening our local forests, the Hemlock Wooly Adelgids, which are spread throughout town woods. They are particularly threatening to Hemlock trees, but also weaken other evergreen species. They have a natural predator that is found locally but is only seen at low levels to date. The plan is to augment local populations of these predators to control Hemlock Wooly Adelgids and reduce their populations to sustainable levels so they will not kill off important tree species.

For more information read the brief synopses below and follow the links for as much detail as you wish to review.

Restoring Native Vegetation along Town Roadsides:

Why: Native vegetation provides habitat for native insects and small animals, and serves over 250 types of native bees that pollinate many varieties of plant life.

How: Kill Japanese Knotweed, a powerful invasive that spreads quickly and displaces native vegetation. Method based on results of organic/inorganic herbicide tests conducted in 2023.

When: late September, post-flowering to protect bees, when sap flows down to be stored in roots for winter.

Click links for more info:

Knotweed Locations on Town Roads (2018 survey – click for Google Map Interactive views of photos)

Harrisville Con Com Summer 2023 Tests of Organic & Conventional Herbicides

NH Dept. of Agriculture Guidelines for Knotweed Removal (Quick Form – 2 pages)

NH Dept of Agriculture Best Practices Manual for Removing Japanese Knotweed (15 pages)

Example: Town of Durham, NH Knotweed Control Program

Protecting Hemlocks from Hemlock Wooly Adelgids

Why:  Hemlocks are a vital forest resource

Hemlocks provide shelter and food in winter for deer, small animals and birds. Hemlocks keep streams cool; Hemlocks absorb far less groundwater in drought, unlike deciduous trees

Hemlock Wooly Adelgids are killing our local hemlock trees. When you suddenly see a severely weakened or dead hemlock trees, look closely at its needled branches. When Hemlock Wooly Adelgid infestation levels rise above 30% of tree branches they can kill healthy mature trees in 4 to 7 years. Many landowners are finding dead hemlocks on their property in Harrisville.

Hemlock Wooly Adelgids used to die off in -20 degree winter weather. Our climate is warmer now, and winters are warming even faster than summers. Today Hemlock Wooly Adelgids are growing out of control and are found in all our Hemlock woods. While not as deadly on other trees, they also attack White Pine, Balsam, Larch and other trees.

Dead trees near homes are a danger to life and property, and costly to remove (I’ve lost 3 large hemlocks in 3 years on a small ¾ acre lot – cost about $3,000 for removal). Landowners lose valuable forest inventory and forests are less healthy when species are removed from their naturally balanced populations.

How: Augment local populations of Laricobius nigrinus beetles, predators of HWA

Laricobius nigrinus beetles are natural predators that exclusively feed on adelgids. Hemlock Wooly Adelegids are invasive aphid-like insects that were inadvertently brought east from the Pacific Northwest in the 1950’s. Researchers at the University of North Carolina realized that Laricobius nigrinus beetles were helping to keep adelgid populations under control in the Pacific Northwest. For the past 20 years they have been gathering Laricobius nigrinus beetles out west and releasing them in NC Hemlock forests where large areas are now recovering from HWA predation.

This approach to restoring a balance in nature is referred as Biocontrol. Unlike pesticide methods like spraying and fertilizing specific trees, Biocontrols establish a lasting balance in nature. Local releases of of Laricobius nigrinus were first done over 10 years ago in Hancock by the NH Forest Health Bureau working under a federal license from the USDA, but it wasn’t clear that the populations had survived the winter environment.

Conservation Commission member Ralph Zingaro, a Research Horticulturalist trained at Cornell, discovered local populations  of Laricobius nigrinus on Noel Greiner’s land this spring proving that not only could populations survive but they were able to spread by about 2 miles per year.

Harrisville Conservation Commission has received a letter of permission and support from the NH Division of Forests & Lands Forest Health Bureau for this project allowing us to work under the State of New Hampshire’s permit from US Department of Agriculture do these releases. The Forest Health Bureau will oversee the releases by inspecting beetles prior to release to ensure that only Laricobius are in the release batches.

Two other Conservation Commission members, John Sandri, an arbiculturalist (tree care) also trained in soil science, and Don Scott, a Landscape Architect with 10 years of experience in environmental restoration, have used computer mapping tools to generate lists of potential release sites. Our goal is to find sites best suited to Laricobious survival and spread across town to create local populations of Laricobius nigrinus that can thrive and protect our Hemlock trees. Over time our project may benefit the entire region.

When: Beetles will be released in late October / Early November 2024.

Click link for more info: BEETLES SAVE NEEDLES  – a detailed explanation of the problem and solution methods

          Submitted by Harry Wolhandler, Chair, Harrisville Conservation Commission

About the Conservation Commission
The Harrisville Conservation Commission protects and preserves vital natural resources, including woodlands and wildlife, agricultural land, wetlands, healthy lakes, and native vegetation along roadsides, as well as community access to nature.

Our charter includes:

• Advising other town boards and committees on environmental risks worthy of attention;
• Offering public education to help neighbors make reasonable environmental decisions as a community;
• Conserving land by facilitating conservation easements and providing oversight; and
• Taking action where feasible to deal with specific environmental problems.

Join the Conservation Commission and work with us!  If you have interest in these areas, we’d welcome your leadership as we work together on behalf of the town:

• Woodland and agricultural management
• Wildlife preservation whether as an environmentalist, hunter or fisherman
• Optimizing community growth and development in ways that support future generations as well as our town

The HCC meets at 7:00 pm on the first Wednesday of each month, both in person at town hall and online over zoom. Links to agendas and meetings are posted in the right hand column on https://harrisvillenh.org.

For information contact HCC Chair Harry Wolhandler at 603-852-8026 or harry@accelara.com.

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• Rain Garden at the Harrisville Pond Boat Ramp

  • The Rain Garden is a project of the Conservation Commission that protects Harrisville Pond from pollution caused by winter sand and salt, and allows storm runoff waters to soak back into the ground before reaching open water. The garden is planted with native vegetation that can withstand both wet and dry conditions.
  • The Rain Garden is an educational demonstration project with displays explaining how rain gardens are designed, and steps homeowners can take to improve stormwater retention on their properties. As a result of climate change, Northern New England is projected to have more major, longer-lasting storms. To reduce the severity of future flooding, homeowners can retain rainwater using swales, retention ponds, rain gardens and other solutions described in New Hampshire’s  State Guide to Homeowner Stormwater Management Solutions.
  • Thanks also to Wes Tarr and the Town Road Crew for  creating this Rain Garden for the town. 

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