This article was featured in the 2026 spring newsletter by Robert Smith, SLELO PRISM.
Updates on Hemlock Woolly Adelgid:
This year, SLELO PRISM surveyed 14 sites for hemlock woolly adelgid (HWA). Eleven of these were completed by the early detection team with some help from volunteers, while three were volunteer surveys led by Megan Pistolese-Shaw. Of these 14 sites, two were found to have HWA present. These were Derby Hill Bird Observatory and Three Mile Bay WMA, both in Oswego County. In addition to these sites, a member of SLELO PRISM’s Volunteer Survelliance Network, Hope Teichroew, found HWA at Hamilton College in Oneida County. This brings the total sites in SLELO PRISM to 13. So far, all of these sites are either along the Lake Ontario shoreline in Oswego County or along the southern regions of Oswego and Oneida Counties. We will continue to provide updates as HWA moves to new portions in our region.
Winter HWA mortality surveys were conducted on April 3rd at Independence Park in Oswego County, NY. These surveys are part of a collaboration between SLELO and the New York State Hemlock Initiative (NYSHI) and have been conducted annually since 2022. As part of the survey, two HWA infested twigs from four hemlock trees for a total of eight were collected and examined using a microscope to determine the percentage of HWA that were dead or alive. The count determines the HWA winter mortality percentage which varies each year depending on the winter temperatures. This year, the winter mortality was 90.5%. Past winter mortality percentage at Independence Park were as follows: 2022: 89.7%, 2023: 97.3%, 2025: 60.5%. HWA Survey Summary Reports can be viewed on the SLELO PRISM Field Reports Webpage.
2026 Early Detection Surveys:
SLELO staff will be conducting surveys at 11 Priority Conservation Areas (PCAs) this summer. Five sites are terrestrial and six are aquatic. As usual, the focus will be on tier 1 and 2 species, but we will also report tier 3 and 4 species, some of which are already being managed. Some native species will also be reported to help us select the best species to plant at the restoration areas. The five terrestrial PCAs are as follows: Black Pond WMA, Brasher State Forest, Chaumont BarrensPreserve, Deer Creek WMA, El Dorado Preserve.
2026 Invasive Species Control Work:
SLELO is changing our contract herbicide applicator from Miller’s Turf to Invasive Plant Control, Inc. out of Nashville, Tennessee this year. The Adirondack PRISM has been working with this contractor for several years and they have agreed to do invasive species management in both PRISMs this year. Due to the contractor working in both PRISMs, we will have them for a more limited amount of time. This means that we will be carefully plotting the routes to maximize the number of sites treated. The potential treatment sites this year will occur on 15 PCAs with breakdown by species of 82 sites with swallowwort, 29 sites with phragmites, 21 sites with invasive knotweed, 9 sites of invasive bittersweet, and 6 sites of yellow iris.
2026 Restoration Areas:
SLELO is now up to eight restoration areas. At two of the sites, El Dorado Preserve and Black Pond WMA, we will be conducting fifth year inventories. Our goal is that the restoration area will have at least 80% of the species richness of the area directly surrounding the sites. At five of the sites, we will be monitoring for reductions in the invasive species and increases in native species. We also have a new site at Battle Hill State Forest where we plan to conduct a first year inventory. This is our first restoration area on state forest land and in the Tug Hill ISPZ. As with last year, we plan to plant additional native species in the fall that are appropriate for each restoration site.
Biological Controls for Invasive Species Suppression:
When possible, biocontrols are being used as an invasive species management tool. In the case of pale swallowwort, our use of Hypena opulenta moths has ceased due to no evidence of establishment. We will continue physical and chemical treatments until another biocontrol is available. We hope that Chrysochus asclepiadeus, a beetle which feeds on the leaves and roots of swallowwort, will be approved within a few years.
SLELO released emerald ash borer biocontrol in 2022 and 2023, with establishment surveys in 2024 and 2025. We were able to find Spathius galinae and Tetrastichus planipennisi two years in a row, which shows that it is likely establishing, but only found Oobius agrili during the first year. The staff at Rice Creek Field Station and volunteers from the previous years decided to continue surveying for Oobius agrili with SLELO PRISM in an advisory role. Sign up to volunteer for this effort!
The biocontrols for Hemlock Woolly Adelgid have been released at several locations in SLELO PRISM. As of now, there are no plans for additional releases, but the New York State Hemlock Initiative does plan to set up traps at Independence Park to determine if the biocontrol, Laricobius nigrinus, is establishing a population at the park. Lastly, biocontrols for spotted knapweed were released along the dunes at Deer Creek WMA last year (Larinus minutus, L. obtusus, Cyphocleonus Achates). We are requesting more of these biocontrols this year from the Montana Biocontrol Coordination Project. These will be released in July and August.
2026 Giant Hogweed Management:
The giant hogweed management season will start in May. SLELO PRISM is responsible for a total of 147 sites. We started managing the giant hogweed in Oneida County last year, which greatly increased our number of sites. This large number required us to prioritize our sites according to several factors including ecological importance and presence on or near public lands. This year, we will only be able to conduct root cut management, which will decrease the number of sites that we can complete to 67. Hopefully, we’ll be able to apply herbicides next year.
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