This article was featured in the 2023 autumn newsletter by Robert Smith-SLELO PRISM.

2023 Management Efforts Update: 


Giant Hogweed Control:

  • 37 total sites managed
  • 19 sites with no germination
  • 4 sites retired
  • 5 sites root cut
  • 12 sites herbicide treatment
  • 1 site no permission to treat


  • 58 sites managed
  • 12 PCAs
  • 113.87 acres under management
  • 27.51 acres of presence area

Invasive Knotweed:

  • 11 Sites being managed
  • 4 PCAs
  • 19.80 Acres under management
  • .78 acres of presence area


  • 8 sites
  • 6 PCAs
  • 17.40 acres under management
  • 1.18 acres presence area

Invasive Bittersweet:

  • 11 sites
  • 3 PCAs
  • 26.18 acres under management
  • 7.96 acres presence area

Emerald Ash Borer (EAB) Biocontrol:

Emerald Ash Borer Biocontrol Updates:

This year was our second year participating in the USDA’s EAB biocontrol release program at Rice Creek Field Station at SUNY Oswego.  This program involves a two year release of three species of parasitoid wasps followed by an EAB biocontrol establishment survey conducted at least a year after the last release of the wasps, which for this site will be 2025.  This will most likely involve using yellow pan traps.  Total parasitoid wasps by species released:

  • 2,347 Spathius galinae
  • 5,652 Tetrastichus planipennisi
  • 2,200 Oobius galinae


Kamal Mohamad Rice Creek Field Station EAB biocontrol.

Swallow-wort Biocontrol:

This year, we completed another biocontrol release of Hypena opulenta moths at four cage  sites; two located at Robert Whele State Park and two located at Grenadier Island.  On June 6th, we received 40 pupae from the NYS Invasive Species Research Institute for each of our four cages. Unfortunately only 6 adults emerged, and those adults did not produce any larvae.  I observed white fungal growth on most of the pupae.  This was observed by other organizations around New York that received pupae from NYISRI.  Some of the pupae were sent to the Dylan Parry Lab at SUNY ESF to determine the exact cause of the lack of emergence from these pupae.

We decided, like last year, to purchase additional Hypena to release in mid-summer.  On July 24, we released 90 larvae, 20 adults and 12 pupae.  Initial June 6th pupae release failed. We had moderate success at cage 1 at Whele and Grenadier Island.

Below is an overview of the caged releases of H. opulenta this year.

Robert Whele Cage Defoliation:

  • Cage 1: 40%
  • Cage 2: 5%

Grenadier Island Cage Defoliation:

  • Cage 1: 40%
  • Cage 2: 10%
  • 90 larvae released 10 ft. from each cage.
  • 20 adults placed in each cage.
  • 12 pupae placed in each cage.
  • 40 pupae received from NYS Invasive Species Research Institute sourced from the Phillip Alampi Beneficial Insects Laboratory in NJ.

Trail Surveys were conducted this year at Robert Wehle State Park.  From June through August, park Staff, the New York Parks Invasive Species Team, and SLELO PRISM each walked a third of the trail system to search for signs of overwintering H. opulenta moths. Residents of Grenadier Island were provided a training and conducted surveys on the island. Unfortunately, no signs of overwintering Hypena moths were found at Whele or Grenadier Island.

Hemlock Woolly Adelgid (HWA) Biocontrol:

Since finding the first HWA site in 2021 at Oswego County Reforestation Area, SLELO PRISM and New York State Parks Staff have found seven sites with HWA (see above map). The sites, mostly located along the Eastern Lake Ontario shoreline, are  listed below along any biocontrol agents that have been released at those sites. 

  • Battle Island
  • Camp Hollis
  • Noyes Bird Sanctuary
  • Oswego County Reforestation Area
  • Independence Park (Laricobius nigrinus beetles-fall 2023)
  • Mexico Point State Park (Laricobius nigrinus beetles-fall 2022)
  • Selkirk Shores State Park (Silver flies Leucotaraxis piniperda-spring 2023)


2023 Early Detection Efforts:

We are currently finishing up our Invasive Species Field Surveys.  There were many Tier 3 and 4 species, such as swallowwort, phragmites, Japanese knotweed, Eurasian watermilfoil,    European frogbit, and many others found at these PCAs, but no Tier 1 or Tier 2 species were found on any of the PCAs surveyed this year. Surveys are completed at the 8 PCAs listed below. 

  • Fish Creek WMA (aquatic/terrestrial)
  • French Creek WMA (aquatic/terrestrial)
  • Little John WMA (terrestrial)
  • Mud Lake (aquatic)
  • Tug Hill ISPZ (terrestrial)
  • Whetstone Reservoir (aquatic)
  • Limerick Cedars (terrestrial)
  • Ontario Bay Initiative-Three Mile Creek (terrestrial)

Vegetation plots were also randomly selected and used a square meter quadrat. Data was recorded in each plot to include the percent of grasses, sedges/rushes, forbs, shrubs, and trees. As well as the species present within and around a 20-foot barrier of the treatment area.


2023 Restoration Sites:

Last year, we conducted surveys and plantings at four restoration sites, which were management/treatment sites where natural establishment of native species seemed unlikely.  This year, we have added four more sites for a total of 8 restoration sites.  Three of the sites were managed for phragmites, two sites for yellow iris, two sites for Japanese knotweed, and one site for pale swallowwort.  Our restoration surveys record the native, nonnative, and target invasive species found in the treatment area and in a 20ft buffer zone around the treatment area.  Vegetation plots were also randomly selected and surveyed for the percent cover of trees, shrubs, grasses, sedges/rushes, and forbs.  Additional plantings will occur at these restoration sites in the fall and will be based on the results of our surveys.  Our goals and objectives include completing the initial site assessment in the 1st year, increasing native species richness of the treatment area to at least 50% of the surrounding region in 3 years, and reducing target invasive species by 95% within 5 years.


Lakeveiw WMA South Colwell Pond restoration plots © SLELO PRISM/TNC.
Stands of Phragmites treated at Selkirk Fen © SLELO PRISM/TNC.

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