ROTTERDAM — The Plotter Kill preserve will be closed Tuesday and Wednesday — and possibly Thursday — as the state Department of Environmental Conservation applies pesticide treatments to fight an invasive species there.
The pesticide targets the hemlock woolly adelgid, a tiny insect native to Japan that can pose significant harm to the forest ecosystem, according to the DEC.
The adelgid was recently discovered in the Plotter Kill and in the Indian Kill Preserve in Glenville.
The pesticide treatments were initially scheduled for late October and — in the event of inclement weather — early November, but weather caused both of those windows to be missed, according to the DEC.
Signs are posted at preserve parking lots, and public access will be restricted during the treatment period.
The recommended treatment is the use of systemic insecticides applied to the trees. The two chemicals most commonly used for HWA management, imidacloprid and dinotefuran, have not been shown to have adverse health or environmental impacts at exposures that will occur with the treatment program, according to the DEC.
DEC developed a HWA management plan for the Plotter Kill preserve, which was approved by SCEAC’s Invasive Species Committee in September.
Hemlocks are an important part of natural ecosystems where they grow along streams and steep slopes and help to provide erosion control along streambanks and waterbodies, as well as provide shade to keep water cool enough to support a healthy aquatic environment.
Pesticide treatments may also be necessary in the Indian Kill preserve to address the HWA infestation there, according to the DEC. The infestations at both preserves are light and limited in distribution, and can be contained if prompt action is taken, the DEC said.
Left untreated, HWA normally kills trees within four to 10 years in the insect’s northern range. Damage from the insect has led to widespread hemlock mortality throughout the Appalachian and southern Catskill mountains, with considerable ecological damage, as well as economic and aesthetic losses.
The two Schenectady County locations are of concern because they are within a likely pathway to the Adirondacks where hemlocks are a very important part of the ecosystem, according to the DEC. An isolated and minor HWA infestation was discovered in Warren County in the southeast Adirondacks in July, the DEC said. That infestation was recently treated by the same method that will be used in the Plotter Kill preserve.