Plotter Kill Preserve in Rotterdam is a nature preserve and popular hiking area by the Mohawk River that has, in recent months, been infested by the invasive species known as the hemlock woolly adelgid (HWA). The preserve is one of two Schenectady County locations where this pest has been discovered, and the NY State Department of Environmental Conservation (DEC) is currently working to combat the spread of it.
Photo provided by the DEC
What Is The Hemlock Woolly Adelgid (HWA)?
According to the DEC, the HWA is an invasive insect that was introduced to the U.S. in the 1920s. Although they are small, these pests can be identified by the white woolly masses that they form on branches and needles. Each one of these masses contains hundreds of eggs.
Once they hatch, the juvenile insects begin to feed on the stored starches inside North American hemlocks. If an infestation of the HWA is left untreated, the health of these damaged trees will decline and cause them die within 4-10 years.
Hemlocks are an important part of natural ecosystems because they grow along rivers and slopes and help provide erosion control for aquatic environments. As such, any infestation of this invasive species must be addressed as soon as possible.
An Infestation In Schenectady County
Recently, the DEC discovered infestations of the HWA in both Plotter Kill Preserve in Rotterdam and Indian Kill Preserve in Glenville. To help limit the spread of it, plans are underway to treat the affected areas.
Due to rain on October 23-25, the DEC now plans to use pesticide treatments in Plotter Kill Preserve on November 1-3. During this time frame, signs will be posted at preserve parking lots and public access will be restricted.
The common treatment for HWA includes the use of systemic insecticides on the affected hemlocks. These chemicals, imidacloprid and dinotefuran, are not known to cause adverse health or environmental impacts.
While this plan is underway, the DEC and the Schenectady County Environmental Advisory Council’s (SCEAC) Invasive Species Committee will continue to monitor the situation at Indian Kill Preserve to determine if treatment is also necessary there.
The hope is that treating the HWA infestation in Schenectady County will prevent the insects from spreading to other areas, such as the Adirondacks.
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- NY State Department of Environmental Conservation – Hemlock Woolly Adelgid