The red pine scale is a scale insect found in Japan that feeds on red pine trees. Red pine scale nymphs sit on a tree’s terminal end branches, feasting on sap and finally killing the tree.
Red pine scale is estimated to be responsible for the historical loss of thousands of red pine trees in the Northeast, including the nearly complete extinction of red pine in Maine.
However, because the tiny insect is difficult to detect and identify, it is unknown to what extent red pine scale was responsible for previous tree loss.
Red pine scale was originally discovered in North America in 1946 in Easton, Connecticut, and then on Long Island in 1950. It was thought to have eradicated all red pine south of Westchester County a few decades after its first identification in New York.
Red pine scale had never been observed in Upstate New York, presumably because cooler winter temperatures kept populations small enough to go undetected. Until now.
This June, a property owner in Hague, NY notified DEC’s Forest Health Research Lab about a dying red pine on Lenni-Lenape Island, Lake George. The property owner explained that the trees had died in less than a year, with no evident cause.
Upon arrival on the island, DEC personnel discovered tiny, white masses of “wool” at the base of needles and along smaller branches of the symptomatic red pine trees. DEC officials also discovered a large number of dead and dying red pine trees on the island’s opposite side.
In October, DEC went to a nearby red pine plantation in the Pharaoh Lake Wilderness Area. Many red pines appeared to be dead or dying, with a white fuzzy substance around the base of the needles, reminiscent of red pine scale.
Samples were collected and delivered, along with specimens from the Lake George infestation, to Cornell’s eDNA and Genomic Core Facility for study. Both findings came back positive for red pine scale.
It is possible that red pine scale is far more widespread in New York’s terrain than previously recognized. As New York’s winters become warmer, red pine scale may continue to spread northward, causing red pine mortality in natural forests.
The DEC’s Bureau of Invasive Species and Ecosystem Health intends to conduct extensive surveys in 2025 to identify the location and abundance of this invasive pest.
You may support their work. If you notice dead or dying red pine with “wool” around the base of the needles, please email images and location information to [email protected].
