Invasive hemlock woolly adelgid found in Tionesta area of Pennsylvania's Allegheny National Forest, leading scientists to suggest warming temperatures are permitting survival of temperature-sensitive insect in once-colder areas
January 10, 2014
– The invasive hemlock woolly adelgid has been found in the Tionesta area of Pennsylvania’s Allegheny National Forest, indicating that the insect is spreading to areas once considered too cold for it to tolerate, The Pike County courier reported on Jan. 9.
The recent finding follows new infestations in several other areas, including the Cook Forest State Park and the Flight 93 National Memorial. Some scientists suggest climate change has created a warming trend in the once-colder areas, permitting the insect to survive, though they admit they can’t conclusively link the bug’s resilience to climate change.
The adelgid, more common to warmer or southerly regions, lays its eggs on hemlock branches. After hatching, young adelgids feed on sap, causing the tree to lose needles and die after five to 10 years. This presents a problem for other native wildlife and plants that depend on shade coverage provided by the large hemlocks.
Scientists believe trees killed by the adelgid can be replaced with a more resistant hardwood, though this would change the ecosystem of one of the last uncut hemlock-beech forests in the Allegheny Plateau region that hosts decades of research projects.
Treatment of the infestation, though possible for some trees, would be too costly and time-consuming to conduct on the entire 4,000-acre Tionesta area. Only a few trees have a confirmed infestation.
The primary source of this article is The Pike County Courier, Milford, Pennsylvania, on Jan. 9