Batesville Herald Tribune, Batesville, Indiana

November 7, 2013

Flight 93 national memorial park battling invasive pest

by David Hurst
CNHI News Service

SHANKSVILLE, Pa. — At first glance, the white specks dotting the Flight 93 crash site's famed hemlock trees give a soft white, welcoming touch.

The tiny puffs almost look like snow. But they're actually egg sacs for invasive insects known as the woolly adelgid, and they are slowly killing the hallowed ground's hemlock grove, according to Keith Newlin, National Park Service deputy superintendent for western region, which manages the Flight 93 National Memorial.

It's an issue the park service and its partners are working to battle through a mix of treatment efforts getting underway this month, park officials said.

"Right now, the trees are still fairly healthy. But we've got to knock these buggers back," Newlin said.

The grove is perhaps the most sacred piece of the Flight 93 property. When the United Airlines plane fell from the sky on Sept. 11, 2001, killing all 40 passengers and crew, the hemlock trees absorbed much of the impact and crash remains, investigators said at the time.

The Hemlock woolly adelgid, or HWA, feed on hemlock needle sap, robbing the trees of nutrients. The needles then turn gray and die, leaving the tree itself to starve to death, often three to five years after the initial infestation, according to the state Department of Conservation and Natural Resources’ website.

A mix of bark spraying, soil tablets and other efforts will be used at different times of the year to drive out the HWA bugs, park superintendent Jeff Reinbold said.

"We hope that these treatment methods will protect the hemlock trees and help us preserve the crash scene," he added.

The treatment plan will continue for the next three years, Newlin said.

David Hurst writes for The Tribune-Democrat in Johnstown, Pa.