Perched on a platform 50 feet above the ground in a big hemlock named Fern, Geoff Elliott points to an unwelcome Asian import: a little bug known as the hemlock woolly adelgid.
Small fuzzy white nymphs cling to the undersides of hemlock branches throughout the grove of trees. Both nymphs and adult adelgids can work quickly to destroy hemlocks 150 feet tall.
"This tree is believed to be somewhere between 200 and 300 years in age and can be taken out by the adelgid in as little as two to four years," says Mr. Elliott, a tour guide for Adventure West Virginia Resort LLC, which operates zip-line tours through the treetops. The company is trying to educate visitors about the dangers of the invasive insect as it diminishes the landscape the business relies on.
"Without any action we could lose the species," said Mark Whitmore, a forest entomologist at Cornell University. He described the hemlock as a "keystone species," because it provides shade that cools streams so fish can survive as well shelter for birds and animals. Losing it would be like "having all your front teeth fall out," he said.
As global trade has mounted, more goods are coming in from overseas, sometimes bringing with them the accidental cargo of destructive bugs and plants. An estimated 500 million plants are imported to the U.S. each year, and shipments through one plant inspection station doubled to 52,540 between 2004 and 2006, according to the U.S. Department of Agriculture. Today, about 30 new invasive insects are discovered annually in the U.S., up sharply over the last decade, the USDA says.
by Kris Maher
Friday, January 15, 2010
Write to Kris Maher at kris.maher@wsj.com
