RICHMOND, Va. — A beetle the size of a single grain of rice is the latest best hope for hemlocks in the Southeast that have been felled by the millions by an invasive bug.
The beetle eats only one thing: the hemlock woolly adelgid, and it does so voraciously.
Researchers are hopeful this new beetle will be a worthy adversary, based on releases of the beetles at sites in Virginia and West Virginia. Like the adelgid, the beetle is native to Japan, and they’re adapting to their new surroundings.
The introduction of the beetle is the latest tack to save the hemlock, a daunting task amid fears the evergreen could be facing the same fate as the American chestnut, which was virtually wiped out by a blight.
“We’re heading down a path that doesn’t look promising for the tree,” said James “Rusty” Rhea, an entomologist with the U.S. Forest Service in Asheville, N.C. “If it goes unchecked, we’re going to see some catastrophic mortality similar to what we had with the chestnut in the ’20s and the ’30s and the ’40s.”
The adelgid has left a terrible path of destruction in forests along the Eastern Seaboard since it was first identified in Virginia in 1951. Its impact has been less severe among interior sections of the Northeast, where long, cold winters keep the pest in check, but it has devastated hemlock stands in Virginia, the Carolinas, Georgia and Tennessee.
The bug has wiped out 90 percent of the hemlocks in Virginia’s Shenandoah National Park and has taken a big bite out of stands in the Great Smoky Mountains. Approximately three-quarters of the hemlocks are infested on the East Coast, while the Southeast has seen nearly half of its hemlocks wiped out.
For the woolly adelgid, it’s been an all-you-can-eat buffet. The bug eats only hemlocks, and it has no native predators.