News Releases

More than 2,500 Pt beetles were transported to the Great Smoky Mountains National Park in a paper bucket on shredded paper. The beetles shown are being encouraged to abandon the paper in favor of their new home, a hemlock woolly adelgid-infested tree. More than 5,000 acres of hemlocks are threatened by the pest in the nation's most visited national park. Download this photo (250 K)

(TOWNSEND, Tenn.) — What can you do with 2,523 beetles?

Researchers with the University of Tennessee Beneficial Insects Laboratory hope the insects will prevent the demise of more than 5,000 acres of hemlock forest in the Great Smoky Mountains National Park as well as save stands of hemlock throughout the region.

The nation's most popular national park, the Great Smoky Mountains are visited by some 9 million people each year. Visitors come to enjoy the park's unique scenery and vast biodiversity.

On April 7, UT entomology professor Dr. Ernest Bernard, along with representatives of the National Park Service and the nonprofit group Friends of the Smokies, released 2,523 tiny beetles bred to preserve part of the park's biodiversity — some of the southernmost stands of hemlock trees. A second release in the park is scheduled for the Deep Creek, North Carolina, area on April 15.

The beetles are expected to combat the hemlock woolly adelgid, an invasive pest that has decimated Northeastern populations of the majestic and ecologically valuable tree. HWA first appeared in the national park in 2002, and the pest is spreading rapidly.

Hemlocks serve as habitat for numerous bird species and they cool the mountain streams that are home to trout and other native fish, as well as crawfish, salamanders, and numerous aquatic insects. Some of the hemlock stands in the Smokies are estimated to be between 400 and 500 years old, and these individuals, as well as their younger relatives, can all be killed by the tiny adelgids in a matter of a few years.

Hemlock woolly adelgids were first introduced in the United States in the 1920s in the Pacific Northwest, and in the early 1950s the pest spread to the Washington, D.C., and Richmond, Virginia, areas.

Natural stands of hemlock from Massachusetts to Georgia are already dead or dying, with many trees standing like dour sentinels in the face of a siege. Foresters predict that if left unchecked the HWA infestation will be comparable to the chestnut blight, which forever changed the composition of
Southeastern forests.

"It could spell disaster for certain ecosystems," said Bernard.

Pt beetles are natural enemies of hemlock woolly adelgids, and scientists believe the tiny beetles are the best tool available for saving infested hemlocks in areas not readily accessible by roads. Download this photo (61 K)

Biologists and forest advocates believe the Pseudoscymus tsugae beetle, or Pt beetle for short, is the best tool for fighting HWA infestations in remote stands of trees. The poppy-seed sized beetles feed almost exclusively on the HWA. In their native Japan and China, the beetles and HWA have a symbiotic relationship, with each population keeping the other in check. However, the HWA has no natural enemies in North America.

"We can use chemical treatments or soap sprays to kill adelgids along roadsides or in easily accessible sites," said Bernard, "but the beetles are really the only method of attacking adelgid infestations in the backcountry."

Kristine Johnson, forestry supervisor for the Great Smoky Mountains National Park, agreed. She chose the Lead Cove release site and also participated in the release. The underside of the branches of nearly every hemlock in the immediate area of the release was marked with the telltale "white wool" of the HWA.

Bernard and others associated with the UT Beneficial Insects Lab are working furiously to breed more Pt beetles. The beetles released April 7 are the first of some 30,000 that researchers hope to produce and release this season. "They are difficult to collect in the wild," Bernard said, "so breeding them in captivity is the best method to generate the needed populations."

Veronica Gibson, a researcher who works in the UT lab said the cost to produce each beetle is approximately $2.

The entomologists believe that releasing 2500 beetles is a sufficient number to create a sustaining population in an area. "As long as they have their food source - the adgelgid - then the beetles should produce offspring," Bernard said. After the release, he pointed out beetles feeding on adelgid. "They seem to be adjusting well to their new home," he said. "They're ravenous eaters."

Johnson will choose the sites and oversee future beetle releases in the national park. She says releases will be scheduled for different areas in an attempt to keep HWA infestions from spreading.

Funded in part with grants from the National Park Service, the USDA and the Friends of the Smokies, the UT Beneficial Insects Lab is one among five Pt beetle-rearing facilities in the nation.

For more information about the regional effort visit the Web site www.saveourhemlocks.org.

###

Contacts:

Dr. Ernest Bernard, 865-974-7135
Patricia McDaniels, 865-974-7141