Predatory beetles to combat spread of hemlock pests Georgia  
DNR, partners fund UGA beetle lab to control hemlock woolly adelgid

ATHENS, Ga. (April 17, 2006) - North Georgia's majestic hemlock trees are under attack from a tiny insect with a voracious appetite, and their best defense could prove to be a predatory beetle that feeds on the pests. The Georgia Department of Natural Resources (DNR) is helping to fund the development of a beetle lab at the University of Georgia as part of a long-term effort to stop the spread of the hemlock woolly adelgid. Other partners in the project include the U.S. Forest Service, Georgia Forestry Commission, U.S. Department of Agriculture - Animal and Plant Health Inspection Service, Georgia Forest Watch, Georgia Wildlife Federation, Georgia Power Company and the Lumpkin Coalition.

   The hemlock woolly adelgid is an aphid-like insect native to Asia that kills Eastern hemlock and Carolina hemlock trees by attaching to the needles and consuming the sap. Insecticides are not effective at controlling the hemlock woolly adelgid on a large scale, but experiments in other states suggest that introducing certain species of predatory beetles can be an effective control measure.

   "We are optimistic that the beetle lab is a step toward controlling the hemlock woolly adelgid in Georgia and protecting stands of hemlock trees," said Georgia DNR Commissioner Noel Holcomb. "We are committed to working to safeguard this important part of our natural resources."

   The Georgia DNR will allocate $175,000 to help fund the start-up costs of a beetle-producing lab at UGA. Plans call for releasing beetles at
114 sites in Georgia, and some scientists believe three different species of beetles will be needed to successfully combat the adelgid.  The UGA lab is expected to focus on two of these: Laricobius nigrinus, native to the Pacific Northwest, and Scymnus sinuanodulas, native to China. Both species have been approved for release by the U.S. Department of Agriculture. Research has shown that the beetles feed only on adelgids, without causing serious impacts to native species.

   The coniferous Eastern hemlock is found on about 250,000 acres of forestland in Georgia, and is the dominant tree species on about half of that area, according to the Georgia Forestry Commission. Tallulah Gorge is the only known location of the closely related Carolina hemlock in Georgia. An estimated 20 to 30 percent of the eastern hemlock range in Georgia is believed to be infested, with the most severe damage occurring in the Chattooga River area. Scientists have predicted that, without significant action, 90 percent of Georgia's hemlocks could be dead by 2015.

   Losing Georgia's hemlocks could have serious impacts on wildlife. The deep shade of hemlock forests helps keep stream temperatures cool enough to support trout, and hemlock dominated watersheds have been found to support more aquatic insect species than streams draining hardwood forests. Bird species heavily dependent on the hemlock include the black-throated green warbler, Blackburnian warbler, Swainson's warbler, red-breasted nuthatch, and red crossbill. The water shrew is a rare mammal common in hemlock forests, as are rare amphibians including the green salamander, hellbender, and shovelnose salamander.

   State-owned wildlife management areas with prominent hemlock stands include Dawson Forest, Smithgall Woods and Pigeon Mountain. State parks in north Georgia that are at significant risk from the adelgids include Tallulah Gorge, Vogel, and Cloudland Canyon. The Georgia Department of Natural Resources and the Georgia Forestry Commission are currently surveying all state-owned lands to detect the presence of the hemlock woolly adelgid. Both agencies are developing a plan that includes predator insect release at designated sites and insecticidal treatments to protect rare or significant groups of hemlock trees.