Date: March 28, 2006
Contact: Nancy Gray, (865) 436-1208
In August 2005 the Great Smoky Mountains National Park prepared and distributed for public input an Environmental Assessment (EA) on the Hemlock Woolly Adelgid (HWA) management strategies for reducing the insect’s impact on forest resources. The EA discussed five possible alternatives and identified a combination of chemical and biological controls for suppressing this invasive, nonnative pest as the preferred alternative. After careful review by the public and agencies, the document was approved by the National Park Service Regional Director Pat Hooks. A Finding of No Significant Impact in support of the preferred alternative was signed in February 2006.
Only about 20 comments were submitted by the public and representatives of state and federal agencies during the public review process, and the comments were overwhelmingly supportive of the Park’s preferred alternative. Many respondents noted the importance of hemlock in the ecosystem and the urgent need to act promptly and comprehensively in protecting the native forests.
Only a few public comments indicated concern regarding the biological control agents. The concerns involved the misperception that the park had released the large, black and orange ladybeetles that congregate in residences. That much larger, multicolored beetle was introduced in the late 1970s for control of various crop pests and has become a nuisance pest in homes. The park has released tiny black ladybeetles that feed only on adelgids. They have been thoroughly studied in the field and do not congregate in large numbers and do not leave the forest during their summer dormant period.
Prior to the EA distribution, a letter of discussion describing in detail potential impacts of HWA infestation and management options was sent to a large mailing list of interested groups, including conservation organizations, city and county officials, congressional representatives and tourism officials from areas surrounding the Park.
National Park Service policy requires managers to protect the natural resources in park areas and, under the Integrated Pest Management program, permits where feasible the introduction and maintenance of nonnative species to control another, already established nonnative species.
The EA documented that the use of the proposed chemicals and biocontrols are feasible for this project and those methods were thoroughly analyzed using information from extensive studies conducted in the field, subject matter experts in the U.S. Forest Service, state and other federal agencies, and university entomologists. These treatment methods also best protect water resources, non-target species, and threatened and endangered species.
The park’s plan is to use treatments that include the release of adult predator beetles and their eggs, insecticidal soap or oil, and systemic insecticides. By using a combination of treatments, Park managers can more effectively use limited funds and resources to treat a greater area across the landscape. The use of biological controls such the predator beetles allows the treatment of trees in the backcountry, in old growth stands and along waterways. Chemical controls are more feasible for treating trees accessible from roads. While pesticides may be used in the backcountry, this option is not feasible on a landscape scale.
“Large scale hemlock mortality has not yet been observed in the Park, but we are beginning to see areas of decline and can expect scattered areas of mortality throughout the Park in the near future,” said Park Superintendent Dale Ditmanson. “The varying methods will give us the flexibility needed to proactively and safely address this long-term threat to our forest environments. Our best hope for success is to reduce hemlock mortality in order to sustain stands of healthy, viable trees, particularly in old growth forests and in high visitor use areas. We are very appreciative of the Friends of the Smokies, The University of Tennessee, State of Tennessee, and U.S. Forest Service for their support. Without those partners, saving such an irreplaceable tree species would not be possible.”
