Hemlock woolly adelgid infestation. Specks on needles are crawlers moving on needles. Photo provided by: Pennsylvania Department of Conservation and Natural Resources – Forestry Archive, Bugwood.org

Close-up of hemlock woolly adelgid eggs. Photo provided by: Shimat Joseph, University of Georgia, Bugwood.org

Injecting insecticide into the tree is one method to control HWA. Photo provided by: Great Smoky Mountains National Park Resource Management Archive, USDI National Park Service, Bugwood.org

Injecting systemic insecticides into the soil (using a Kioritz here) is another way to treat for HWA. Photo provided by: Great Smoky Mountains National Park Resource Management Archive, USDI National Park Service, Bugwood.org

Spraying insecticides in another method to control HWA. Photo provided by: Great Smoky Mountains National Park Resource Management Archive, USDI National Park Service, Bugwood.org