Hemlocks in decline or dying from Hemlock woolly adelgid infestations. Photo by: William M. Ciesla, Forest Health Management International, Bugwood.org.

Hemlock infested with Hemlock Woolly Adelgid. Photo by: Brian Kunkel, Ornamentals IPM Specialist, University of Delaware.

Close-up of cottony adults. Photo by: Brian Kunkel, Ornamentals IPM Specialist, University of Delaware.

Close-up of HWA crawler and adult. Photo by: Pennsylvania Department of Conservation and Natural Resources – Forestry Archive, , Bugwood.org.