Hemlock Woolly Adelgid Infestation (IMAGE) USDA Forest Service ‑ Southern Research Station Caption Hemlock woolly adelgids feed at the base of hemlock needles, depriving the tree of food and eventually killing it. Credit USDA Forest Service Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.