I’m writing to raise awareness of a newer challenge to our area’s forests. In 2023, Royal Botanical Gardens staff found that some eastern hemlock trees around Cootes Paradise showed the fuzzy telltale signs of a new threat: hemlock woolly adelgid (HWA). Hemlock woolly adelgid is a sap-sucking bug first detected in Hamilton in the early 2020s. The individual insects are just two millimetres long and are spread by birds. With climate change, recent warmer winters (on average) help them to survive. The arrival of the hemlock woolly adelgid means that eastern hemlock may join the sad list of magnificent trees in southern Ontario already seriously affected by invasive insects and diseases, like white ash, American elm and American chestnut. …Eastern hemlocks are important trees that create deep shade and habitat for birds and other animals.