The fascinating complex life cycle of hemlock wooly adelgid (HWA), Adelges tsugae Annand

Hemlock woolly adelgid (HWA), Adelges tsugae, is an invasive insect that causes tree decline and mortality of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana) in eastern North America. It was first detected in Virginia in 1951 and has since spread through much of the eastern United States and into southern Canada.