Deal, Isaac K.. Life History of Hemlock Woolly Adelgid, Adelges tsugae Annand, on Eastern Hemlock, Tsuga canadensis (L.) Carriere, in the Southern Appalachians and Assessment of Egg Releases of Sasajiscymnus tsugae (Sasaji and McClure) for Its Management In Entomology and Plant Pathology. Knoxville, TN: University of Tennessee, 2007.