1. Anonymous, 2007. Hemlock woolly adelgid infestations 2006. USDA Forest Service. http://www.na.fs.fed.us/fhp/hwa/maps/hwa_2006.pdf.
2. Degradation and sorption of imidacloprid in dissimilar surface and subsurface soils;Anhalt;Journal of Environmental Science and Health,2008
3. Asaro, C., Berisford, C.W., Montgomery, M.E., Rhea, J., Hanula, J., 2005. Biological control of the hemlock woolly adelgid in the southern Appalachians. In: Onken, B., Reardon, R. (Compilers). Third Symposium on Hemlock Woolly Adelgid in the Eastern United States, Ashville, NC, February 1–3, 2005, USDA Forest Service FHTET-2005-01, Morgantown, WV, pp. 248–251.
4. Seasonal synchrony of life cycles between the exotic predator, Pseudoscymnus tsugae (Coleoptera: Coccinellidae) and its prey, the hemlock woolly adelgid, Adelges tsugae (Homoptera: Adelgidae);Cheah;Agricultural and Forest Entomology,2000
5. Cheah, C.A.S.-J., Montgomery, M.E., Salom, S., Parker, B.L., Costa, S., Skinner, M., 2004. Biological control of hemlock woolly adelgid. USDA Forest Service, FHTET-2004-04. In: Reardon, R., Onken, B. (Tech. Coordinators), 22 pp.