Comparison of fecundity and survival of hemlock woolly adelgid (Hemiptera: Adelgidae) in northern and southern populationsThis article is part of a larger document. View the larger document here.
The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an introduced species first reported in the eastern United States in 1951. The infestation has since spread in all directions from its initial sighting in Virginia, to its current range from northern Georgia, to southern Maine, and westward into Tennessee, causing substantial mortality to eastern (T. canadensis) and Carolina (T. caroliniensis) hemlocks. Tree death often occurs in as little as 4 years, especially in southern populations; however, in New England, it has been shown that A. tsugae populations may often persist at relatively low density for many years.