The hemlock woolly adelgid, Adelges tsugae Annand, (Homoptera:Adelgidae) is one of the most important forest pest of the eastern United States. Thought to be native to Japan, it was first recorded in Virginia in 1951 and its current range spans from Connecticut south to North Carolina. Extensive mortality of both eastern hemlock, Tsuga canadensis (L.) and Carolina hemlock, Tsuga caroliniana Englemann occurs throughout the adelgid's distribution in the eastern United States. Current sampling procedures are extremely tedious and not related to tree health or damage. A sampling procedure that accurately estimates HWA population density will be invaluable in both the prioritization of stands for treatment and in assessing the effectiveness of biocontrol agents released.
Before we can develop a sampling procedure, we need to understand the spatial distribution of adelgids within individual trees and within stands from the first years of infestation through to tree mortality. Permanent sample plots were established in recently infested eastern hemlock stands in southwestern Virginia in November 2000. Branches were sampled at each cardinal direction at two different heights of 10 eastern hemlocks in each of the five plots in November 2000, June 2001 and November 2001. Adelgid numbers and on new and old growth were recorded and entered into a spatial database for analysis. Various ecological measures were also taken at each plot in efforts of identifying variables that help explain temporal and spatial variability in adelgid populations.
Species 1: Homoptera Adelgidae Adelges tsugae (hemlock woolly adelgid)
Keywords: insect distribution, sampling procedure
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA