Monday, December 10, 2007 - 9:53 AM

The spider community of eastern hemlock: Potential population regulators of hemlock woolly adelgid (Adelges tsugae)?

Rachael Elaina Mallis,, Lynne Rieske Kinney,, and James Harwood, University of Kentucky, Entomology, S-225 Agricultural Science Center North, Lexington, KY

Spiders are ubiquitous generalist predators, and as such, are often overlooked candidates for biological control of invasives. It is important, however to evaluate all potential native predators on invasives, before non-natives are released. One area that is of great importance to the eastern United States is the control of hemlock woolly adelgid (HWA) on Eastern hemlock. To date, little work has been done to document the spider communities of eastern hemlocks in the United States. Spiders and opilionids have typically been disregarded as potential predators of the adelgid, because no direct field observations of predation have been recorded. By surveying non-infested hemlocks and HWA-infected hemlocks in Kentucky along the border of the advancing adelgid invasion, this study aims to describe the hemlock spider community and the effects of adelgid on spider diversity and abundance. A beat-sheet method was employed for collection from branches or small trees that were vigorously shaken. Spiders were immediately contained via aspirator. Adults were classified to species and genera level, with most juveniles classified to family. Spider diversity and richness will be calculated and correlated with adelgid presence/absence. ANOVA will be used to analyze the interactions of abundance, richness and diversity of spiders as dependent variables. In the future, an ELISA will be used to confirm predation of adelgids. This study is significant because a new spider community will have been defined; the community ecology of HWA will be examined and ultimately this can contribute to conservation efforts of eastern hemlocks and the ecosystems they comprise.

Species 1: Araneae Araneidae (spiders)
Species 2: Hemiptera Adelgidae Adelges tsugae (hemlock woolly adelgid)
Species 3: Araneae Linyphiidae (spiders)