Insect Fauna Associated with Eastern Hemlock, Tsuga canadensis (L.), in the Great Smoky Mountains National Park

Eastern hemlock, Tsuga Canadensis (L.), is an integral part of the forest system in eastern North America. These trees contribute to the biological diversity, environmental health, and economic stability of the regions that they inhabit by producing unique microclimates, cool shady recreational areas, and unmatched beauty. Information regarding the insect fauna associated with eastern hemlock is sparse and scattered with in the literature. Because of this, the insect fauna associated with eastern hemlock was assessed at four sites, representing new and old growth, and nine alternate sites in the Great Smoky Mountains National Park (GSM). Sites were sampled using malaise traps, pitfall traps, beat sheeting, and direct collection. Species diversity was assessed using the Shannon-Weiner diversity indices and species richness estimates were made using the program estimateS.

The rich insect fauna of the eastern hemlocks in the GSM yielded 2,516 specimens representing 280 species in 87 families and eight orders. Species richness and abundance was highest and at site 3 (Chimney tops old growth) with 801 specimens and 113 species. Species richness estimators determined that species richness associated with eastern hemlock is between 420 and 550 species. Pests of eastern hemlock including the hemlock looper, Lambdina fiscellaria (Guenee), were collected, as well as nine species that are predators of the exotic pest hemlock woolly adelgid, Adelges tsuga (Annand).

Data collected in this study offer a listing of insect fauna associated with eastern hemlock in the GSM. These results will assist in the development and management of forest containing and dominated by eastern hemlock. In addition, due to the threat of hemlock woolly adelgid, information collected in this study provides a baseline of the insect fauna associated with eastern hemlock prior to disturbances altering species composition.