Soil Arthropod Biodiversity: An Investigation in Eastern Hemlocks Following Chemical Treatment

Julia Thomas, eperryma@unca.edu

jthoma11@unca.edu

Office of Sustainability & McCullough Institute

The hemlock woolly adelgid (Adelges tsugae) (HWA) is an invasive species that poses a significant threat to eastern hemlocks (Tsuga canadensis) and is the main contributor to the declining eastern hemlock populations. The HWA infestations have prompted the use of chemical neonicotinoid pesticide treatments across the eastern US. Previous research has demonstrated that the environmental consequences of these chemicals are a concern for many surrounding animal populations such as birds and invertebrates. This study investigated the impact of dinotefuran and imidacloprid (neonicotinoids) treatments on soil arthropod communities in Sandy Mush Game Land (SMGL), Western North Carolina. For this experiment, we examine the impacts of different combinations of the type of chemical control (imidacloprid, dinotefuran and imidacloprid), and time after application (no treatment, 5 years, and less than a year). Leaf litter samples were collected from five different plots, processed in the laboratory using Berlese Funnels, and observed organisms were classified by order. Based on the results, no significant differences in arthropod biodiversity were observed between plots in this experiment. Differences in abundance varied across groups and could suggest both direct and indirect implications of neonicotinoid use immediately after treatment. These findings suggest that the use of neonicotinoids does not have long term implications for arthropod diversity and abundance and that chemical treatment should proceed to avoid ecological implications of the loss of hemlock stands. Further research should take place with a more extensive experimental area and period of time to continue to investigate direct and indirect impacts of neonicotinoids on the soil organism biodiversity.

Dec-15-2023