Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Wildlife and Fisheries Resources
The insecticide imidacloprid is widely used to mitigate hemlock (Tsuga spp.) mortality resulting from the invasive hemlock woolly adelgid (HWA), but evidence suggests that
imidacloprid can have negative effects on adjacent stream systems. Imidacloprid exposure causes physiological changes, bioaccumulation, and reduced survival in anurans, and induces physiological impairment and reduced survival in benthic macroinvertebrates. In this thesis, we assessed whether HWA treatments using imidacloprid affect stream salamander abundances and benthic macroinvertebrate community composition. We also investigated whether imidacloprid or its metabolites bioaccumulate in benthic macroinvertebrates or salamanders and cause sublethal effects. We conducted this study in two National Park Service units of West Virginia and the Monongahela National Forest (MNF) and used standard sampling methods to survey stream salamanders and benthic macroinvertebrates. We also euthanized salamanders of the genus Desmognathus to assess imidacloprid and metabolite bioaccumulation and concentrations of the stress hormone, corticosterone. We provide strong evidence that salamanders and stream invertebrates bioaccumulate imidacloprid and that imidacloprid is associated with sublethal effects in salamanders, including reduced body condition and increased corticosterone levels. Additionally, we detected negative effects of imidacloprid treatments on Desmognathus spp. abundances and on benthic macroinvertebrate community composition within MNF. This study demonstrates unintended effects of imidacloprid treatment on adjacent stream organisms.
Crayton, Sara M., "STREAM SALAMANDER AND BENTHIC MACROINVERTEBRATE COMMUNITY RESPONSES TO IMIDACLOPRID EXPOSURE" (2019). Graduate Theses, Dissertations, and Problem Reports. 4015.