Pest management programs that use imidacloprid to preserve hemlock resources from an invasive insects may have unknown long-term impacts on aquatic resources. Throughout many National Park Service(NPS)units, hemlock-dominated forests are ecologically important but threatened by an exotic insect pest, the hemlock woolly adelgid (HWA). HWA management decisions have been made based on limited knowledge of the effects of imidacloprid on non-target species, and its persistence in soil and aquatic environments.

This study will assess the risks and non-target impacts of imidacloprid treatments in riparian hemlock forests on water quality, benthic macroinvertebrates, and stream salamanders. Results may be used to reassess the HWA treatment programs in our three study parks as well as many other NPS units that have HWA treatment programs.