Impact of Hemlock Woolly Adelgid Imidacloprid Treatments on Water Quality and Aquatic Macroinvertebrate Communities
Ten conservation areas in which hemlocks in riparian areas were given soil imidacloprid applications were selected. Stream sampling sites were chosen upstream and downstream from each conservation area, for a total of ten paired upstream – downstream sites. Surface water samples and aquatic macroinvertebrate samples were collected from each sampling location.
Concentration of imidacloprid in parts per trillion (ppt) was determined using liquid chromatography mass spectroscopy (LC/MS). Aquatic macroinvertebrate communities were assessed as indicators of water quality.
Imidacloprid was detected in seven of ten downstream locations. Concentrations ranged from 28.5 to 379 ppt, which are below USEPA chronic and acute aquatic macroinvertebrate aquatic life benchmarks. Aquatic macroinvertebrate taxa from upstream and downstream sites were similar. While potential impacts of HWA imidacloprid treatments on surface water quality are minimal, the extent of treatments should be carefully considered for overall system health.
See more of: Student Ten Minute Paper Competition