Pesticide concentrations in moths and other insects collected from the United States and Canada, 2022 to 2024

Both aquatic and terrestrial insects can undergo complex evolutionary phases throughout their lifespan. Insects in a larval phase can accumulate and retain some chemicals, such as pesticides, throughout their various life cycles. Mature insects are often more mobile than their younger counterparts, making them able to transport pesticides over further distances. Insectivores (animals that eat insects) can potentially consume these insects resulting in pesticide exposure and accumulation. This data set includes a variety of moth and other insect species at various life stages that were analyzed for pesticide residues. Insects were collected from agricultural land and remote areas in the United States (Montana, Colorado, Iowa, Nebraska) and Canada (Ontario). 25 Environmental samples were collected. Of these 25 samples, the most abundant species were the army cutworm moth (3), the true armyworm moth (3), and the wheat stem sawfly (5). All other samples consisted of separate individual species. There were two larvae (true armyworm moth and wheat stem sawfly) included in the analyzed samples. Samples were analyzed for 190 pesticide compounds and pesticide transformation products (TPs). Overall, 25 pesticides and TPs were detected. Of these detections, there were 10 herbicides, 7 insecticides, and 8 fungicides. The number of pesticide compounds detected in a sample ranged from one to seven. The most frequently detected pesticides by use class were the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D) (44%), the insecticide TP p,p'-DDE (dichlorodiphenyldichloroethylene) (36%), and the fungicide pyraclostrobin (8%). Concentrations across all samples ranged from not detected to 194.8 nanograms per gram (ng/g) dry weight.