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Wild bee exposure to pesticides in conservation grasslands increases along an agricultural gradient: A tale of two sample types

December 27, 2022

Conservation efforts have been implemented in agroecosystems to enhance pollinator diversity by creating grassland habitat, but little is known about the exposure of bees to pesticides while foraging in these grassland fields. Pesticide exposure was assessed in 24 conservation grassland fields along an agricultural gradient at two time points (July and August) using silicone band passive samplers (nonlethal) and bee tissues (lethal). Overall, 46 pesticides were detected including 9 herbicides, 19 insecticides, 17 fungicides, and a plant growth regulator. For the bands, there were more frequent/higher concentrations of herbicides in July (maximum: 1600 ng/band in July; 570 ng/band in August), while insecticides and fungicides had more frequent/higher concentrations in August (maximum: 110 and 65 ng/band in July; 1500 and 1700 ng/band in August). Pesticide concentrations in bands increased 16% with every 10% increase in cultivated crops. The bee tissues showed no difference in detection frequency, and concentrations were similar among months; maximum concentrations of herbicides, insecticides, and fungicides in July and August were 17, 27, and 180 and 19, 120, and 170 ng/g, respectively. Pesticide residues in bands and bee tissues did not always show the same patterns; of the 20 compounds observed in both media, six (primarily fungicides) showed a detection-concentration relationship between the two media. Together, the band and bee residue data can provide a more complete understanding of pesticide exposure and accumulation in conserved grasslands.

Citation Information

Publication Year 2023
Title Wild bee exposure to pesticides in conservation grasslands increases along an agricultural gradient: A tale of two sample types
DOI 10.1021/acs.est.2c07195
Authors Michelle Hladik, Johanna M. Kraus, Cassandra Smith, Mark W. Vandever, Dana W. Kolpin, Carrie E Givens, Kelly Smalling
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Science and Technology
Index ID 70239117
Record Source USGS Publications Warehouse
USGS Organization California Water Science Center; Columbia Environmental Research Center; Fort Collins Science Center; New Jersey Water Science Center; Oregon Water Science Center; Central Midwest Water Science Center; Upper Midwest Water Science Center