Impact of pesticide use on wild bee distributions across the United States
The decline of many wild bee species has major consequences for pollination in natural and agro-ecosystems. One hypothesized cause of the declines is pesticide use; neonicotinoids and pyrethroids in particular have been shown to have pernicious effects in laboratory and field experiments, and have been linked to population declines in a few focal species. We used aggregated museum records, ecological surveys and community science data from across the contiguous United States, including 178,589 unique observations from 1,081 bee species (33% of species with records in the United States) across six families, to model species occupancy from 1995 to 2015 with linked land use data. While there are numerous causes of bee declines, we discovered that the negative effects of pesticides are widespread; the increase in neonicotinoid and pyrethroid use is a major driver of changes in occupancy across hundreds of wild bee species. In some groups, high pesticide use contributes to a 43.3% decrease in the probability that a species occurs at a site. These results suggest that mechanisms that reduce pesticide use (such as integrative pest management) can potentially facilitate pollination conservation.
There are widespread reports of bee declines in Europe and North America, but the status of most species is poorly known1,2,3,4,5,6. Insect pollination, largely from wild and managed bees, benefits ~75% of crop species worldwide and 88% of flowering plant species1. Further, the majority of crop pollination is provided by wild pollinators worldwide, and wild pollinators can enhance yields regardless of managed bee abundances7,8. Overall, this suggests that the decline of wild pollinators will have strong detrimental effects on pollination services, with both economic and ecological consequences.
