During the past 20 years, insecticides applied to U.S. agricultural landscapes have become significantly more toxic—over 120-fold in some midwestern states—to honey bees when ingested, according to a team of researchers, who identified rising neonicotinoid seed treatments in corn and soy as the primary driver of this change. The study is the first to characterize the geographic patterns of insecticide toxicity to bees and reveal specific areas of the country where mitigation and conservation efforts could be focused.