A federal appellate court has invalidated the U.S. EPA’s approval of a new pesticide, sulfoxaflor, concluding that the agency’s decision was based on “flawed and limited data” and was unsupported by substantial evidence. Pollinator Stewardship Council v. United States Environmental Protection Agency, No. 13-722346 (9th Cir., Sept. 10, 2015). Sulfoxaflor is part of a subclass of neonicotinoids, systemic pesticides that are absorbed and distributed throughout the plant’s vascular system into tissues, pollen and nectar. Some studies have linked use of neonicotinoids to Colony Collapse Disorder and associated rapid declines in honey bee populations from long-term exposure to pollen and nectar containing the pesticide. The EPA determined that sulfoxaflor was “very highly toxic” to honey bees and that studies submitted by the applicant regarding its impact on bees were incomplete, but nonetheless approved the product for use at lower concentrations with specified mitigation measures. In setting aside the approval, the court said that “given the precariousness of bee populations, leaving the EPA’s registration of sulfoxaflor in place risks more potential environmental harm than vacating it.” The court’s decision precludes use of the insecticide pending new studies to determine its long-term impacts on bees. Read our full Update on the case here.