It is an important ritual that is being disrupted by one of the most pervasive forms of air pollution—diesel exhaust—according to a new study published Thursday in Scientific Reports. The research pinpoints the mechanism by which the fuel-combustion pollutants degrade certain chemicals in floral odors. The absence of those chemicals affects honeybees’ ability to recognize the scent. (See related quiz: “What You Don’t Know About Cars and Fuel.”)

Engine exhaust is hardly the only threat facing the honeybee. It is well recognized that exposure to multiple pesticides can impair bees’ olfactory skills, while ground-level ozone, or smog, and ultraviolet (UV) radiation can also degrade floral odor compounds that bees pick up on. Authorities around the globe are grappling with