One of those alternatives is a pesticide called Sivanto, made by Bayer CropScience. Sivanto is Bayer’s brand name for a pesticide called flupyradifurone, and the company has stressed that the pesticide is safe on bees, to the point of commissioning studies affirming the fact. Bayer’s American director of pollinator safety even gave this quote: “No new insecticide has been as thoroughly tested with respect to bee safety prior to registration.”

Now, researchers from the University of California, San Diego havereleased the results of a years-long study in which they tested whether Sivanto really is bee-friendly. What they found is that the “thorough testing” may have excluded some pretty common use cases, and that in those, Sivanto is associated with greater mortality and some abnormal behavior than compared with a control group.