A pesticide banned for outdoor use by the EU could be less harmful to bees than had been thought. This is the conclusion of a study that exposed bumblebee colonies to sulfoxaflor, an insecticide approved in the EU in 2015 but banned for outdoor use in April 2022.
The new study, carried out at the University of Reading and Royal Holloway, tested the effects of field-realistic levels of sulfoxaflor in the presence of a common bee parasite, Crithidia bombi, on the buff-tailed bumblebee, Bombus terrestris. The parasite gave the bees an extra challenge, to try to replicate the multiple stressors pollinators often face in the wild.
The finding that sulfoxaflor had no impact on bumblebee colonies or the pollination of bean flowers, enclosed so that only the study bumblebees could visit them, runs counter to comparable studies on neonicotinoids, also carried out at the University of Reading.
‘This changes our understanding of how sulfoxaflor impacts bee reproduction and pollination, and means it is less harmful than the neonicotinoids,’ says Edward Straw, a bee ecologist at Trinity College Dublin who carried out the research. However, he stresses that this only holds true for the conditions that were tested.
