Flupyradifurone is a novel insecticide licensed for use on bee-visited crops. It was thought to cause less harm to pollinators. But, a new study suggests that the chemical kills 100% of Mason Bees.
Neonicotinoids are the most common insecticides globally. When bees come into contact with them, their ability to find food, think, fly, and stay warm can be harmed. This affects their reproduction, abundance, and diversity. Some neonicotinoids are now banned for non-farm use.
Flupyradifurone is a systemic insecticide being approved worldwide. It targets pests resistant to neonicotinoids and works similarly by affecting insect nerve receptors. Despite its different chemical structure, it functions in the same way as neonicotinoids.
Flupyradifurone has low toxicity to honeybees, allowing its use on flowering crops during bloom. However, its effects on solitary bees have not been well-studied.
Solitary bees are important pollinators of crops and wildflowers. However, they are more vulnerable to pesticide exposure than social bees. In this study, scientists exposed solitary bees (Osmia lignaria) to pesticide-treated wildflowers to investigate the sub-lethal effects of flupyradifurone on them.
Bee nesting blocks for solitary bees (Osmia lignaria). Credit: Harry Siviter
They found several negative impacts on the bees. After seven days of exposure, these bees were unable to start nesting. They likely had lower survival rates and were less efficient foragers.
The study was initially designed to examine sublethal effects, but contrary to scientists’ expectations, 100 % of bees released into pesticide-treated cages died within three days of exposure.
Lead author Harry Siviter from Bristol‘s School of Biological Sciences explained, “These results demonstrate that exposure to this novel insecticide poses significant threats to solitary bees and add to a growing body of evidence indicating that this pesticide can have negative impacts on wild bees at field-realistic concentrations.”
“Restricting commercial pesticides containing flupyradifurone to non-flowering crops would be sensible while more research is conducted.”
“In the long-term, as we are already seeing in the EU, a move towards a more holistic approach to risk assessment that considers the biology of non-Apis bees is required to better protect pollinators from the unintended negative impacts of pesticides.”
Journal Reference:
- Harry Siviter, Jennie DeVore, et al. A novel pesticide has lethal consequences for an important pollinator. Science of The Total Environment. DOI: 10.1016/j.scitotenv.2024.175935
