Pesticide Imidacloprid Threatens Ground-Nesting Bees

A University of Guelph study found female hoary squash bees exposed to the insecticide imidacloprid dug 85% fewer nests, collected less pollen from crop flowers and produced 89% fewer offspring than unexposed bees. Imidacloprid is a neonicotinoid pesticide commonly used to control cucumber beetles on squash and pumpkins. Meanwhile, the hoary squash bee and other ground-nesting bees are important pollinators for many food crops. “Solitary ground-nesting bees make up about 70% of bee species. It’s a really important ecological group and is also really important in crop pollination,” said one of the scientists who conducted the study. The study mimicked real-world exposure conditions such as those bees would experience in farm fields.