Microparticles protect bees from pesticides

Pesticides used to shield crops from damaging insects have the unintended effect of killing pollinators such as bees. Researchers have now made consumable microparticles that resemble pollen grains as a way to protect bees from organophosphate pesticides. Jing Chen, James Webb, and Minglin Ma of Cornell University and coworkers make the microparticles of calcium carbonate nanoparticles that assemble around phosphotriesterase enzymes (Nat. Food 2021, DOI: 10.1038/s43016-021-00282-0). The enzymes then degrade the organophosphates. Adding gelatin to the mixture helps nucleate the microparticles and makes them consistently about 4 µm in diameter. The researchers fed bees a mixture of the microparticles suspended in a sugar solution. Those that ate the microparticles were protected against exposure to the organophosphate pesticides paraoxon and malathion. Following exposure for 12 h to pollen contaminated with paraoxon, 70% of bees that ate the microparticles survived. In 10-day studies with paraoxon and malathion, 38% of bees that ate the microparticles survived. Bees that didn’t eat the microparticles died after 5 days of exposure to paraoxon or malathion. The researchers say the microparticles are intended for managed pollinators, not wild ones. Chen, Webb, and Ma are involved with a company that is commercializing the technology.