Pollen-mimicking, enzyme-loaded microparticles to reduce organophosphate toxicity in managed pollinators

Abstract Pollinators support the production of 87 of the leading food crops worldwide and contribute over $15 billion to U.S. farm income. Organophosphates are a heavily used group of insecticides that pollinators can be exposed to, especially during crop pollination. Exposure to lethal or sub-lethal doses can impair fitness of wild and managed bees, risking pollination quality and food security. Here, we report a low-cost, scalable in vivo detoxification strategy for organophosphate insecticides involving encapsulation of phosphotriesterase (OPT) in pollen-mimicking microparticles (PMMs). We developed uniform and consumable PMMs capable of loading OPT at 90% efficiency and protecting OPT from degradation in the pH of a bee gut. Microcolonies of bumble bees (Bombus impatiens) fed malathion-contaminated pollen patties demonstrated 100% survival when fed OPT-PMMs but 0% survival with OPT alone and 0% survival with plain sucrose within 5 and 4 days, respectively. Thus, the detrimental effects of malathion were eliminated when bees consumed OPT-PMMs. This design presents a versatile and scalable treatment for managed pollinators to reduce risk from organophosphate insecticides, which can be integrated into supplemental feeds such as pollen patties or dietary syrup.