Backyard Sprays May Be Breeding Insecticide-Resistant Mosquitoes in North Carolina

A nine-year study in Wake County, NC found a mutation in Asian tiger mosquitoes (Aedes albopictus) that lets them survive common pyrethroid insecticides; the mutation appeared in 2018 and, by 2023, was spread across the area, with more than a third of relevant gene copies carrying the resistant variant, likely aided by uneven backyard spraying. The findings suggest backyard and private-sector spraying can drive resistance, potentially undermining disease-control tools and calling for coordinated monitoring and management that includes private yards.