D3081: Insecticide resistance in Aedes mosquitoes along the Texas/Mexico border in 2020

Insecticide resistance is an increasing challenge for disease control. For control efforts to be effective, it is critical to assess if mosquito populations are becoming more resistant to commonly used insecticides. Starting in 2018, we initiated a long-term effort to identify patterns in insecticide resistance in cities along the Texas/Mexico border. We collected Aedes mosquito eggs weekly in multiple cities along the border. Collected eggs were hatched in the lab, identified for species as adults, and then tested for insecticide resistance using the CDC Bottle Bioassay to commonly used insecticides: permethrin, deltamethrin, sumethrin. Efforts in 2020 were disrupted due to the COVID pandemic but have resumed starting in late fall 2020. Here we highlight some key findings in patterns of resistance as well as species distribution. Key findings are discussed as they relate to concerns regarding insecticide resistance and efficacy of control efforts.