35 - The NEVBD Pesticide Resistance Monitoring Program: six years of larvicide resistance surveillance in the Northeastern US

Abstract: The Northeast Regional Center for Excellence in Vector-Borne Diseases (NEVBD-TEC) Pesticide Resistance Monitoring Program was established in 2019 to assess resistance to insecticides in mosquitoes collected from an area covering 13 Northeastern/Mid-Atlantic states and the District of Columbia. Larval bioassay protocols were developed to address regional needs given that the majority of mosquito control activity targets larval stages. Regional partners collect and ship mosquito eggs or larvae to Cornell University annually, where they are evaluated in pesticide resistance bioassays. Targeted species include Aedes albopictus, Culex pipiens, Culex restuans, and Culiseta melanura. An essential first step in evaluating resistance was the development of larval mortality curves using susceptible strains of Ae. albopictus and Cx. pipiens for methoprene, Bti, and L. sphaericus to establish lethal concentration (LC99) doses for each species. Six years of larval resistance surveillance data will be presented, and results will be discussed in the context of broader regional resistance patterns and areas for future investigation. In addition to the annual submission system, NEVBD-TEC collaborates with local agencies to answer specific larval control questions through technical advising, training, and project assistance; several of these efforts will be highlighted.