Assessment of genotype-specific sensitivity to three insecticides in honey bees (Apis mellifera) via acute oral exposure

Honey bees are essential pollinators in agricultural and wild ecosystems, yet their frequent exposure to pesticides poses significant risks. This study examined genotype-specific differences in oral acute toxicity by testing three insecticides: flupyradifurone (Sivanto® Prime), lambda-cyhalothrin (Karate Zeon®), and cyantraniliprole (Minecto™ One), across five European honey bee genotypes: Apis mellifera, A. m. carnica, A. m. ligustica, Buckfast, and a local population from JKI, Braunschweig. Insecticide sensitivity was assessed by calculating LD₅₀ values and performing Kaplan-Meier survival analysis and Cox proportional hazards modeling. Significant genotype-dependent differences were evident, with LD₅₀ values varying up to 3.2-fold across observation times depending on insecticide and genotype. A. m. mellifera showed significantly higher tolerance to lambda-cyhalothrin and to cyantraniliprole, and moderate tolerance to flupyradifurone. These findings highlight that toxicity profiles vary by genotype and insecticide mode of action, underscoring the importance of reporting genotype in ecotoxicological studies to better understand pesticide impacts.