Pomacea canaliculata is one of the most destructive threats to the safe production of rice. Molluscicides are the primary measure for controlling this pest species. Tea saponin (TS) is a plant secondary metabolite with a high snail-killing activity. However, some individuals have enhanced detoxification metabolism against TS, leading to a weakened control efficiency of TS to P. canaliculata. To clarify the detoxification and metabolic mechanisms of TS in P. canaliculata, we characterized the toxicity of TS against the snails. Additionally, we examined its biochemical and molecular effects on glutathione S-transferases (GSTs) and monoamine oxidase (MAO) activities, as well as their corresponding gene expression levels. The results showed that the LC