Abstract: In this paper, the toxicity of Ligularia virgaurea essential oil to armyworm larvae was studied, and the response mechanism of nerve transduction related enzymes in armyworm larvae to the stress of L. virgaurea essential oil was investigated. The indoor toxicity was determined by leaf immersion method. As a result, L. virgaurea essential oil showed strong biological activity with LC₅0 of 4.584 mg/mL. Enzyme-linked immunosorbent assay (ELISA) was used to determine the effect of essential oil on nerve conduction-related enzyme activity in armyworm larvae at different time. The results revealed that essential oil at the mass concentration of LC₅0 could significantly inhibit the activities of acetylcholinesterase and Na⁺-K⁺-ATPase. These results assume that L. virgaurea essential oil may be neurotoxic to armyworm larvae, and hence be potential to be developed as a new bio-pesticide.

Key words: essential oil, AChE, Na⁺-K⁺-ATPase, bio-pesticide, neurotoxicity