Abstract: The bioactivity of Artemisia argyi essential oil on Tetranychus cinnabarinus was investigated using slide-dip and fumigation methods. The activities of three protective enzymes (SOD, POD, and CAT) and protease in female adults exposed to essential oil at sublethal dosages (LD₁₀, LD₂₀, and LD₃₀) and median lethal dosage (LD₅₀) were analyzed at 4, 8, 12, 16, 20 and 24 hours post-treatment. The results showed that female adults died at 21.48%, 27.41%, and 77.78% at 24, 48, and 72 h post-treatment at 2.0% concentration, and the LD₅₀ values were 23.03%, 13.25%, and 0.35%, respectively. Moreover, the fumigation effect of A. argyi essential oil was stronger on eggs than on female adults, and the ID₅₀andLD₅₀ values were 0.21 and 8.93 μL/L, respectively. SOD and POD were activated, and CAT and protease activities were inhibited after treatment with different doses (LD₁₀, LD₂₀, and LD₃₀). Treatment at LD₁₀, LD₂₀, and LD₃₀ for 8 hours increased SOD activities by 0.43, 1.29, and 1.60 times in comparison with the control group, respectively; POD was activated by 54.64%, 31.96% and 5.15%, respectively; CAT was inhibited by 27.03%, 20.46% and 31.65%, respectively; Protease inhibition rates were 21.53%, 29.16% and 45.09%, respectively. The results indicate that treatment ofA. argyi essential oil at sublethal dosages can disturb the dynamic balance of protective enzymes and inhibit protease activity, which disturbs normal metabolism and produces toxic effects on T. cinnabarinus adult females. These results support the use of A. argyi essential oil as a control agent against T. cinnabarinus.

Key words: Artemisia argyi essential oil, Tetranychus cinnabarinus, bioactivity, sublethal dosage, protective enzymes