Abstract: To identify the toxicity of chlorantraniliprole against Harmonia axyridis and how the insecticide impacts the natural enemy’s predation ability, insecticide-impregnated filter method was used to determine non-target toxicity of chlorantraniliprole, and its predation ability on Spodoptera frugiperda was also evaluated by predator-prey functional response model. The results showed that chlorantraniliprole induced toxic effect in H. axyridis (2^nd instar larvae), with LC₅₀(25.216 mg/L). Sub-lethal concentration of chlorantraniliprole would not change the type of functional response, which was still Holling II, but the model parameters changed. After treatment with sub-lethal concentration LC₁₀, the attack rates of 4^thinstar larvae, female and male adults respectively decreased by 18.61%, 28.03%, and 10.41%, the handling time respectively increased by 61.54%, 23.08%, and 25.00%, and the maximum number of preys consumed per day respectively decreased by 49.62%, 41.52%, and 28.33%. After treatment with sub-lethal concentration LC₂₀, the attack rate respectively decreased by 21.99%, 26.67%, and 14.30%, the handling time respectively increased by 107.69%, 76.92%, and 91.67%, and the maximum number of preys consumed per day respectively decreased by 62.44%, 58.56%, and 55.28%. The results showed that chlorantraniliprole exposure would significantly impact the predator-prey functional response of H. axyridis, with a greater effect on the 4^th instar larvae. The results provided data support for the screening of chemical insecticides compatible with natural enemies and helped H. axyridis work better.

Key words: chlorantraniliprole, sub-lethal effect, non-target toxicity, predation ability, searching effect