Abstract: 【Aim】 This study aims to explore the sublethal effects of cyantraniliprole on Spodoptera exigua (Hübner)so as to provide a scientific basis for the integrated management program for S. exigua and the rational use of cyantraniliprole. 【Methods】 The toxicity of cyantraniliprole on the 3rd instar larvae of S. exigua was assayed with diet-incorporation bioassays, and the effects of cyantraniliprole at two sublethal doses (LC₁₀ and LC₂₅) on the growth and development of S. exigua and the activities of three detoxifying enzymes were assayed. 【Results】 When the S. exigua larvae were treated with two sublethal doses of cyantraniliprole (LC₁₀ and LC₂₅), their growth was significantly restrained compared to that in the control group, the average body weight was inhibited by 11.55% and 27.68% and the developmental durations from the 3rd instar larva to pupa were elongated by 0.07 and 0.20 d, respectively. The pupation rates in the LC₁₀ and LC₂₅ treatment groups were 63.89% and 49.43% and were significantly lower than that of the control (80.93%). The adult longevity in the LC₁₀ and LC₂₅ treatment groups was obviously shortened by 1.11 d and 2.08 d, respectively, and the number of eggs laid per female and the egg hatching rates in the two treatment groups were significantly lower than those of the control. The activities of carboxylesterase (CarE) and glutathione- S-transferases (GSTs) in the 3rd instar larvae treated with the two sublethal doses of cyantraniliprole were promoted first and then decreased from 24 h to 96 h aftertreatment. The activities of mixed function oxidase (MFO) were also inhibited at 48 h and 72 h after treatment, and the inhibition effect was in proportion to the cyantraniliprole dose. 【Conclusion】 These results demonstrate that sublethal dose of cyantraniliprole can significantly restrain the growth and development of S. exigua and the activities of three detoxifying enzymes in its larvae.

Key words: Spodoptera exigua, cyantraniliprole, sublethal effect, growth and development, detoxifying enzyme