Abstract: To elucidate the sublethal effects of indoxacarb on Scopula subpunctaria and their impact on population growth，the laboratory toxicity of 15% indoxacarb suspension concentrate（SC）against the 3rd⁃ and 5th⁃instar larvae was assessed using the leaf⁃dipping method. The sublethal concentrations LC₅，LC₁₅，and LC₂₅ were determined，and the changes in larval development，adult longevity，and reproductive parameters following treatment with these concentrations were observed. The results indicated that indoxacarb was more toxic to 3rd⁃instar larvae than to 5th⁃instar larvae. At 72 h post⁃treatment，the LC₅₀，LC₂₅，and LC₁₅ for 5th⁃instar larvae were 2 704.21，167.26，and 37.57 mg/L，corresponding to 6.71，2.72，and 1. 68 times those for 3rd⁃instar larvae，respectively，whereas the LC₅ for 5th⁃instar larvae was only 74.39% of that for 3rd⁃instar larvae. The 5th⁃instar⁃to⁃pupation period was significantly prolonged by 2.9 d at LC₂₅，whereas sublethal concentrations did not significantly affect pupal duration. Sublethal treatments shortened the adult longevity of both females and males to varying degrees，with the most significant reduction（16.53 d）observed in female adults derived from 5th⁃instar larvae treated with LC₂₅. Only the LC₁₅ treatment of 5th⁃instar larvae significantly extended the pre⁃oviposition period by approximately 2.87 days. All three sublethal concentrations significantly shortened the oviposition period by 5.07—13.07 days across both instar treatments，and in the 5th⁃instar larval treatments，the post⁃oviposition period was significantly reduced by 2.73—4.33 days. All sublethal treatments significantly reduced the fecundity per female. Compared with the control，the fecundity per female under LC₂₅ treatment decreased by 91.31% in the 3rd⁃instar group and 95.73% in the 5th⁃instar group. In summary，sublethal concentrations of indoxacarb can effectively suppress the population growth potential of S.subpunctaria by inhibiting adult longevity and reproductive capacity.Thus，indoxacarb is a suitable agent for green control in tea plantations，and should be applied rationally during the early larval stages with due attention to resistance management.

Key words: Scopula subpunctaria, Indoxacarb, Sublethal effect, Developmental inhibition, Fecundity, Laboratory toxicity

摘要： 为明确茚虫威对茶银尺蠖（Scopula subpunctaria）的亚致死效应及其对种群增长的影响，采用浸叶法测定15%茚虫威悬浮剂对茶银尺蠖3龄和5龄幼虫的室内毒力，确定亚致死浓度LC₅（5%致死浓度）、LC₁₅（15%致死浓度）和LC₂₅（25%致死浓度），并观察这3种浓度浸叶处理后幼虫生长发育、成虫寿命及繁殖参数的变化。结果表明，茚虫威对3龄幼虫的毒力高于5龄幼虫，茚虫威处理72 h，5龄幼虫的LC₅₀、LC₂₅和LC₁₅分别为2 704.21、167.26、37.57 mg/L，分别是3龄幼虫的6.71倍、2.72倍和1.68倍，但5龄幼虫的LC₅仅为3龄幼虫LC5的74.39%。亚致死浓度处理幼虫对蛹期无显著影响，但LC₂₅处理使5龄幼虫至化蛹的历期显著延长2.9 d。亚致死浓度处理3龄和5龄幼虫不同程度缩短雌、雄成虫寿命，其中LC₂₅处理5龄幼虫的雌成虫寿命减少最显著，缩短16.53 d。仅LC15处理5龄幼虫产卵前期显著延长（约2.87 d）；3种亚致死浓度处理3龄和5龄幼虫后产卵期显著缩短5.07~13.07 d，处理5龄幼虫后产卵后期显著缩短2.73~4.33 d。所有亚致死浓度处理均导致单雌产卵量显著下降，LC₂₅处理3龄和5龄幼虫的单雌产卵量较对照分别降低91.31%和95.73%。综上，亚致死浓度茚虫威可通过抑制成虫寿命和繁殖能力，有效降低茶银尺蠖的种群增长潜力，是茶园绿色防控的适用药剂，建议在低龄幼虫期合理施用并注意抗性管理。

关键词: 茶银尺蠖, 茚虫威, 亚致死效应, 发育抑制, 产卵量, 室内毒力