【目的】 明确植物次生代谢物对甜菜夜蛾 Spodoptera exigua细胞凋亡的影响，探索利用植物次生代谢物防控甜菜夜蛾的潜在途径。【方法】 本研究选用含0.01%香豆素或0.01%槲皮素的人工饲料，分别饲喂甜菜夜蛾3龄初幼虫，以未添加次生物的人工饲料为对照，通过流式细胞仪分别在处理后24、48和72 h测定各处理组幼虫血细胞凋亡率；采用酶联免疫法测定各处理组幼虫两种半胱天冬酶（Caspase-1和Caspase-5）和凋亡抑制蛋白（Inhibitor of apoptosis protein，IAP）活性；采用RT-qPCR法测定各处理组幼虫血细胞凋亡相关基因的相对表达量。【结果】 两种植物次生代谢物和处理时间的交互作用均显著影响甜菜夜蛾幼虫凋亡率、SeCaspase活性和基因相对表达量（P < 0.05）。与对照组相比，0.01%香豆素或0.01%槲皮素处理后，幼虫的凋亡率、SeCaspase-1、SeCaspase-5、SeIAP活性和基因相对表达量显著升高（P < 0.05）。香豆素处理组幼虫细胞凋亡率显著高于槲皮素处理组。在处理后24 h，香豆素处理组SeCaspase活性和基因相对表达量显著高于槲皮素处理组，而槲皮素处理组的SeIAP基因相对表达量显著高于香豆素处理组（P < 0.05）。【结论】 香豆素和槲皮素对甜菜夜蛾细胞凋亡均存在显著的促进作用（P < 0.05），相同含量的香豆素比槲皮素对甜菜夜蛾细胞凋亡的诱导作用更为显著。

[Objectives]  To investigate the effects of plant secondary metabolites on apoptosis in Spodoptera exigua, and investigate the potential of these compounds to control this pest. [Methods]  Artificial diets containing either 0.01% coumarin or 0.01% quercetin were fed to early 3rd instar S. exigua larvae. The control group was fed an artificial diet without plant secondary metabolites. The apoptosis rate of larval cells in each treatment group was determined by flow cytometry 24, 48, and 72 h after treatment. Caspase (Secaspase-1, Secaspase-5) activity and that of the inhibitor of apoptosis protein (IAP) were determined by enzyme-linked immunosorbent assay, and gene expression levels were measured using RT-qPCR. [Results]  The interaction between the two secondary metabolites and time after treatment significantly affected both the apoptosis rate, and the activity and expression of SeCaspase and SeIAP. The apoptosis rate, enzyme activity, and relative gene expression (SeCaspase-1, SeCaspase-5, and SeIAP) of larvae fed artificial diets containing either 0.01% coumarin or 0.01% quercetin were markedly higher than those of the control group, and the apoptosis rate of the coumarin treatment group was significantly higher than that of the quercetin treatment group. After 24 h, the SeCaspase (SeCaspase-1 and SeCaspase-5) activity and gene expression level of the coumarin treatment group were significantly higher than those of the quercetin treatment group, and the SeIAP gene expression level of the quercetin treatment group was significantly higher than that of the coumarin treatment group. [Conclusion]  Although both coumarin and quercetin promote apoptosis in S. exigua, the same amount of coumarin induces a higher rate of apoptosis than quercetin.