【目的】 明确乌桕Triadica sebifera的防御物质单宁和类黄酮在应对多种昆虫危害时的响应。【方法】 开展野外调查，记录乌桕所受昆虫取食类型（孔食状、缘食状、卷叶状）及各类型取食率，检测乌桕叶片和根部单宁与类黄酮的含量变化；室内控制实验采用单一昆虫（黄刺蛾Cnidocampa flavescens、乌桕卷象Heterapoderopsis bicallosicolli、红胸律点跳甲Bikasha collari）或多种昆虫（两两组合）对乌桕进行取食诱导，测定乌桕叶片和根中单宁及类黄酮含量。【结果】 野外调查表明，孔食状取食率（R²=0.053 7，P= 0.015 9）和缘食状取食率（R²=0.060 6，P=0.008 9）增加会显著提高乌桕叶片中的单宁含量，但对乌桕根中单宁含量无影响（P>0.05）。缘食状取食率增加会显著提高乌桕叶片（R²=0.081 9，P=0.017 2）和根（R²=0.133 4，P=0.002 8）中的类黄酮含量。并且缘食状取食对乌桕叶片中单宁含量（贡献率：8.3%，R²=0.134）和根中类黄酮含量（贡献率：19.76%，R²=0.230）变化的贡献率最大。室内控制实验的结果表明，与无昆虫取食对照相比，跳甲取食（P<0.001）、黄刺蛾取食（P=0.002）、卷象取食（P=0.003）均会显著增加乌桕叶片单宁含量而不会影响乌桕根中的单宁含量（P>0.05）。黄刺蛾取食（P<0.001）、卷象取食（P=0.001）会显著增加乌桕叶片类黄酮的含量，而跳甲取食（P=0.003）、黄刺蛾+跳甲取食（P=0.002）会显著降低乌桕叶片类黄酮含量。仅黄刺蛾+卷象取食（P<0.001）会显著增加乌桕根中的类黄酮含量。【结论】 乌桕受到地上昆虫取食时，其地上部分和地下部分次生代谢物质呈不对称响应。不同取食类型的昆虫所诱导的次生代谢响应也有所不同，且两种不同类型的昆虫所诱导的次生代谢响应可能相互拮抗。

[Aim]  To elucidate the defensive substances, specifically tannins and flavonoids, released by Triadica sebifera in response to feeding damage inflicted by various herbivores. [Methods]  A field survey was conducted to document the types of damage inflicted by herbivores, and the rates of herbivory, on T. sebifera. Concentrations of tannins and flavonoids in the leaves and roots of T. sebifera were also determined. In a laboratory experiment, a single species of herbivore (either Cnidocampa flavescens, Bikasha collari or Heterapoderopsis bicallosicolli), or pairs of these species, were allowed to feed on T. sebifera plants and changes in the tannins and flavonoids in the leaves and roots of these plants were measured and compared. [Results]  The field survey indicated that an increase in the hole feeding rate (R²=0.053 7, P=0.015 9) and in the marginal feeding rate (R²=0.060 6, P=0.008 9) significantly elevated the tannin concentration in leaves, but not in roots (P>0.05). An increase in the marginal feeding rate, however, significantly raised the flavonoid concentration in both the leaves (R²=0.081 9, P=0.017 2) and the roots (R²=0.133 4, P=0.002 8). Marginal feeding was the most significant factor driving changes in leaf tannins (contribution rate: 8.3%, R²=0.134) and root flavonoids (contribution rate: 19.76%, R²=0.230). The results of laboratory experiments revealed that feeding by C. flavescens, B. collari or H. bicallosicolli significantly increased the tannin concentration in leaves but did not affect that in the roots. Feeding by C. flavescens significantly enhanced the flavonoid concentration in the leaves, whereas simultaneous feeding by C. flavescens and H. bicallosicolli significantly raised the flavonoid concentration in the roots. [Conclusion]  Feeding by above-ground herbivores induces different secondary metabolic responses in both the above-ground and below-ground parts of T. sebifera. Furthermore, feeding by different herbivores induced different secondary metabolic responses. Notably, when T. sebifera is fed upon by two species of herbivores, the induced secondary metabolic responses appear to be antagonistic towards one another.