摘  要  【目的】 为了更好的了解寄主植物和甜菜夜蛾Spodoptera exigua幼虫对淡足侧沟茧蜂Microplitis pallidipes趋向行为的影响。【方法】 本研究选用玉米和苋菜两种寄主植物，采用“Y”型嗅觉仪测定了淡足侧沟茧蜂对正常植物和幼虫-植物复合体的行为反应，并对其释放的挥发性物质进行了GC-MS分析与鉴定。【结果】 正常的玉米和苋菜对淡足侧沟茧蜂无明显引诱作用，而幼虫-玉米复合体和幼虫-苋菜复合体均有显著的吸引作用，且幼虫-玉米复合体对该寄生蜂的引诱作用更强。GC-MS检测结果显示在正常玉米中含有22种化合物，主要为烷烃和芳香烃类化合物；幼虫-玉米复合体中有31种化合物，以烷烃和醇类化合物为主；在正常苋菜检测到的16种化合物中，烷烃类化合物含量最高，约占54.75%；而幼虫-苋菜复合体中含有55种化合物，其中以烷烃、芳香烃、烯烃、酸类和醛类物质含量相对较高。另外，与正常植物相比，2-己烯醛、(+)-柠檬烯、α-石竹烯、DMNT和α-雪松烯等化合物仅在幼虫-植物复合体中产生或含量明显升高。【结论】 淡足侧沟茧蜂更倾向于幼虫-玉米复合体，并且玉米和苋菜在遭受甜菜夜蛾取食后，会释放出更多种类的化合物。

Abstract  [Aim]  To better understand the effect of host plants and Spodoptera exigua on the tendency behavior of Microplitis pallidipes. [Methods]  Maize and amaranth were chosen and the behavioral responses of M. pallidipes to normal plants and larva-plant complex were determined with Y-tube olfactometer, and the volatile compounds were analyzed and identified by GC-MS. [Results]  The normal maize and amaranth had no attraction effect on M. pallidipes, but larva-maize complex and larva-amaranth complex exhibited significant attractiveness, and larva-maize complex showed stronger activity than larva-amaranth complex. GC-MS indicated that 22 compounds were detected in normal maize leaves with alkanes and aromatic hydrocarbons as the main constitutes, while 31 compounds were identified in the larva-maize complex and mainly alkanes and alcohols. Similarly, there were 16 compounds in normal amaranth and the content of alkane compounds was the highest with 54.75%. The larva-amaranth complex contained 55 compounds, and alkanes, aromatics, alkenes, acids and aldehydes were relatively high. In addition, some compounds were only produced or increased remarkably in larva-plant complex, such as 2-hexenal, (+) -limonene, α-caryophyllene, DMNT, and α-himachalene. [Conclusion]  M. pallidipes were prefer the larva-maize complex, and a wider variety of compounds were released by maize and amaranth after feeding by Spodoptera exigua.