【目的】 旨在明确草地贪夜蛾Spodoptera frugiperda在墨西哥玉米草Zea mexicana、高丹草Sorghum bicolor × So. sudanense和狼尾草Pennisetum alopecuroides 3种牧草植物上的寄主适合度，为制定科学的草地贪夜蛾防控策略以及保障农牧业安全生产提供参考依据。【方法】 恒温27 ℃，采用叶片饲喂观察法，系统比较取食3种牧草植物叶片的草地贪夜蛾不同虫态的发育历期、存活率、蛹重、化蛹率、羽化率、单雌产卵量和生命表参数等。【结果】 取食墨西哥玉米草、高丹草和狼尾草的草地贪夜蛾幼虫总历期分别为13.27、14.33和15.04 d，三者间差异显著（P < 0.05）；取食墨西哥玉米草的草地贪夜蛾雌虫蛹重（165.40 mg）显著高于取食高丹草和狼尾草的雌虫蛹重（P < 0.05）；取食墨西哥玉米草、高丹草和狼尾草的草地贪夜蛾单雌产卵量分别为487.09、329.15和184.47粒，三者间差异显著（P < 0.05）；取食墨西哥玉米草的幼虫存活率、化蛹率和羽化率均与取食高丹草的无显著差异（P > 0.05），但与取食狼尾草的差异显著（P < 0.05）；取食墨西哥玉米草、高丹草和狼尾草的草地贪夜蛾寄主适合度指数分别为12.33、7.76和6.03；生命表参数比较发现，取食墨西哥玉米草、高丹草和狼尾草的草地贪夜蛾净增殖率（R₀）分别为217.32、144.85和59.17。【结论】 草地贪夜蛾在墨西哥玉米草、高丹草和狼尾草上均能完成生活史实现种群繁衍，墨西哥玉米草表现出更高的寄主适合度，其次是高丹草，狼尾草最不适宜。因此，在玉米等粮食作物和牧草植物的混合种植区，亟需提前防范草地贪夜蛾转移至牧草植物为害的风险。

 [Aim]  To determine the suitability of three pasture grasses, Zea mexicana, Sorghum bicolor × So. sudanense and Pennisetum alopecuroides, as host plants for Sp. frugiperda, and thereby contribute to the development of effective control strategies for this pest. [Methods]  Sp. frugiperda were randomly assigned to one of three treatment groups, which were each fed the leaves of one of the three grasses at a constant temperature of 27 ℃. The developmental duration of different life stages, the survival rate, pupal weight, pupation rate, eclosion rate, fecundity (eggs laid per female), and life table parameters, of each treatment group were then systematically measured and compared. [Results]  There was a significant difference (P < 0.05) in the duration of the larval periods of Sp. frugiperda that fed on Z. mexicana, So. bicolor × So. sudanense, and P. alopecuroides (13.27, 14.33, and 15.04 d, respectively). The pupal weight of female Sp. frugiperda fed on Z. mexicana (165.40 mg) was significantly higher than that of those fed on So. bicolor × So. sudanense or P. alopecuroides (P < 0.05). There was a significant difference (P < 0.05) in the fecundity of Sp. frugiperda fed on Z. mexicana, So. bicolor × So. sudanense, and P. alopecuroides (487.09, 329.15, and 184.47 eggs, respectively). No significant difference were found in the larval survival rate, pupation rate, or eclosion rate between Sp. frugiperda that fed on Z. mexicana and those that fed on So. bicolor × So. sudanense (P > 0.05), but there was a significant difference compared to those that fed on P. alopecuroides (P < 0.05). The host suitability indices of Sp. frugiperda for each of the three grass types were 12.33 (Z. mexicana), 7.76 (So. bicolor × So. sudanense), and 6.03 (P. alopecuroides). Comparison of life table parameters indicated that the net reproductive rates (R₀) of S. frugiperda that fed on Z. mexicana, So. bicolor × So. sudanense, and P. alopecuroides were 217.32, 144.85, and 59.17, respectively. [Conclusion]  Sp. frugiperda is able to complete its life cycle and reproduce on all three grass types tested. Among these, Z. mexicana has the highest host suitability, followed by So. bicolor × So. sudanense, whereas P. alopecuroides is the least suitable. Therefore, where crops such as maize are intercropped with pasture grasses, it is crucial to implement early preventive measures to reduce the risk of Sp. frugiperda damaging these.