This study compared the development of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), on forage species of different genera (Arachis, Axonopus, and Cynodon) in relation to maize (preferred host) as well as its adaptability on these forage species, which are the main cultivated forages in southern Brazil. The biological performance of S. frugiperda fed on host plants studied showed the highest adaptation index (AI) in maize (26.89), followed by bermudagrass (22.02), suggesting that bermudagrass is the most suitable alternative host for the development of S. frugiperda. In contrast, the giant missionary grass (18.80) and Pinto peanut (13.81) showed lower adequacy, with a relative adaptation index (RAI) 69.93 and 51.35%, respectively, using maize as standard. The cluster analysis based on similarity of the chemical-bromatological parameters showed that maize has a richer composition than the other plant species studied. The multivariate correlation analysis between AI and chemical-bromatological composition showed a positive correlation between AI and contents of ashes, ethereal extract, potassium, phosphorus, and magnesium and, to a lesser extent, with contents of nitrogen, crude protein, and copper. In this context, complexity of host composition and balance between components could explain the biological fitness of S. frugiperda on host plant species. Pasture diversification with giant missionary grass, or especially with Pinto peanut, may be an interesting strategy for integrated pest management of fall armyworm in pasturelands in a regional context.

这项研究比较了秋季粘虫Spodoptera frugiperda（JE Smith）（鳞翅目：Noctuidae ）在与玉米（首选寄主）有关的不同属（花生，轴索和犬齿）的饲草物种上的发育及其对这些作物的适应性。牧草种，这是巴西南部主要的牧草。以研究的寄主植物为食的S. frugiperda的生物学性能显示，玉米中的适应指数（AI）最高（26.89），其次是百慕大草（22.02），这表明百慕大草是S. frugiperda发育的最合适替代寄主。。相反，以玉米为标准，巨型传教草（18.80）和Pinto花生（13.81）表现出较低的适应性，相对适应指数（RAI）分别为69.93和51.35％。基于化学-微生物学参数相似性的聚类分析表明，玉米的成分比研究的其他植物种类更丰富。AI与化学-微生物学组成之间的多元相关分析显示，AI与骨灰，以太提取物，钾，磷和镁的含量呈正相关，在较小程度上与氮，粗蛋白和铜的含量呈正相关。在这种情况下，宿主组成的复杂性和成分之间的平衡可以解释弗氏链球菌的生物学适应性。在寄主植物上 在区域背景下，使用大型传教草，或尤其是使用Pinto花生进行牧草多样化，可能是在牧场中对秋夜蛾进行综合害虫管理的有趣策略。