Bacillus thuringiensis (Bt)-based bioinsecticides and transgenic plants expressing proteins with insecticidal activity (Cry and Vip) have been successfully used in several integrated pest management programs worldwide. Lepidoptera comprise some of the most economically important insect pests of the major agricultural crops. In this study, the toxicity of 150 Bt strains was evaluated against Helicoverpa armigera (Hübner) larvae. Eight strains (426, 520B, 1636, 1641, 1644, 1648, 1657 and 1658) showed high insecticide activity against H. armigera and were therefore tested against Anticarsia gemmatalis (Hübner), Spodoptera cosmioides (Walker), Chrysodeixis includens (Walker), and Diatraea saccharalis (Fabricius) larvae. Our results showed that most of the Bt strains were also toxic to these lepidopteran species. The biochemical and molecular analyses of these strains revealed that they had a similar protein profile; however, their cry and vip gene contents were variable. In addition, the median lethal concentration (LC₅₀) of the selected strains indicated that the strains 1636, 1641, and 1658 were the most effective against H. armigera, showing LC₅₀ values of 185.02, 159.44, and 192.98 ng/cm², respectively. Our results suggest that the selected Bt strains have great potential to control the lepidopteran pests H. armigera, A. gemmatalis, D. saccharalis, S. cosmioides, and C. includes.

基于苏云金芽孢杆菌( Bt ) 的生物杀虫剂和表达具有杀虫活性的蛋白质（Cry 和 Vip）的转基因植物已成功用于全球多个综合害虫管理计划。鳞翅目包括一些主要农作物的经济上最重要的害虫。在这项研究中，评估了 150 个Bt菌株对棉铃虫（Hübner）幼虫的毒性。8 个菌株（426、520B、1636、1641、1644、1648、1657和 1658）对棉铃虫表现出很高的杀虫活性，因此测试了对棉铃虫（Hübner）、Spodoptera cosmioides（Walker）、Chrysodeixis includens (Walker) 和Diatraea saccharalis (Fabricius) 幼虫。我们的结果表明，大多数Bt菌株对这些鳞翅目物种也有毒。这些菌株的生化和分子分析表明它们具有相似的蛋白质谱；然而，他们的cry和vip基因含量是可变的。此外，所选菌株的中位致死浓度 (LC ₅₀ ) 表明菌株1636、1641和 1658 对棉铃虫最有效，其 LC ₅₀值为 185.02、159.44 和 192.98 ng/cm ²，分别。我们的结果表明，所选的的Bt菌株具有很大的潜力以控制鳞翅目害虫棉铃虫，A.藜豆夜蛾，小蔗，S. cosmioides，和C.包括。