The two biological control methods, inherited sterility technique (IST) and Bacillus thuringiensis (Bt), are considered as the two promising methods for lepidopteran pest management. Simultaneous treatment with both techniques was assessed against the cotton leaf worm, Spodoptera littoralis (Boisd.) (Noctuidae: Lepidoptera) compared to individual treatment for developing the lepidopteran management program. Pupation and adult emergence were significantly lower in simultaneous treatment than irradiated insects individually. Larval mortality test estimated a LC50 of 1.6 × 104 IU/mg (Bt), in which decreased to 1.5 × 104 IU/mg (Bt and 75 Gy), and 7.7 × 103 IU/mg (Bt and 125 Gy). Insect survival was prolonged for both individual and simultaneous treatments. The ratio of males was 3.5-fold to females in 1.5 × 104 IU/mg and 75 Gy, while threefold of males to females was recorded in the treatments of 3.75 × 103 IU/mg and 75 Gy, 7.5 × 103 IU/mg and 75 Gy, 7.5 × 103 IU/mg and 125 Gy and 1.5 × 104 IU/mg and 125 Gy. Results of fecundity, fertility and sperm transfer of F1 males were significantly lowered in irradiated insect combined with Bt than individual treatment. Gamma irradiation treatment combined with Bt concentrations achieved a high reduction of S. littoralis, and the toxicity effect of Bt increased as compared with individual treatments taking advantage as compatible control tactics. Simultaneous treatment of IST and Bt could be considered as a competent approach for S. littoralis population suppression.

中文翻译：

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伽马辐射和苏云金芽孢杆菌同时处理对棉叶虫 Spodoptera littoralis (Boisd.) (夜蛾科：鳞翅目) 的影响

遗传不育技术（IST）和苏云金芽孢杆菌（Bt）这两种生物防治方法被认为是鳞翅目害虫防治的两种有前景的方法。对棉叶虫 Spodoptera littoralis (Boisd.) (Noctuidae: Lepidoptera) 的两种技术的同时处理进行了评估，与制定鳞翅目管理计划的个体处理相比。同时处理的化蛹和成虫出现明显低于单独照射的昆虫。幼虫死亡率测试估计 LC50 为 1.6 × 104 IU/mg (Bt)，其中降至 1.5 × 104 IU/mg（Bt 和 75 Gy）和 7.7 × 103 IU/mg（Bt 和 125 Gy）。个体和同时治疗都延长了昆虫存活率。在 1.5 × 104 IU/mg 和 75 Gy 下，男性与女性的比例是 3.5 倍，而在 3.75 × 103 IU/mg 和 75 Gy、7.5 × 103 IU/mg 和 75 Gy、7.5 × 103 IU/mg 和 125 Gy 和 1.5 × 104 IU/mg 和 125吉。辐照昆虫联合Bt比单独处理显着降低F1雄性的繁殖力、生育力和精子转移结果。伽马辐射处理与 Bt 浓度相结合实现了 S. littoralis 的高度减少，并且与作为相容控制策略的单独处理相比，Bt 的毒性作用增加。IST 和 Bt 的同时治疗可以被认为是抑制 S. littoralis 种群的有效方法。辐照昆虫联合Bt比单独处理显着降低F1雄性的繁殖力、生育力和精子转移结果。伽马辐射处理与 Bt 浓度相结合实现了 S. littoralis 的高度减少，并且与作为相容控制策略的单独处理相比，Bt 的毒性作用增加。IST 和 Bt 的同时治疗可以被认为是抑制 S. littoralis 种群的有效方法。辐照昆虫联合Bt比单独处理显着降低F1雄性的繁殖力、生育力和精子转移结果。伽马辐射处理与 Bt 浓度相结合实现了 S. littoralis 的高度减少，并且与作为相容控制策略的单独处理相比，Bt 的毒性作用增加。IST 和 Bt 的同时治疗可以被认为是抑制 S. littoralis 种群的有效方法。与利用作为相容控制策略的个体治疗相比，Bt 的毒性作用增加。IST 和 Bt 的同时治疗可以被认为是抑制 S. littoralis 种群的有效方法。与利用作为相容控制策略的个体治疗相比，Bt 的毒性作用增加。IST 和 Bt 的同时治疗可以被认为是抑制 S. littoralis 种群的有效方法。