Successful pest management using parasitoids requires careful evaluation of host-parasitoid interactions. Here, we report the performance of larval ecto-parasitoid wasp, Bracon brevicornis (Wesmael) on important agricultural pests, Spodoptera litura (Fabricius) and S. frugiperda (J.E. Smith). Biology of B. brevicornis was studied on different host instars under laboratory and cage setup. In no-choice assay, the parasitoid development was highest on fifth-instar S. litura larvae as the wasp laid ~ 253 eggs with 62% hatching, 76% pupae formation and 78% adult emergence. Similarly, these parameters were highest on fifth instar S. frugiperda larvae (293 eggs, 57% hatching, 80% pupae formation, 70% adult emergence). In two-choice assay, B. brevicornis preferred fourth or fifth over third instar larvae of both hosts. Successful parasitism depends on host paralysis and suppression of host immunity. B. brevicornis interaction downregulated cellular immunity of both hosts as shown by reduced hemocyte viability and spreading. The percent parasitism rate of B. brevicornis was unaltered in the presence of host plant, Zea mays in cage study. 76 and 84% parasitism was observed on fifth-instar larvae of S. litura and S. frugiperda, respectively. We evaluated the performance of B. brevicornis as a biocontrol agent on S. frugiperda in maize field. Our results show 54% average reduction in infestation after release of B. brevicornis. Taken together, we report the performance of B. brevicornis on important insect pests for the first time in laboratory and field conditions. Our findings indicate that B. brevicornis is a promising candidate for integrated pest management.

要使用寄生虫成功防治害虫，需要仔细评估宿主-寄生虫的相互作用。在这里，我们报告了幼虫外寄生类黄蜂，短臂Bracon brevicornis（Wesmael）对重要农业害虫，斜纹夜蛾（Fabodius ）和S. frugiperda（JE Smith）的表现。在实验室和笼子设置下，在不同宿主幼虫上研究了短双歧杆菌的生物学。在无选择试验中，由于黄蜂产下〜253个卵，孵化率为62％，formation的形成为76％，成虫的出现率为78％，因此，在五龄的斜纹链球菌幼虫上，类寄生虫的发育最高。同样，这些参数在五龄S. frugiperda上最高幼虫（293个卵，孵化率57％，formation形成80％，成虫出现70％）。在二选法中，短双歧杆菌优选两个宿主的第三龄幼虫。寄生成功与否取决于宿主麻痹和抑制宿主免疫力。短杆菌介导的相互作用下调了两个宿主的细胞免疫，如降低的血细胞活力和扩散所示。在寄主植物Zea mays的笼子研究中，短双歧杆菌的寄生率百分率没有改变。在斜纹夜蛾和frugiperda的五龄幼虫上分别观察到76％和84％的寄生虫。我们评估了短双歧杆菌的性能作为玉米田中S. frugiperda的生物防治剂。我们的结果表明，短双歧杆菌释放后，侵扰平均减少了54％。两者合计，我们首次在实验室和野外条件下报告了短杆菌B.在重要害虫上的表现。我们的发现表明，短双歧杆菌是病虫害综合治理的有前途的候选者。