Biocontrol potential of Beauveria bassiana (Balsamo) Vuillemin and Bacillus thuringiensis (Berliner) was investigated under laboratory conditions against maize stem borer Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae). Three dose rates of B. bassiana (1 × 10⁴, 1 × 10⁶ and 1 × 10⁸ conidia/ml) and one of B. thuringiensis (0.75 µg/g) were applied alone and in combination against 2nd and 4th larval instars of C. partellus. Larval mortality, pupation, adult emergence, mycosis and sporulation varied against different individual concentrations of B. bassiana and its integrated application with B. thuringiensis. Results of the experiment revealed that combined application of highest concentration of B. bassiana (1 × 10⁸ spores/ml) and B. thuringiensis (0.75 µg/g) exhibited highest larval mortality both in 2nd and 4th instars larvae of C. partellus. The mortality data also demonstrated that 2nd instar larvae were more susceptible to the tested microbial treatments than 4th larval instars. Moreover, less pupation and adult emergence was observed in combined treatments of entomopathogens rather than their individual applications. Maximum mycosis and sporulation was recorded in the cadavers of C. partellus where B. bassiana was applied alone at dose rate of 1 × 10⁴ conidia/ml. These outcomes suggest that combined application of B. bassiana and the toxic protein produced by B. thuringiensis could be a promising ecofriendly approach for the successful management of maize stem borer.

中文翻译：

---

球孢白僵菌和苏云金芽孢杆菌对玉米干Bor虫Chilo Partellus（Swinhoe）（鳞翅目：Pyralidae）的功效

在实验室条件下研究了球孢白僵菌（Balsamo）Vuillemin和苏云金芽孢杆菌（Berliner）对玉米stem虫Chilo partellus（Swinhoe）（鳞翅目：Pyralidae）的生物防治潜力。分别对两种和两种幼虫分别施用三种剂量率的球孢杆菌（1×10 ^4，1 ×10 ⁶和1×10 ⁸ 分生孢子/毫升）和一种苏云金芽孢杆菌（0.75 µg / g）。的C. partellus。幼虫死亡率，化up，成年出苗，真菌病和孢子形成因不同的球孢杆菌浓度而异及其与苏云金芽孢杆菌的综合应用。该实验的结果显示的最高浓度的，联合应用球孢白僵菌（1×10 ⁸ 个孢子/ ml）和苏云金芽孢杆菌（0.75微克/克）表现出无论是在第二和第四龄期的最高幼虫死亡率的幼虫C. partellus。死亡率数据还表明，第二龄幼虫比第四龄幼虫更容易受到微生物处理。此外，在昆虫病原体的联合治疗中观察到化脓和成年少，而不是单独应用。最大霉菌病和孢子形成被记录在的尸体C. partellus其中白僵菌单独以1×10 ⁴ 分生孢子/ ml的剂量使用。这些结果表明，B。bassiana和苏云金芽孢杆菌产生的有毒蛋白质的联合应用可能是成功管理玉米stem虫的一种有前途的生态友好方法。