Effectiveness of botanical pesticide combined with <i>Beauveria bassiana</i> on mortality, nutritional index and fecundity of <i>Spodoptera litura</i> L.

This study aimed to evaluate the effect of botanical pesticides mixed with entomopathogenic <i>Beauveria bassiana</i> on the growth and development of <i>Spodoptera litura</i>. This study adopted an experimental approach using a completely randomized design consisting of three treatments (botanical pesticides, <i>B. bassiana</i>, and a mixture of botanical pesticides and <i>B. bassiana</i>) and two control. The treatment and control had five concentration levels and were repeated four times. The test used the dip feed method. The relation between treatments and <i>S. litura</i> mortality was analyzed using probit analysis. Differences in means between treatment and control were analyzed using ANOVA. The results showed that both single and mixed treatments decreased relative consumption, inhibited relative growth rate and reduced fecundity of <i>S. litura</i>. The activity of the mixture of pesticides at the LC₅₀ level has shown a synergistic effect. Thus, the mixture of botanical pesticides and <i>B. bassiana</i> could be developed as an alternative pesticide for sustainable biological control of <i>S. litura</i>.本研究旨在评估植物源农药（botanical pesticides）与昆虫病原球孢白僵菌（*Beauveria bassiana*）复配后对斜纹夜蛾（*Spodoptera litura*）生长发育的影响。本研究采用完全随机设计（completely randomized design）的实验方法，设置3组处理（植物源农药组、球孢白僵菌组以及植物源农药与球孢白僵菌复配组）与2组对照组。所有处理组与对照组均设置5个浓度梯度，且每组重复4次。试验采用浸叶饲喂法（dip feed method）。采用概率单位分析（probit analysis）对各处理组与斜纹夜蛾死亡率之间的相关性进行分析，采用方差分析（ANOVA）比较处理组与对照组间的均值差异。研究结果显示，单一处理组与复配处理组均可降低斜纹夜蛾的相对取食量，抑制其相对生长速率，并降低其繁殖力。在半致死浓度（LC₅₀）水平下，该复配农药制剂表现出协同增效作用。综上，植物源农药与球孢白僵菌的复配制剂可开发为可持续生物防治斜纹夜蛾的新型替代农药。