The black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is considered as one of the most destructive pests of many field crops in Egypt. Entomopathogenic fungi (EPF) have long been accepted as relatively safe alternatives to chemical insecticides. In the past decades, many researchers have compared the effective local isolates of EPF to the formulated product of the same fungus and reported that local isolates were more efficient than formulations when used against target insects. The present study discussed the pathogenic activity of local isolate after scientific characterization. Two insect species [Galleria mellonella L. and Agrotis ipsilon (Hufn.)] were used in this evaluation. The fungus was isolated from soil samples by trapping method, and fourth-instar larvae of Galleria were used to evaluate the pathogenicity of the isolate. The isolate was identified as Beauveria bassiana. Different levels of the fungus development depending on the test temperatures (20, 25, 30, 35 and 40 °C) were tested. Optimal growth of the isolate fungus was recorded at 25 °C. The corrected mortality rate for fourth-instar larvae of G. mellonella treated with the isolate spores at 6.4 × 105 spores/ml was (96%) after 10 days, while the mortality of last instar larvae of A. ipsilon was (48 and 100%) at the concentrations of 9.2 × 104 and 2.9 × 106 spores/ml, respectively, after 14 days compared to (24%) in the control. Both pupation and the sex ratio in adults were affected at different levels according to the concentration. The effect was also very clear in the increased rates of malformation in adults. The EPF, B. bassiana, isolated from the soil, was highly effective against G. mellonella larvae in storage and A. ipsilon larvae in soil; therefore, it could be recommended as an alternative control agent for chemical pesticides.

中文翻译：

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从埃及土壤中分离出的昆虫病原真菌对 Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) 黑地老虎幼虫的鉴定和评价

黑地老虎，Agrotis ipsilon (Hufnagel) (鳞翅目：夜蛾科)，被认为是埃及许多大田作物中最具破坏性的害虫之一。昆虫病原真菌 (EPF) 长期以来一直被认为是化学杀虫剂的相对安全替代品。在过去的几十年中，许多研究人员将 EPF 的有效局部分离物与相同真菌的制剂产品进行了比较，并报告说，当用于对抗目标昆虫时，局部分离物比制剂更有效。本研究在科学鉴定后讨论了局部分离物的致病活性。在该评估中使用了两种昆虫 [Galleria mellonella L. 和 Agrotis ipsilon (Hufn.)]。采用诱捕法从土壤样品中分离出真菌，用Galleria的四龄幼虫和四龄幼虫评估分离物的致病性。该分离株被鉴定为白僵菌。测试了取决于测试温度（20、25、30、35 和 40 °C）的不同水平的真菌发育。在 25°C 记录了分离真菌的最佳生长。用 6.4 × 105 孢子/ml 的分离孢子处理的 G. mellonella 四龄幼虫在 10 天后的校正死亡率为 (96%)，而 A. ipsilon 最后一龄幼虫的死亡率为 (48 和 100) %) 在 9.2 × 104 和 2.9 × 106 孢子/ml 的浓度下，14 天后分别与对照中的 (24%) 相比。根据浓度的不同，成虫化蛹和雌雄比均受到不同程度的影响。成人畸形率增加的影响也非常明显。从土壤中分离出的 EPF B. bassiana 对储存中的 G. mellonella 幼虫和土壤中的 A. ipsilon 幼虫非常有效；因此，可以推荐它作为化学农药的替代控制剂。