In the recent years, the keen interest has been increased towards biological control-based management practices using entomopathogenic fungi (EPF) for the control of many economically important insects. In this management practices, selection of right strains of EPF is an important criteria to control the target pests in effective manner. In this context, this research work was formulated to find out environmentally effective strains of EPF in the soils of costal districts of Andhra Pradesh. Out of 135 soil samples collected, 8 soil samples yielded 8 strains of Metarhizium anisopliae. Among all 8 M. anisopliae isolates, the least median lethal concentration (LC50) for 2nd instar of the tobacco caterpillar, Spodoptera litura (Lepidoptera: Noctuidae) was 1.24 × 105 spores ml-1 in M-7, followed by 1.72 × 105 spores ml-1 in M-5 and 1.86 × 105 spores ml-1 in M-4 in an increasing order. Likewise, the median lethal time (LT50) values of different isolates of EPF against 2nd instar of S.litura were calculated for a uniform highest dose of 1 × 108 spores ml−1. Among all 8 M. anisopliae isolates, the lowest LT50 was observed as 186.44 hours post infection (hpi) with M-5 and 189.34 hpi with M-7.

中文翻译：

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从土壤中探查本地绿色毒蕈碱真菌菌株及其对烟草毛毛虫斜纹夜蛾（Fabodius）的致病性（鳞翅目：夜蛾科）

近年来，人们越来越关注使用昆虫病原真菌（EPF）来控制许多具有经济意义的昆虫的基于生物控制的管理方法。在这种管理实践中，选择正确的EPF菌株是有效控制目标害虫的重要标准。在这种情况下，这项研究工作的制定是为了找出安得拉邦沿海地区土壤中对环境有效的EPF菌株。在收集的135个土壤样品中，有8个土壤样品产生了8个金属异化菌。在所有8种分离的M. anisopliae中，烟草毛虫第二龄幼虫（Spodoptera litura（Lepidoptera：Noctuidae））的最低中值致死浓度（LC50）为M-7中的1.24×105孢子ml-1，其次是1.72×105孢子M-1和M-1中的ml-1。M-4中的86×105个孢子ml-1升序排列。同样，针对均匀最高剂量为1×108孢子ml-1，计算了不同的EPF分离株对利特酵母第二龄的平均致死时间（LT50）值。在所有的8种分离的M. anisopliae中，最低的LT50为M-5感染后（hpi）186.44小时，M-7为189.34 hpi。