Abstract The native isolates of entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, were evaluated against the third instar larvae of the chickpea pod borer, Helicoverpa armigera, for mortality, infection rate and LT50 under laboratory conditions in Nepal. Out of four isolates of M. anisopliae and two isolates of B. bassiana evaluated, M. anisopliae M1 and B. bassiana B3, were the most virulent ones of all isolates evaluated, with a concentration at 107 conidia/ml. The M1 and B3 isolates had the highest mortality rates and required the shortest time to kill the larvae of H. armigera. After treatment with M1 and B1 isolates for 10 days, the larval mortality exceeded 85%. These data lay the ground work for further studies in optimizing the effectiveness of indigenous virulent isolates, M. anisopliae M1 and B. bassiana B3 against H. armigera in Nepal.
摘要 在尼泊爾，於實驗室條件下，將蟲生真菌——黑殭菌 (Metarhizium anisopliae) 與本土白殭菌 (Beauveria bassiana) 的本土分離株對於蕃茄夜蛾 (Helicoverpa armigera) 三齡幼蟲的致死率、感染率及 LT50 進行評估。加上 4 個黑殭菌分離株與 2 個本土白殭菌分離株，黑殭菌 M1 與本土白殭菌 B3 是所有分離株在濃度 107 conidia/ml 下毒性最強者。M1 與 B3 分離株具有最高的致死率，且可用最短時間殺死蕃茄夜蛾幼蟲。於施用 M1 與 B3 分離株十天後，幼蟲致死率超過 85%。在尼泊爾欲善加利用本土毒性分離株——黑殭菌 M1 與本土白殭菌 B3，以達最佳功效，這些數據可作為未來研究的基礎。
| Key words: Beauveria bassiana, Metarhizium anisopliae, LT50, Helicoverpa armigera | | 關鍵詞: 本土白殭菌、黑殭菌、LT50、番茄夜蛾。 |
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