Effect of different grain media on sporulation, germination and virulence of Beauveria bassiana (Balsamo) Vuillemin against Spodoptera litura Fabricius larvae.

摘要

A laboratory experiment was conducted to study the influence of different grain based media on the sporulation, germination and virulence of Beauveria bassiana against third instar larvae of Spodoptera litura. Among the six grain based media, i.e. barley, finger millet, maize, sorghum, soyabean and wheat, the highest spore production (5.39x107 conidia/ml) and spore viability (86.6%) was observed in conidia produced from finger millet. The production and viability of conidia increased which ranged from 5.0 to 11.5% and 1.70 to 4.65%, respectively, when the media was supplemented with sucrose. The conidia produced from finger millet showed the highest virulence against the third instar larvae of S. litura with LC50 value of 1.56x106 conidia/ml, while soyabean was lowest with LC50 value of 4.98x106 conidia/ml. However, conidia produced from SDA medium showed the highest spore production (6.36x107 conidia/ml), viability (93.75%) and virulence (0.95x106 conidia/ml) against third instar larvae of S. litura..