Efficacy of white muscardine fungus (Beauveria bassiana) on rice hispa (Dicladispa armigera)

A laboratory experiment was conducted to evaluate the toxicity of Beauveria bassiana (Bals.) Vuill. on the adults of rice hispa [Dicladispa armigera (Olivier)] (Coleoptera: Chrysomelidae), under controlled conditions (25±1.00°C temperature and 80±1.00% relative humidity). The efficacy of B. bassiana was found to reduce gradually with an increase in the period of release of rice hispa adults after spraying the fungus. Simultaneous release of adults after spray (0h) and 12h later resulted in adult mortality 93.33 and 83.33 per cent, were statistically superior over other treatments and found as a potential bio-agent against D. armigera. The fungus was highly pathogenic and the LT₅₀ was observed at 5.50 days. White frosty mycelia growth covered the entire body surface including the appendages of the adults.