Bioefficacy of white muscardine fungus, Beauveria bassiana (Balsamo) Vuillemin and entomopathogenic nematode, Heterorhabditis indica (Poinar) against rice blue beetle, Leptispa pygmaea Baly

摘要

Laboratory studies were conducted during the year 2005-2006 to find out the efficacy of the white muscardine fungus, Beauveria bassiana (Balsamo) Vuillemin and the entomopathogenic nematode, Heterorhabditis indica (Poinar) against adult and grubs of rice blue beetle, Leptispapygmaea Baly. B. bassiana caused a cumulative adult mortality of 56.67 - 80.00 per cent at 105 - 109 spores ml~(-1) and the LC_(50) value was 2.26 x 104 spores ml1. The entomopathogenic nematode, H. indica caused a cumulative mortality of 66.67 - 91.67 per cent at concentrations of 51 Js to 9IJs in the grubs of L. pygmaea. The cumulative LC_(50) value was 3.83IJs. The mortality of L. pygmaea was found to increase with reducing dose and increasing exposure period of both B. bassiana and H. indica. The effective pathogenicity of B. bassiana and H. indica against L. pygmaea is reported for the first time.