White muscardine fungus (Beauveria bassiana) pathogenic to different stages of rice hispa (Dicladispa armigera)

Abstract

An experiment was conducted during summer, autumn and spring seasons of 1990, 1991 and 1992 to study the infection of the white muscardine fungus (Beauveria bassiana(Bals.) VuilL] on eggs and adults of rice hispa [Dicladispa armigera (Olivier)] (Coleoptera : Chrysomelidae) in rice (Oryza sativa L.) fields of Sibsagar district. The field and laboratory tests, confirmed its pathogenicity on eggs, larvae, pupae and adults. In the field, infection on egg was 16.95-45.1%, depending on the season: being more than that during other stages. Low (1.67%) to very high (40.63%) level of infection of adults was also observed in summer, autumn and spring seasons.