RESUMO
As such in search of alternative to chemical insecticides against insect pest of rice resulted in identifying white muscardine fungus, Beauveria bassiana an entomopathogen out of several entomogenous fungi prevalent in rice ecosystem as the potential mycoinsecticides. The fungus has 78-87% virulence against rice hispa with LC 50 value of 90.16. Under field situations it is required that the effectiveness of the bioagents is enhanced by combining them with compatible pesticides. A sublethal dose of a pesticide would make the insect physiologically weak which makes it much more susceptible to the attack of the entomogenous organisms. In view of this, compatibility test was conducted with 14 different commonly applied insecticides at two different doses i.e., recommended and half of the recommended dose. In small scale field trial chloropyriphos at half of the recommended dose along with B. bassiana was the best treatment in controlling the pest along with increased yield of the crop consecutively for two years. Similarly, in multilocational field demonstration trial conducted in hispa endemic areas of Assam viz., Sibsagar and Jorhat covering six different localities B. bassiana (@ 10 million spore/ml dilution) and half of the recommended dose of chlorpyriphos proved superiority then the commonly applied insecticides in decreasing the pest population with increased yield of crop.