PREPARATION OF GRAIN FORMULATIONS OF NOMURAEA RILEYI (FARLOW) SAMSON AND TESTING VIRULENCE AGAINST 3RD INSTAR OF SPODOPTERA LITURA

Abstract

Lab experiment was conducted at department of Entomology, S.V Agricultural College, Tiruati during 2013-14 to evaluate the efficacy of grain formulations of Nomuraea rileyi against 3rd instar larvae of Spodoptera litura. Among the different treatments tested, Maize grain formulation recorded highest virulence (ranging from 57 to 67 percent at 4ºC and 47 to 57 percent at 25ºC). Lowest virulence was recorded in Ragi grain formulation (ranging from 30 40 at 4ºC and 20 to 27 at 25ºC). The grain formulations stored at 4ºC were shown 10 percent higher response with regard to virulence when compared to grain formulations stored at 25ºC. The mortalities gradually reduced with concentrations (showing least at 1×105spores ml-1 and highest at 1×108spores ml-1).The larval mortalities are positively associated with concentrations and negatively associated with storage period.