Relative Susceptibility of Brinjal Spotted Beetle, Henosepilachna vigintioctopunctata (Fabricius) to Certain Isolates of Beauveria bassiana (Bals.) Vuill
Beauveria bassiana, Field Application, Henosepilachna vigintioctopunctata, Persistence, Virulence.
Abstract
Pathogenicity of Beauveria bassiana (Bals.) Vuill isolates to the brinjal spotted beetle, Henosepilachna vigintioctopunctata (Fabricius) has been recorded for the first time. Virulence of the isolates was assessed at different developmental stages of the beetle from laboratory bioassay experiments. Pathogenic strains showing rapid germination and profuse sporulation were found to be more virulent to the pest. LT50 values of the second instar larvae ranged from 1.33 to 4.8 days in the different isolates. Larval stages appeared to be more susceptible than prepupal and adult stages. Field performance of the pathogen tested by applying the mass multiplied inoculum to the infested brinjal plants revealed persistence of the biocontrol agent in the soil for 30 days.