Capsule formulations of Beauveria bassiana (balsamo) vuillemin for the management of pseudostem weevil, Odoiporus longicollis (oliver)

Capsules of Beauveria bassiana (Balsamo) Vuillemin were developed to target exact delivery at the site of infestation. Biocapsules formulated using gelatin coating, conidial powder and chitosan and talc as carriers were tested for their efficacy against pseudostem weevil. Five month old plants of variety Nendran, artificially infested with second instar grubs were used for the study. Capsules were placed in the leaf axils @ four per plant, one each on four sides of the plant. Damage Index (DI) and pest population were recorded two weeks after releasing weevils, in prophylactic control and two weeks after treatment in curative control. Analysis of data revealed efficacy of biocapsules, spore suspension @10⁸ spores mL⁻¹ and chlorpyriphos 20 EC 0.05% at par for prophylactic management of pseudostem weevil, as indicated by a common DI of one. Treatment with the capsules resulted in 91.67% reduction in population, as against 100% with spore suspension and chlorpyriphos. For curative treatment, plants treated with talc based capsules and chlorpyriphos 20 EC 0.05% exhibited 100% reduction in pest count, while that with spore suspension caused 83.33% reduction in weevil population. Both talc based and chitosan based Beauveria capsules were found highly effective for prophylactic treatment.