Reduction of Banana Weevil Populations Using Different Formulations of the Entomopathogenic Fungus Beauveria bassiana

Abstract

One of the major constraints for banana production in Uganda is the banana weevil, Cosmopolites sordidus (Germar), (Coleoptera: Curculionidae). Investigations were carried out to evaluate the efficacy of maize, soil-based and oil formulations of an indigenous isolate of Beauveria bassiana for the control of the banana weevil. Weekly trapping of weevils over a 9-month monitoring period showed significant reduction in unmarked and marked weevil population in B. bassiana treated plots. Application of maize formulation at 2 &#50 10 15 conidia ha -1 proved most effective, reducing the weevil populations by 63-72% within 8 weeks after a single application. The soil based formulation at 2 &#50 10 14 conidia ha -1 was intermediate while the oil formulation at 6 &#50 10 15 conidial ha -1 was least effective. Trapping efficiency declined in B. bassiana treated and untreated banana plots but was greatest in the latter.