Screening and secretomic analysis of enthomopatogenic Beauveria bassiana isolates in response to cowpea weevil (Callosobruchus maculatus) exoskeleton.

The production of cowpea (Vigna unguiculata), an important self-sustained crop in Latin America and Africa, is severely affected by damage by the cowpea weevil Callosobruchus maculatus. The presence of a single larva in stored seeds can lead to losses of almost 40%. Control of C. maculatus currently relies on the inefficient use of chemical insecticides and post-harvest treatments. The use of entomopathogenic fungus became a reliable alternative for coleopteran pest control and has been extensively investigated. Among them, Beauveria bassiana and Metarhizium anisopliae were widely evaluated in order to measure their virulence toward many insects. In this report, we evaluated the insecticidal activity of ten strains of B. bassiana and the most lethal fungi strains were analyzed for proteinaceous secretions by two dimensional electrophoresis and for enzyme activities, including chitinolytic, proteolytic and alpha-amylolytic activities. This study could, in the near future, help to establish novel biotechnological tools to use for cowpea weevil control.