Endophytic Beauveria bassiana in banana (Musa spp.) reduces banana weevil (Cosmopolites sordidus) fitness and damage

The effect of endophytic Beauveria bassiana in banana (Musa spp.) plants against the banana weevil Cosmopolites sordidus was examined in a screenhouse study in Uganda. Tissue-cultured banana plants (cv. Kibuzi, genome group EA-AAA) were inoculated by dipping roots in a B. bassiana suspension of 1.5 × 107 conidia/ml for 2 h. C. sordidus larvae were introduced 2 months later. Two weeks after larval infestation, endophytic B. bassiana significantly reduced larval survivorship (23.5–88.9% mycosis), resulting in 42.0–86.7% reduction of plant damage. This study has demonstrated for the first time that endophytic B. bassiana can be used to target the cryptic and damaging stage of C. sordidus, and offers an alternative, effective delivery mechanism for this biological control agent.