Investigation of Pathogenic Potential of Native Isolates of Beauveria bassiana for the Management of Guava Fruit Fly (Bacterocera zonata)

Frugivorous tephritid fruit fly is a significant pest of guava. Because of its invasive nature and major quarantine concern, significant efforts have been made in developing an effective control strategy. Use of entomopathogenic fungi as bio -control has been reported worldwide for decades. The present study was conducted to investigate the pathogenic potential of native isolates of Beauveria bassiana against guava fruit fly. The study evaluated the toxicity of entomopathogenic fungi, specifically Beauveria spp., on all life stages of Bactrocera zonata. The virulence and aggressiveness analysis of Beauveria isolates was done in laboratory conditions by following the parameters like spore production, spore germination and vegetative growth on Potato Dextrose Agar (PDA). The efficacy of entomopathogenic fungi at three different stages viz. larva, pupa and adult was evaluated to determine the most susceptible stage of fruit fly. Results showed that the highest larval (94%), pupal (92%) and adult mortality (93%) was observed at 1 x 10(8) spore/mL. The study identified Beauveria bassiana isolates: FMB-BB-FF 04 and FMB-BB-FF 02 as the most effective, suggesting these isolates for further greenhouse and field trials. This research marks a significant step towards ecofriendly sustainable management of B. zonata and can be useful for other fruit fly pests.