Evaluating the Pathogenic Effects of Three Cuticle-Degrading Enzymes from Beauveria bassiana on Various Life Stages of Bactrocera zonata

Background: This study focused on managing Bactrocera zonata, an invasive Tephritid fruit fly that attacks a variety of fruits, by applying cuticle degrading enzymes (CDE) extracted from Beauveria bassiana, a phytopathogenic agent for the biological control of insect pests, as confirmed by SDS-PAGE analysis.

Methodology: Proteases, lipases, and chitinases were among the cuticle-degrading enzymes with varying molecular weights of 19–47 kDa, 32 kDa, and 49.47 kDa, respectively. The crude enzymes that were extracted and employed at doses of 1.5, 3, 5, 7, and 10µL were applied to larvae, pupae, and adults.

Results: At 10µL/mL, the death rates for larvae and adults were found to be 78.50±2.10% and 80±2.15%, respectively. Lower amounts (1.5µL/mL) resulted in a mortality rate of 13.33±1.92%, with control coming in second. The treated insects showed a low proportion of adult emergence (10±2.63%) from pupae, while the untreated group of insects showed a greater percentage (65.0±5.77%) of adult emergence.

Conclusion: The outcome demonstrated that concentration affected both adult emergence from pupae and mortality. Consequently, the pathogenicity of B. bassiana mycelium against B. zonata was increased by the addition of CDE.