Susceptibility of oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) pupae to entomopathogenic fungi

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is considered as a highly invasive and destructive agricultural pest due to its strong dispersal and adaptive capacity. We evaluated the susceptibility of B. dorsalis pupae to six entomopathogenic fungi (Isaria fumosorosea IFCF01, Beauveria bassiana Bb02, B. bassiana Bb04, Metarhizium anisopliae Ma01, M. anisopliae Ma04, and M. anisopliae Ma09) in the laboratory through impregnation method (immersing fly pupae into conidial suspension). Results indicated that fungus treatment during the pupal stage of B. dorsalis, not only caused significant mortality of target pupae (4.4–14.4% mortality), but also influence the survival of the emerged adults (38.9–72.8% mortality on the 10 days post-emergence). Among the six entomopathogenic fungi, M. anisopliae Ma04 presented the highest virulence against B. dorsalis. Results of virulence bioassay indicated that the LC50 values of M. anisopliae Ma04 against B. dorsalis declined from 5.2 × 1028 to 5.2 × 107 conidia/ml over a 1–10-day period post adult emergence, and the LT50 values decreased from 5.25 to 2.78 days with the concentrations of conidial suspension increasing from 1.0 × 108 to 1.0 × 1010 conidia/ml. Therefore, M. anisopliae Ma04 have a greater potential for B. dorsalis control.