ABSTRACT
The effectiveness of native entomopathogenic Beauveria bassiana isolates in the biological control of the Mediterranean fruit fly (Ceratitis capitata) was evaluated under laboratory and field conditions. Local isolates (P. Bv32, P. Bv39, P. Bv41, P. Bv51, and P. Bv52) of the fungus B. bassiana induced higher adult mortalities (77%, 65%, 65%, 65%, and 58%, respectively) than a control against the Mediterranean fruit fly under laboratory conditions. Adult mortality increased by increasing the conidial concentrations. In addition, the lethal time (LT50) for killing adult C. capitata ranged from 3.91 to 5.60 days, and the logged lethal concentration (LC50) ranged from 3.80 to 10.50, depending on the isolate. Furthermore, the contact application method induced significantly higher mortality than feeding alone, compared with the control. In addition, spraying peaches with a conidial suspension of the isolates P. Bv32 and P. Bv39 significantly reduced infestation by the fruit fly, compared with the control. The isolates grew well at a temperature range of 25°C - 30°C; germination of the conidia occurred at 15°C - 30°C, and sporulation occurred at 20°C - 25°C. High Mediterranean fruit fly mortalities were induced at 15°C - 30°C, with significant differences among the isolates. However, the isolates failed to grow, germinate, or sporulate above 35°C or below 10°C. Under field conditions, a formula of the bioinsecticide containing the isolate P. Bv32 of B. bassiana significantly reduced peach infestation with Medfly maggots by 25% compared with the control, and by 30% when combined with a low dose of the commercial insecticide Confidor®.