Ceratitis capitata is one of the world's most destructive and damaging fruit pest, and causes important economic losses in the 85 countries where is distributed. The control methods used for this pe=st are mainly based on chemical insecticides, which are not specific and environmentally harmful. Due the economic importance of C. capitata new control methods are required, being promising alternative insecticides based on biological agen=ts. The entomopathogenic bacteria from Bacillus genus are natural agents=for biological control of invertebrate pests and are the basis of many commerci=al insecticides. Until now, it has not been described any strain of Bacillus that could be used as bioinsecticide against C. capitata. Here we report the isolation of 1=04 bacterial strains from samples collected from agricultural fields where medfly is well established, and 11 strains isolated f=rom dead larvae of C. capitata found in fruits. The toxicity of these 115 bacterial strains was assessed in bioassays carried out with first instar larvae=and adults of medfly. A Bacillus strain was pathogenic against larvae, killing 80-100% of the larvae 15 days after the bioassay began. Preliminary data show that this strain causes more mortality under certain conditions of cold stress. Our results suggest that this strain of Bacillus may have potential as a control agent for medfly.

<=o:p> 

<=o:p> 

<=o:p> 

<=o:p>