(Diptera: Tephritidae) is responsible for extensive damage in agriculture with important economic losses. Several strategies have been proposed to control this insect pest including insecticides and the Sterile Insect Technique. Traditional control methods should be implemented by innovative tools, among which those based on insect symbionts seem very promising. Our study aimed to investigate, through the 16S Miseq analysis, the microbial communities associated with selected organs in three different medfly populations to identify possible candidates to develop symbiont-based control approaches. Our results confirm that and are the dominant bacteria in guts, while a more diversified microbial community has been detected in reproductive organs. Concertedly, we revealed for the first time the presence of and as stable components of the medfly's microbiota. Additionally, in the reproductive organs, we detected , a bacterium already proposed as a tool in the Symbiotic Control of Vector-Borne Diseases. A strain of , genetically modified to produce a green fluorescent protein, was used to ascertain the ability of to colonize specific organs of . Our study lays the foundation for the development of control methods for based on the use of symbiont bacteria.