Community structure of the mediterranean fruit fly microbiota: Seasonal and spatial sources of variation

Fruit flies (Diptera: Tephritidae) maintain diverse yet stable communities of Enterobacteriaceae that reside in their digestive system. Focusing on one species of this family, Ceratitis capitata, the Mediterranean fruit fly (medfly), we applied the PCR-DGGE approach to study the influence of temporal and spatial variations on the composition and diversity of the enterobacterial community associated with the medfly. Our results revealed that the Enterobacteriaceae constituted not only dominant, but also constant and stable populations in the medfly's gut. Nevertheless, changes in both time and space had an impact on the structure and diversity of these bacterial populations, and while some populations (e.g., Klebsiella spp.) were stable, others fluctuated. Whether the bacterial population fluctuated according to the ecological needs of the insect during different environmental conditions, or reflected opportunistic colonization abilities of some bacterial strains, remains to be determined.