Symbiotic bacteria of worldwide natural populations of the Mediterranean fruit fly, Ceratitis capitata

The Mediterranean fruit fly, Ceratitis capitata, is a cosmopolitan agricultural pest of worldwide economic importance and a model for the development of the Sterile Insect Technique (SIT) for fruit flies of the Tephritidae family (Diptera). SIT relies on the effective mating of laboratory-reared strains and natural populations, and therefore requires an efficient mass-rearing system that will allow for the production of high-quality males. Adaptation of wild flies to an artificial laboratory environment can be accompanied by negative effects on several life history traits through changes in their genetic diversity and symbiotic bacterial communities. Such changes may lead to reduced biological quality and mating competitiveness in respect to the wild populations. We analyzed the gut symbiotic communities of 265 individuals (adults) from 11 natural medfly populations of worldwide distribution, including Europe, Africa, Australia, and the Americas using the 16S rRNA gene-based amplicon sequencing approach (V3-V4 region, 460 bp). Alpha and beta diversity of bacterial communities pointed to an overall reduced symbiotic diversity and the influence of the geographic location on the bacterial profile.