Abstract Dermanyssus gallinae is considered to be the most economically significant ectoparasite affecting egg-laying poultry in Europe. This mite can also act as a vector for a number of pathogens. To date, little information is available concerning the array of bacteria associated with D. gallinae mites while it could provide insight into the biology and population dynamics of arthropods. In order to understand intra- and inter population diversity of its associated microbiota, we analysed the whole internal bacterial community of natural populations of D. gallinae originating from two types of poultry farm habitats (standard and free-range) in two regions of France (Brittany and Rhône-Alpes). Total DNA was extracted from individual or pooled mites, and PCR temporal temperature gradient gel electrophoresis of 16S rRNA was then undertaken to separate bacterial DNA fragments associated with the host arthropod. A large diversity of bacteria was detected including mainly firmicutes and Gamma-Proteobacteria. Between Group analyses of TTGE banding patterns revealed that bacterial populations clustered into categories according to geographical origin and habitat specific of farms. Some degree of stability of bacterial populations was observed within a specific time year scale. These results suggest that environmental factors that could be recent (e.g. poultry farming practices) or long-standing (e.g. geographic isolation) may affect bacterial communities assembly in D. gallinae. Further knowledge of microbiota associated D. gallinae and its variation would indeed offer new perspectives of biological control in preventing the establishment, proliferation and transmission of pathogenic bacteria. Key words: D. gallinae, microbiota, diversity, biological control