Orthotomicus erosus (Wollaston, 1857) (Coleoptera: Curculionidae: Scolytinae) is one of the principal pests of Eurasian forests. Gathering data from this study concerning population genetic structure of O. erosus would help improving new strategies to control the pest by giving new insights on forest management. The aims of the study were to resolve the population genetic structure of Orthotomicus erosus which distributes Mediterranean Region of Turkey and to determine the factors (such as host pine species and geographic barriers) that contributed to the current distribution of genetic diversity. The beetle samples were collected from 20 stands from the pine forests included in the Mediterranean Region of Turkey. 67 samples were studied using mitochondrial cytochrome oxidase subunit I (COI) gene and Neighbor Joining (NJ) and Maximum Likelihood (ML) analyses were performed. As a result of the study, thirty-seven distinct haplotypes from sixty-seven samples were determined. The species did not form any phylogroup in populations depending on the geographical location according to the NJ and ML analysis. The NJ and ML trees revealed that those O. erosus individuals that fed on different pine species did not have genetic variations. Consequently, NJ and ML analysis results reveals that different populations of the species across the Mediterranean Region were not disconnected and isolated geographically either.