Abstract: Drosophila suzukii is an important fruit pest native to Southeast Asia. During the past several years, it has been introduced in North America and Europe where it has caused severe damages. In this study, the infection of Wolbachia in seven geographical populations of D.suzukii (five Chinese populations, one Korean population, and one American population) was detected using the 16S rDNA and wsp specific primers (16S-F/16S-R and 81F/691R, respectively), the infection charateristics of Wolbachia within the seven populations were compared, and the 16S rDNA gene fragements within the populaitons were sequenced and then used to determine the classification of Wolbachia. Based on the 16S rDNA primers, we found that all five Chinese populations were infected with Wolbachia with a high infection rate (ranged from 36.7% to 80.0%), while the population from Korea and the United States was not infected with this symbiont. However, the infection of Wolbachia was not detectable using the wsp specific primers. The phylogenetic tree constructed with 16S rDNA gene shows that all of Wolbachia within Chinese populations belong to group A. The results lay a foundation for revealing the biological and ecological effects of Wolbachia on the host D.suzukii. 

Key words:  Drosophila suzukii, geographical population, endosymbiont, Wolbachia, 16S rDNA, wsp, phylogenetic analysis