The occurrence of the endosymbiont Wolbachia in Bactrocera dorsalis in Pakistan

The bacterial endosymbiont Wolbachia can manipulate the reproduction of arthropod species by feminization, male killing, parthenogenesis and cytoplasmic incompatibility CI. Consequently, Wolbachia has been suggested as mean to control pest insects via incompatible insect technique IIT. In this study we characterized Wolbachia in the economically important oriental fruit fly, Bactrocera dorsalis, an endemic species in Southeast Asia and invasive e.g. in Hawaii. Previous work on B. dorsalis in China screening 1500 individuals showed only an infection rate of 1.26% and authors characterized four Wolbachia strains, wDorHN1, wDorYN1, wDorGD3 and wDorFJ1. We collected 200 specimens from three localities in Pakistan. Wolbachia was characterized by sequencing the Wolbachia surface protein wsp and five MLST loci. Wolbachia amplicons with wsp primers were detected in all B. dorsalis specimens and sequence comparison based on wsp showed one dominant Wolbachia strain named wDorP1. wDorP1 was ident to some strains of the mel-clade of the supergroup A. Further some B. dorsalis individuals were infected with a second Wolbachia strain, wDorP2, a strain closely related to the mel-clade. The four Wolbachia strains detected in China, wDorHN1, wDorYN1, wDorGD3 and wDorFJ1, however, were quite distant from the ones reported here. The findings and the potential use of these strains to control pest populations will be discussed.