Population genetic structure of Bactrocera dorsalis based on cox1 sequences from Bangladesh and neighboring countries

Oriental fruit fly, Bactrocera dorsalis (Hendel), is a destructive and highly polyphagous invasive fruit fly species of numerous fruit crops in global agriculture. Population genetic structure of this species from five different locations of Bangladesh was examined with other samples (collected from GenBank) from 15 sites of neighboring Asian countries. A fragment of 770 bp mitochondrial DNA cox1 was used to investigate the genetic diversity and the relationship between genetic patterns and geographical distribution of B. dorsalis. A total of 232 variable sites (33.23% of the 698 bp aligned consensus sequences) and 419 unique haplotypes were identified from 710 individuals. Indices of genetic diversity suggested that without exclusion from geographical areas, B. dorsalis retained a relatively high degree of genetic diversity. A demographic assessment [Tajimas' D test, Fu's Fs test and sum of square deviation (SSD values)] revealed that both current and historical variables performed a significant role in deciding the weak genetic structure with some exceptions. In Bangladesh, high levels of genetic diversity with a weak genetic structure indicated that the severity of this pest might increase in the future. Proper management techniques should be taken to overcome the future severity of this kind of destructive insect.