Phylogenetic analysis reveals the overlapping distribution of the Indian and Southeast Asian clades of Oecophylla smaragdina (Fabricius) (Hymenoptera, Formicidae) in Central Bangladesh

Oecophylla smaragdina, the weaver ant species is widely distributed from India through Southeast Asia to Northern Australia including many tropical Western Pacific Islands. In the previous phylogeographic study, the populations was divided into 7 groups, of which Indian populations are the sister group to other 6 Southeast Asian groups. Central Bangladesh populations of weaver ant have been reported Southeast Asian groups in spite of its geographical proximity however, a recent phylogenetic study of 0. smaragdina revealed that the western Bangladesh population belongs to Indian clade. The purpose of the present study was to analyze the phylogeographic distribution of Southeast Asian and Indian clades of weaver ant in Bangladesh along with the haplotype diversity of these two clades. Adult Oecophylla smaragdina workers were collected from 71 colonies at 67 localities in 38 districts belonging to 7 divisions of Bangladesh during 2013 to 2016 to infer the phylogenetic position. Their haplotype and phylogenetic relationships were determined by analyzing 2 mitochondrial loci: Cytochrome b Oxidase subunit 2 (Cytb) consisting of 580 bp and Cytochrome c oxidase subunit I (COI) consisting of 725 bp. Bayesian analysis inferred that the western parts of Bangladesh were occupied by mitochondrial Indian haplotype, whereas the eastern parts were dominated by the haplotypes of SE Asian clade. The central parts consisted of the mixture of both Indian and SE Asian clades. This study suggested that the Indian and Souheast Asian clades of 0. smaragdina expanded their distribution northward after glaciation and the two clades supposedly encountered and overlapped in central Bangladesh.