Phylogenetic Study and Divergence of Weaver Ant, <i>Oecophylla smaragdina</i> Fabricius in Bangladesh (Hymenoptera: Formicidae)

The weaver ant species, Oecophylla smaragdina, is widely distributed from India through Southeast Asia to northern Australia including many tropical Western Pacific islands. Recent phylogenetic study of O. smaragdina showed that the species is divided into 7 groups based on mtDNA and the Bangladesh populations belong to SE Asian mainland clade despite its geographical proximity to India. The present study aims to reveal the phylogenetic aspect of O. smaragdina in Bangladesh with its divergence time estimation based on extensive materials. Sampling was executed according to zonation of 5 areas which are demarcated by 3 main rivers and a total of 95 colonies from 87 localities of 47 Districts were collected during 2013 to 2018 from Bangladesh. The molecular analyses, using 2 mitochondrial loci: Cytochrome b oxidase subunit 2 (Cytb) consisting of 507 bp and Cytochrome c oxidase subunit I (COI) consisting of 639 bp done in Ku, Japan. The analysis of 84 colonies revealed that 47 are the Indian clade (Indian type) and 37 are the SE Asian mainland clade (SE Asian type). The distribution of mtDNA types showed the occurrence of both the two types with some overlapping distribution in the central part of Bangladesh. The divergence time analysis in Bangladesh populations, resulted that Indian type diverged ca. 2.2 Ma and SE Asian type diverged ca. 0.20 Ma corresponding to early to late Pleistocene. This study suggested a comprehensive phylogenetic scenario of O. smaragdina in Bangladesh.