Abstract

                                The present study aimed to the delimitation of Aulacophora spp. from Tamil Nadu through DNA-barcoding. Samples were collected from three districts of Tamil Nadu and cytochrome c oxidase subunit I (COI) gene ofthree species (A. foveicollis, A. lewisii and A. cincta) was sequenced. Eight specimens were sequenced and was submitted to the Genbank. Molecular delineation of species was done using tree-based (phylogenetic tree), and distance-based (Automatic Barcode Gap Discovery) approaches. The data set consists of 35 sequences, including an out-group. Two phylogenetic trees were constructed using neighborhood joining and maximum likelihood method. Both the trees resulted in six distinct species groups, and the branching topology was also similar for both the trees. A. foveicollis, A. abdominalis and A. relicta had branched into three distinct groups from a single node, and A. cincta and A. lewisii sub-branched into different clades from another node. ABGD method gave six identical species groups similar to that of morphological data. The p-value for the grouping ranges from 0.001–0.0359, which gave satisfactory results for species delineation. Both tree-based and distance-based approachesenabled the rapid delineation of species with accurate species identification.

Key words : Aulacophora; Crop pest; Mitochondrial cytochrome oxidase I; Phylogenetic analysis; Automatic Barcode Gap Discovery; Species delineation