Exploring the utility of DNA barcoding in species delimitation of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae).

In this study, we tested the utility of the mitochondrial gene cytochrome c oxidase subunit 1 (CO1) as the barcode region to deal with taxonomical problems of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae). The 114 DNA barcodes representing 27 morphospecies are divided into 33 well separated clusters based on both Neighbor Joining and Maximum Likelihood methods. DNA barcodes revealed an 82% success rate in matching with morphospecies. The selected DNA barcode data support 37-64 operational taxonomic units (OTUs) based on the methods of Automatic Barcode Gap Discovery (ABGD) and Poisson Tree Process (PTP). Furthermore, a priori species based on consistent phenotypic variations were attested by molecular analysis, and a taxonomical misidentification of barcode sequences from GenBank was found. We could not observe a distinct barcode gap but an overlap ranged from 9-12%. Our results supported DNA barcoding as an ideal method to detect cryptic species, delimit sibling species, and associate different life stages in non-biting midges.