Species delimitation and DNA barcoding for Chinese Mantodea (Insecta, Dictyoptera)

Abstract

DNA barcoding has been proposed as a rapid and reliable tool for animal identification and species delineation. The 5' end of the mitochondrial cytochrome c oxidase I gene (COI-5P) was sequenced for 318 specimens of 55 mantis species. Of these, 44 species had not been sequenced before, thus being new COI-5P barcode sequences to science. Another 61 COI-5P barcode sequences comprising five species were retrieved from the Barcode of Life Database (BOLD; www.boldsystems.org). Five species delimitation algorithms were employed to sort barcode sequences into Molecular Operational Taxonomic Units (MOTUs), namely the distance-based Barcode Index Number (BIN) System, Generalized Mixed Yule Coalescent (GMYC), a Java program that uses an explicit, determinate algorithm to define Molecular Operational Taxonomic Unit (jMOTU), Assemble Species by Automatic Partitioning (ASAP), and Bayesian implementation of the Poisson Tree Processes model (bPTP). All species, except Hierodulachinensis Werner, 1929, were recovered as monophyletic on the neighbor-joining (NJ) tree. For the final dataset, 379 COI-5P barcode sequences were assigned to 68 BINs. Fifty-five out of 68 BINs obtained were new to BOLD. The low level of BIN overlap with other nations highlights the importance of constructing a regional DNA barcode reference library. The algorithms ASAP, jMOTU, bPTP, and GMYC clustered barcode sequences into 32, 58, 68, and 60 MOTUs, respectively. All species delimitation algorithms (except ASAP analysis) split Anaxarchasinensis Beier, 1933, Anaxarchazhengi Ren & Wang, 1994, H.chinensis, Spilomantisoccipitalis (Westwood, 1889), Titanodulaformosana Giglio-Tos, 1912 into more than one MOTUs. All algorithms merged Hierodula sp. BCM-2019 and H.chinensis into the same MOTU, as for Tenoderaaridifolia Stoll, 1813 and Tenoderasinensis Saussure, 1871. More accurate identification results need to be supplemented by detailed morphological classification.

Keywords: COI-5P; China; DNA barcoding; Mantodea; mantis; species delimitation.

Figure 1.

Inter- and intraspecific genetic divergence based on K2P distances. A Distance distribution histograms of mean intra-specific distances B distance distribution histograms of distance to nearest neighbor C maximum intra-specific vs nearest-neighbor distances D mean intraspecific vs nearest-neighbor distances E number of individuals in each species against their maximum intraspecific distances.

Figure 2.

Taxon ID Tree of mantis COI-5P barcode sequences using the neighbor-joining (NJ) method based on K2P distances (left) and groups showing contrasting species delimitation results (right). The scale bar shows K2P distances. Numbers in the rectangles indicate the number of MOTUs.