Phylogeny and species delimitation of the genus Longgenacris and Fruhstorferiola viridifemorata species group (Orthoptera: Acrididae: Melanoplinae) based on molecular evidence

Abstract

Phylogenetic positions of the genus Longgenacris and one of its members, i.e. L . rufiantennus are controversial. The species boundaries within both of L . rufiantennus + Fruhstorferiola tonkinensis and F . viridifemorata species groups are unclear. In this study, we explored the phylogenetic positions of the genus Longgenacris and the species L . rufiantennus and the relationships among F . viridifemorata group based on the 658-base fragment of the mitochondrial gene cytochrome c oxidase subunit I ( COI ) barcode and the complete sequences of the internal transcribed spacer regions ( ITS1 and ITS2 ) of the nuclear ribosomal DNA. The phylogenies were reconstructed in maximum likelihood framework using IQ-TREE. K2P distances were used to assess the overlap range between intraspecific variation and interspecific divergence. Phylogenetic species concept and NJ tree, K2P distance, the statistical parsimony network as well as the generalized mixed Yule coalescent model (GMYC) were employed to delimitate the species boundaries in L . rufiantennus + F . tonkinensis and F . viridifemorata species groups. The results demonstrated that the genus Longgenacris should be placed in the subfamily Melanoplinae but not Catantopinae, and L . rufiantennus should be a member of the genus Fruhstorferiola but not Longgenacris . Species boundary delimitation confirmed the presence of oversplitting in L . rufiantennus + F . tonkinensis and F . viridifemorata species groups and suggested that each group should be treated as a single species.

Molecular phylogeny and species delimitation of the genus Tonkinacris (Orthoptera, Acrididae, Melanoplinae) from China

“…The two Japanese Tonkinacris species were not included in this study because they are morphologically extremely different from the four species distributed in continental China and Vietnam and may not belong to the genus Tonkinacris. More importantly, the only mitochondrial COI fragments sequenced by Grzywacz et al [20] for the Japanese species T. ruficerus and T. yaeyamaensis do not overlap even partially with, but are distantly separated from, the standard barcoding region sequenced in this study and our previous similar studies [18,22]. Therefore, the partial COI sequences of T. ruficerus and T. yaeyamaensis sequenced in Grzywacz et al's study [20] cannot be combined into our dataset for analysis.…”

“…Since molecular data has demonstrated its significant implication in exploring phylogeny and species delimitation in many grasshopper groups (see reference [22] for a short review), we decided to investigate through molecular approaches the phylogeny of Chinese Tonkinacris…”

“…A total of 218 individuals representing 2 suborders 3 families 17 genera and 22 species were sampled (S2 Table ). The sampling strategy was the same as that in our previous studies [18,22]. Species assignation of specimens was performed mainly following Li & Xia's [11] keys to species.…”

“…All specimens were preserved in anhydrous ethanol and stored at room temperature. The protocols for DNA extraction, PCR amplification, sequencing, sequence assembly and alignment followed those in our previous studies [18,22]. COI barcode region for animals, ITS1 and ITS2 were newly sequenced for 149 individuals and the remaining sequences were derived from our previous studies (S3 Table) [18,22].…”

“…Although Tonkinacris was involved in a few monographs on grasshopper taxonomy [7][8][9][10][11][12][13], and a few species of the genus were occasionally sampled in some molecular studies (S1 Table) [14][15][16][17][18][19][20][21][22], there was no revisionary research devoted to the genus based on morphological or molecular data. Tonkinacris usually had a closest relationship to the genera Sinopodisma [14,[16][17][18], Pedopodisma [23,24], Podisma [15], Fruhstorferiola [19][20][21] or Ognevia [22] in the molecular studies above-mentioned depending on the differences in sampling strategies. However, phylogenetic relationship within the genus Tonkinacris has never been explored until now.…”