Species delimitation in the Andean grasshopper genusOrotettix Ronderos & Carbonell (Orthoptera: Melanoplinae): an integrative approach combining morphological, molecular and biogeographical data

Barcoding Fails to Delimit Species in Mongolian Oedipodinae (Orthoptera, Acrididae)

Mongolia, a country in central Asia, with its vast grassland areas represents a hotspot for Orthoptera diversity, especially for the Acrididae. For Mongolia, 128 Acrididae species have been documented so far, of which 41 belong to the subfamily Oedipodinae (band-winged grasshoppers). Yet, few studies concerning the distribution and diversity of Oedipodinae have been conducted in this country. Molecular genetic data is almost completely absent, despite its value for species identification and discovery. Even, the simplest and most used data, DNA barcodes, so far have not been generated for the local fauna. Therefore, we generated the first DNA barcode data for Mongolian band-winged grasshoppers and investigated the resolution of this marker for species delimitation. We were able to assemble 105 DNA barcode (COI) sequences of 35 Oedipodinae species from Mongolia and adjacent countries. Based on this data, we reconstructed maximum likelihood and Bayesian inference phylogenies. We, furthermore, conducted automatic barcode gap discovery and used the Poisson tree process (PTP) for species delimitation. Some resolution was achieved at the tribe and genus level, but all delimitation methods failed to differentiate species by using the COI region. This lack of resolution may have multiple possible reasons, which likely differ between taxa: the lack of resolution in the Bryodemini may be partially explained by their massive genomes, implying the potential presence of large numbers of pseudogenes, while within the Sphingonotini incomplete lineage sorting and incorrect taxonomy are more likely explanations for the lack of signal. Further studies based on a larger number of gene fragments, including nuclear DNA, are needed to distinguish the species also at the molecular level.

Relationships and taxonomy of the genus Diponthus Stl (Orthoptera: Acridoidea: Romaleidae)

Diponthus Stl, one of the most diversified and widely distributed Romaleinae genera, is endemic to southern South America. This colorful grasshopper genus is placed within Romaleini and currently includes 16 valid species from a total of 22 nominal ones, most of them only known from their original descriptions. The aims of this study were to propose a morphology-based phylogenetic hypothesis of relationships among the species of Diponthus, and to conduct a taxonomic revision, including the description of four previously unknown species. Parsimony analysis of 79 morphological characters strongly recovered the monophyly of genus Diponthus, and Gurneyacris as its sister group. Internal clades within Diponthus were supported by external morphology and coloration patterns, while characters from male genitalia were shown to be more useful for species differentiation. Based on the results of the taxonomic review, Diponthus is constituted by 16 valid species, with the following nomenclatural changes proposed: Diponthus nigroconspersus (Stl) is considered a valid name; D. invidus Carl and D. bilineatus Rehn are synonymized under D. virgatus (Gerstaecker); Diponthus clarazianus Pictet & Saussure is synonymized under D. cribratus (Serville); D. paulista Rehn is synonymized under D. porphyreus (Gerstaecker); D. maculiferus (Walker) is synonymized under D. electus (Serville). New names are proposed for four undescribed species from Bolivia (D. colorbellus sp. nov. and D. dilatatus sp. nov.), Argentina (D. paranaensis sp. nov.) and Brazil (D. salvadorii sp. nov.).

New Species and Conservation Status of the Genus Group Scotussae (Orthoptera: Acrididae) in the Atlantic Forest

Two new brachypterous species of the genus Scotussa, with restricted distributions, are described for one of the most important and greatly threatened biodiversity hotspots, the Atlantic Forest. These species belong to the genus group Scotussae, a diverse group regarding mobility and oviposition habits. It has been mentioned that these characteristics could lead to restrictions in the species distribution. Based on these antecedents and considering the importance of biodiversity conservation within the Atlantic Forest, we performed novel conservation indices for this group. The rapid assessment indices calculated herein are based upon Red List status, endemism, dispersal capacity, and life-history traits that allowed us to identify areas for conservation for this group of grasshoppers. For a better understanding of the conservation status of the group, the results of the indices were compared with protected areas and Key Biodiversity Areas. Moreover, historical biome stability was also considered since it has been associated with different distributional and diversification patterns within the genus group Scotussae. The approach applied indicates that the indices recovered different but complementary information. The Grasshopper Biotic Index (GBI) determined important regions for conservation within the richest region of the group while the GBI/SiteScore located regions with lower diversity values for the group but with high importance regarding endemisms.

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

Tonkinacris is a small group in Acrididae. While a few species were occasionally sampled in some previous molecular studies, there is no revisionary research devoted to the genus. In this study, we explored the phylogeny of and the relationships among Chinese species of the genus Tonkinacris using the mitochondrial COI barcode and the complete sequences of ITS1 and ITS2 of the nuclear ribosomal DNA. The phylogeny was reconstructed in maximum likelihood and Bayesian inference frameworks, respectively. The overlap range between intraspecific variation and interspecific divergence was assessed via K2P distances. Species boundaries were delimitated using phylogenetic species concept, NJ tree, K2P distance, the statistical parsimony network as well as the GMYC model. The results demonstrate that the Chinese Tonkinacris species is a monophyletic group and the phylogenetic relationship among them is (T. sinensis, (T. meridionalis, (T. decoratus, T. damingshanus))). While T. sinensis, T. meridionalis and T. decoratus were confirmed being good independent species strongly supported by both morphological and molecular evidences, the validity of T. damingshanus was not perfectly supported by molecular evidence in this study.

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

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.

Unraveling the diversification history of grasshoppers belonging to the "Trimerotropis pallidipennis" (Oedipodinae: Acrididae) species group: a hotspot of biodiversity in the Central Andes

The Andean Mountain range has been recognized as one of the biodiversity hotspots of the world. The proposed mechanisms for such species diversification, among others, are due to the elevation processes occurring during the Miocene and the intensive glacial action during the Pleistocene. In this study we investigated the diversification history of the grasshopper Trimerotropis pallidipennis species complex which shows a particularly wide latitudinal and altitudinal distribution range across the northern, central and southern Andes in South America. Many genetic lineages of this complex have been so far discovered, making it an excellent model to investigate the role of the central Andes Mountains together with climatic fluctuations as drivers of speciation. Phylogenetics, biogeographic and molecular clock analyses using a multi-locus dataset revealed that in Peru there are at least two, and possibly four genetic lineages. Two different stocks originated from a common ancestor from North/Central America—would have dispersed toward southern latitudes favored by the closure of the Panama Isthmus giving rise to two lineages, the coastal and mountain lineages, which still coexist in Peru (i.e., T. pallidipennis and T. andeana). Subsequent vicariant and dispersal events continued the differentiation process, giving rise to three to six genetic lineages (i.e., clades) detected in this study, which were geographically restricted to locations dispersed over the central Andes Mountains in South America. Our results provide another interesting example of “island diversification” motored by the topography plus unstable climatic conditions during the Pleistocene, pointing out the presence of a hotspot of diversification in the Andean region of Peru.

Insect phylogenetics in the digital age

Insect systematists have long used digital data management tools to facilitate phylogenetic research. Web-based platforms developed over the past several years support creation of comprehensive, openly accessible data repositories and analytical tools that support large-scale collaboration, accelerating efforts to document Earth's biota and reconstruct the Tree of Life. New digital tools have the potential to further enhance insect phylogenetics by providing efficient workflows for capturing and analyzing phylogenetically relevant data. Recent initiatives streamline various steps in phylogenetic studies and provide community access to supercomputing resources. In the near future, automated, web-based systems will enable researchers to complete a phylogenetic study from start to finish using resources linked together within a single portal and incorporate results into a global synthesis.