Systematic Entomology最新文献

X-ray micro-computed tomography (micro-CT) of dried and pinned museum specimens combined with advanced image processing can provide a useful, novel and non-destructive tool for integrative insect taxonomy. This paper demonstrates how micro-CT can be applied to provide unambiguous illustrations of diagnostic morphological characters for new taxa description and to understand how micro-CT imaging may complement other imaging techniques. Following micro-CT scanning, a semi-automatic segmentation and volume rendering protocol was used to portray the wing venation and diagnostic structures and ornamentation of male genitalia from multiple angles. Using micro-CT images, we provide the description of a conspicuous geometrid moth from southern Africa (Lepidoptera: Geometridae), which has been present in collections since 1894, but left without an available name. Using a multigenetic dataset comprising 273 terminal taxa from the superfamily Geometroidea, we constructed a molecular phylogeny to place our study species to an isolated lineage in Geometridae: Larentiinae, tribe Xanthorhoini sensu lato. We describe it as Chloecolora vergetaria new genus, new species Englund & Staude, and provide diverse ecological information on its distribution, habitat, host plant, adult and immature stages, and parasites. We found micro-CT imaging particularly useful in two- and three-dimensional imaging of wings, providing detailed information for instance on non-tubular folds that may be difficult to distinguish using other techniques.

South Pacific archipelagos are central in the biogeographic debate on the relative importance of vicariance and dispersal in shaping the distribution of species. However, each taxonomic group was subject to different processes and histories, and here, we reveal the historical biogeography of the diverse Eumolpinae leaf beetles, widely distributed in the region. Extensive taxon sampling focusing on South Pacific Eumolpinae was used to infer the first molecular phylogeny of the group using three single-copy protein-coding nuclear and two mitochondrial markers. Upon assessing the clade of interest for lineage-specific variation in substitution rates, the age of the most recent common ancestors was estimated using out-group calibration and multi-gamma site models (MGSMs). Biogeographic analyses used standard event-based inferences also incorporating phylogenetic uncertainty. Zealandian Eumolpinae are monophyletic and appear to have split from their global relatives in the transition from the Cretaceous to the Paleogene. Variation in the rates of molecular evolution affected the in-group stem branch, with a significant drop in the substitution rate, and the MGSM correction recovered the crown age of Zealandian Eumolpinae during the Late Eocene–Oligocene transition. Biogeographic inference resolved the origin of the radiation in New Caledonia, favouring a null model without island age constraints, and repeated dispersal events to the other islands, including three independent but synchronous colonisations of New Zealand during the Miocene. New Caledonia, with a highly diverse Eumolpinae fauna of uncertain origin, acted as a hub and pump of biodiversity of these beetles in the entire South Pacific region, sending migrants to other islands through long-distance dispersal with lineages establishing when land became available.

Hybridisation and introgression are increasingly seen as important drivers of the evolution of organisms, particularly in Lepidoptera. One group that is gaining attention due to recently published cases of interspecific gene flow is the genus Melitaea Fabricius (Nymphalidae). In this study, we used genomics to investigate the role of hybridisation in the evolution of the western Palearctic species of the Melitaea phoebe group M. ornata Christoph, the recently described M. pseudornata Muñoz Sariot & Sánchez Mesa, M. phoebe (Denis & Schiffermüller), M. punica Oberthür, and M. telona (Fruhstorfer). We provide evidence of asymmetric gene flow from M. phoebe to both M. ornata and M. pseudornata. Gene flow from M. phoebe to M. pseudornata was very high (25.0%–31.9%), widespread throughout the distribution of the latter, and not equally distributed along the genome. The Z chromosome showed patterns compatible with the large-Z effect, which were mimicked by two autosomes. Melitaea pseudornata endured massive introgression while remaining a separate entity from M. phoebe, although gene flow may have altered its phenotype, including its voltinism and the morphology of the adults and caterpillars. These findings suggest that hybridisation may be pervasive in this genus and highlight its key role in the evolution of butterflies, emphasising the need for further research on this topic.

The slug moth family Limacodidae is a cosmopolitan group of economic importance, but its higher level systematics remains poorly understood. Here, we present a robust, higher level phylogenetic framework for Palaearctic and Indomalayan members of the family using sequence capture data of 148 nuclear protein-coding and 13 mitochondrial markers from 145 samples of 126 species in 67 genera representing all five morphologically delineated limacodid lineages. Our results strongly support the monophyly of Limacodidae in which six major clades are recognized. The relationships among these clades are revealed, with Phrixolepia-clade being the most basal group followed by Apoda-clade, Euphlyctinides-clade, Cania-clade and Phlossa-clade + Parasa-clade, respectively. We also add publicly available DNA barcode sequences from additional species worldwide to this phylogenetic framework to infer the most completely sampled phylogeny of Limacodidae to date. Our work provides a major step towards understanding the systematics and evolution of slug moths.

Orthoptera species are characterised by their expansive genomes. However, crickets, the third largest group of this order, have notably smaller genomes than grasshoppers or katydids. The evolutionary drivers behind these differences in genome size (GS) remain largely uncharted. In our study involving 56 cricket species, we assessed GS using flow cytometry and assembled 43 novel mitochondrial genomes for phylogenetic analysis. Model fitting indicated that GS generally conformed to an Ornstein-Uhlenbeck adaptive evolutionary model, displaying a 5.1-fold range of variation in GS, from 0.82 pg in Myrmecophilus quadrispina Perkins to 4.68 pg in Ornebius formosanus Shiraki. Remarkably, despite such variations, no significant trends in genome contraction or expansion were detected, suggesting an adaptive stabilisation. We found strong evidence that expansions of repeat elements, particularly transposable elements (TEs), are key drivers of the large GS in crickets. Across the 56 cricket species analysed, TE content exhibited substantial variability, spanning from a mere 3.63% to a pronounced 31.22%. Clades exhibiting significant GS or TE variations, such as mole crickets (Gryllotalpidae), ant-loving crickets (Myrmecophilidae) and scaly crickets (Mogoplistidae), are often observed at basal phylogenetic nodes and exhibit distinct ecological niches and morphological divergences. This implies that cricket genomes undergo early mutations and stabilise throughout evolution. Our findings shed light on common patterns and uncover lineage-specific differences in content and evolution of TEs in crickets. We anticipate that our study will provide a foundation for future comparative research on the insect TE repertoire.

The phylogenetic relationships among major lineages of the globally distributed leafhopper subfamily Coelidiinae were reconstructed by analysis of 2903 nucleotide positions from two mitochondrial genes (COI and 16S), four nuclear genes (28S, H3, H2A and Wingless) and 102 discrete morphological characters, compiled for 86 species representing 52 genera within 9 coelidiine tribes broadly representative of the world fauna in addition to 12 outgroup taxa. Maximum likelihood and Bayesian analyses yielded well-resolved phylogenetic estimates that were highly congruent with most branches receiving strong support. The results indicate Coelidiinae sensu stricto (=Coelidiinae sensu lato without Equeefini and Macroceratogoniini), Thagriini, Tharrini, Tinobregmini and Equeefini are monophyletic. However, the two largest tribes, Coelidiini and Teruliini, are paraphyletic, as well as Youngolidiini and most genera of Oriental Coelidiini. Fossil-calibrated molecular divergence time analysis indicates that the Coelidiinae sensu stricto originated ca. 149 Ma, prior to the complete separation of the Gondwanan continents, and the tribe-level lineages diverged between the Lower and Upper Cretaceous (92.77–138.03 Ma). The major lineages of Coelidiinae arose in the Oriental and Neotropical regions, and Oriental Coelidiini arose as a result of dispersal and colonisation from the Afrotropical region.

Fossils are valuable indicators of the evolutionary history of the clades to which they belong to, especially when they are incorporated as terminal taxa in a total-evidence phylogeny. According to their state of preservation, fossils are often incompletely described for key morphological characters, such as genitalic structures. Here, the internal parts of the genitalia of a male fossil cricket from Cretaceous amber, †Picogryllus carentonensis Josse & Desutter-Grandcolas (Oecanthidae, Podoscirtinae), together with other key morphological characters (i.e., metanotal structures and tibial spurs), were reconstructed for the first time by 3D microtomography. Total-evidence phylogeny and dating combining morphological data (fossils and extant taxa), molecular data (extant taxa only) and time calibration (fossil dates) were performed to evaluate the tempo and mode of evolution of the cricket family Oecanthidae. Divergence time estimates were thus refined and the patterns of transformation for key morphological structures contrasted through the analysis of phylogenetic morphological partitions. Our results show that Oecanthidae date back to the Upper Jurassic (Oxfordian, around 162 Ma) and attest to the presence of the Podoscirtinae in Western Europe during the Lower Cretaceous. Morphological evolution may have been driven by the conquest of new resources (as shown by leg evolution in ancestral Oecanthidae) and/or the ‘conquest of silence’ (as shown by repetitive and definitive losses of acoustic structures). By contrast, genitalia evolution proved more diffuse.

Recent progress in beetle palaeontology has incited us to re-address the evolutionary history of the group. The Permian †Tshekardocoleidae had elytra that covered the posterior body in a loose tent-like manner. The formation of elytral epipleura and a tight fit of elytra and abdomen were important evolutionary transformations in the Middle Permian, resulting in a tightly enclosed subelytral space. Permian families were likely associated with dead wood of gymnospermous trees. The end-Permian extinction event resulted in a turnover in the composition of beetle faunas, especially a decline of large-bodied wood-associated forms. Adephaga and Myxophaga underwent a first wave of diversification in the Triassic. Polyphaga are very rare in this period. The first wave of diversification of this suborder occurs in the Jurassic, with fossils of Elateriformia, Staphyliniformia and Cucujiformia. The Cretaceous fossil record has been tremendously enriched by the discovery of amber inclusions. Numerous fossils represent all major polyphagan lineages and also the remaining suborders. Improved analytical methods for documenting and placing extinct taxa are discussed. Different factors have played a role in the diversification of beetles. The enormous number of species associated with flowering plants, and timing and patterns of diversification in phytophagous lineages indicate that the angiosperm radiation played a major role in beetle macroevolution. Moreover, the evolution of intimate partnerships with symbionts and the acquisition of novel genes—obtained from fungi and bacteria via horizontal gene transfers—facilitated the use of plant material as a food source and were key innovations in the diversification of plant-feeding beetles.

Recent progress in beetle palaeontology has incited us to re-address the evolutionary history of the group. The Permian †Tshekardocoleidae had elytra that covered the posterior body in a loose tent-like manner. The formation of elytral epipleura and a tight fit of elytra and abdomen were important evolutionary transformations in the Middle Permian, resulting in a tightly enclosed subelytral space. Permian families were likely associated with dead wood of gymnospermous trees. The end-Permian extinction event resulted in a turnover in the composition of beetle faunas, especially a decline of large-bodied wood-associated forms. Adephaga and Myxophaga underwent a first wave of diversification in the Triassic. Polyphaga are very rare in this period. The first wave of diversification of this suborder occurs in the Jurassic, with fossils of Elateriformia, Staphyliniformia and Cucujiformia. The Cretaceous fossil record has been tremendously enriched by the discovery of amber inclusions. Numerous fossils represent all major polyphagan lineages and also the remaining suborders. Improved analytical methods for documenting and placing extinct taxa are discussed. Different factors have played a role in the diversification of beetles. The enormous number of species associated with flowering plants, and timing and patterns of diversification in phytophagous lineages indicate that the angiosperm radiation played a major role in beetle macroevolution. Moreover, the evolution of intimate partnerships with symbionts and the acquisition of novel genes—obtained from fungi and bacteria via horizontal gene transfers—facilitated the use of plant material as a food source and were key innovations in the diversification of plant-feeding beetles.

Synthetic studies of arthropod systematics and biodiversity are hindered by overreliance on ‘preferred’ semaphoronts, those life stages (typically adult males) that provide the most taxonomically distinctive characters. However, modern sequence-based methods for inventory have no such limitations and permit incorporation of any and all representatives of a species. Here, we briefly review the growth and potential of these approaches to faunistic and systematic studies and share results from our own recent work that illustrate the value that other morphs, immature stages and females added to these studies.