Systematic Entomology最新文献

Maritime chironomid midges (Diptera) are diverse, yet these ‘pearls of the ocean’ are little known. Emphasizing Pacific Ocean taxa, we used six genetic markers (18S, 28S, CAD1, CAD4, FolCOI and COI) and fossil calibrations to produce Bayesian time-calibrated phylogenies to date eight independent marine transitions in three subfamilies. Deep nodes involve subfamily Telmatogetoninae (originating mid-Cretaceous, 101–128, 114 Ma), with sister genera Telmatogeton Schiner and Thalassomya Schiner splitting later in the Cretaceous (56–82, 69 Ma). Two transitions in Orthocladiinae involve Clunio Haliday and Pseudosmittia Edwards, dating from the upper Cretaceous, both with Eocene crown groups. In subfamily Chironominae, transitions to marine occur in two tribes. Four transitions occur within the otherwise nonmarine crown groups Kiefferulus Goetghebuer, Dicrotendipes Kieffer, Polypedilum Kieffer and Ainuyusurika Sasa & Shirasaka. Two separate robust clades in tribe Tanytarsini involve: (1) a minor radiation within Paratanytarsus dated to the mid-Eocene around 43 Ma; and (2) an unexpected but fully supported diversification in Pontomyia Edwards plus Yaetanytarsus Sasa dated to around 47 Ma, with separation of Pontomyia from Yaetanytarsus around 40 Ma. Crown Pontomyia, represented by three species, was estimated to have diverged around 19 Ma, whereas the crown radiation of Yaetanytarsus, with 12 sampled species, dates to the mid-Eocene. In a comprehensive global review we concisely document new synonymies and new combinations revealed by the study. The evolutionary timing estimate provides insights into the frequency of marine transitions and diversifications in the Chironomidae in association with dynamic oceanic changes during the Oligocene and Miocene.

The suborder Auchenorrhyncha (“true hoppers”) comprises nearly half of known Hemiptera, with >43,000 known species of sap-sucking herbivores distributed worldwide, including many important agricultural pests and vectors of plant disease. More than half of the known Auchenorrhyncha belong to superfamily Membracoidea (leaf- and treehoppers), which has been a source of phylogenetic contention for many years. To construct an improved backbone phylogeny of this superfamily, we obtained transcriptome data for multiple representatives of all 5 previously established extant families and nearly all subfamilies to test their monophyly and relationships. 138 taxa (132 Membracoidea and 6 outgroups) were sampled with an emphasis on families Cicadellidae and Membracidae, which were paraphyletic as previously defined by most authors, several problematic subfamilies (Aphrodinae, Eurymelinae, Ledrinae, Nicomiinae, Stegaspidinae and Tartessinae). We analysed different combinations of data sets (amino acid, complete nucleotide and degeneracy-coded nucleotide) using different modelling schemes. The resultant trees based on different analyses are congruent in most nodes. Discordant nodes mainly pertain to relationships among cicadellid subfamilies and tribal relationships within Aphrodinae and Eurymelinae. Analyses of gene- and site concordance factors and quartet scores indicate that this instability is largely attributable to an overall lack of informative characters across genes and sites rather than strongly supported conflict among genes. According to the congruent nodes, we make the following revisions: combine Stegaspidinae and Centrotinae into a single subfamily, Centrotinae sensu lato; restore Stenocotini from Tartessinae to its original position in the Ledrinae; and transform Holdgatiella Evans from Nicomiinae to Melizoderinae. In addition, to solve the paraphyly of both Cicadellidae and Membracidae, a preferred option would be to combine all five previously recognized families into a single family, Membracidae sensu lato; the other option could be to render Cicadellidae monophyletic by excluding Megophthalminae and Ulopinae from Cicadellidae and elevating them to status as separate families.

The factors leading to the extraordinary diversity of the bees of the genus Andrena Fabricius, the second most speciose genus among bees, remain largely unknown. To examine the pattern of diversification in this genus, we investigate species boundaries within the controversial Andrena proxima-complex using a dataset of ultra-conserved elements and various species delimitation analyses (admixture analyses, BPP, DAPC). Our results confirm the presence of three separate species in this species group (Andrena proxima (Kirby), A. ampla Warncke and A. alutacea Stöckhert) and suggest very low levels of interspecific gene flow. Andrena proxima and A. alutacea are regularly found in sympatry, suggesting an advanced stage of speciation. By contrast, A. ampla shows a parapatric distribution with both other species. Andrena alutacea harbours a unique strain of Wolbachia Hertig, absent in the other two species, which are infected by the two same strains of Wolbachia. In addition, the three species have distinct phenologies, with A. proxima flying earlier in the season and A. alutacea significantly later; the phenology of A. ampla is intermediate. Our results suggest that Wolbachia-induced incompatibilities and phenological differences maintain species boundaries in this group. The most advanced stage of speciation is observed in the two species showing putatively incompatible strains of Wolbachia and strongly distinct phenologies, A. alutacea and A. proxima. We propose that the smaller differences in phenological differentiation between A. ampla and both other species may explain the observed pattern of parapatric distribution. We discuss how these factors may underlie the high diversification rate observed in other groups of Andrena, a genus characterized by particularly variable and short flying periods.

The tribe Acanthoplectrini (Myrmeleontidae: Dendroleontinae) includes a group of antlion genera widely distributed across the Australasian and Oriental regions. The intergeneric and interspecific relationships between or within the Australian and Oriental lineages of this tribe as well as their historical biogeography remain largely unexplored. Here, we present a molecular phylogenetic and biogeographic analyses of Acanthoplectrini to infer the diversification history of this tribe, with emphasis on the Oriental lineage. Both the Oriental and Australian lineages are monophyletic and recovered as sister groups. Ancestral area reconstruction suggests that the ancestor of Acanthoplectrini might have been once widely distributed from Indochina to Australia and then split into the Oriental and Australian lineages during the early-Miocene. Our analyses recovered northeastern Indochina and south China as the ancestral range of the Oriental Acanthoplectrini. During the mid-Miocene to the mid-Pliocene, orographic events such as the rising of mountain ranges (including the Himalayas) and the formation of major islands in southeastern Asia triggered several dispersal and vicariance events in the Oriental Acanthoplectrini, driving their speciation. We revise the classification of the Oriental Acanthoplectrini, establishing the new genus Paralayahima gen. n., which is recovered sister to Layahima Navás. Moreover, we describe four new species of Layahima, Layahima aspoeckorum sp. n., Layahima monba sp. n., Layahima lhoba sp. n. and Layahima xinliae sp. n., and we reinstate two previously synonymized species, Layahima melanocoris (Yang) stat. rev. and comb. n. and Layahima nebulosa Navás stat. rev.

The Coleoptera provides an excellent example of the value of fossils for understanding the evolutionary patterns of recent lineages. We reevaluate the morphology of the Early Permian †Tshekardocoleidae to test alternative phylogenetic hypotheses relating to the Palaeozoic evolution of the order. We discuss prior interpretations and revise an earlier data matrix. Both Bayesian and parsimony analyses support the monophyly of Coleoptera excluding †Tshekardocoleidae (= Mesocoleoptera), and of Coleoptera excluding †Tshekardocoleidae and †Permocupedidae (= Metacoleoptera). Plesiomorphies preserved in †Tshekardocoleidae are elytra, which rest over the body in a loose tent-like manner, with flat lateral flanges, projecting beyond the abdominal apex, and abdomens that are flexible and nearly cylindrical. Apomorphies of Mesocoleoptera include shortening of the elytra and a closer fit with the flattened and probably more rigid abdomen. A crucial synapomorphy of Metacoleoptera is the tightly sealed subelytral space, which may have been advantageous during the Permian aridification. Taxon exclusion experiments show that †Tshekardocoleidae is crucial for understanding the early evolution of Coleoptera and that its omission strongly affects ancestral state polarities as well as topology, including crown-group taxa. By constraining the relationships of extant taxa to match those supported by phylogenomic analysis, we demonstrate that features shared by Archostemata with Permian stem groups are most reasonably supported as plesiomorphic and that the smooth and simplified body forms of Polyphaga, Adephaga, Myxophaga, and Micromalthidae were derived in parallel. Our study highlights the reciprocal illumination of molecular, morphological, and paleontological data, and paves the way for tip-dating analysis across the order.

Species that are dispersed across oceanic islands can have strong population structure due to genetic isolation, which makes it difficult to determine realistic and meaningful species boundaries. This becomes especially problematic when pest species are involved, and can result in undetected new invasions. The mango fruit fly, Bactrocera frauenfeldi (Schiner), is currently considered to be one of five morphologically similar members in a monophyletic species group distributed across Southeast Asia, Australasia, and Oceania, including three major pests. We used a phylogenomic approach with highly multiplexed amplicon sequencing to test species limits and evaluate the relationships among species in the B. frauenfeldi species complex and two closely related species. We obtained sequence data from 196 specimens for 395 nuclear DNA loci, totalling 102 kb, of which 2.2 kb were parsimony informative sites. Based on morphology, biogeography, and phylogenetic analyses, we conclude that there are five distinct species in the complex in our phylogeny. Our results show that the morphological differences between B. frauenfeldi and B. albistrigata (de Meijere) are part of a continuum that cannot be phylogenetically separated into monophyletic groups. We therefore synonymize the names of two major pests: B. albistrigata syn. rev. with B. frauenfeldi, making B. frauenfeldi now recognized as a widespread pest across Australasia and Southeast Asia. We evaluated the use of COI for pest recognition and conclude that it cannot reliably distinguish between six of the seven species we studied, thus new molecular approaches will be necessary for effective management and the prevention of incursions.

Patterns in morphological variation are a central theme of evolution. Uncovering links between morphological character evolution and natural history, specifically feeding behaviour, is important to understanding biological diversity. Species within the sap beetles (Nitidulidae) exhibit a tremendous diversity of feeding behaviours. This immense diversity of feeding can be seen both between major lineages and very closely related taxa. Feeding behaviour diversity may drive morphological variation in several character systems (e.g., eyes). For example, in a shift from feeding on rotting fruit to flower-visiting (anthophily), selective pressures on the visual system may vary and ultimately lead to differences in eye morphology. We tested for potential morphological shifts in relative eye size among adult beetles. We specifically tested for significant relationships between relative eye size and the following factors flower-visiting and sex. We also tested for the influence of phylogeny on the evolution of relative eye size, implementing tests of trait correlation across a topology. We found greater relative eye size in taxa exhibiting anthophilous behaviour, regardless of phylogenetic relatedness or feeding behaviour of sister taxa. We were unable to recover a relationship between relative eye size and sex. Thus, feeding behaviour is currently the strongest predictor of eye size in sap beetles.