We present a genome assembly from an individual male Dascillus cervinus (the Orchid Beetle; Arthropoda; Insecta; Coleoptera; Dascillidae). The genome sequence is 282.7 megabases in span. Most of the ...assembly is scaffolded into 9 chromosomal pseudomolecules, including the X and Y sex chromosomes. The mitochondrial genome has also been assembled and is 20.66 kilobases in length. Gene annotation of this assembly on Ensembl identified 15,761 protein coding genes.
Abstract
We analyze the relationships of the click beetles (Elateridae) Paulusiella Löbl, 2007, and Analestesa Leach, 1824 (=Cebriognathus Chobaut, 1899). Both are incapable of jumping, with ...soft-bodied habitus caused by the incomplete sclerotization of the cuticle during the metamorphosis and unknown females. Their phylogenetic positions have been an uncertain issue. We use mitochondrial genomes and nuclear genes to test their current placement in Cebrionini (=Cebriognathini) and Elaterinae incertae sedis, respectively. We recover Paulusiella as a sister to Hemiops Laporte, 1838 (Hemiopinae) and Analestesa as one of the serially splitting branches in Cardiophorinae, both with robust support. Paulusiellini trib. nov. is proposed for Paulusiella in Hemiopinae due to high morphological disparity. Analestesa is transferred to Cardiophorinae, and Cebriognathini Paulus, 1981, an earlier synonym of Elaterinae: Cebrionini, is a synonym of Cardiophorinae Candèze, 1859. The click beetles affected by ontogenetic modifications converge to similar forms. As a result, their phylogenetic position cannot be reliably inferred by morphological analyses and needs to be validated by molecular data. Paulusiella and Analestesa represent two additional cases of the shift to incomplete sclerotization in elaterids raising the total number to 6. The present transfers of extant taxa between subfamilies call for a cautious interpretation of morphology in other soft-bodied groups, including the taxa described from amber deposits.
Graphical Abstract
Graphical Abstract
Synchonnus Waterhouse, 1879 from Australia is revised. Achras Waterhouse, 1879 and Enylus Waterhouse, 1879 are found to be junior synonyms of Synchonnus due to the absence of diagnostic characters ...and result in the new combinations of Synchonnus amplus (Kleine, 1930), S. limbatum (Waterhouse, 1877), and S. segregatus (Waterhouse, 1879). Synchonnus is reported from the Australian mesic and monsoon zones, and 11 new species are described: S. flavonotatum sp. nov., S. maseki sp. nov., S. ailaketoae sp. nov., S. dubenovae sp. nov., S. chilvertonensis sp. nov., S. slipinskii sp. nov., S. monteithi sp. nov., S. eungellensis sp. nov., S. crypticum sp. nov., S. variabilis sp. nov. and S. campestris sp. nov. The morphology‐based species limits are compared with delimitation inferred from the shape of the phylogenetic tree and genetic distance. DNA‐based species limits agree with morphological delimitation in two clades, but a deep conflict was identified in another clade of Synchonnus consisting of three species with allopatric distributions and diversified genitalia, but strong similarities in cox1 mtDNA sequences. The failure of molecular species delimitation in some Synchonnus points to our inability to predict the performance of a barcoding approach even in closely related lineages and calls for an integrative taxonomical approach whenever possible. The Synchonnus fauna of Australia is presented as highly diverse and fragmentation of habitat in the last ~15 million years is hypothesised as the principal factor leading to the observed alpha‐taxonomic diversity.
We evaluated the red net-winged beetle populations’ morphological and genetic divergence within the Holarctic region. In contrast with relatives, D. aurora occurs in an exceptionally large range and ...very different ecosystems. In Northern America, we found an earlier undetected cryptic species isolated by the Bering Strait since the mid-Miocene. D. aurora colonized Fennoscandia from at least two refugia after the last glacial maximum. The absence of morphological differentiation is supposedly affected by the selection for similarity in the Müllerian mimicry ring. The results exemplify the phylogeographic history in the Holarctic region and contribute to understanding the morphological stasis in an extensive circumpolar range. The elateroid family Lycidae is known for limited dispersal propensity and high species-level endemism. The red net-winged beetle, Dictyoptera aurora (Herbst, 1874), differs from all relatives by the range comprising almost the entire Holarctic region. Based on a five-marker phylogeny and 67 barcode entries (cox1-5′ mtDNA) from the whole range, we recovered two genetically distinct species within traditionally defined D. aurora and resurrected the name D. coccinata (Say, 1835) as the oldest available synonym for Nearctic populations. Yet, no reliable morphological trait distinguishes these species except for minute differences in the male genitalia. D. coccinata is a monophylum resulting from a single Miocene dispersal event, ~15.8 million years ago, and genetic divergence implies long-term isolation by the Bering Strait. Far East Asian and west European populations are also genetically distinct, although to a lower extent. Two independent colonization events established the Fennoscandian populations after the last glacial maximum. Besides intrinsic factors, the high morphological similarity might result from stabilizing selection for shared aposematic signals. The rapidly accumulating barcode data provide valuable information on the evolutionary history and the origins of regional faunas.
This study addresses the long-standing uncertainty about the internal classification of soldier beetles (Elateroidea: Cantharidae). Four datasets were compiled and analysed: 66 genes for 14 ...terminals, 15 mtDNA genes for 79 terminals, one mtDNA and two rRNA genes for 217 terminals, and barcodes for 576 terminals. Based on congruent topologies, Chauliognathinae is proposed as a sister to the remaining Cantharidae, followed by the redefined Malthininae (including Tytthonyxini), the paraphyletic "dysmorphocerine" lineages (Dysmorphocerinae sensu stricto and Heteromastiginae subfam. nov.), and Silinae + Cantharinae as a terminal clade. The present phylogeny supersedes earlier morphology and short-fragment molecular hypotheses that have not converged on a consensus. Few morphological characters corroborate the DNA-based relationships (see the adults and larval keys). However, morphology-based hypotheses have relied on a few informative characters, and no evidence strongly rejects the preferred molecular topology. The interpretation of morphological characters and uncertain polarity resulting from the high phenotypic disparity of Elateroidea are discussed in detail. The dated phylogeny hypothesizes the earliest split within the Cantharidae in the Berriasian stage (Early Cretaceous, ~141 Myr) and the diversification of most extant subfamilies and tribes already in the Late Cretaceous. The most diverse subfamily, Cantharinae, represents a delayed radiation that started during the Eocene climatic optimum, 55.5 Myr. The late origin of Cantharinae questions the classification of Cretaceous Cantharidae as members of Cantharinae. Instead, the results suggest their deeper rooting after separating from dysmorphocerine lineages and before the node between Cantharinae and Silinae.
Abstract
The Lycidae genera have seldom been tested with phylogenetic analyses. Therefore, we assembled genomic data to estimate the phylogenetic backbone of the porrostomines, one of ...Metriorrhynchina’s major clades. Further, mtDNA and morphology were employed to assign 352 analyzed species to genera. We present evidence for the paraphyly of Metriorrhynchus and terminal position of Porrostoma, revise the generic classification, and describe eight genera: Maraiakoreus gen. nov., Kuarhynchus gen. nov., Riedelrhynchus gen. nov., Bundikanus gen. nov., Yamarhynchus gen. nov., Bekorhynchus gen. nov., Sundarhynchus gen. nov., and Isuarhynchus gen. nov. We synonymize Stadenus Waterhouse, 1879, syn. nov., Metriorrhynchoides Kleine, 1923, syn. nov., and Oriomum Bocak, 1999a, syn. nov., to Porrostoma Castelnau, 1838. Next, we propose 75 new combinations and four new species: Bundikanus styskalai sp. nov., Kuarhynchus sisrangensis sp. nov., Maraiakoreus argenteus sp. nov., and Yamarhynchus sinopassensis sp. nov. We identified repeated origins of several external morphological traits earlier used to delimitate genera. Therefore, we prefer concordant evidence from the densely sampled mitochondrial phylogenies and male genitalia. The analyses identify high phylogenetic diversity and species richness in New Guinea, much lower phylogenetic diversity of the Australian continental fauna, and the limited permeability of the Wallacea that resulted in a single porrostomine genus in Asia. We point to the common acceptance of paraphyletic and polyphyletic taxa in the current classification. As a result, taxonomy has not provided expected support for any state-of-the-art evolutionary and zoogeographic studies. The phylogeny, species inventory, and classification of porrostomines set the basis for future evolutionary and zoogeographical studies.
Dermestidae (Bostrichoidea) exploit diverse food sources including fungal mycelia, but notably they as saprophagous, feeding on decomposing and dried flesh and keratin of animals and plants. Some of ...them live in spider webs, vertebrate and social insect nests, while others cause damage in human dwellings. Here, we use mitogenomics to reconstruct their phylogeny and evolution of life history strategies. We recovered serial splits of Orphilinae, Thorictinae + Dermestinae, Attageninae, Trinodinae and Megatominae, and we dated the origins of all subfamilies between the Middle Jurassic and Upper Cretaceous. Extant genera started their diversification in the Middle Cretaceous, except for Dermestes that originated in the Eocene. Mycetophagy, the likely feeding style of the common ancestor with Endecatomidae, was retained only by Orphilinae. Since the Late Jurassic, most dermestids have been saprophagous with the preference for desiccated tissue. We infer a scenario of feeding preferences from mycetophagy moving to saprophagy, always depending on food with low water content, followed by the shift from cryptic life in crevices and wood, to commensalism with social Hymenoptera, and ultimately feeding on angiosperm pollen as adults. The dependence on spider larders evolved already in the Early Cretaceous, but lineages with this specialized strategy remained species‐poor. We date the origin of exploitation of vertebrate carcasses to the Eocene when modern mammalian fauna became dominant. The diversification of Megatominae (62% of known dermestids) and Attagenus Latreille (17%) coincides with the radiation of angiosperms.
Using mitogenomic phylogeny, we analysed relationships among dermestid subfamiles and dated the origins of major groups.
The dating analyses estimate the split of Dermestidae and Ptinidae + Bostrichidae to the Middle Triassic and the origins of major genera to the Middle Cretaceous.
Mycetophagy predisposes to saprophagy; flightlessness and host specificity drive diversification; free living in crevices precedes commensalism; and association with the angiosperms is important for groups living in arid ecosystems.
Systematic bias is one of the major phylogenetic issues arising over the last two decades. Using methods designed to reduce compositional and rate heterogeneity, hence systematic bias, Cai and ...co‐workers (2022) (= CEA22) reanalyzed the DNA sequence dataset for Coleoptera of Zhang et al. (2018) (= ZEA). CEA22 suggest that their phylogenetic results and major evolutionary hypotheses about the Coleoptera should be favoured over other recently published studies. Here, we discuss the methodology of CEA22 with particular attention to how their perfunctory reanalysis of ZEA obfuscates rather than illuminates beetle phylogeny. Similar to published rebuttals of an earlier study of theirs, we specifically find that many of their claims are misleading, unsupported, or false. Critically, CEA22 fail to establish the stated premise for their reanalysis. They fail to demonstrate how composition or rate heterogeneity supposedly impacted the phylogeny estimate of ZEA, let alone the results of other recent studies. Moreover, despite their claim of comprehensive sampling of Coleoptera, their dataset is neither the most diverse with respect to species and higher taxa included, nor anywhere near the largest in terms of sequence data and sampled loci. Although CEA22 does contribute additional fossils for calibration, those seeking the best available estimate for Coleoptera phylogeny and evolution based on molecular data are advised to look elsewhere.
Major claims of Cai et al. (2022) et al. on beetle evolution are not justified
A placement of Adephaga as sister of the other suborders is unsupported
An aquatic origin of Coleoptera does not appear likely
Bioluminescence has been hypothesized as aposematic signalling, intersexual communication and a predatory strategy, but origins and relationships among bioluminescent beetles have been contentious. ...We reconstruct the phylogeny of the bioluminescent elateroid beetles (i.e. Elateridae, Lampyridae, Phengodidae and Rhagophthalmidae), analysing genomic data of Sinopyrophorus Bi & Li, and in light of our phylogenetic results, we erect Sinopyrophoridae Bi & Li, stat.n. as a clicking elaterid‐like sister group of the soft‐bodied bioluminescent elateroid beetles, that is, Lampyridae, Phengodidae and Rhagophthalmidae. We suggest a single origin of bioluminescence for these four families, designated as the ‘lampyroid clade’, and examine the origins of bioluminescence in the terminal lineages of click beetles (Elateridae). The soft‐bodied bioluminescent lineages originated from the fully sclerotized elateroids as a derived clade with clicking Sinopyrophorus and Elateridae as their serial sister groups. This relationship indicates that the bioluminescent soft‐bodied elateroids are modified click beetles. We assume that bioluminescence was not present in the most recent common ancestor of Elateridae and the lampyroid clade and it evolved among this group with some delay, at the latest in the mid‐Cretaceous period, presumably in eastern Laurasia. The delimitation and internal structure of the elaterid‐lampyroid clade provides a phylogenetic framework for further studies on the genomic variation underlying the evolution of bioluminescence.
Phylogenomic analyses define the ‘lampyroid clade’ with bioluminescent elaterid‐like Sinopyrophorus Bi & Li as a sister to soft‐bodied bioluminescent fireflies, glowworms and railroad worms (Lampyridae, Rhagophthalmidae, Phengodidae).
The ‘lampyroid clade’ is a sister to click beetles (Elateridae), but the support for the monophyletic click beetles remains low.
Fireflies and their non‐clicking relatives are modified click beetles. The first luminescent elateroid was a clicking beetle, with an estimated origin in the lower Cretaceous, putatively in Eastern Asia.
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