Museomics unveil systematics, diversity and evolution of Australian cycad-pollinating weevils

Weevils have been shown to play significant roles in the obligate pollination of Australian cycads. In this study, we apply museomics to produce a first molecular phylogeny estimate of the Australian cycad weevils, allowing an assessment of their monophyly, placement and relationships. Divergence dating suggests that the Australian cycad weevils originated from the Late Oligocene to the Middle Miocene and that the main radiation of the cycad-pollinating groups occurred from the Middle to the Late Miocene, which is congruent with the diversification of the Australian cycads, thus refuting any notion of an ancient ciophilous system in Australia. Taxonomic studies reveal the existence of 19 Australian cycad weevil species and that their associations with their hosts are mostly non-species-specific. Co-speciation analysis shows no extensive co-speciation events having occurred in the ciophilous system of Australian cycads. The distribution pattern suggests that geographical factors, rather than diversifying coevolution, constitute the overriding process shaping the Australian cycad weevil diversity. The synchronous radiation of cycads and weevil pollinators is suggested to be a result of the post-Oligocene diversification common in Australian organisms.

The Australian genus Rhytiphora (Coleoptera: Cerambycidae: Lamiinae) with a revision of the Rhytiphora collaris group

We present a review of the Australian species of Rhytiphora Audinet-Serville, 1835, the most speciose longhorn beetle (Cerambycidae) genus in Australia. The morphological definition of the genus is updated, including useful features to distinguish Rhytiphora from closely related genera within Niphonini. Key characteristics of the two molecularly determined subclades are also provided. The collaris group of Rhytiphora is revised and Rhytiphora garnetensis sp. nov. is described from Queensland. A neotype is designated for Saperda collaris Donovan, 1805; lectotypes are designated for R. amicula White, 1859, Symphyletes vestigialis Pascoe, 1864, Symphyletes compos Blackburn, 1902, R. maculosella Blackburn, 1902, R. uniformis Blackburn, 1901, R. piperitia Hope, 1842 and Symphyletes humeralis White, 1858. A number of species complexes that require genetic confirmation before being synonymised (or separated) are discussed. Finally, we provide a new checklist of the Australian Rhytiphora species which, incorporating synonymies and other changes, reduces the total number of species from 206 to 163. The following species have been synonymised (junior synonym listed first): Coptops abdominalis White, 1858 (= Lamia bankii Fabricius, 1775); Penthea adamsae McKeown, 1938 (= Penthea macularia Pascoe, 1867); R. affinis Breuning, 1970 (= Symphyletes farinosus Pascoe, 1863); Prosoplus albidus Aurivillius, 1917 and Prosoplus minimus Breuning, 1938 (= Corrhenes pauxilla Blackburn, 1901); Prosoplus albostriatus Breuning, 1938 and Prosoplus demarzi Breuning, 1963 (= Niphona oblita Pascoe, 1863); Saperda albocincta Guérin-Méneville, 1831, Symphyletes compos Blackburn, 1902, R. donovani Newman, 1851, R. intertincta Pascoe, 1867, R. maculosella Blackburn, 1902, R. parafarinosa Breuning, 1970, R. vermiculosa Breuning, 1970 and Symphyletes vestigialis Pascoe, 1864 (= Saperda collaris); R. albolateraloides Breuning, 1970 (= Platyomopsis cinerascens Aurivillius, 1917); Symphyletes anaglyptus Pascoe, 1867, Saperdopsis armata Thomson, 1864, Symphyletes moratus Pascoe, 1863 and Symphyletes vetustus Pascoe, 1862 (= Lamia pulverulens Boisduval, 1835); Symphyletes arctos Pascoe, 1865 (= Symphyletes fumatus Pascoe, 1864); Pterolophia australica Breuning, 1938 (= Apomecyna nigrita Pascoe, 1859); R. barnardi Breuning, 1982 (= Symphyletes capreolus Pascoe, 1867); Platyomopsis basalis Aurivillius, 1917 (= Saperdopsis ochreobasalis Breuning, 1938); R. corrhenoides Breuning, 1970 (= Corrhenes cruciata Pascoe, 1875); R. dawsoni Breuning, 1970 (= Symphyletes fasciatus Blackburn, 1901); Symphyletes defloratus Pascoe, 1869 (= Symphyletes gallus Pascoe, 1864); Trichoprosoplus demarzi Breuning, 1961 and Paradaxata spinosa Breuning, 1938 (= Paradaxata villosa Breuning, 1938); Prosoplus elongatus Breuning, 1938 (= Prosoplus metallescens Breuning, 1938); Corrhenes flavovittata Breuning, 1938, Saperda funesta Pascoe, 1859, Anaesthetis lepida Germar, 1848 and Cobria rufa Breuning, 1961 (= Saperda paulla Germar, 1848); Corrhenes guttulata Pascoe, 1865, Corrhenes macmillani Gilmour, 1950 and Saperda mystica Pascoe, 1863 (= Saperda stigmatica Pascoe, 1863); Xiphotheopsis hathlioides Breuning, 1961 (= Xiphohathlia lobata Breuning, 1961); Symphyletes iliacus Pascoe, 1866 (= Symphyletes deserti Blackburn, 1896); Saperdopsis laterialba Breuning, 1938 (= Symphyletes satelles Pascoe, 1865); Etaxalus laterialbus Breuning, 1968 (= Achriotypa basalis Pascoe, 1875); Prosoplus laterinigricollis Breuning, 1961 and Prosoplus mediofasciatus Breuning, 1938 (= Niphona bakewelli Pascoe, 1859); R. leucolateralis Breuning, 1970 (= R. subargentata Breuning, 1970); Penthea lichenosa McKeown, 1942 and Penthea obscura Breuning, 1961 (= Penthea scenica Pascoe, 1863); Sysspilotus macleayi Pascoe, 1865 and Menyllus maculicornis Pascoe, 1864 (= Menyllus rotundipennis Breuning, 1968); R. multituberculata Breuning, 1966 (= Saperdopsis sellata Breuning, 1938); Symphyletes nodosus Newman, 1842 (= Acanthocinus piliger Macleay, 1826); Hathliodes pseudomurinus Breuning, 1938 (= Hathliodes virgatus Breuning, 1938); Penthea sectator Pascoe, 1865 (= Penthea crassicollis Pascoe, 1864); R. simsoni Blackburn, 1901 (= R. mista Newman, 1842); Penthea solida Pascoe, 1863 (= Lamia vermicularia Donovan, 1805); Platyomopsis spinosa Thomson, 1864 (= Lamia obliqua Donovan, 1805); R. truncata Breuning, 1940 (= R. piperitia Hope, 1842); R. uniformis Blackburn, 1901 (= Platyomopsis delicatula McKeown, 1948); Mimiphiastus vivesi Breuning, 1978 (= Symphyletes variolosa Pascoe, 1862). Pterolophia bispinosa Breuning, 1938 is renamed to R. subovata new name (junior homonym of Saperdopsis bispinosa Breuning, 1938), R. browni McKeown, 1938 is reinstated as its own species, and Corrhenes flavovittata demarzi Breuning, 1963 is elevated to species status and renamed R. rentzi new name (junior homonym of Trichoprosoplus demarzi).

Review of the Australian endemic genus Tasmosalpingus Lea, 1919 (Coleoptera, Cucujoidea, Tasmosalpingidae)

The sole genus of the Australian endemic family Tasmosalpingidae, Tasmosalpingus Lea, 1919, is revised and T. promiscuus Lea, 1919 is proposed as a junior synonym of T. quadrispilotus Lea, 1919. T. magnus sp. nov. is described from New South Wales and Victoria, representing the northernmost distribution of this family. A predicted distribution of the genus is given, and the relationships between Tasmosalpingidae, Cyclaxyridae and Lamingtoniidae are discussed.

The resurrection of Cerasommatidiidae, an enigmatic group of coccinelloid beetles (Coleoptera: Coccinelloidea) based on molecular and morphological evidence

The family Cerasommatidiidae was proposed by Brèthes in 1925 for his new genus Cerasommatidia from Brazil, described as an intermediate taxon between Endomychidae and Coccinellidae (Coccinelloidea). This group was neglected for decades until 1994 when the resemblance of Cerasommatidia with the eupsilobiine genus Ibicarella was noticed, and Cerasommatidiidae was synonymized with Eupsilobiinae (Endomychidae). Based on the newly discovered material from the Neotropical and Afrotropical regions with clear resemblance to Cerasommatidia and Ibicarella, the phylogenetic placement of these taxa and new allied genera was reassessed based on phylogenetic analyses of molecular, morphological and combined datasets. The data were analysed under Bayesian (BI), maximum likelihood (ML) and parsimony (MP) frameworks. Our results support the restoration of Cerasommatidiidae as a distinct family in Coccinelloidea. Close affinity of Cerasommatidiidae with Coccinellidae, Eupsilobiidae and Mycetaeidae is recovered and the sister-relationship to Mycetaeidae is highly supported. Ibicarella is found to be a junior synonym of Cerasommatidia. Three new genera and six new species are described and illustrated: Yamuy gen. nov. (type species, Y. marginatus sp. nov.; and Y. constratus sp. nov.) and Karumbe gen. nov. (type species, K. geiseri sp. nov.; K. brethesi sp. nov. and K. pakaluki sp. nov.) from the Neotropics and Mahavelo gen. nov. (type species, M. madagasus sp. nov.) from Madagascar.

Phylogenomics resolves timing and patterns in the evolution of Australasian Cerambycinae (Coleoptera: Cerambycidae), and reveals new insights into the subfamily-level classification and historical biogeography of longhorn beetles

Cerambycinae is the second-largest subfamily of longhorn beetles in the Southern Hemisphere. The phylogeny of Cerambycinae is poorly known, resulting in a highly artificial tribal-level classification and a largely speculative evolutionary history. We reconstructed the phylogenetic relationships of Cerambycinae at the generic level using anchored hybrid enrichment data from hundreds of nuclear genes, with a primary focus on the extraordinarily diverse faunas of Australia and New Zealand. We also estimated divergence times by incorporating fossil calibrations in our analyses. We identified two main clades within Cerambycinae, which can also be separated morphologically by a distinct type of antennal foramen. We recovered a Late Jurassic origin of crown Cerambycinae. Dorcasominae, which was newly found to have representatives in Australia, was notably derived from within Cerambycinae. We recovered two independent origins of Australian Cerambycinae: one clade originated in the Early Cretaceous and is likely endemic to the Southern Hemisphere, while the other clade appears to have immigrated to Australia, perhaps from the Northern Hemisphere. Within the Australian lineages were multiple independent origins of New Zealand taxa, all of which are relative host-plant generalists. Tribal relationships and assignments are discussed, and based on our results, the following major nomenclatural acts were made: Dorcasominae Lacordaire, 1868 is downgraded to a tribe Dorcasomini of Cerambycinae Latreille, 1804; Neostenini Lacordaire, 1868syn. nov. is treated as a junior synonym of Uracanthini Blanchard, 1851.

Integrated phylogenomics and fossil data illuminate the evolution of beetles

Beetles constitute the most biodiverse animal order with over 380 000 described species and possibly several million more yet unnamed. Recent phylogenomic studies have arrived at considerably incongruent topologies and widely varying estimates of divergence dates for major beetle clades. Here, we use a dataset of 68 single-copy nuclear protein-coding (NPC) genes sampling 129 out of the 193 recognized extant families as well as the first comprehensive set of fully justified fossil calibrations to recover a refined timescale of beetle evolution. Using phylogenetic methods that counter the effects of compositional and rate heterogeneity, we recover a topology congruent with morphological studies, which we use, combined with other recent phylogenomic studies, to propose several formal changes in the classification of Coleoptera: Scirtiformia and Scirtoidea sensu nov., Clambiformia ser. nov. and Clamboidea sensu nov., Rhinorhipiformia ser. nov., Byrrhoidea sensu nov., Dryopoidea stat. res., Nosodendriformia ser. nov. and Staphyliniformia sensu nov., and Erotyloidea stat. nov., Nitiduloidea stat. nov. and Cucujoidea sensu nov., alongside changes below the superfamily level. Our divergence time analyses recovered a late Carboniferous origin of Coleoptera, a late Palaeozoic origin of all modern beetle suborders and a Triassic-Jurassic origin of most extant families, while fundamental divergences within beetle phylogeny did not coincide with the hypothesis of a Cretaceous Terrestrial Revolution.

A New Genus and Species of Lophocateridae from Mid-Cretaceous Amber of Myanmar (Coleoptera)

A new genus and species of the cleroid family Lophocateridae are described and illustrated from the mid-Cretaceous amber of northern Myanmar. Gracilenticrus burmiticus Yu, Kolibáč & Ślipiński gen. et sp. nov. is unique among Lophocateridae in the tiny body size, frontoclypeal suture and antennal grooves absent, symmetrical antennal clubs, protrochantin reduced, tarsal claws small and widened at base. A key to the species of Mesozoic Lophocateridae is also provided. Morphological characters of the newly discovered Gracilenticrus were analyzed together with representatives of 43 extant genera of Cleroidea (broadly defined Trogossitidae) in a matrix of 91 characters. Gracilenticrus burmiticus was resolved as a member of Lophocateridae. The discovery of a diverse fauna of Lophocateridae in the mid-Cretaceous sheds a new light on the early evolution of superfamily Cleroidea.

Phylogeny and evolution of Mesozoic and extant lineages of Histeridae (Coleoptera), with discovery of a new subfamily Antigracilinae from the Lower Cretaceous

In order to place a newly discovered species Antigracilus costatus gen. sp. n. from the Lower Cretaceous Yixian Formation (China) and to assess previously unplaced fossil taxa, we investigated the relationships of extant and extinct lineages of Histeridae based on three data sets: (i) 69 morphological characters belonging to 48 taxa (representing all 11 subfamilies and 15 of 17 tribes of modern Histeridae); (ii) partitioned alignment of 6030 bp from downloaded nucleotide sequences (28S, CAD, COI, 18S) of 50 taxa (representing 10 subfamilies and 15 of 17 tribes of modern Histeridae); and (iii) a combined morphological and molecular dataset for 75 taxa. Phylogenetic analyses of the morphology and combined matrices recovered the new Lower Cretaceous taxon as a sister group to remaining Histeridae and it is placed in †Antigracilinae subfam. n. †Antigracilinae constitutes the earliest record of Histeridae from the Lower Cretaceous Yixian Formation (∼125 Myr), backdating the minimum age of the family by 25 Myr from the earliest Cenomanian (~99 Myr) to the Barremian of the Cretaceous Period. Our molecular phylogeny supports Histeridae to be divided into seven different clades, with currently recognised subfamilies Abraeinae (sensu lato), Saprininae, Chlamydopsinae, and Histerinae (sensu lato) recovered as monophyletic, while Dendrophilinae, Onthophilinae, and Tribalinae are polyphyletic taxa. The Burmese amber species †Pantostictus burmanicus Poinar & Brown is placed as a sister group to the tribe Plegaderini (Abraeinae) and was assigned as a new tribe Pantostictini trib. n. Both molecular and combined phylogenies recovered the subfamilies Trypanaeinae and Trypeticinae deeply within the subfamily Abraeinae (sensu lato), and they are downgraded into Trypanaeini stat. n. and Trypeticini stat. n.

Revision of the subfamily Ostomopsinae (Coleoptera: Cerylonidae)

The subfamily Ostomopsinae of Cerylonidae is revised. Six nominal species are recognized and described or redescribed: Ostomopsis cudak sp. n. (Thailand), O. kuscheli sp. n. (New Caledonia), O. neotropicalis Lawrence Stephan (USA: Florida; Mexico: San Luis Potosi, Veracruz; Panama, Cuba, Hispaniola, Jamaica, Guadeloupe, Montserrat), O. solitaria Scott (Seychelles, New Caledonia, Christmas Island, Northern Mariana Islands), O. solomon sp. n. (Solomon Islands), and O. watti sp. n. (New Caledonia). Morphological structures of the type species of Ostomopsis are illustrated and described in detail, and identification key to Ostomopsis species is given.

Anchored Phylogenomics, Evolution and Systematics of Elateridae: Are All Bioluminescent Elateroidea Derived Click Beetles?

Simple Summary

In the era of phylogenomics, new molecular sequencing and computational techniques can aid in resolving phylogenetic relationships that were previously intractable by morphological or limited molecular data. In this study, we used anchored hybrid enrichment—designed to recover DNA sequences from hundreds of single-copy orthologous genes—to resolve the phylogeny of the Elateridae (click-beetles) and establish their placement within superfamily Elateroidea. The resulting data were compatible with published transcriptomes, allowing for integrating our dataset with previously published data. Using a wide range of analyses on these molecular data, we tested hypotheses long-debated in the morphological literature and also the robustness of our phylogenetic inferences. Our results placed the bioluminescent lampyroids (fireflies and relatives) within the click-beetles, challenging the current classification of Elateridae, Lampyridae, Phengodidae, and Rhagophthalmidae. However, despite the large amount of molecular data analyzed, a few nodes with conflicting phylogenetic signals could not be unambiguously resolved. Overall, we recovered well-resolved tree topologies that will serve as a framework for further systematic and evolutionary studies of click-beetles. This work further demonstrates that the click-beetle lineage contains not only pest wireworms, but also many species that benefit agriculture.

Abstract

Click-beetles (Coleoptera: Elateridae) are an abundant, diverse, and economically important beetle family that includes bioluminescent species. To date, molecular phylogenies have sampled relatively few taxa and genes, incompletely resolving subfamily level relationships. We present a novel probe set for anchored hybrid enrichment of 2260 single-copy orthologous genes in Elateroidea. Using these probes, we undertook the largest phylogenomic study of Elateroidea to date (99 Elateroidea, including 86 Elateridae, plus 5 non-elateroid outgroups). We sequenced specimens from 88 taxa to test the monophyly of families, subfamilies and tribes. Maximum likelihood and coalescent phylogenetic analyses produced well-resolved topologies. Notably, the included non-elaterid bioluminescent families (Lampyridae + Phengodidae + Rhagophthalmidae) form a clade within the otherwise monophyletic Elateridae, and Sinopyrophoridae may not warrant recognition as a family. All analyses recovered the elaterid subfamilies Elaterinae, Agrypninae, Cardiophorinae, Negastriinae, Pityobiinae, and Tetralobinae as monophyletic. Our results were conflicting on whether the hypnoidines are sister to Dendrometrinae or Cardiophorinae + Negastriinae. Moreover, we show that fossils with the eucnemid-type frons and elongate cylindrical shape may belong to Eucnemidae, Elateridae: Thylacosterninae, ancestral hard-bodied cantharoids or related extinct groups. Proposed taxonomic changes include recognition of Plastocerini as a tribe in Dendrometrinae and Hypnoidinae stat. nov. as a subfamily within Elateridae.

The mid-Miocene Zhangpu biota reveals an outstandingly rich rainforest biome in East Asia

During the Mid-Miocene Climatic Optimum [MMCO, ~14 to 17 million years (Ma) ago], global temperatures were similar to predicted temperatures for the coming century. Limited megathermal paleoclimatic and fossil data are known from this period, despite its potential as an analog for future climate conditions. Here, we report a rich middle Miocene rainforest biome, the Zhangpu biota (~14.7 Ma ago), based on material preserved in amber and associated sedimentary rocks from southeastern China. The record shows that the mid-Miocene rainforest reached at least 24.2°N and was more widespread than previously estimated. Our results not only highlight the role of tropical rainforests acting as evolutionary museums for biodiversity at the generic level but also suggest that the MMCO probably strongly shaped the East Asian biota via the northern expansion of the megathermal rainforest biome. The Zhangpu biota provides an ideal snapshot for biodiversity redistribution during global warming.

Horizontally acquired antibacterial genes associated with adaptive radiation of ladybird beetles

BACKGROUND

Horizontal gene transfer (HGT) has been documented in many herbivorous insects, conferring the ability to digest plant material and promoting their remarkable ecological diversification. Previous reports suggest HGT of antibacterial enzymes may have contributed to the insect immune response and limit bacterial growth. Carnivorous insects also display many evolutionary successful lineages, but in contrast to the plant feeders, the potential role of HGTs has been less well-studied.

RESULTS

Using genomic and transcriptomic data from 38 species of ladybird beetles, we identified a set of bacterial cell wall hydrolase (cwh) genes acquired by this group of beetles. Infection with Bacillus subtilis led to upregulated expression of these ladybird cwh genes, and their recombinantly produced proteins limited bacterial proliferation. Moreover, RNAi-mediated cwh knockdown led to downregulation of other antibacterial genes, indicating a role in antibacterial immune defense. cwh genes are rare in eukaryotes, but have been maintained in all tested Coccinellinae species, suggesting that this putative immune-related HGT event played a role in the evolution of this speciose subfamily of predominant predatory ladybirds.

CONCLUSION

Our work demonstrates that, in a manner analogous to HGT-facilitated plant feeding, enhanced immunity through HGT might have played a key role in the prey adaptation and niche expansion that promoted the diversification of carnivorous beetle lineages. We believe that this represents the first example of immune-related HGT in carnivorous insects with an association with a subsequent successful species radiation.

New insights into the phylogeny and evolution of lady beetles (Coleoptera: Coccinellidae) by extensive sampling of genes and species

Ladybirds (family Coccinellidae) are one of the most diverse groups of beetles and globally comprise over 6000 species. Despite their scientific and economic significance, the taxonomy of Coccinellidae remains unstable, and we still know little about their evolutionary history. By using a small number of genes, previous phylogenetic analyses have not reliably resolved the relationships among major ladybird lineages. In this study, we sequenced 94 nuclear protein-coding genes for 214 species of Coccinellidae and 14 outgroups, covering 90 genera and 35 tribes. We found that nucleotide compositional heterogeneity is present among ladybird tribes so that phylogenetic inference at the amino acid level is more reliable than at the DNA level. Based on the maximum likelihood analyses of the amino acid dataset, we recognize three subfamilies in Coccinellidae: Microweiseinae, Monocoryninae stat. nov., and Coccinellinae. The subfamily relationships are strongly supported as (Microweiseinae, (Monocoryninae stat. nov., Coccinellinae)). The tribes of ladybirds are mostly monophyletic, except Ortaliini, Sticholotidini, Scymnini, and Coccidulini. The phylogenetic relationships among tribes of Coccinellinae are still not well resolved, with many nodes weakly supported. Our divergence time analysis suggests that the crown group of extant lady beetles arose in the Early Cretaceous ~ 143 million years ago (Mya) and experienced a rapid diversification during the Late Cretaceous (120-70 Mya). We hypothesize that the boom of angiosperms in the Late Cretaceous promoted the diversification of herbivorous Sternorrhyncha insects, especially aphids, which in turn drove the rapid radiation of predatory lady beetles. In summary, our work provides a comprehensive time-calibrated phylogeny of Coccinellidae that provides a sound framework for revising their classification and understanding the origin of their biodiversity.

Descriptions of larval and pupal morphologies of Macrohyliota militaris (Erichson) (Silvanidae: Brontinae: Brontini)

The mature larva and pupa of the Australian silvanid species, Macrohyliota militaris (Erichson) are described from laboratory reared material. This is the first description of immature stages of Silvanidae from Australia. The larva of M. militaris conforms to the general body shape and apparent morphological features of known Brontini and is very similar to the Asian M. sculptus Yoshida & Hirowatari. Larval and pupal features of M. militaris are compared with other known larvae and pupae of Brontini described in the literature.

The extant species of the genus Omma Newman and description of Beutelius gen. nov. (Coleoptera: Archostemata: Ommatidae: Ommatinae)

The genus Omma Newman (type species Omma stanleyi Newman) is revised and redefined based on extant species, with examination of additional fossil species. As a result, only the species O. stanleyi Newman is retained in Omma and a new genus, Beutelius gen. nov. (type species Omma mastersi MacLeay), is described to accommodate the remaining Australian species: B. mastersi (MacLeay), comb. nov., B. sagitta (Neboiss), comb. nov. and B. rutherfordi (Lawrence), comb. nov. A new species, Beutelius reidi sp. nov., is described from Melville Range Nature Reserve in New South Wales, Australia. Diagnoses and new records for extant Ommatinae, including the male of B. sagitta and female of B. mastersi, are provided, as well as a key to extant genera and species.

Basal polyphagan beetles in mid-Cretaceous amber from Myanmar: biogeographic implications and long-term morphological stasis

The origin and early evolutionary history of polyphagan beetles have been largely based on evidence from the derived and diverse 'core Polyphaga', whereas little is known about the species-poor basal polyphagan lineages, which include Scirtoidea (Clambidae, Decliniidae, Eucinetidae, and Scirtidae) and Derodontidae. Here, we report two new species Acalyptomerus thayerae sp. nov. and Sphaerothorax uenoi sp. nov., both belonging to extant genera of Clambidae, from mid-Cretaceous Burmese amber. Acalyptomerus thayerae has a close affinity to A. herbertfranzi, a species currently occurring in Mesoamerica and northern South America. Sphaerothorax uenoi is closely related to extant species of Sphaerothorax, which are usually collected in forests of Nothofagus of Australia, Chile, and New Zealand. The discovery of two Cretaceous species from northern Myanmar indicates that both genera had lengthy evolutionary histories, originated at least by the earliest Cenomanian, and were probably more widespread than at present. Remarkable morphological similarities between fossil and living species suggest that both genera changed little over long periods of geological time. The long-term persistence of similar mesic microhabitats such as leaf litter may account for the 99 Myr morphological stasis in Acalyptomerus and Sphaerothorax. Additionally, the extinct staphylinoid family Ptismidae is proposed as a new synonym of Clambidae, and its only included species Ptisma zasukhae is placed as incertae sedis within Clambidae.

The evolution and genomic basis of beetle diversity

The order Coleoptera (beetles) is arguably the most speciose group of animals, but the evolutionary history of beetles, including the impacts of plant feeding (herbivory) on beetle diversification, remain poorly understood. We inferred the phylogeny of beetles using 4,818 genes for 146 species, estimated timing and rates of beetle diversification using 89 genes for 521 species representing all major lineages and traced the evolution of beetle genes enabling symbiont-independent digestion of lignocellulose using 154 genomes or transcriptomes. Phylogenomic analyses of these uniquely comprehensive datasets resolved previously controversial beetle relationships, dated the origin of Coleoptera to the Carboniferous, and supported the codiversification of beetles and angiosperms. Moreover, plant cell wall-degrading enzymes (PCWDEs) obtained from bacteria and fungi via horizontal gene transfers may have been key to the Mesozoic diversification of herbivorous beetles-remarkably, both major independent origins of specialized herbivory in beetles coincide with the first appearances of an arsenal of PCWDEs encoded in their genomes. Furthermore, corresponding (Jurassic) diversification rate increases suggest that these novel genes triggered adaptive radiations that resulted in nearly half of all living beetle species. We propose that PCWDEs enabled efficient digestion of plant tissues, including lignocellulose in cell walls, facilitating the evolution of uniquely specialized plant-feeding habits, such as leaf mining and stem and wood boring. Beetle diversity thus appears to have resulted from multiple factors, including low extinction rates over a long evolutionary history, codiversification with angiosperms, and adaptive radiations of specialized herbivorous beetles following convergent horizontal transfers of microbial genes encoding PCWDEs.

Evolution of a hyper-complex intromittent organ in rove beetles – the endophallus of Xantholinini (Staphylinidae: Coleoptera)

Studies on the functional morphology and evolution of genitalia have been crucial to understanding sexual traits in speciation, reproductive isolation and sexual selection in Coleoptera and insects in general. However, the focus of investigation of the intromittent organ of beetles was largely confined to the sclerotized elements of the aedeagus, whereas the membranous structures of the endophallus (=internal sac) have often not been adequately considered. Using a micro-operating technique, we observed living male rove beetles and found five different types of endophallus eversion and related morphological modifications. Analysing genital data of a larger sample of Xantholinini, we could demonstrate that endophallus complexity and modifications tend to vary inversely with the median lobe (penis: intromittent organ). Our comparative morphological study, combined with a molecular phylogenetic analysis, suggests that endophallus spiralling occurring after endophallus eversion is an innovation in beetle evolution.

Genomic changes in the biological control agent Cryptolaemus montrouzieri associated with introduction

Biological control is the main purpose of intentionally introducing non-native invertebrate species. The evolutionary changes that occur in the populations of the introduced biological control agents may determine the agent's efficiency and the environmental safety. Here, to explore the pattern and extent of potential genomic changes in the worldwide introduced predatory ladybird beetle Cryptolaemus montrouzieri, we used a reduced-representation sequencing method to analyze the genome-wide differentiation of the samples from two native and five introduced locations. Our analyses based on a total of 53,032 single nucleotide polymorphism loci showed that beetles from the introduced locations in Asia and Europe exhibited significant reductions in genetic diversity and high differentiation compared with the samples from the native Australian range. Each introduced population belonged to a unique genetic cluster, while the beetles from two native locations were much more similar. These genomic patterns were also detected when the dataset was pruned for genomic outlier loci (52,318 SNPs remaining), suggesting that random genetic drift was the main force shaping the genetic diversity and population structure of this biological control agent. Our results provide a genome-wide characterization of polymorphisms in a biological control agent and reveal genomic differences that were influenced by the introduction history. These differences might complicate assessments of the efficiency of biological control and the invasion potential of this species but also indicate the feasibility of selective breeding.

A Mesozoic clown beetle myrmecophile (Coleoptera: Histeridae)

Complex interspecies relationships are widespread among metazoans, but the evolutionary history of these lifestyles is poorly understood. We describe a fossil beetle in 99-million-year-old Burmese amber that we infer to have been a social impostor of the earliest-known ant colonies. Promyrmister kistneri gen. et sp. nov. belongs to the haeteriine clown beetles (Coleoptera: Histeridae), a major clade of 'myrmecophiles'-specialized nest intruders with dramatic anatomical, chemical and behavioral adaptations for colony infiltration. Promyrmister reveals that myrmecophiles evolved close to the emergence of ant eusociality, in colonies of stem-group ants that predominate Burmese amber, or with cryptic crown-group ants that remain largely unknown at this time. The clown beetle-ant relationship has been maintained ever since by the beetles host-switching to numerous modern ant genera, ultimately diversifying into one of the largest radiations of symbiotic animals. We infer that obligate behavioral symbioses can evolve relatively rapidly, and be sustained over deep time.

Contribution to the genus Filipinolotis Miyatake, 1994 (Coleoptera, Coccinellidae, Sticholotidini)

The genus Filipinolotis Miyatake has been reviewed in this study. Descriptions and illustrations of two species (F.latefasciata Miyatake and F.purpuratorotunda Wang, Zhang & Ślipiński, sp. n.) in the Luzon island of the Philippines, are given. The male genitalia of F.latefasciata are described for the first time. A key to known species is also provided.

Evolutionary history of Coleoptera revealed by extensive sampling of genes and species

Beetles (Coleoptera) are the most diverse and species-rich group of insects, and a robust, time-calibrated phylogeny is fundamental to understanding macroevolutionary processes that underlie their diversity. Here we infer the phylogeny and divergence times of all major lineages of Coleoptera by analyzing 95 protein-coding genes in 373 beetle species, including ~67% of the currently recognized families. The subordinal relationships are strongly supported as Polyphaga (Adephaga (Archostemata, Myxophaga)). The series and superfamilies of Polyphaga are mostly monophyletic. The species-poor Nosodendridae is robustly recovered in a novel position sister to Staphyliniformia, Bostrichiformia, and Cucujiformia. Our divergence time analyses suggest that the crown group of extant beetles occurred ~297 million years ago (Mya) and that ~64% of families originated in the Cretaceous. Most of the herbivorous families experienced a significant increase in diversification rate during the Cretaceous, thus suggesting that the rise of angiosperms in the Cretaceous may have been an 'evolutionary impetus' driving the hyperdiversity of herbivorous beetles.

Late Permian wood-borings reveal an intricate network of ecological relationships

Beetles are the most diverse group of macroscopic organisms since the mid-Mesozoic. Much of beetle speciosity is attributable to myriad life habits, particularly diverse-feeding strategies involving interactions with plant substrates, such as wood. However, the life habits and early evolution of wood-boring beetles remain shrouded in mystery from a limited fossil record. Here we report new material from the upper Permian (Changhsingian Stage, ca. 254-252 million-years ago) of China documenting a microcosm of ecological associations involving a polyphagan wood-borer consuming cambial and wood tissues of the conifer Ningxiaites specialis. This earliest evidence for a component community of several trophically interacting taxa is frozen in time by exceptional preservation. The combination of an entry tunnel through bark, a cambium mother gallery, and up to 11 eggs placed in lateral niches-from which emerge multi-instar larval tunnels that consume cambium, wood and bark-is ecologically convergent with Early Cretaceous bark-beetle borings 120 million-years later.Numerous gaps remain in our knowledge of how groups of organisms interacted in ancient ecosystems. Here, Feng and colleagues describe a late Permian fossil wood-boring beetle microcosm, with the oldest known example of complex tunnel geometry, host tissue response, and the presence of fungi within.

Molecular phylogeny reveals food plasticity in the evolution of true ladybird beetles (Coleoptera: Coccinellidae: Coccinellini)

BACKGROUND

The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. Many species are aphidophagous, feeding as larvae and adults on aphids, but some species also feed on other hemipterous insects (i.e., heteropterans, psyllids, whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species (e.g., Harmonia axyridis (Pallas)). Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions. This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography).

RESULTS

We present the most comprehensive phylogenetic analysis of Coccinellini to date, based on three nuclear and one mitochondrial gene sequences of 38 taxa, which represent all major Coccinellini lineages. The phylogenetic reconstruction supports the monophyly of Coccinellini and its sister group relationship to Chilocorini. Within Coccinellini, three major clades were recovered that do not correspond to any previously recognised divisions, questioning the traditional differentiation between Halyziini, Discotomini, Tytthaspidini, and Singhikaliini. Ancestral state reconstructions of food preferences and morphological characters support the idea of aphidophagy being the ancestral state in Coccinellini. This indicates a transition from putative obligate scale feeders, as seen in the closely related Chilocorini, to more agile general predators.

CONCLUSIONS

Our results suggest that the classification of Coccinellini has been misled by convergence in morphological traits. The evolutionary history of Coccinellini has been very dynamic in respect to changes in host preferences, involving multiple independent host switches from different insect orders to fungal spores and plants tissues. General predation on ephemeral aphids might have created an opportunity to easily adapt to mixed or specialised diets (e.g. obligate mycophagy, herbivory, predation on various hemipteroids or larvae of leaf beetles (Chrysomelidae)). The generally long-lived adults of Coccinellini can consume pollen and floral nectars, thereby surviving periods of low prey frequency. This capacity might have played a central role in the diversification history of Coccinellini.

The first elateroid beetles (Coleoptera: Polyphaga: Elateroidea) from the Upper Jurassic of Australia

The first elateroid fossils from the Upper Jurassic Talbragar Fish Bed in Australia are described and illustrated. Wongaroo amplipectorale gen. et sp. n., based on two specimens, is placed in the family Cerophytidae due to its convex, posteriorly weakly angled and laterally carinate pronotum obscuring the head in dorsal view, its relatively long, pointed elytra and slender legs, its 9-striate elytra with deep basal pits and the absence of metacoxal plates. Beattieellus jurassicus gen. et sp. n., described from one specimen, possesses the acutely angled pronotum without a carina on the posterolateral angles and the ventral click apparatus typical of Eucnemidae and is classified in this family. Assignment of it to a eucnemid subfamily is impossible because of the insufficient preservation of relevant characters in the fossil. Four other elateroid fossils, possibly representing eucnemids and elaterids, are illustrated and briefly described but not named, due to their insufficient preservation. These fossils represent the first of their kind in Australia and in the Southern Hemisphere, and Beattieellus is also the oldest eucnemid fossil known and extends the fossil record of Eucnemidae into the Upper Jurassic. The discovery of elateroid fossils in the Talbragar Fish Bed adds to the coleopteran diversity of this ancient lake ecosystem, indicating that it was well wooded and provided suitable habitats of rotten wood for the development of the larvae of these taxa.

Review of the genus Tricheops Newman (Coleoptera: Cerambycidae: Cerambycinae) with description of two new species from Western Australia

Two new species of Tricheops Newman, T. remus sp. nov. and T. guillemeti sp. nov. from Western Australia are described and illustrated. The genus Tricheops is redescribed and a key to species is provided. The structures associated with the unusual three-lobed eyes of Tricheops and Bardistus Newman are discussed.

Variation in life history traits and transcriptome associated with adaptation to diet shifts in the ladybird Cryptolaemus montrouzieri

BACKGROUND

Despite the broad diet range of many predatory ladybirds, the mechanisms involved in their adaptation to diet shifts are not completely understood. Here, we explored how a primarily coccidophagous ladybird Cryptolaemus montrouzieri adapts to feeding on aphids.

RESULTS

Based on the lower survival rate, longer developmental time, and lower adult body weight and reproduction rate of the predator, the aphid Megoura japonica proved being less suitable to support C. montrouzieri as compared with the citrus mealybug Planococcus citri. The results indicated up-regulation of genes related to ribosome and translation in fourth instars, which may be related to their suboptimal development. Also, several genes related to biochemical transport and metabolism, and detoxification were up-regulated as a result of adaptation to the changes in nutritional and non-nutritional (toxic) components of the prey.

CONCLUSION

Our results indicated that C. montrouzieri succeeded in feeding on aphids by regulation of genes related to development, digestion and detoxification. Thus, we argue that these candidate genes are valuable for further studies of the functional evolution of ladybirds led by diet shifts.

Episodic positive selection at mitochondrial genome in an introduced biological control agent

Artificial introduction in classical biological control provides a unique opportunity to understand mitochondrial evolution driving adaptation to novel environments. We studied mitochondrial genomes of a world-wide introduced agent, Cryptolaemus montrouzieri. We detected positive selection in complex I genes (ND5 and ND4) against a background of widespread negative selection. We further detected significant signals in neutrality tests within 11 populations at ND5 gene, indicating a recent selective sweep/positive selection. Our results imply that these candidate mutations may contribute local adaptation of exotic biological control agents and these provide new insights into the improvement of classical biological control programs.

Genetic Differentiation in Native and Introduced Populations of Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) and Its Implications for Biological Control Programs

Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) is an effective biological control agent of Australian origin, which has been introduced worldwide to control mealybugs. Although successfully used for >100 yr, its introduction in a new area may cause environmental risks should the populations become invasive. In the present study, a population genetics method was used to make predictions of the invasive potential of C. montrouzieri. Our results showed a similar level of genetic diversity among all populations. No significant genetic differentiation between native and introduced populations was observed, while three populations from the native region were significantly divergent. The fact that genetic diversity was not reduced in introduced areas suggests that no bottleneck effect has occurred during introduction. To avoid rapid evolution of the introduced C. montrouzieri, the introduction records of each population should be clearly traced and introductions from multiple sources into the same area should be avoided.

Notes on Australian Laius Guérin-Méneville, Dicranolaius Champion and Intybia Pascoe with description of new species related to Dicranolaius c-purpureus (Lea) (Coleoptera: Melyridae: Malachiinae)

Remarks on Laius Guérin-Méneville and Dicranolaius Champion are provided. Laius falcifer Champion, 1921 is designated as the type species of Dicranolaius Champion, 1921. Dicranolaius bellulus is attributed to Boisduval (1835) not to Guérin-Méneville (1830). Dicranolaius c-purpureus (Lea) is redescribed and two closely related new species are described: D. weiri sp. n., and D. similis sp. n. Intybia Pascoe, 1866 is recorded from Australia for the first time and Laius filamentarius Lea, 1917 is regarded as member of Intybia comb. n..

Ladies in stripes: taxonomic confusion in a potential mimicry complex among Wallacean Coccinellidae (Coleoptera: Coccinellidae)

Two species of ladybird beetles, one belonging to Phrynocaria Timberlake (Coccinellni) and the second to Chilocorus Leach (Chilocorini) collected by R.A. Wallace in the Maluku Islands (Indonesia) have identical body size and colour pattern with longitudinal stripes on elytra. Their external features were so similar that G.R. Crotch included both of them in the type series of Chilocorus wallacii Crotch, 1874. The specimen designated as the lectotype of Chilocorus wallacii belongs to Phrynocaria. Coelophora wallacii Crotch, 1874 is also transferred to Phrynocaria (new comb.) and becomes senior homonym and Phrynocaria crotchi new name is proposed for the secondary junior homonym. Chilocorus crotchi sp. nov. is described for the taxon misidentified as Chilocorus wallacii Crotch.

Description of a new species of Anomala Samouelle (Coleoptera: Scarabaeidae: Rutelinae) from Northern Territory, Australia

A new species of Anomala Samouelle (Coleoptera: Scarabaeidae: Rutelinae) is described from the Northern Territory of Australia. The new species is diagnosed by the single tooth along the external margin of protibia, medially interrupted marginal bead on pronotal base and the clypeus weakly reflexed anteriorly. The illustrated diagnoses of the remaining Australian species and the key to their identification is also provided.

A revision of the Pediacus Shuckard 1839 (Coleoptera: Cucujidae) of Asia and Australasia

The Pediacus Shuckard fauna of Asia and Australasia is revised. Eighteen species are recorded, described and illustrated from the regions and a key to species is provided. Nine new species are described: Pediacus australis sp. nov. (Australia, Papua New Guinea, Philippines, Thailand), P. carinatus sp. nov. (Indonesia, Malaysia, Thailand), P. fujianensis sp. nov. (China), P. japonicoides sp. nov. (Taiwan); P. leei sp. nov. (Taiwan), P. pendleburyi sp. nov. (Malaysia), P. sinensis sp. nov. (China), P. taiwanensis sp. nov. (Taiwan) and P. thomasi sp. nov. (Taiwan). A checklist of the Pediacus fauna of the world is given, listing a total of 31 species. 

The genus Microserangium Miyatake (Coleoptera, Coccinellidae) from China

The genus Microserangium Chapinfrom China is reviewed. Nine species are recognized, including seven new species: M. erythrinum Wang & Ren, sp. n., M. fuscum Wang & Ren, sp. n., M. glossoides Wang & Ren, sp. n., M. shennongensis Wang & Ren, sp. n., M. semilunatum Wang & Ren, sp. n., M. deltoides Wang & Ren, sp. n., M. dactylicum Wang & Ren, sp. n. Male genitalia of M. hainanensis Miyatake, 1961 are described for the first time. All species are described and illustrated. A key and distribution map to the known species from China are given.

The first complete 3D reconstruction of a Spanish fly primary larva (Lytta vesicatoria, Meloidae, Coleoptera)

The first detailed anatomical study of a primary larva of Meloidae is presented. Thereby techniques such as three-dimensional reconstructions, microtome sections, SEM (scanning electronic microscopy) and CLSM (confocal laser scanning microscopy) are applied. The structural features are discussed in the context of phylogeny, but also possible correlations with parasitism, phoresy and miniaturisation. The triungulin first instar larva is likely an apomorphy of Meloidae excl. Eleticinae and linked with a specialisation on acridoid eggs or larvae and provisions of bees. The campodeid body shape of Lytta and Meloinae is a groundplan feature of Meloidae, whereas a navicular body is an autapomorphy of the generally phoretic larvae of Nemognathinae. Head structures of Lytta and features of the postcephalic body are largely plesiomorphic. The musculature of the head is only moderately simplified while the one of the postcephalic body is well developed. Its thorax is largely characterised by plesiomorphies. The characteristics of the legs suggest phoretic habits, even though this does not apply to larvae of Lytta. It is conceivable that a phoretic behaviour is secondarily lost, together with some but not all morphological modifications related to it. Derived features of the abdomen of Meloidae are the complete loss of the fixed urogomphi (also missing in Rhipiphoridae and other related groups) and the presence of one or two conspicuous caudal bristles. Only few features of Lytta are shared with the parasitic larvae of Rhipiphoridae and Strepsiptera. These characteristics, which are possibly linked with specialised life habits, have obviously evolved independently. Miniaturisation effects are minimal in the larvae of Lytta.