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.

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 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).

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, 1868 syn. 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.

Platycrus-a remarkable new genus of the tribe Platynaspini (Coleoptera: Coccinellidae) from Laos.

A new remarkable ladybird beetle Platycrus laotanus gen. et sp. nov. is described from Laos. It is placed in the tribe Platynaspini, but it differs from the remaining members of the tribe by having unusually expanded legs, a peculiar pocket-like structure to accommodate the tarsi in repose, and the antennae consisting of 11 antennomeres. Detailed morphological description and illustrations are provided. Taxonomic placement of the newly described taxon is discussed, and a transfer of the genera Crypticolus Strohecker and Hornious Weise from Platynaspini to Coccinellinae as incerte sedis.

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, Kolibác & Slipinski 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.

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

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.

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.

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.

Description of a new species of Eucinetidae (Coleoptera, Scirtoidea) from Cretaceous Burmese amber.

Eucinetus parvus sp. nov. is described from late Cretaceous Burmese amber, representing the second record of Eucinetidae from the Burmese amber and the first species of the family with simple, not piercing, mouthparts. A comparison between Mesocinetidae and Eucinetidae is provided.

Discovery of the genus Cycloxenus Arrow, 1925 (Coleoptera, Euxestidae) in mainland China, with the description of a new species.

The termitophilous genus Cycloxenus Arrow (Coleoptera, Euxestidae) is reported from mainland China for the first time. A new species, Cycloxenus guangxiensis sp. nov., is described from Guangxi Province, China. The new species lives in nests of a fungus-growing termite (Odontotermes sp.) where it can be collected in the fungus gardens of the termite colony. The new species is compared with its congeners and new biological information for the genus Cycloxenus is provided. An identification key to all known Cycloxenus species is also provided.

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.

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.

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.

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.

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.

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.