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Undarobius gen. n., a new genus of cavernicolous weevils with two new species, U. howarthi sp. n. and U. irvini sp. n., is described from the Undara Lava Cave system in north-eastern Queensland, Australia. These are the first cavernicolous weevils to be described from Australia, and U. howarthi is a new addition to the rich arthropod fauna of Bayliss Cave. Undarobius weevils are relatively large in size (4.05.5 mm long), anophthalmic and apterous with a robust, flattened body and long legs. The genus has affinities with Leptopiini, but its placement in the tribe is uncertain. We also provide a list of the known anophthalmic and microphthalmic weevils in Australia, spanning 65 species classified in 20 genera, eight tribes and about seven subfamilies and found in diverse hypogean habitats, mainly leaf litter but also soil, beach sand, subterranean aquifers and mosses.
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Briófitas , Escarabajos , Gorgojos , Animales , Australia , Ecosistema , SueloRESUMEN
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.
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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.
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Antibiosis/genética , Evolución Biológica , Escarabajos/genética , Transferencia de Gen Horizontal , Genes Bacterianos , Genes de Insecto , Adaptación Biológica , Animales , Pared Celular/química , Pared Celular/enzimología , Escarabajos/enzimología , Interacciones Huésped-Patógeno , Hidrolasas/genéticaRESUMEN
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.
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Escarabajos/clasificación , Escarabajos/genética , Genes de Insecto , Filogenia , Aminoácidos/genética , Animales , Composición de Base/genética , Codón/genética , Nucleótidos/genética , Factores de TiempoRESUMEN
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.
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Escarabajos , Animales , Australia , Femenino , Fósiles , MasculinoRESUMEN
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.
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Biodiversidad , Evolución Biológica , Escarabajos/genética , Transferencia de Gen Horizontal , Genoma de los Insectos , Animales , Bacterias/enzimología , Bacterias/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pared Celular/química , Pared Celular/metabolismo , Celulasas/genética , Celulasas/metabolismo , Escarabajos/enzimología , Escarabajos/microbiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hongos/enzimología , Hongos/genética , Herbivoria/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Lignina/química , Lignina/metabolismo , Filogenia , Plantas/química , Polisacárido Liasas/genética , Polisacárido Liasas/metabolismo , Polisacáridos/química , Polisacáridos/metabolismoRESUMEN
BACKGROUND: The diversity and evolutionary success of beetles (Coleoptera) are proposed to be related to the diversity of plants on which they feed. Indeed, the largest beetle suborder, Polyphaga, mostly includes plant eaters among its approximately 315,000 species. In particular, plants defend themselves with a diversity of specialized toxic chemicals. These may impose selective pressures that drive genomic diversification and speciation in phytophagous beetles. However, evidence of changes in beetle gene repertoires driven by such interactions remains largely anecdotal and without explicit hypothesis testing. RESULTS: We explore the genomic consequences of beetle-plant trophic interactions by performing comparative gene family analyses across 18 species representative of the two most species-rich beetle suborders. We contrast the gene contents of species from the mostly plant-eating suborder Polyphaga with those of the mainly predatory Adephaga. We find gene repertoire evolution to be more dynamic, with significantly more adaptive lineage-specific expansions, in the more speciose Polyphaga. Testing the specific hypothesis of adaptation to plant feeding, we identify families of enzymes putatively involved in beetle-plant interactions that underwent adaptive expansions in Polyphaga. There is notable support for the selection hypothesis on large gene families for glutathione S-transferase and carboxylesterase detoxification enzymes. CONCLUSIONS: Our explicit modeling of the evolution of gene repertoires across 18 species identifies putative adaptive lineage-specific gene family expansions that accompany the dietary shift towards plants in beetles. These genomic signatures support the popular hypothesis of a key role for interactions with plant chemical defenses, and for plant feeding in general, in driving beetle diversification.
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Adaptación Biológica , Evolución Biológica , Escarabajos/genética , Herbivoria , Familia de Multigenes , Animales , Escarabajos/enzimología , Genómica , Modelos GenéticosRESUMEN
The beetle superfamily Dytiscoidea, placed within the suborder Adephaga, comprises six families. The phylogenetic relationships of these families, whose species are aquatic, remain highly contentious. In particular the monophyly of the geographically disjunct Aspidytidae (China and South Africa) remains unclear. Here we use a phylogenomic approach to demonstrate that Aspidytidae are indeed monophyletic, as we inferred this phylogenetic relationship from analyzing nucleotide sequence data filtered for compositional heterogeneity and from analyzing amino-acid sequence data. Our analyses suggest that Aspidytidae are the sister group of Amphizoidae, although the support for this relationship is not unequivocal. A sister group relationship of Hygrobiidae to a clade comprising Amphizoidae, Aspidytidae, and Dytiscidae is supported by analyses in which model assumptions are violated the least. In general, we find that both concatenation and the applied coalescent method are sensitive to the effect of among-species compositional heterogeneity. Four-cluster likelihood-mapping suggests that despite the substantial size of the dataset and the use of advanced analytical methods, statistical support is weak for the inferred phylogenetic placement of Hygrobiidae. These results indicate that other kinds of data (e.g. genomic meta-characters) are possibly required to resolve the above-specified persisting phylogenetic uncertainties. Our study illustrates various data-driven confounding effects in phylogenetic reconstructions and highlights the need for careful monitoring of model violations prior to phylogenomic analysis.
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Clasificación , Escarabajos/clasificación , Escarabajos/genética , Genómica , Filogenia , Aminoácidos/genética , Animales , Secuencia de Bases , Codón/genética , Genoma , Funciones de Verosimilitud , Transcriptoma/genéticaRESUMEN
Cycads, unlike modern wind-pollinated conifers and Ginkgo, are unusual in that they are an ancient group of gymnosperms pollinated by insects [1-3]. Although it is well documented that cycads were diverse and abundant during the mid-Mesozoic, little is known about their biogeography and pollination before the rise of angiosperms. Direct fossil evidence illuminating the evolutionary history of cycads is extremely rare [4, 5]. Here we report a specialized beetle-mediated pollination mode from the mid-Cretaceous of Myanmar, wherein a new boganiid beetle, Cretoparacucujus cycadophilus, with specialized pollen-feeding adaptations in its mouthparts and legs, was associated with many pollen grains of Cycadopites. Phylogenetic analyses indicate Cretoparacucujus as a sister group to the extant Australian Paracucujus, which pollinate the cycad Macrozamia riedlei. Our discovery, along with the current disjunct distribution of related beetle-herbivore (tribe Paracucujini) and cycad-host (tribe Encephalarteae) pairs in South Africa and Australia, indicate a probable ancient origin of beetle pollination of cycads at least in the Early Jurassic, long before angiosperm dominance and the radiation of flowering-plant pollinators later in the Cretaceous.
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Escarabajos/anatomía & histología , Cycas/fisiología , Fósiles , Polen/clasificación , Polinización , Ámbar , Animales , Escarabajos/clasificación , Escarabajos/genética , Microscopía Electrónica de Rastreo , Mianmar , FilogeniaRESUMEN
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.
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Escarabajos/clasificación , Escarabajos/genética , Animales , Evolución Biológica , Escarabajos/crecimiento & desarrollo , Escarabajos/fisiología , Evolución Molecular , Preferencias Alimentarias , Especies Introducidas , Larva/fisiología , Filogenia , Conducta PredatoriaRESUMEN
Ulodidae is a small family of saproxylic and fungus feeding beetles restricted to New Zealand, Australia, Chile and New Caledonia. The phylogeny of this family is presented for the first time, based on a cladistic analysis of 53 adult characters from 16 ulodid genera, rooted with Parahelops Waterhouse (Promecheilidae). The topology shows Arthopus Sharp at the base of the tree and confirms the placement of Meryx Latreille as a member of Ulodidae and closely related to the Chilean genus Trachyderas Philippi & Philippi. The extinct New Zealand genus Waitomophylax Leschen & Rhode was placed among a clade consisting of Brouniphylax Strand, Exohadrus Broun, and Pteroderes Germain. Two new genera and two new species are described: Ulobostrichus gen. n. (type species: Ulobostrichus monteithi sp. n.) and Ulocyphaleus gen. n. (type species: Cyphaleus valdivianus Philippi & Philippi, 1864, now U. valdivianus (Philippi & Philippi) n. comb.; U. laetus sp. n.). Dipsaconia pyritosa Pascoe is designated as the type species of Dipsaconia Pascoe and a lectotype was designated for C. valdivianus. A fully illustrated key to the genera and a checklist of the 16 genera and 42 species is included. Based on the phylogeny, the following characters are derived in the family: tuberculate body surface and the presence of scales and /or encrustations. The presence of pore-fields in the abdominal cuticle has evolved at least three times in Meryx Latreille (Australia), Syrphetodes Pascoe (New Zealand) and Trachyderastes Kaszab (New Caledonia).
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Escarabajos/anatomía & histología , Escarabajos/clasificación , Filogenia , Animales , Femenino , Fósiles , Masculino , Especificidad de la EspecieRESUMEN
The world genera of Mycetophagidae are reviewed and four new genera described. Several adult features of Mycetophagidae are discussed, and some newly discovered secondary sexual characters are described and illustrated. A key is given to the adults of all mycetophagid genera. The following new genera and species are proposed: Afrotyphaeola gen. n. (South Africa), A. natalensis sp. n. (South Africa), Neotriphyllus gen. n. (southwestern USA to Central America), Nototriphyllus gen. n. (New Zealand, Madagascar, Chile and Argentina), N. araucania sp. n. (Chile, Argentina), Zeclaviger gen. n. (New Zealand) and Z. explanatus sp. n. (New Zealand). The following synonymies are proposed: Litargus Erichson, 1846 (= Catopius Sharp, 1902) syn. n., Litargus balteatus LeConte, 1856 (= Triphyllus minor Lea, 1895) syn. n., Mycetophagus confusus Horn, 1878 (= Triphyllus perfectus Sharp, 1902) syn. n. The following new combinations are proposed: Litargops intricatus (Blackburn, 1891) (Triphyllus, Litargus) comb. n., L. multiguttatus (Lea, 1895) (Triphyllus, Litargus) comb. n., Litargus irregularis (Sharp) (Catopius) comb. n., Mycetophagus (Paralitargus) didesmus (Say) (Litargus) comb. n., Neotriphyllus confusus (Horn) (Mycetophagus) comb. n. Nototriphyllus aciculatus (Broun, 1880) (Cryptophagus) comb. n., N. adspersus (Broun, 1880) (Cryptophagus) comb. n., N. constans (Broun, 1914) comb. n., N. fuliginosus (Broun, 1880) (Cryptophagus) comb. n., N. hispidellus (Broun, 1880) (Cryptophagus) comb. n., N. integritus (Broun, 1893) comb. n., N. pubescens (Broun, 1909) comb. n., N. madagascariensis (Fairmaire, 1898) (Triphyllus) comb. n., N. punctulatus (Broun, 1880) (Cryptophagus) comb. n., N. rubicundus (Sharp, 1886) (Triphyllus) comb. n., N. serratus (Broun, 1880) (Cryptophagus) comb. n., N. substriatus (Broun, 1880) (Cryptophagus) comb. n. The larva of Nototriphyllus araucania is briefly described and compared with other known myceophagid larvae. The genus Nesolathrus Scott (1922), described in Latridiidae and considered incertae sedis in Mycetophagidae by Lawrence & Newton (1995), is placed in the subfamily Bergininae, following Lawrence & Slipinski (2013). The tribe Typhaeini Thomson (1863), as delimited by Nikitsky (1993), based on the lateral closure of the mesocoxal cavity by the mesoventrite and metaventrite, is considered to be non-monophyletic. Rhipidonyx adustus Reitter (1876), described in Mycetophagidae, is transferred to Tenebrionidae: Alleculinae, based on the description and examination of a specimen presumed to be the type.
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Escarabajos/anatomía & histología , Escarabajos/clasificación , Animales , Argentina , Femenino , Masculino , Nueva ZelandaRESUMEN
The ladybird beetle genus Hong Slipinski was previously known from a single female specimen from a subtropical forest in South East Queensland, Australia. Hong guerreroi sp. nov. and H. slipinskii sp. nov. from a temperate forests of Central and Southern Chile are described and illustrated. A key for the species of the genus and complementary characters, including the first description of males, are provided.