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Chalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra-conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first-instar larvae. The phylogeny suggests a transition from smaller soft-bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the "Angiosperm Terrestrial Revolution". Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3-180.5 Ma) and a crown age of 162.2 Ma (153.9-169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history.
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Parasitos , Vespas , Animais , Vespas/genética , Filogenia , Evolução BiológicaRESUMO
Recent technical advances combined with novel computational approaches have promised the acceleration of our understanding of the tree of life. However, when it comes to hyperdiverse and poorly known groups of invertebrates, studies are still scarce. As published phylogenies will be rarely challenged by future taxonomists, careful attention must be paid to potential analytical bias. We present the first molecular phylogenetic hypothesis for the family Chalcididae, a group of parasitoid wasps, with a representative sampling (144 ingroups and seven outgroups) that covers all described subfamilies and tribes, and 82% of the known genera. Analyses of 538 Ultra-Conserved Elements (UCEs) with supermatrix (RAxML and IQTREE) and gene tree reconciliation approaches (ASTRAL, ASTRID) resulted in highly supported topologies in overall agreement with morphology but reveal conflicting topologies for some of the deepest nodes. To resolve these conflicts, we explored the phylogenetic tree space with clustering and gene genealogy interrogation methods, analyzed marker and taxon properties that could bias inferences and performed a thorough morphological analysis (130 characters encoded for 40 taxa representative of the diversity). This joint analysis reveals that UCEs enable attainment of resolution between ancestry and convergent/divergent evolution when morphology is not informative enough, but also shows that a systematic exploration of bias with different analytical methods and a careful analysis of morphological features is required to prevent publication of artifactual results. We highlight a GC content bias for maximum-likelihood approaches, an artifactual mid-point rooting of the ASTRAL tree and a deleterious effect of high percentage of missing data (>85% missing UCEs) on gene tree reconciliation methods. Based on the results we propose a new classification of the family into eight subfamilies and ten tribes that lay the foundation for future studies on the evolutionary history of Chalcididae.
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Sequência Conservada , Himenópteros/anatomia & histologia , Himenópteros/classificação , Himenópteros/genética , Filogenia , Animais , Composição de Bases , Biodiversidade , Evolução Biológica , Técnicas Genéticas , Funções VerossimilhançaRESUMO
Despite many attempts in the Sanger sequencing era, the phylogeny of fig trees remains unresolved, which limits our ability to analyze the evolution of key traits that may have contributed to their evolutionary and ecological success. We used restriction-site-associated DNA sequencing (c. 420 kb) and 102 morphological characters to elucidate the relationships between 70 species of Ficus. To increase phylogenetic information for higher-level relationships, we targeted conserved regions and assembled paired reads into long loci to enable the retrieval of homologous loci in outgroup genomes. We compared morphological and molecular results to highlight discrepancies and reveal possible inference bias. For the first time, we recovered a monophyletic subgenus Urostigma (stranglers) and a clade with all gynodioecious Ficus. However, we show, with a new approach based on iterative principal component analysis, that it is not (and will probably never be) possible to homogenize evolutionary rates and GC content for all taxa before phylogenetic inference. Four competing positions for the root of the molecular tree are possible. The placement of section Pharmacosycea as sister to other fig trees is not supported by morphological data and considered a result of a long-branch attraction artefact to the outgroups. Regarding morphological features and indirect evidence from the pollinator tree of life, the topology that divides Ficus into monoecious versus gynodioecious species appears most plausible. It seems most likely that the ancestor of fig trees was a freestanding tree and active pollination is inferred as the ancestral state, contrary to previous hypotheses. However, ambiguity remains on the ancestral breeding system. Despite morphological plasticity, we advocate restoring a central role to morphology in our understanding of the evolution of Ficus, as it can help detect systematic errors that appear more pronounced with larger molecular datasets.
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Evolução Biológica , DNA de Plantas/genética , Ficus/anatomia & histologia , Ficus/fisiologia , Filogenia , Raízes de Plantas/fisiologia , Animais , DNA de Plantas/análise , Melhoramento Vegetal , PolinizaçãoRESUMO
The bark beetle genus Dendroctonus contains some of the most economically important pests of conifers worldwide. Despite many attempts, there is no agreement today on the phylogenetic relationships within the genus, which limits our understanding of its evolutionary history. Here, using restriction-site associated DNA (RAD) markers from 70 specimens representing 17 species (85% of the known diversity) we inferred the phylogeny of the genus, its time of origin and biogeographic history, as well as the evolution of key ecological traits (host plants, larval behavior and adults' attack strategies). For all combinations of tested parameters (from 6444 to 23,570 RAD tags analyzed), the same, fully resolved topology was inferred. Our analyses suggest that the most recent common ancestor (mrca) of all extant Dendroctonus species was widely distributed across eastern Palearctic and western Nearctic during the early Miocene, from where species dispersed to other Holarctic regions. A first main inter-continental vicariance event occurred during early Miocene isolating the ancestors of D. armandi in the Palearctic, which was followed by the radiation of the main Dendroctonus lineages in North America. During the Late Miocene, the ancestor of the 'rufipennis' species group colonized north-east Palearctic regions from western North America, which was followed by a second main inter-continental vicariance event isolating Pleistocene populations in Asia (D. micans) and western North America (D. murrayanae and D. punctatus). The present study supports previous hypotheses explaining intercontinental range disjunctions across the Northern Hemisphere by the fragmentation of a continuous distribution due to climatic cooling, host range fragmentation and geological changes during the late Cenozoic. The reconstruction of ancestral ecological traits indicates that the mrca bored individual galleries and mass attacked the boles of pines. The gregarious feeding behavior of the larvae as well as the individual attack of the base of trees have apparently independently evolved twice in North America (in the 'rufipennis' and the 'valens' species groups), which suggests a higher adaptive potential than previously thought and may be of interest for plant protection and biodiversity conservation in a rapidly changing world.
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Besouros/classificação , Besouros/genética , Marcadores Genéticos/genética , Filogenia , Animais , Ásia , Biodiversidade , América do Norte , Mapeamento por Restrição , Análise de Sequência de DNARESUMO
A phylogeny of the Torymidae (Chalcidoidea) is estimated using 4734 nucleotides from five genes. Twelve outgroups and 235 ingroup taxa are used, representing about 70% of the recognized genera. Our analyses do not recover Torymidae as monophyletic and we recognize instead two families: Megastigmidae (stat. rev.) and Torymidae s.s. (stat. rev.). Within Torymidae s.s., we recognize six subfamilies and six tribes, including Chalcimerinae, Glyphomerinae and Microdontomerinae (subf. nov.), and two new tribes: Boucekinini and Propalachiini (trib. nov.). Seven unclassified genera (i.e. Cryptopristus, Echthrodape, Exopristoides, Exopristus, part of Glyphomerus, Thaumatorymus, Zaglyptonotus) are assigned to tribes within our new classification. Five genera are restored from synonymy-Ameromicrus and Didactyliocerus from under Torymoides (stat. rev.), Iridophaga and Iridophagoides from under Podagrionella (stat. rev.) and Nannocerus from under Torymus (stat. rev.)-and three genera are synonymized-Allotorymus under Torymussyn. nov., Ditropinotus under Eridontomerussyn. nov. and Pseuderimerus under Erimerussyn. nov. A Palaearctic or Eurasian origin for Torymidae is proposed. The ancestral area of Megastigmidae is indicated as the Australian region. The most probable ancestral life strategy for Torymidae s.s. is ectoparasitism on gall-forming Cynipidae. The life strategy and putative hosts of the common ancestor of Megastigmidae remain uncertain.
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BACKGROUND: Interspecific interactions have long been assumed to play an important role in diversification. Mutualistic interactions, such as nursery pollination mutualisms, have been proposed as good candidates for diversification through co-speciation because of their intricate nature. However, little is known about how speciation and diversification proceeds in emblematic nursery pollination systems such as figs and fig wasps. Here, we analyse diversification in connection with spatial structuring in the obligate mutualistic association between Ficus septica and its pollinating wasps throughout the Philippines and Taiwan. RESULTS: Ceratosolen wasps pollinating F. septica are structured into a set of three vicariant black coloured species, and a fourth yellow coloured species whose distribution overlaps with those of the black species. However, two black pollinator species were found to co-occur on Lanyu island. Microsatellite data on F. septica indicates the presence of three gene pools that broadly mirrors the distribution of the three black clades. Moreover, receptive fig odours, the specific message used by pollinating wasps to locate their host tree, varied among locations. CONCLUSIONS: F. septica and its black pollinator clades exhibited similar geographic structuring. This could be due originally to geographic barriers leading to isolation, local adaptation, and finally co-structuring. Nevertheless, the co-occurrence of two black pollinator species on Lanyu island suggests that the parapatric distribution of the black clades is now maintained by the inability of migrating individuals of black pollinators to establish populations outside their range. On the other hand, the distribution of the yellow clade strongly suggests an initial case of character displacement followed by subsequent range extension: in our study system, phenotypic or microevolutionary plasticity has allowed the yellow clade to colonise hosts presenting distinct odours. Hence, while variation in receptive fig odours allows specificity in the interaction, this variation does not necessarily lead to coevolutionary plant-insect diversification. Globally, our results evidence evolutionary plasticity in the fig-fig wasp mutualism. This is the first documentation of the presence of two distinct processes in pollinating fig wasp diversification on a host species: the formation of vicariant species and the co-occurrence of other species over large parts of their ranges probably made possible by character displacement.
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Biodiversidade , Ficus/fisiologia , Polinização/fisiologia , Simbiose , Vespas/fisiologia , Animais , Ficus/genética , Geografia , Repetições de Microssatélites/genética , Odorantes , Filipinas , Filogenia , Análise de Componente Principal , Taiwan , Vespas/genéticaRESUMO
UNLABELLED: In an attempt to make the processing of RAD-seq data easier and allow rapid and automated exploration of parameters/data for phylogenetic inference, we introduce the perl pipeline RADIS Users of RADIS can let their raw Illumina data be processed up to phylogenetic tree inference, or stop (and restart) the process at some point. Different values for key parameters can be explored in a single analysis (e.g. loci building, sample/loci selection), making possible a thorough exploration of data. RADIS relies on Stacks for demultiplexing of data, removing PCR duplicates and building individual and catalog loci. Scripts have been specifically written for trimming of reads and loci/sample selection. Finally, RAxML is used for phylogenetic inferences, though other software may be utilized. AVAILABILITY AND IMPLEMENTATION: RADIS is written in perl, designed to run on Linux and Unix platforms. RADIS and its manual are freely available from http://www1.montpellier.inra.fr/CBGP/software/RADIS/. CONTACT: astrid.cruaud@supagro.inra.fr SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Filogenia , Análise de Sequência , SoftwareRESUMO
Next-generation sequencing opened up new possibilities in phylogenetics; however, choosing an appropriate method of sample preparation remains challenging. Here, we demonstrate that restriction-site-associated DNA sequencing (RAD-seq) generates useful data for phylogenomics. Analysis of our RAD library using current bioinformatic and phylogenetic tools produced 400× more sites than our Sanger approach (2,262,825 nt/species), fully resolving relationships between 18 species of ground beetles (divergences up to 17 My). This suggests that RAD-seq is promising to infer phylogeny of eukaryotic species, though potential biases need to be evaluated and new methodologies developed to take full advantage of such data.
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Evolução Molecular , Filogenia , Análise de Sequência de DNA/métodos , Animais , Besouros/classificação , Besouros/genética , DNA/genética , DNA Mitocondrial/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Dados de Sequência Molecular , Especificidade da EspécieRESUMO
We use an integrative taxonomic approach to revise the genus Anisopteromalus. In particular, we apply multivariate ratio analysis (MRA), a rather new statistical method based on principal component analysis (PCA) and linear discriminant analysis (LDA), to numerous body measurements and combine the data with those from our molecular analysis of Cytb and ITS2 genetic markers (on a subset of species) and all available published data on morphology, karyology, behaviour, host associations and geographic distribution. We demonstrate that the analysis of quantitative characters using MRA plays a major role for the integration of name-bearing types and thus for the association of taxa with names. Six species are recognized, of which two are new: A. cornis Baur sp.n. and A. quinarius Gokhman & Baur sp.n. For Anisopteromalus calandrae (Howard), a well-known, cosmopolitan parasitoid of stored-product pests, we have selected a neotype to foster continuity and stability in the application of this important name. The species was sometimes confused with the related A. quinariussp.n., another cosmopolitan species that is frequently encountered in similar environments. We also show that several species originally described or later put under Anisopteromalus actually belong to different genera: Cyrtoptyx camerunus (Risbec) comb.n.; Meraporus glaber (Szelényi) comb.n.; Dinarmus schwenkei (Roomi, Khan & Khan) comb.n.Neocatolaccus indicus Ayyar & Mani is confirmed as a junior synonym of Oxysychus sphenopterae (Ferrière) syn.n. and Anisopteromalus calandrae brasiliensis (Domenichini) stat.rev. must be considered as a valid but doubtful taxon. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:BDFE96D3-D0F4-4012-90F5-9A087F7F5864.
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Eurytomidae (Chalcidoidea) species associated with fig trees (Ficus) are still poorly documented. A phylogenetic analysis of 63 morphological characters was conducted to revise Afrotropical species of Sycophila Walker and Ficomila Bouek associated with fig trees. Based on our results, which also included Palaearctic species of Sycophila, three subgenera of Sycophila are proposed: Sycophila s. str., Tineomyza Rondani stat. rev. and a new subgenus, Ficorytoma subgen. n. Lotfalizadeh & Rasplus. Ficomila is maintained as a valid genus. Thirty-six species are also newly described by Lotfalizadeh & Rasplus, namely Ficomila artocarpoides sp. n., F. carolae sp. n., F. bouceki sp. n., F. comptoni sp. n., F. flava sp. n., F. gabonensis sp. n., F. gibba sp. n., F. guinensis sp. n., F. sinai sp. n., F. tanzanica sp. n., F. vannoorti sp. n., Sycophila (Tineomyza) beninensis sp. n., S. (T.) busseicola sp. n., S. (T.) glumosae sp. n., S. (T.) luteacola sp. n., S. (T.) maldesi sp. n., S. (T.) minuta sp. n., S. (T.) platygastra sp. n., S. (T.) risbeci sp. n., S. (T.) wiebesi sp. n., S. (T.) zebrogastra sp. n., S. (Ficorytoma) delvarei sp. n., S. (F.) persicae sp. n., S. (Sycophila) annae sp. n., S. (S.) bidentata sp. n., S. (S.) longiflagellata sp. n., S. (S.) chirindensis sp. n., S. (S.) ficophila sp. n., S. (S.) fusca sp. n., S. (S.) lasallei sp. n., S. (S.) macrospermae sp. n., S. (S.) meridionalis sp. n., S. (S.) nigra sp. n., S. (S.) nigriterga sp. n., S. (S.) suricola sp. n., S. (S.) zebra sp. n.. Seven described species of Sycophila are reclassified in the subgenus Tineomyza: Sycophila (Tineomyza) flaviclava Bouek, 1981; S. (T.) modesta Bouek, 1981; S. (T.) naso Bouek, 1981; S. (T.) punctum Bouek, 1981; S. (T.) ruandensis Risbec, 1957; S. (T.) sessilis Bouek, 1981 and S. (T.) setulosa Zerova, 2009. After this revision, Ficomila and Sycophila include 46 species associated with Afrotropical Ficus. Detailed morphological descriptions and illustrations as well as identification keys are provided for the subgenera, species-groups and species of Ficomila and Sycophila associated with Afrotropical fig trees; their host fig association and relative lack of host-specificity are also discussed.
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Ficus , Gastrópodes , Himenópteros , Caramujos , Animais , FilogeniaRESUMO
It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant-insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by >750 interacting species pairs has hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale cophylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two supermatrices were assembled: on an average, wasps had sequences from 77% of 6 genes (5.6 kb), figs had sequences from 60% of 5 genes (5.5 kb), and overall 850 new DNA sequences were generated for this study. We also developed a new analytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based cophylogenetic analyses further support the codiversification hypothesis. Biogeographic analyses indicate that the present-day distribution of fig and pollinator lineages is consistent with a Eurasian origin and subsequent dispersal, rather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term codiversification. [Biogeography; coevolution; cospeciation; host switching; long-branch attraction; phylogeny.].
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Ficus/classificação , Filogenia , Vespas/classificação , Animais , Teorema de Bayes , Ficus/genética , Especiação Genética , Filogeografia , Polinização , Simbiose , Vespas/genéticaRESUMO
INTRODUCTION: In the past decade ecological speciation has been recognized as having an important role in the diversification of plant-feeding insects. Aphids are host-specialised phytophagous insects that mate on their host plants and, as such, they are prone to experience reproductive isolation linked with host plant association that could ultimately lead to species formation. The generality of such a scenario remains to be tested through macroevolutionary studies. To explore the prevalence of host-driven speciation in the diversification of the aphid genus Cinara and to investigate alternative modes of speciation, we reconstructed a phylogeny of this genus based on mitochondrial, nuclear and Buchnera aphidicola DNA sequence fragments and applied a DNA-based method of species delimitation. Using a recent software (PhyloType), we explored evolutionary transitions in host-plant genera, feeding sites and geographic distributions in the diversification of Cinara and investigated how transitions in these characters have accompanied speciation events. RESULTS: The diversification of Cinara has been constrained by host fidelity to conifer genera sometimes followed by sequential colonization onto different host species and by feeding-site specialisation. Nevertheless, our analyses suggest that, at the most, only half of the speciation events were accompanied by ecological niche shifts. The contribution of geographical isolation in the speciation process is clearly apparent in the occurrence of species from two continents in the same clades in relatively terminal positions in our phylogeny. Furthermore, in agreement with predictions from scenarios in which geographic isolation accounts for speciation events, geographic overlap between species increased significantly with time elapsed since their separation. CONCLUSIONS: The history of Cinara offers a different perspective on the mode of speciation of aphids than that provided by classic models such as the pea aphid. In this genus of aphids, the role of climate and landscape history has probably been as important as host-plant specialisation in having shaped present-day diversity.
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Chalcidoidea (Hymenoptera) is extremely diverse with an estimated 500 000 species. We present the first phylogenetic analysis of the superfamily based on both morphological and molecular data. A web-based, systematics workbench mx was used to score 945 character states illustrated by 648 figures for 233 morphological characters for a total of 66 645 observations for 300 taxa. The matrix covers 22 chalcidoid families recognized herein and includes 268 genera within 78 of 83 subfamilies. Morphological data were analysed alone and in combination with molecular data from ribosomal 18S (2105 bp) and 28S D2-D5 expansion regions (1812 bp). Analyses were analysed alone and in combined datasets using implied-weights parsimony and likelihood. Proposed changes in higher classification resulting from the analyses include: (i) recognition of Eriaporidae, revised status; (ii) recognition of Cynipencyrtidae, revised status; (iii) recognition of Azotidae, revised status; (iv) inclusion of Sycophaginae in Agaonidae, revised status; (v) reclassification of Aphelinidae to include Aphelininae, Calesinae, Coccophaginae, Eretmocerinae and Eriaphytinae; (vi) inclusion of Cratominae and Panstenoninae within Pteromalinae (Pteromalidae), new synonymy; (vii) inclusion of Epichrysomallinae in Pteromalidae, revised status. At a higher level, Chalcidoidea was monophyletic, with Mymaridae the sister group of Rotoitidae plus the remaining Chalcidoidea. A eulophid lineage was recovered that included Aphelinidae, Azotidae, Eulophidae, Signiphoridae, Tetracampidae and Trichogrammatidae. Eucharitidae and Perilampidae were monophyletic if Eutrichosomatinae (Pteromalidae) was included, and Eupelmidae was monophyletic if Oodera (Pteromalidae: Cleonyminae) was included. Likelihood recovered a clade of Eupelmidae + (Tanaostigmatidae + (Cynipencyrtus + Encyrtidae). Support for other lineages and their impact on the classification of Chalcidoidea is discussed. Several life-history traits are mapped onto the new phylogeny.
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Epitrix species (Coleoptera: Chrysomelidae) feed mostly on plants from the family Solanaceae and some of them are major pests of potato crops. All Epitrix species are morphologically highly similar, which makes them difficult to identify and limits their study and management. Identification of species is mostly based on the observation of the genitalia and requires a high level of expertise. Here, we propose a tool to reliably identify all developmental stages of the most economically important Epitrix species feeding on potato in Europe and North America (Epitrix cucumeris, Epitrix similaris, Epitrix tuberis, Epitrix subcrinita and Epitrix hirtipennis). We first sequenced two DNA markers (mitochondrial cytochrome c oxidase I (COI) and nuclear internal transcribed spacer 2 (ITS2)) to test their effectiveness in differentiating among six Epitrix species (126 specimens). Morphospecies of Epitrix were well-differentiated by both DNA barcodes and no mitochondrial introgression was detected. Then, we developed an RFLP-based diagnostic method and showed that unambiguous species discrimination can be achieved by using the sole restriction enzyme TaqI on COI polymerase chain reaction products. The tool proposed here should improve our knowledge about Epitrix species biology, distribution and host range, three capacities that are particularly important in the detection and management of these pest species. Specifically, this tool should help prevent the introduction of E. tuberis and E. subcrinita in Europe and limit the spread of the recently introduced E. cucumeris and E. similaris, with minimal disruption to Solanaceae trade.
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Besouros/genética , Marcadores Genéticos/genética , Solanum tuberosum/parasitologia , Animais , Sequência de Bases , Código de Barras de DNA Taxonômico/métodos , DNA Intergênico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Europa (Continente) , Controle de Insetos/métodos , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , América do Norte , Filogenia , Polimorfismo de Fragmento de Restrição/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
Carpocoris mediterraneus Tamanini, 1958, synonymized with Carpocoris fuscispinus (Boheman, 1851) by Ribes et al. (2007), is restored to the species level. The shape of the pronotum is a good diagnostic character to distinguish the two species. The existence of two valid species is supported by geographical distribution patterns in Western Europe: Mediterranean-Atlantic for C. mediterraneus, and Continental for C. fuscispinus. In France and Spain, in some areas, the two species are found in sympatry (sometimes even on the same plant). Morphological observations are confirmed at the molecular level by sequencing of the mitochondrial Cytochrome c oxidase I standard barcode fragment. Indeed, inter-specific divergence largely exceeded intra-specific divergence and our phylogenetic reconstructions reveal that Carpocoris mediterraneus and Carpocoris fuscispinus form two reciprocally monophyletic genetic lineages. A morphological identification key is proposed for all the European species of the genus Carpocoris, to facilitate identification. Carpocoris fuscispinus is first time recorded from Portugal.
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Hemípteros , Animais , Europa (Continente) , Feminino , Hemípteros/anatomia & histologia , Hemípteros/classificação , Hemípteros/genética , Masculino , FilogeografiaRESUMO
Philaenus spumarius (Ps) is considered the main insect vector of the bacterium Xylella fastidiosa (Xf) in Europe. As such, it is a key actor of the Xf pathosystem on which surveillance and management strategies could be implemented. Although research effort has increased in the past years, the ecological factors shaping Ps abundance and distribution across landscapes are still poorly known in most regions of Europe. We selected 64 plots of 500m2 in Corsican semi-natural habitats in which we sampled nymphs and adults of Ps during three years. While local or surrounding vegetation structure (low or high scrubland) had little effect on Ps abundance, we highlighted a positive relationship between Ps abundance and the density of Cistus monspeliensis in the plots. We also found larger populations of Ps in cooler and moister plots. The pattern of host association highlighted here is unique, which calls for more studies on the ecology of Ps in Europe, to help designing surveillance and management strategy for Xf.
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Hemípteros , Xylella , Animais , Doenças das Plantas/microbiologia , França , Europa (Continente) , Hemípteros/microbiologiaRESUMO
The order Hymenoptera (wasps, ants, sawflies, and bees) represents one of the most diverse animal lineages, but whether specific key innovations have contributed to its diversification is still unknown. We assembled the largest time-calibrated phylogeny of Hymenoptera to date and investigated the origin and possible correlation of particular morphological and behavioral innovations with diversification in the order: the wasp waist of Apocrita; the stinger of Aculeata; parasitoidism, a specialized form of carnivory; and secondary phytophagy, a reversal to plant-feeding. Here, we show that parasitoidism has been the dominant strategy since the Late Triassic in Hymenoptera, but was not an immediate driver of diversification. Instead, transitions to secondary phytophagy (from parasitoidism) had a major influence on diversification rate in Hymenoptera. Support for the stinger and the wasp waist as key innovations remains equivocal, but these traits may have laid the anatomical and behavioral foundations for adaptations more directly associated with diversification.
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Formigas , Vespas , Abelhas , Animais , Aclimatação , Carnivoridade , FenótipoRESUMO
The accidental endogenization of viral elements within eukaryotic genomes can occasionally provide significant evolutionary benefits, giving rise to their long-term retention, that is, to viral domestication. For instance, in some endoparasitoid wasps (whose immature stages develop inside their hosts), the membrane-fusion property of double-stranded DNA viruses have been repeatedly domesticated following ancestral endogenizations. The endogenized genes provide female wasps with a delivery tool to inject virulence factors that are essential to the developmental success of their offspring. Because all known cases of viral domestication involve endoparasitic wasps, we hypothesized that this lifestyle, relying on a close interaction between individuals, may have promoted the endogenization and domestication of viruses. By analyzing the composition of 124 Hymenoptera genomes, spread over the diversity of this clade and including free-living, ecto, and endoparasitoid species, we tested this hypothesis. Our analysis first revealed that double-stranded DNA viruses, in comparison with other viral genomic structures (ssDNA, dsRNA, ssRNA), are more often endogenized and domesticated (that is, retained by selection) than expected from their estimated abundance in insect viral communities. Second, our analysis indicates that the rate at which dsDNA viruses are endogenized is higher in endoparasitoids than in ectoparasitoids or free-living hymenopterans, which also translates into more frequent events of domestication. Hence, these results are consistent with the hypothesis that the endoparasitoid lifestyle has facilitated the endogenization of dsDNA viruses, in turn, increasing the opportunities of domestications that now play a central role in the biology of many endoparasitoid lineages.
Assuntos
Vírus , Vespas , Animais , Feminino , Evolução Biológica , DNA , Domesticação , Genoma Viral , Vírus/genética , Vespas/genéticaRESUMO
Despite the number of evolutionary, ecological and conservation studies that are conducted on Carabus, the global evolutionary history of the genus remains poorly understood. Here, we analysed 7.5 kilobases of DNA sequence data (six mitochondrial and four nuclear genes) from a worldwide sample of 45% of the known subgenera (99 species and 14 subspecies). We compared the nuclear and mitochondrial phylogenies obtained from Maximum likelihood and Bayesian analyses through topological tests of congruence and dating analyses. Our results mostly corroborate the monophyly of the morphological subgroups of Carabus. However, current morphological and molecular data appear unable to accurately infer the deep branchings within the genus. We show that Carabus originated ca. 16.7-25.1 Ma, approximately 25 Myr later than previously estimated. Major groups of Carabus are subdivided into clades that diverged from each other in a relatively short period of time around 10 Ma (6.6-14.8). This time frame suggests that the present-day distribution of Carabus subgroups may be explained by isolation resulting from Eurasian forest fragmentation brought on by Miocene climate changes and by mountain orogenesis. Finally, we highlight several conflicts between mitochondrial and nuclear topologies that may be explained by mitochondrial introgression.