91 research outputs found

    Phylogeographic structure and ecological niche modelling reveal signals of isolation and postglacial colonisation in the European stag beetle

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    Lucanus cervus (L.), the stag beetle, is a saproxylic beetle species distributed widely across Europe. Throughout its distribution the species has exhibited pronounced declines and is widely considered threatened. Conservation efforts may be hindered by the lack of population genetic data and understanding of the spatial scale of population connectivity. To address this knowledge gap this research details the first broad scale phylogeographic study of L. cervus based on mitochondrial DNA (mtDNA) sequencing and microsatellite analysis of samples collected from 121 localities across Europe. Genetic data were complemented by palaeo-distribution models of spatial occupancy during the Last Glacial Maximum to strengthen inferences of refugial areas. A salient feature of the mtDNA was the identification of two lineages. Lineage I was widespread across Europe while lineage II was confined to Greece. Microsatellites supported the differentiation of the Greek samples and alongside palaeo-distribution models indicated this area was a glacial refuge. The genetic endemism of the Greek samples, and demographic results compatible with no signatures of spatial expansion likely reflects restricted dispersal into and out of the area. Lineage I exhibited a shallow star like phylogeny compatible with rapid population expansion across Europe. Demographic analysis indicated such expansions occurred after the Last Glacial Maximum. Nuclear diversity and hindcast species distribution models indicated a central Italian refuge for lineage I. Palaeo-distribution modelling results also suggested a western refuge in northern Iberia and south-west France. In conclusion the results provide evidence of glacial divergence in stag beetle while also suggesting high, at least on evolutionary timescales, gene flow across most of Europe. The data also provide a neutral genetic framework against which patterns of phenotypic variation may be assessed.</div

    Guidelines for the monitoring of Rosalia alpina

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    Rosalia alpina (Linnaeus, 1758) is a large longhorn beetle (Coleoptera: Cerambycidae) which is protected by the Habitats Directive and which typically inhabits beech forests characterised by the presence of mature, dead (or moribund) and sun-exposed trees. A revision of the current knowledge on systematics, ecology and conservation of R. alpina is reported. The research was carried out as part of the LIFE MIPP project which aims to find a standard monitoring method for saproxylic beetles protected in Europe. For monitoring this species, different methods were tested and compared in two areas of the Apennines, utilising wild trees, logs and tripods (artificially built with beech woods), all potentially suitable for the reproduction of the species. Even if all methods succeeded in the survey of the target species, these results showed that the use of wild trees outperformed other methods. Indeed, the use of wild trees allowed more adults to be observed and required less intensive labour. However, monitoring the rosalia longicorn on wild trees has the main disadvantage that they can hardly be considered “standard sampling units”, as each tree may be differently attractive to adults. Our results demonstrated that the most important factors influencing the attraction of single trunks were wood volume, sun-exposure and decay stage. Based on the results obtained during the project LIFE MIPP, as well as on a literature review, a standard monitoring method for R. alpina was developed

    Molecular biogeography of Mediterranean and southern African disjunctions as exemplified by pollen beetles of the Meligethes planiusculus species-group and related taxa (Coleoptera: Nitidulidae; Meligethinae)

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    We investigated the apparent disjunction expressed in two related assemblages of species of the genus Meligethes, i.e. M. fruticola and its allies in the Cape region of South Africa and the M. planiusculus group in the Mediterranean region. We also inferred possible dynamics in the radiation of the Meligethes planiusculus complex within Macaronesia utilizing morphological, molecular and bionomical data, exploring potential historical and palaeoecological scenarios regulated by a molecular clock dating system. We reconstructed phylogenetic relationships of the M. planiusculus complex and of related Mediterranean (M. tristis), tropical (M. scotti) and southern African (M. chevrolati, M. conformis, and M. fruticola) species, using COI mitochondrial gene sequences. Phylogenetic reconstructions support an unambiguous distinction of two major clades grouping European-Mediterranean M. canariensis, M. isoplexidis andM. planiusculus specimens in one clade and the South-African specimens related to M. fruticola in another. Molecular markers suggested that the European-Mediterranean taxon M. tristis is unambiguously more distantly related to the partly sympatric M. canariensis, M. isoplexidis and M. planiusculus, than to the geographically isolated Southern African taxon, M. fruticola. However, morphological data revealed that M. tristis is more closely related to M. planiusculus and its allies while occupying a position internal to the M. planiusculus species group, but external to the M. planiusculus complex. Results of divergence estimation analyses suggest a splitting between ancestors of the European-Mediterranean species of the M. planiusculus complex and that of the African species M. fruticola at ~21-23 MYA. Molecular results also demonstrated that the remaining Afrotropical species are more related to the M. planiusculus and M. fruticola complexes than to M. tristis. This evidence clearly indicates that the Holarctic M. planiusculus group represents a paraphyletic assemblage with heterochronic Afrotropical origin. The estimated times of divergence supports evidence from other researchers of an ‘Arid Corridor’, or of a ‘Central or Eastern High Africa Corridor’, which connected several times in the last twenty MY the European-Mediterranean and eastern/southern African areas, and facilitated species migration northwards and southwards. The dynamics of the Meligethes planiusculus complex radiation in Macaronesia apparently followed a contradictory biogeographical scenario than the sequence of events recently hypothesized for their host-plants (Echium, Boraginaceae)

    UPDATING THE TAXONOMY AND DISTRIBUTION OF THE EUROPEAN OSMODERMA, AND STRATEGIES FOR THEIR CONSERVATION (COLEOPTERA, SCARABAEIDAE, CETONIINAE)

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    Results of a molecular analysis on the European hermit beetles (the Osmoderma eremita species-complex), recently published in a companion paper, are shortly dis- cussed and commented. These results indicate a clear-cut distinction between two clades. The first one includes the W-European O. eremita Scopoli, 1763, and the two Italian endemic taxa O. italicum Sparacio, 2000 and O. cristinae Sparacio, 1994, from southern peninsular Italy and Sicily, respectively. The second one includes the widespread E-European O. barnabita Motschulsky, 1845 (nom. resurr.), and the southern Balcanic O. lassallei Baraud &amp; Tauzin, 1991 from Greece and European Turkey. Within the two clades, molecular data well support a specific rank for O. lassallei and O. barn­abita on one side, and of O. eremita and O. cristinae on the other side, while the taxonomic position of O. italicum, more closely related with O. eremita, is still uncertain, waiting for analysis of additional specimens of this very rare taxon. Current geographical distribution, interspecific genetic diversification, and relatively low levels of intraspecific genetic divergence in O. eremita sensu stricto, are hypothesized to be the result of multiple speciation events (mainly occurred in refugial forest areas of the Italian and Balkan peninsulas and Sicily before and during the Pleistocene glacial peaks), followed by fast post-glacial northward and westward expansion of some species. The need of further genetic data on the rare and threatened hermit beetle species and the importance of more detailed information on their distribution ranges are emphasized and discussed, in order to plan conservation strategies in the near future. An updated worldwide checklist of the species of the genus Osmoderma is finally presented

    UPDATING THE TAXONOMY AND DISTRIBUTION OF THE EUROPEAN OSMODERMA, AND STRATEGIES FOR THEIR CONSERVATION (Coleoptera, Scarabaeidae, Cetoniinae)

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    Results of a molecular analysis on the European hermit beetles (the Osmoderma eremita species-complex), recently published in a companion paper, are shortly dis- cussed and commented. These results indicate a clear-cut distinction between two clades. The first one includes the W-European O. eremita Scopoli, 1763, and the two Italian endemic taxa O. italicum Sparacio, 2000 and O. cristinae Sparacio, 1994, from southern peninsular Italy and Sicily, respectively. The second one includes the widespread E-European O. barnabita Motschulsky, 1845 (nom. resurr.), and the southern Balcanic O. lassallei Baraud &amp; Tauzin, 1991 from Greece and European Turkey. Within the two clades, molecular data well support a specific rank for O. lassallei and O. barn­abita on one side, and of O. eremita and O. cristinae on the other side, while the taxonomic position of O. italicum, more closely related with O. eremita, is still uncertain, waiting for analysis of additional specimens of this very rare taxon. Current geographical distribution, interspecific genetic diversification, and relatively low levels of intraspecific genetic divergence in O. eremita sensu stricto, are hypothesized to be the result of multiple speciation events (mainly occurred in refugial forest areas of the Italian and Balkan peninsulas and Sicily before and during the Pleistocene glacial peaks), followed by fast post-glacial northward and westward expansion of some species. The need of further genetic data on the rare and threatened hermit beetle species and the importance of more detailed information on their distribution ranges are emphasized and discussed, in order to plan conservation strategies in the near future. An updated worldwide checklist of the species of the genus Osmoderma is finally presented

    Compost stream as a potential biomass for humic acid production: Focus on compost seasonal and geographical variability

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    Compost is a voluminous stream rich in humic and fulvic acids, which may be recovered as high-added value compounds. These soluble bio-based lignin-like polymeric substances (SBO) can be extracted through a completely green process developed at pilot scale, whose main core is the hydrolytic route in aqueous solutions at relatively mild temperature (< 140 °C) at ACEA Pinerolese Industriale premises. Due to their chemical-physical properties, the SBO compounds can be used with advantage for myriads of industrial applications, from the formulation of detergents to the production of agriculture biostimulants, answering the increasing demand for bio-compound utilization. In view of LIFECAB project (LIFE16 ENV/IT/000179), the characterization of starting materials and the derived compost has been performed over four seasons and over three European countries (Italy, Greece ad Cyprus). In view of establishing a relationship between SBO molecules and compost properties, this work is a challenging opportunity for assessing the compost variability and its temporal evolution during the composting process. Analyses of pH, salinity, total carbon, total nitrogen and C/N ratio, critically assessed by means of a statistical approach, provide important information about compost composition according to the season and to the local environmental conditions

    A machine-learning based bio-psycho-social model for the prediction of non-obstructive and obstructive coronary artery disease

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    Background: Mechanisms of myocardial ischemia in obstructive and non-obstructive coronary artery disease (CAD), and the interplay between clinical, functional, biological and psycho-social features, are still far to be fully elucidated. Objectives: To develop a machine-learning (ML) model for the supervised prediction of obstructive versus non-obstructive CAD. Methods: From the EVA study, we analysed adults hospitalized for IHD undergoing conventional coronary angiography (CCA). Non-obstructive CAD was defined by a stenosis &lt; 50% in one or more vessels. Baseline clinical and psycho-socio-cultural characteristics were used for computing a Rockwood and Mitnitski frailty index, and a gender score according to GENESIS-PRAXY methodology. Serum concentration of inflammatory cytokines was measured with a multiplex flow cytometry assay. Through an XGBoost classifier combined with an explainable artificial intelligence tool (SHAP), we identified the most influential features in discriminating obstructive versus non-obstructive CAD. Results: Among the overall EVA cohort (n = 509), 311 individuals (mean age 67 ± 11&nbsp;years, 38% females; 67% obstructive CAD) with complete data were analysed. The ML-based model (83% accuracy and 87% precision) showed that while obstructive CAD was associated with higher frailty index, older age and a cytokine signature characterized by IL-1ÎČ, IL-12p70 and IL-33, non-obstructive CAD was associated with a higher gender score (i.e., social characteristics traditionally ascribed to women) and with a cytokine signature characterized by IL-18, IL-8, IL-23. Conclusions: Integrating clinical, biological, and psycho-social features, we have optimized a sex- and gender-unbiased model that discriminates obstructive and non-obstructive CAD. Further mechanistic studies will shed light on the biological plausibility of these associations. Clinical trial registration: NCT02737982

    Sistematica e filogenesi del complesso di specie di Meligethes coracinus Sturm (Coleoptera, Nitidulidae): evidenze molecolari ed ecologiche.

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    Dottorato di Ricerca in Biologia Animale, XVI ciclo, Università degli Studi di Roma “La Sapienza”, Facoltà di Scienze Matematiche, Fisiche e Naturali
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