177 research outputs found

    Importance of biotic predictors in estimation of potential invasive areas: The example of the tortoise beetle Eurypedus nigrosignatus, in Hispaniola

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    This work is licensed under a Creative Commons Attribution 4.0 International License.Climatic variables have been the main predictors employed in ecological niche modeling and species distribution modeling, although biotic interactions are known to affect species’ spatial distributions via mechanisms such as predation, competition, and mutualism. Biotic interactions can affect species’ responses to abiotic environmental changes differently along environmental gradients, and abiotic environmental changes can likewise influence the nature of biotic interactions. Understanding whether and how to integrate variables at different scales in ecological niche models is essential to better estimate spatial distributions of species on macroecological scales and their responses to change. We report the leaf beetle Eurypedus nigrosignatus as an alien species in the Dominican Republic and investigate whether biotic factors played a meaningful role in the distributional expansion of the species into the Caribbean. We evaluate ecological niche models built with an additive gradient of unlinked biotic predictors—host plants, using likelihood-based model evaluation criteria (Akaike information criterion and Bayesian information criterion) within a range of regularization multiplier parameter values. Our results support the argument that ecological niche models should be more inclusive, as selected biotic predictors can improve the performance of models, despite the increased model complexity, and show that biotic interactions matter at macroecological scales. Moreover, we provide an alternative approach to select optimal combination of relevant variables, to improve estimation of potential invasive areas using global minimum model likelihood scores.Conselho Nacional de Desenvolvimento Científico e Tecnológico (No. 201275/2012–0)University of KansasPanorama AwardMuseum of Comparative ZoologyHarvard UniversityErnst Mayr Travel GrantGraduate Student Research Enhancement Award, from the Coleopterists Societ

    On the Identity of the Adventive Species of Eufriesea Cockerell in the USA: Systematics and Potential Distribution of the Coerulescens Species Group (Hymenoptera, Apidae)

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    In the summer of 2010, two male specimens of the neotropical orchid bee genus Eufriesea Cockerell were collected in the Guadalupe Mountains of western Texas and southeastern New Mexico, USA. We tentatively identified them as E. coerulescens (Lepeletier de Saint Fargeau) because of the uncertainty surrounding the limits of this taxon and hypothesized that they were members of a persistent bee population, rather than long-distance transient vagrants. The goals of this paper are to clarify the identity of these specimens, assess the species limits of E. coerulescens, and to evaluate suitability of habitats in the USA for this adventive species. Herein, we revise the species in the coerulescens group using morphological features of both sexes and confirm that the specimens of Eufriesea from the USA are E. coerulescens. We recognize the following six species in the coerulescens group: E. coerulescens, E. micheneri Ayala & Engel, E. simillima (Moure & Michener), which is reinstated from synonym with E. coerulescens, and three new species from Mexico (E.barthelli Gonzalez & Griswold, sp. n., E. engeli Gonzalez & Griswold, sp. n., and E. oliveri Gonzalez & Griswold, sp. n.). To facilitate the identification of these taxa, we present a fully illustrated account of the species, comparative diagnoses, descriptions, and an updated key to all Mexican species of Eufriesea. Our analyses using species distribution modelling show an absence of suitable habitat for E. coerulescens in western Texas and southeastern New Mexico, thus favoring the long-distance dispersal hypothesis. The analyses also suggest high suitability of habitats across the Caribbean and some areas in Florida, as well as in other regions in Mexico and Central America. We discuss the implications of these results and compare them with the predicted distribution available for the other two known adventive orchid bee species in the USA

    Importance of biotic predictors in estimation of potential invasive areas: the example of the tortoise beetle Eurypedus nigrosignatus, in Hispaniola

    Get PDF
    Climatic variables have been the main predictors employed in ecological niche modeling and species distribution modeling, although biotic interactions are known to affect species’ spatial distributions via mechanisms such as predation, competition, and mutualism. Biotic interactions can affect species’ responses to abiotic environmental changes differently along environmental gradients, and abiotic environmental changes can likewise influence the nature of biotic interactions. Understanding whether and how to integrate variables at different scales in ecological niche models is essential to better estimate spatial distributions of species on macroecological scales and their responses to change. We report the leaf beetle Eurypedus nigrosignatus as an alien species in the Dominican Republic and investigate whether biotic factors played a meaningful role in the distributional expansion of the species into the Caribbean. We evaluate ecological niche models built with an additive gradient of unlinked biotic predictors—host plants, using likelihood-based model evaluation criteria (Akaike information criterion and Bayesian information criterion) within a range of regularization multiplier parameter values. Our results support the argument that ecological niche models should be more inclusive, as selected biotic predictors can improve the performance of models, despite the increased model complexity, and show that biotic interactions matter at macroecological scales. Moreover, we provide an alternative approach to select optimal combination of relevant variables, to improve estimation of potential invasive areas using global minimum model likelihood scores

    Regional anthropogenic disturbance and species-specific niche traits influence the invasiveness of European beetle species

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    Coleoptera are key elements of terrestrial trophic interactions and generate significant economic and ecological benefits, but their representatives also represent severe pest species. Understanding how invasive species operate is indispensable to identify and anticipate potential invasion areas. However, few studies have explored niche dynamics and drivers of invasions in this group. Here we examined niche dynamics across 54 invasive beetle species native to Europe and assessed whether factors such as human influence index, feeding habits, body size, and niche breadth are associated with the degree of invasion. The realized niches had low similarity in invasive and native ranges (i.e., invaded areas are climatically dissimilar to native ranges). This included a high degree of niche expansion in invaded areas but also environments occupied in the native ranges but unoccupied in the invasive range (unfilling), suggesting that altered species–climate relationships during invasion processes are common. Niche expansions showed positive association with small native niche breadth sizes and movements from highly disturbed native areas to less disturbed invaded ranges; unfilling was associated with invaded niche breadth size and frequency of species occurrence. Both were related to dissimilar realized climatic niches in invaded ranges. Colonization of invaded areas might be triggered by low quality resources in native areas. Unfilling levels might be related to the year of introduction and loss of biotic constraints present in their native distribution, leading to the use of different climatic spaces in the invasive areas. This idea is reinforced by larger invasive climatic niche breadth. Our results provide insight into patterns of invasive species, and initial holistic exploration towards the understanding of invasive species dynamics.journal articl

    Potential geographic shifts in the coral reef ecosystem under climate change

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    The coral reefs are the most diverse marine ecosystem in the world. Considering its contribution as a natural resource for humanity and global biodiversity, it is critical to understand its response to climatic change. To date, no global predictions have been made about potential ecosystem changes in relation to its inhabiting species. Predicting changes in species' climatic suitability under increasing temperature and comparing them among species would be the first step in understanding the geographic and taxonomic coherence and discrepancies that may occur within the ecosystem. Using 57 species-specific global climate suitability models (of corals, molluscs, fish, crustaceans, and polychaetes) under present and future climate scenarios (RCP 4.5 and 8.5), we compared the potential coherence and differences and their cumulative impact on the ecosystem in warm, cold, shallow, and deep waters. Under the climatic scenarios, nearly 90% of 30 warm-water species were predicted to lose their suitability in the parts of the Indo-west Pacific, the Coast of Northern Australia, the South China Sea, the Caribbean Sea, and the Gulf of Mexico, resulting in the overall southward shift in their distributions. In contrast, a mixed response occurred in 27 cold-water species, with most northern temperate/boreal ones increasing their suitability in the Arctic Ocean and the Arctic species declining overall. We noticed that irrespective of their taxonomic group, the species with wider distribution ranges (thermal and geographic) had larger predicted gains in their suitability than their stenothermal counterparts, suggesting an increase of generalist species and a decline of specialist (endemic) species of the ecosystem under a warming climate. Our coherent projections of species' climatic suitability in warm and cold habitats of the tropics, temperate, boreal, and the Arctic, represent significant taxonomic groups of the ecosystem. This might indicate mass extinction risk (local– in the tropics and northern temperate regions, and overall– in the Arctic) in native habitats and a high species turnover across the ecosystem under a warming climate. This may also destabilise predator–prey dynamics in the ecosystem, especially if foraging specialists dominate coral food webs and adversely affect the associated countries. Our global projections highlight the regions of species’ potential loss and gain; stakeholders could use the information to protect biodiversity and maintain human well-being

    ï»żLife history and biogeography of the enigmatic mantid Nilomantis floweri (Mantodea, Nanomantidae)

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    The biology and distribution patterns of the Sahelian mantid species Nilomantis floweri are still insufficiently known. For the first time, records are confirmed of this species from Iran and the distribution map of its native range is updated. Records are compiled from the Sahel zone of North Africa, the Arabian Peninsula, and Iran. Detailed information on its biology, oothecal characteristics, male genitalia variation, and intraspecific molecular diversity in the mitochondrial gene cytochrome c oxidase are provided, and ecological niche modelling was used to gain insight into the overall species distribution and understand its climatic niche limits. Genetic analysis revealed only one haplotype shared between Iran and Oman. The Iranian populations likely represent two distinct clusters, both more related to the diverse Oman haplotypes than to each other. Based on new data, N. floweri appears to be mostly associated with coastal areas in southwestern Asia, with the vast majority of records found along the Red Sea, Persian Gulf, and Oman Gulf coasts. This distribution contrasts markedly with N. floweri records in the Sahel, where most collections have been reported in the transitional zone between the southern Sahara and arid thorn savannah, far off the coast. This study contributes to a comprehensive understanding of this still enigmatic mantid species

    Flavonoids as Modulators of Synaptic Plasticity: Implications for the Development of Novel Therapeutic Strategies for Healthy Lifestyle

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    Flavonoids are potential group of phytochemicals found in normal diets capable of mediating improvements in cognition and may reverse age-related declines in memory. Aging is associated with alteration of hippocampal synaptic plasticity and contribute to decline in cognitive functions. The current studies are directed at a greater understanding of how and why the brain modifies synaptic strength with dietary-derived phytochemicals (flavonoids) and age-related declines in cognitive functions (such as learning and memory). Flavonoids modulate neuronal function and thereby influence cognition. In addition, it has been suggested that flavonoids may delay the development of Alzheimer’s disease-like pathology, anxiety, and depression disorders, suggesting a novel therapeutic strategy. Emerging evidence suggest that flavonoids are modulators of signaling pathways critical for controlling synaptic plasticity in the brain. For example, phosphatidylinositol-3 kinase (PI3K)/Akt, mitogen-activated protein kinase, protein kinase C, pathways could be involved Ca2+ signaling. Significants questions such as: (i) How does flavonoids affect plasticity? (ii) What receptors are modulating by flavonoids and how are they regulated? (iii) Do flavonoids have a neuroprotective effect in aging? are asked

    Espécies de Cerambycidae (Insecta, Coleoptera) Ocorrentes no Estado do Rio de Janeiro (Brasil)

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    A list of the Cerambycidae species from Rio de Janeiro State is presented. The inventory was realized based on the bibliography and the Cerambycidae collection of the Museu Nacional, Rio de Janeiro. 1149 species are registered, distributed in five subfamilies. One map with the distribution of the Callichromatini species registered to the State is provided.É apresentada uma lista das espécies de Cerambycidae que ocorrem no Estado do Rio de Janeiro. O inventário foi realizado através da bibliografia e da coleção de Cerambycidae do Museu Nacional. São registradas 1149 espécies distribuĂ­das em cinco subfamílias. Um mapa com a distribuição das espécies de Callichromatini registradas para o Estado é fornecido

    ENMTools 1.0: an R package for comparative ecological biogeography

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    The ENMTools software package was introduced in 2008 as a platform for making measurements on environmental niche models (ENMs, frequently referred to as species distribution models or SDMs), and for using those measurements in the context of newly developed Monte Carlo tests to evaluate hypotheses regarding niche evolution. Additional functionality was later added for model selection and simulation from ENMs, and the software package has been quite widely used. ENMTools was initially implemented as a Perl script, which was also compiled into an executable file for various platforms. However, the package had a number of significant limitations; it was only designed to fit models using Maxent, it relied on a specific Perl distribution to function, and its internal structure made it difficult to maintain and expand. Subsequently, the R programming language became the platform of choice for most ENM studies, making ENMTools less usable for many practitioners. Here we introduce a new R version of ENMTools that implements much of the functionality of its predecessor as well as numerous additions that simplify the construction, comparison and evaluation of niche models. These additions include new metrics for model fit, methods of measuring ENM overlap, and methods for testing evolutionary hypotheses. The new version of ENMTools is also designed to work within the expanding universe of R tools for ecological biogeography, and as such includes greatly simplified interfaces for analyses from several other R packages
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