202 research outputs found

    Tapinoma nigerrimum as safeguard for Italian myrmecofauna against Argentine ant

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    Asthma is the most common chronic disease in pediatrics.Most data on the prevalence of childhood allergic diseasescome from the International Study of Asthma and Allergiesin Childhood (ISAAC) phase II held in 1995 and phase III from2002. ISAAC created a methodology for studying two agegroups 6---7 and 13---14 years old.1In 2002, according to thedata gathered in the phase III of ISAAC, the prevalence ofasthma among Portuguese children from 6 to 7 years old was9.4%, 29.1% for rhinitis and 28.1% for wheezing.2In the last decade, little information on the prevalenceof childhood asthma and rhinitis in Portugal has been docu-mented, and to the best of our knowledge, none in Coimbra.In 2002, 5 centers from 5 Portuguese cities joined the ISAACproject: Lisbon, Oporto, Coimbra, PortimĂŁo and Funchal.The Coimbra research center only studied 13---14 years oldadolescents.2The district of Coimbra, with a total area of 3974 km2,is located in central Portugal and has 434,311 inhabitants.Coimbra is the biggest city in the central region, and the 6thlargest in Portugal

    Nectar in plant-insect mutualistic relationships: from food reward to partner manipulation

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    It has been known for centuries that floral and extrafloral nectar secreted by plants attracts and rewards animals. Extrafloral nectar is involved in so-called indirect defence by attracting animals (generally ants) that prey on herbivores, or by discouraging herbivores from feeding on the plant. Floral nectar is presented inside the flower close to the reproductive organs and rewards animals that perform pollination while visiting the flower. In both cases nectar is a source of carbon and nitrogen compounds that feed animals, the most abundant solutes being sugars and amino acids. Plant-animal relationships involving the two types of nectar have therefore been used for a long time as text-book examples of symmetric mutualism: services provided by animals to plants in exchange for food provided by plants to animals. Cheating (or deception or exploitation), namely obtaining the reward/service without returning any counterpart, is however well known in mutualistic relationships, since the interacting partners have conflicting interests and selection may favour cheating strategies. A more subtle way of exploiting mutualism was recently highlighted. It implies the evolution of strategies to maximize the benefits obtained by one partner while still providing the reward/service to the other partner. Several substances other than sugars and amino acids have been found in nectar and some affect the foraging behaviour of insects and potentially increase the benefits to the plant. Such substances can be considered plant cues to exploit mutualism. Recent evidence motivated some authors to use the term “manipulation” of animals by plants in nectar-mediated mutualistic relationships. This review highlights the recent background of the “manipulation” hypothesis, discussing it in the framework of new ecological and evolutionary scenarios in plant-animal interactions, as a stimulus for future research

    Public Engagement Provides First Insights on Po Plain Ant Communities and Reveals the Ubiquity of the Cryptic Species Tetramorium immigrans (Hymenoptera, Formicidae)

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    Ants are considered a useful model for biodiversity monitoring and several of their characteristics make them promising for citizen science (CS) projects. Involving a wide range of public figures into collecting valuable data on the effect of human impact on ant biodiversity, the School of Ants (SoA) project represents one of the very few attempts to explore the potential of these insects in CS. Through the collaboration with the "BioBlitz Lombardia" project, we tested the SoA protocol on 12 Northern Italy parks, ranging from urban green to subalpine protected sites. As a result, we obtained some of the very first quantitative data characterizing the ants of this region, recording 30 species and highlighting some interesting ecological patterns. These data revealed the ubiquitous presence of the recently taxonomically defined cryptic species Tetramorium immigrans, which appears to be probably introduced in the region. We also discuss advantages and criticisms encountered applying the SoA protocol, originally intended for schools, to new categories of volunteers, from BioBlitz participants to park operators, suggesting best practices based on our experience

    Ergatandromorphism in the Ant Myrmica lobulicornis Nylander, 1857 (Formicidae: Myrmicinae)

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    Ergatandromorphism is the result of an aberrant development in which part of the body of a social insect shows the traits of the worker caste, while the other resembles a male. It is considered a specific case of gynandromorphism. Specimens with these characteristics have rarely been collected in different ant lineages across the world. Here, we provide the first description of ergatandromorphism in the ant Myrmica lobulicornis Nylander, 1857: an ergatandromorphous specimen was recovered during an arthropod sampling campaign across altitudinal and ecological gradients on the Italian Alps (Stelvio National Park), together with 480 workers and 4 queens of the same species, which expressed the normal phenotype

    A new exception to the dominance-discovery trade-off rule in ant communities

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    Interspecific competition is one of the main factor shaping ant community structure. The “dominance-discovery trade-off’’, an inverse relationship between interference and exploitative competitive ability, is thought to be a fundamental mechanism facilitating coexistence of ants. Despite its widely acceptance in literature, this trade-off appears to be broken in several cases and needs further investigations. Thus, the aim of the present study was to detect the presence/absence of the dominance-discovery trade-off in Mediterranean ant communities. Samplings were conducted inside the Presidential Estate of Castelporziano (Rome, Italy) and seven sampling sites were selected according to their vegetation structure. In each site, baiting was conducted to assess two behavioural indices for each species: the monopolization index and the discovery ability index. Correlation analyses showed no evidence for the existence of a dominance-discovery trade-off. Furthermore, a positive correlation between the two indices was detected in some of the sampling sites. The dominance-discovery trade-off seems therefore to be just one of the possible mechanisms facilitating species coexistence in ant communities

    On the Cosmic-Ray Spectra of Three-Body Lepton-Flavor-Violating Dark Matter Decays

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    We consider possible leptonic three-body decays of spin-1/2, charge-asymmetric dark matter. Assuming a general Dirac structure for the four-fermion contact interactions of interest, we study the cosmic-ray electron and positron spectra and show that good fits to the current data can be obtained for both charged-lepton-flavor-conserving and flavor-violating decay channels. We find that different choices for the Dirac structure of the underlying decay operator can be significantly compensated by different choices for the dark matter mass and lifetime. The decay modes we consider provide differing predictions for the cosmic-ray positron fraction at energies higher than those currently probed at the PAMELA experiment; these predictions might be tested at cosmic-ray detectors like AMS-02.Comment: 14 pages LaTeX, 3 figures (8 eps files). v2 and v3: clarifications and references adde
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