2,936 research outputs found

    The response of neotropical dragonflies (Insecta: Odonata) to local and regional abiotic factors in small streams of the Amazon

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    Since the relative role of local and regional abiotic factors on the Odonata diversity in rainforest streams is still poorly understood, we evaluated the effects of these factors on adult Odonata (Insecta) from preserved and altered streams in the Amazonian region. Adult Odonata were sampled in 98 streams in the Eastern Amazon, Pará, Brazil. Six variables were used to measure local environmental factors: habitat integrity index; mean canopy over the channel; and four physical and chemical descriptors of the water. To measure regional environmental factors, six variables were also used: altitude gradient, three bioclimatic variables and two percentage forest variables. In partial redundancy analysis, both abiotic factors (local and regional) were important to explain the variation in the Odonata community. The Odonata community can be influenced by regional and local factors. The relationship between Odonata and the local (e.g., integrity, canopy cover, and physical and chemical descriptors of the water) and regional (e.g., bioclimatic and forest cover variables) environmental variables recorded in this study has important implications for the use of these organisms to monitor small streams of the Eastern Amazon. The scale at which habitat is measured is an important issue in community structuring studies considering the rapid environmental changes. It is of great importance to consider the different scales in studies assessing community structure, once an adequate habitat must meet the ecological needs of all stages of the life of the Odonata.Funding Agency National Council for Scientific and Technological Development (CNPq) CNPq Amazonian Biodiversity and Land Use project CNPq 574008/2008-0 Brazilian Agricultural Research Company-EMBRAPA SEG: 02.08.06.005.00 Darwin Initiative, United Kingdom 17-023 Nature Conservancy and Natural Environment Research Council (NERC) NE/F01614X/1 NE/G000816/1 National Council for Scientific and Technological Development (CNPq) 307597/2016-4 Portuguese Foundation for Science and Technology UID/Multi/04326/2019 PROPESP/UFPA through Edital 01/2018 (Programa de Apoio a Publicacao Qualificada-PAPQ)info:eu-repo/semantics/publishedVersio

    Higher gregarine parasitism often in sibling species of host damselflies with smaller geographical distributions

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    1. This study investigated inter-specific variation in parasitism by gregarines (Eugregarinorida: Actinocephalidae), among sibling species of damselflies (Odonata: Zygoptera), in relation to relative size of geographical ranges of host species. 2. Gregarines are considered generalist parasites, particularly for taxonomically related host species collected at the same sites or area. Prevalence and median intensity of gregarine parasitism was obtained for 1338 adult damselflies, representing 14 species (7 sibling species pairs) across 3 families within the suborder Zygoptera. Damselflies were collected at three local sites in Southeastern Ontario, during the same periods over the season. 3. Five out of seven species pairs had significant differences in parasitism between sibling species. The less widespread host species was the more parasitised for three species pairs with significant differences in gregarine prevalence, and for two species pairs with differences in median intensity. The more widespread host had a higher intensity of infection as expected, in two species pairs. 4. Future studies on ecological determinants of parasitism among related species should examine robust measures of abundance of species and representation of species regionally

    The impacts of environmental warming on Odonata: a review

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    Climate change brings with it unprecedented rates of increase in environmental temperature, which will have major consequences for the earth's flora and fauna. The Odonata represent a taxon that has many strong links to this abiotic factor due to its tropical evolutionary history and adaptations to temperate climates. Temperature is known to affect odonate physiology including life-history traits such as developmental rate, phenology and seasonal regulation as well as immune function and the production of pigment for thermoregulation. A range of behaviours are likely to be affected which will, in turn, influence other parts of the aquatic ecosystem, primarily through trophic interactions. Temperature may influence changes in geographical distributions, through a shifting of species' fundamental niches, changes in the distribution of suitable habitat and variation in the dispersal ability of species. Finally, such a rapid change in the environment results in a strong selective pressure towards adaptation to cope and the inevitable loss of some populations and, potentially, species. Where data are lacking for odonates, studies on other invertebrate groups will be considered. Finally, directions for research are suggested, particularly laboratory studies that investigate underlying causes of climate-driven macroecological patterns

    Previously unpublished Odonata records from Sarawak, Borneo : part 1, Kuching Division excluding Kubah National Park, and Samarahan Division

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    Records of Odonata from Kuching and Samarahan, the western administrative divisions of Sarawak in Malaysian Borneo, are presented. Forty-two species are listed from Bako National Park, and eighty-nine species are listed from various other locations. Notable records, not yet publishedin detail elsewhere, include Aciagrion ?fasiculare, Bornargiolestes species, Pericnemis species cf triangularis, Coeliccia new species and Tetrathemis flavescens

    Flight of the dragonflies and damselflies

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    This work is a synthesis of our current understanding of the mechanics, aerodynamics and visually mediated control of dragonfly and damselfly flight, with the addition of new experimental and computational data in several key areas. These are: the diversity of dragonfly wing morphologies, the aerodynamics of gliding flight, force generation in flapping flight, aerodynamic efficiency, comparative flight performance and pursuit strategies during predatory and territorial flights. New data are set in context by brief reviews covering anatomy at several scales, insect aerodynamics, neuromechanics and behaviour. We achieve a new perspective by means of a diverse range of techniques, including laser-line mapping of wing topographies, computational fluid dynamics simulations of finely detailed wing geometries, quantitative imaging using particle image velocimetry of on-wing and wake flow patterns, classical aerodynamic theory, photography in the field, infrared motion capture and multi-camera optical tracking of free flight trajectories in laboratory environments. Our comprehensive approach enables a novel synthesis of datasets and subfields that integrates many aspects of flight from the neurobiology of the compound eye, through the aeromechanical interface with the surrounding fluid, to flight performance under cruising and higher-energy behavioural modes

    Acanthagrion marinae sp. Nov. (zygoptera: Coenagrionidae): A new species of the apicale group

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    Acanthagrion marinae sp. nov. (Holotype male: BRASIL, Mato Grosso do Sul, Campo Grande, UFMS, 20°29’56.26’’S-54°36’48.43’’W, 547m, leg. M.E. Rodrigues, 03.ii.2015, collection code: VZYG437, MLP) is described and illustrated on the basis of 15 males. The new species belongs to the apicale species group by having horns on S10 and sclerotized hooks on tip of distal segment of the genital ligula. It can be easily distinguished from other species of the group by a combination of characters of the genital ligulae (presence of setae on segment two; absence of setae at flexure; distal lateral lobes of segment three absent). Notes on habitat and a modification of previous keys for the species of the apicale group are provided.Fil: Lozano, Federico. Universidad Nacional de Avellaneda. Departamento de Ciencias Ambientales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodrigues, Marciel E. Universidade Estadual de Santa Cruz; Brasi

    Description of the final instar larva of argia serva hagein selys, 1865 (Odonata coenagrionidae)

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    The American genus Argia, with more than 100 species described, is the most speciose genus of Odonata in the world. In this contribution, the final stadium larva of Argia serva, the southernmost distributed species of Argia, is described and diagnosed based on reared material from MartĂ­n GarcĂ­a island, Buenos Aires, Argentina. The larva of this species can be easily separated from the other Argentinean Argia by the following combination of characters: sternum of S8 covered with spines (bare in A. translata); antennal segment 3 longer than 1+2 (equal to or shorter than 1+2 in A. joergenseni and A. jujuya); palpal setae absent (present in A. croceipennis). A key to the known larvae of Argia of the Southern Cone is provided.Fil: del Palacio, Alejandro. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad Nacional de Avellaneda. Departamento de Ciencias Ambientales; ArgentinaFil: Lozano, Federico. Universidad Nacional de Avellaneda. Departamento de Ciencias Ambientales; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: MuzĂłn, Javier. Universidad Nacional de Avellaneda. Departamento de Ciencias Ambientales; Argentin

    Previously unpublished Odonata records from Sarawak, Borneo : part 2, Kubah National Park

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    Records of Odonata from Kubah National Park, near Kuching in west Sarawak, are presented. Eighty-five species are known from the national park. Notable records include Drepanosticta drusilla, Rhinocypha species cf spinifer, Bornagriolestes species, Anaciaeschna species and Macromidia genialis erratica

    Primer Frenguelliidae (Insecta: Odonata) del Eoceno de RĂ­o PichileufĂş, Patagonia, Argentina

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    Se describe un nuevo género, Treintamilun gen. nov., basado en Treintamilun vuelvenlucha sp. nov. de la localidad de Río Pichileufú (Luteciano), Provincia de Río Negro, Patagonia, Argentina. El nuevo género se asigna a Frenguelliidae. El hallazgo de un segundo género y tercera especie de Frenguelliidae es digno de mención, contribuyendo a un mejor conocimiento de esta pequeña familia y confirma su presencia en el Eoceno de la Patagonia. Mientras las especies previamente registradas de Frenguelliidae son del Ypresiano (52 Ma) de Laguna del Hunco, la nueva especie viene de la localidad vecina a 160 Km y con una edad de 48 Ma. Los Frenguelliidae comparten un surco nodal reducido, una ScP llegando al margen alar muy oblicua al nodus, una Cr nodal subvertical y un nodus vertical, y uno de los caracteres aparentes del plan básico de los Epiproctophora, una CuP curvada. Palabras clave: Odonata, Frenguelliidae, Treintamilun vuelvenlucha gen. nov. et sp. nov., Luteciano, Patagonia, Argentina.A new genus, Treintamilun gen. nov., based on Treintamilun vuelvenlucha sp. nov. is described from Río Pichileufú (Lutetian), Río Negro province, Patagonia, Argentina. The new genus is assigned to Frenguelliidae. The finding of a second genus and third species of Frenguelliidae is noteworthy, contributing to the better knowledge of this little known family and bear out its presence in the Eocene of Patagonia. While the previous species of Frenguelliidae were recorded from the Ypresian (52 Ma) of Laguna del Hunco, the new one comes from the neighbour locality 160 Km far and 48 Ma old. The Frenguelliidae share a nodal furrow reduced, a ScP reaching costal margin very obliquely at nodus, a nodal Cr sub-vertical and subnodus vertical, and one of the groundplan apparent characters of the Epiproctophora, a curved CuP.Fil: Petrulevicius, Julian Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentin
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