80 resultados para GRASSHOPPER KOSCIUSCOLA-TRISTIS


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These data sets report the fossil beetle assemblages identified from the Mesolithic to Late Bronze Age at eight sites in the London region. All but one of the study sites are within 2 km of the modern course of the Thames. The sites produced 128 faunal assemblages that yielded 218 identified species in 41 families of Coleoptera (beetles).  Beetle faunas of Mesolithic age indicate extensive wetlands near the Thames, bordered by rich deciduous woodlands. The proportion of woodland species declined in the Neolithic, apparently because of the expansion of wetlands, rather than because of human activities. The Early Bronze Age faunas contained a greater proportion of coniferous woodland and aquatic (standing water) species. An increase in the dung beetle fauna indicates the presence of sheep, cattle and horses, and various beetles associated with crop lands demonstrate the local rise of agriculture, albeit several centuries after the beginnings of farming in other regions of Britain. Late Bronze Age faunas show the continued development of agriculture and animal husbandry along the lower Thames. About 33% of the total identified beetle fauna from the London area sites have limited modern distributions or are extinct in the U.K. Some of these species are associated with the dead wood found in primeval forests; others are wetland species whose habitat has been severely reduced in recent centuries. The third group is stream-dwelling beetles that require clean, clear waters and river bottoms.

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Changes in land use and land cover throughout the eastern half of North America have caused substantial declines in populations of birds that rely on grassland and shrubland vegetation types, including socially and economically important game birds such as the Northern Bobwhite (Colinus virginianus; hereafter bobwhites). As much attention is focused on habitat management and restoration for bobwhites, they may act as an umbrella species for other bird species with similar habitat requirements. We quantified the relationship of bobwhites to the overall bird community and evaluated the potential for bobwhites to act as an umbrella species for grassland and shrubland birds. We monitored bobwhite presence and bird community composition within 31 sample units on selected private lands in the south-central United States from 2009 to 2011. Bobwhites were strongly associated with other grassland and shrubland birds and were a significant positive predictor for 9 species. Seven of these, including Bell's Vireo (Vireo bellii), Dicksissel (Spiza americana), and Grasshopper Sparrow (Ammodramus savannarum), are listed as species of conservation concern. Species richness and occupancy probability of grassland and shrubland birds were higher relative to the overall bird community in sample units occupied by bobwhites. Our results show that bobwhites can act as an umbrella species for grassland and shrubland birds, although the specific species in any given situation will depend on region and management objectives. These results suggest that efficiency in conservation funding can be increased by using public interest in popular game species to leverage resources to meet multiple conservation objectives.

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Predators of herbivorous animals can affect plant populations by altering herbivore density, behavior, or both. To test whether the indirect effect of predators on plants arises from density or behavioral responses in a herbivore population, we experimentally examined the dynamics of terrestrial food chains comprised of old field plants, leaf-chewing grasshoppers, and spider predators in Northeast Connecticut. To separate the effects of predators on herbivore density from the effects on herbivore behavior, we created two classes of spiders: (i) risk spiders that had their feeding mouth parts glued to render them incapable of killing prey and (ii) predator spiders that remained unmanipulated. We found that the effect of predators on plants resulted from predator-induced changes in herbivore behavior (shifts in activity time and diet selection) rather than from predator-induced changes in grasshopper density. Neither predator nor risk spiders had a significant effect on grasshopper density relative to a control. This demonstrates that the behavioral response of prey to predators can have a strong impact on the dynamics of terrestrial food chains. The results make a compelling case to examine behavioral as well as density effects in theoretical and empirical research on food chain dynamics.

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In North America there are two generally recognized pathotypes (pathotypes 1 and 2) of the fungus Entomophaga grylli which show host-preferential infection of grasshopper subfamilies. Pathotype 3, discovered in Australia, has a broader grasshopper host range and was considered to be a good biocontrol agent. Between 1989 and 1991 pathotype 3 was introduced at two field sites in North Dakota. Since resting spores are morphologically indistinguishable among pathotypes, we used pathotype-specific DNA probes to confirm pathotype identification in E. grylli-infected grasshoppers collected at the release sites in 1992, 1993, and 1994. In 1992, up to 23% of E. grylli-infected grasshoppers of the subfamilies Melanoplinae, Oedipodinae, and Gomphocerinae were infected by pathotype 3, with no infections > 1 km from the release sites. In 1993, pathotype 3 infections declined to 1.7%. In 1994 grasshopper populations were low and no pathotype 3 infections were found. The frequency of pathotype 3 infection has declined to levels where its long-term survival in North America is questionable. Analyses of biocontrol releases are critical to evaluating the environmental risks associated with these ecological manipulations, and molecular probes are powerful tools for monitoring biocontrol releases.

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El desarrollo de la Floricultura en Córdoba puede constituirse como una actividad productiva sustentable que contribuya a la generación de empleo y cubra la demanda de un mercado local actualmente satisfecho por producciones distantes de nuestra Provincia, especialmente Buenos Aires, Rosario y Mendoza. Como asi también por importaciones provenientes de Ecuador, Colombia y Brasil, en periodos de alta demanda y baja producción en el pais. Una limitante para el inicio de esta actividad productiva la constituye la falta de estudios con rigor científico que permitan la correcta elección de especies y variedades con altos rendimientos en nuestras condiciones ambientales. En tal sentido la Cátedra de Floricultura de la Universidad Nacional de Córdoba, desde hace 15 años aborda la tematica, abarcando los aspectos tecnológicos, de manejo y comercilalizacion de numerosas especies florales para corte entre ellas: Clavel. Rosa, Crisantemo, Lisianthus, Gipsofila, Fresia, Tulipán, Girasol, Alstromelia, Antirrhinum, Gladiolus tristis entre otras. Esta constante investigación ha sido presentada en congresos de la especialidad y publicados en los correspondientes ámbitos científicos. Sin embargo al momento no existe un documento en soporte papel que la concentre de manera didáctica para el lenguaje del productor y los receptores interesados en esta informacion. El acercamiento de toda esta experiencia al sector productivo y/potencial productor, es una responsabilidad de los científicos que trabajamos incesantemente para resolver problematicas concretas del sector. Entre los grupos contactados interesados en recibir la información, figuran productores independientes, ya que no hay una organización que los agrupe, una escuela que tiene orientación en Ciencias Naturales, Una comercializadora de flores, la carrera de Licenciatura en Administracion Agragria de la Universidad Siglo XXI y la Tecnicatura en Floricultura y Jardinería de la FCA-UNC de reciente inauguración. La divulgación escrita con imágenes y resultados de pruebas de variedades, será una herramienta de mucha utilidad para el productor actual que lo ayudara en elección de variedades que fueron probadas y que funcionan en las condiciones agroecológicas de Córdoba

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An industrial manipulator equipped with an automatic clay extruder is used to realize a machine that can manufacture additively clay objects. The desired geometries are designed by means of a 3D modeling software and then sliced in a sequence of layers with the same thickness of the extruded clay section. The profiles of each layer are transformed in trajectories for the extruder and therefore for the end-effector of the manipulator. The goal of this thesis is to improve the algorithm for the inverse kinematic resolution and the integration of the routine within the development software that controls the machine (Rhino/Grasshopper). The kinematic model is described by homogeneous transformations, adopting the Denavit-Hartenberg standard convention. The function is implemented in C# and it has been preliminarily tested in Matlab. The outcome of this work is a substantial reduction of the computation time relative to the execution of the algorithm, which is halved.

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The apotheosis of the Reverend Mr. Spangler.--The note.--The grasshopper and the ant.--Amelia.--"An exceeding high mountain."--At the stuffed-animal house.

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Introduces Illinois insects including the house fly, mosquito, grasshopper, dragonfly, praying mantis, monarch butterfly, firefly, honey bee, water strider, and ladybug.

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Introduces Illinois insects including the house fly, mosquito, grasshopper, dragonfly, praying mantis, monarch butterfly, firefly, honey bee, water strider, and ladybug.

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The Australian and zone harbours a surprising number of parthenogenetic organisms. including the well known case of the grasshopper Warramaba virgo. Less well known is the case of the stick insects of the Sipyloidea complex, which. despite its presence in the literature for over 15 years. has gone entirely unnoticed by workers in the field. We draw attention to the remarkable similarities between the evolution of parthenogenesis in Warramaba and Sipyloidea and analyse the geographic distributions of parthenogenetic and sexual forms with respect to six Climatic variables. We provide evidence that a combination of Climatic and vegetative barriers are responsible for the current distribution patterns in these taxa. Comparisons are also made with patterns of geographic parthenogenesis in lizards of the Heteronotia binoei complex. In general. there has been a strong tendency for parthenogenesis to originate via hybridization in the western part of the and zone with subsequent eastward spread throughout mulga woodlands and mallee shrublands where rainfall is both low and aseasonal. We propose that the hybridization events leading to parthenogenesis in these diverse taxa were driven by a common biogeographic process - that is, by range shifts associated with changes in aridity during the late Pleistocene.