995 resultados para BEES APIS-MELLIFERA


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La Loque Americana es la enfermedad de origen bacteriano más grave de la etapa larval de la abeja (Apis melífera). Desde su detección en el país en 1989 ya se ha establecido en 11 provincias incluida Córdoba. Su agente causal es Paenibacillus larvae White y su efecto final, la muerte de todo cría en su estadio de propupa. Es muy contagiosa, puede eliminar a toda la colmena y una vez establecida en una región difícilmente pueda ser erradicada por tratarse de una bacteria formadora de esporas que se diseminan: a través de determinados comportamientos de las abejas, con el polen o la miel y por la actividad del apicultor. Siendo Córdoba una provincia con posibilidades para incrementar esta actividad productiva donde ya la enfermedad está establecida, debe tenerse en cuenta que el manejo intensivo de las colmenas es factor desencadenante de diseminación. Se requiere, por lo tanto, contar con técnicas de control de probada efectividad, factibles de ser utilizadas por los productores en sus apiarios. Una manera de disminuir el grado de difusión es mantener lo más bajo posible los niveles de infección. (...) En Argentina, hasta el presente ninguna técnica por sí sola ha resultado eficaz. Este trabajo tiene como hipótesis demostrar que el enjambrado artificial, con la aplicación de un antibiótico durante el desarrollo inmediato posterior al trasvase de las colonias, puede resultar un método efectivo para el control de la enfermedad y la recuperación de los apiarios afectados de Loque Americana. El Objetivo del proyecto es determinar la eficiencia del Cepillado como método alternativo factible de ser usado para controlar la enfermedad y recuperar las colonias infectadas.

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Although the ASP model has been around for over a decade, it has not achieved the expected high level of market uptake. This research project examines the past and present state of ASP adoption and identifies security as a primary factor influencing the uptake of the model. The early chapters of this document examine the ASP model and ASP security in particular. Specifically, the literature and technology review chapter analyses ASP literature, security technologies and best practices with respect to system security in general. Based on this investigation, a prototype to illustrate the range and types of technologies that encompass a security framework was developed and is described in detail. The latter chapters of this document evaluate the practical implementation of system security in an ASP environment. Finally, this document outlines the research outputs, including the conclusions drawn and recommendations with respect to system security in an ASP environment. The primary research output is the recommendation that by following best practices with respect to security, an ASP application can provide the same level of security one would expect from any other n-tier client-server application. In addition, a security evaluation matrix, which could be used to evaluate not only the security of ASP applications but the security of any n-tier application, was developed by the author. This thesis shows that perceptions with regard to fears of inadequate security of ASP solutions and solution data are misguided. Finally, based on the research conducted, the author recommends that ASP solutions should be developed and deployed on tried, tested and trusted infrastructure. Existing Application Programming Interfaces (APIs) should be used where possible and security best practices should be adhered to where feasible.

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The yellow passion Passiflora edulis f. flavicarpa Deg. is allogamous, self incompatible, and it depends of insects pollinators to disseminate the pollen grains. The field work was conducted at Campos dos Goytacazes, Rio de Janeiro, Brazil, from October 17 to November 9 and December 12 to 21, 1995. It was analyzed 1565 flower buds, from which 423 showed well developed ovaries, five days after opening, this represents 27% of fruit set by natural pollination. It was observed 76,86 % of completely curved flowers, 21,22 % of partially curved flowers, and 1,92 % flowers without curvature. Five species of bees where observed on the flowers, from which two were the effective pollinator of yellow passion flower: Xylocopa (Megaxylocopa) frontalis (Olivier, 1789) and X. (Neoxylocopa) ordinaria Smith, 1874.

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The study was carried out in a 8.2 ha area in an environmental protection area of tropical sea coastal sand dune with "restinga" vegetation in Salvador, Bahia, northeastern Brazil. A total of 1760 bees of Xylocopa (Neoxylocopa) cearensis Ducke, 1910 were netted during the whole year on flowers of 43 plant species belonging to 26 botanic families. The majority of the individuals (79%) concentrated their foraging activity in five plant species. Individuals foraged all day long being the greatest activity between 8 h and 14 h. Similar proportions of young and old bees were sampled over the year. The density of substrates used for nesting was 4.56/ha. In total, 94% of the nests were found in branches of Agaristha revoluta (Spr.) DC. (Ericaceae). The great occurrence (68.7%) of old perforations indicates that the nests were used twice or more times by bees.

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Workers of Melipona quadrifasciata anthidioides (Lepeletier, 1836) develop their ovaries and lay eggs, therefore the production of vitellogenin is expected. In electrophoretic profiles only fat body extracts from nurse workers and ovary extracts from newly-emerged workers show protein with molecular mass similar to vitellogenin. However, an increase in the protein content was detected in forager fat body. This increase was attributed to storage of vitellogenin or other proteins in the previous phase and not discharged into the hemolymph or to an effect of the increased titre of juvenile hormone in this phase of worker life over the fat body functioning.

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Flight activity of foragers of four colonies of Plebeia remota (Holmberg, 1903) was registered from December 1998 to December 1999, using an automated system (photocells and PLC system). The colonies originated from two different regions: Cunha, state of São Paulo, and Prudentópolis, state of Paraná, Brazil. Flight activity was influenced by different climatic factors in each season. In the summer, the intensity of the correlations between flight activity and climatic factors was smaller than in the other seasons. During the autumn and winter, solar radiation was the factor that most influenced flight activity, while in the spring, this activity was influenced mainly by temperature. Except in the summer, the various climatic factors similarly influenced flight activity of all of the colonies. Flight activity was not affected by geographic origin of the colonies. Information concerning seasonal differences in flight activity of P. remota will be useful for prediction of geographic distribution scenarios under climatic changes.

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Con la deforestación, los incendios y la utilización indebida de los agrotóxicos, las abejas nativas de Brasil corren un serio peligro de extinción. Ello se debe a que estas abejas construyen sus nidos en los huecos de los troncos de los árboles y también a que sus fuentes de alimentación son cada vez más escasas. Por ello cada vez son más los que se dedican a la meliponicultura, de esta manera se conservan las abejas y además, se obtiene una renta extra. Mediante el presente proyecto se capacitó en meliponicultura a una muestra de la población de Poço Redondo, para que de esta manera se empiece a recuperar su entorno y también su situación económica actual. Para poder conseguirlo se llevó a cabo el diseño del curso mediante la documentación previa, el trabajo de campo y el análisis de los datos. El resultado fue la capacitación, con la que se formó y concienció ambientalmente a personas para que se dedicaran a la meliponicultura de manera profesional.

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The evolution of eusociality is one of the major evolutionary transitions of life on earth. For investigating the conditions and processes that are central to the origin of such integrated social organization, it is best to study organisms in which individuals have retained some flexibility in their reproductive strategies. Halictid bees are especially well suited as model organisms, because they show huge variation in social systems, both within and between species. In this thesis, I investigated female reproductive strategies in the primitively eusocial bee Halictus scabiosae, with a focus on the role of helpers, in order to get insight into the mechanisms governing the evolution and maintenance of eusociality. This species produces two broods per year. The females from the first brood can stay in the natal nest to help raise a second brood of males and gynes that become the next-generation foundresses in spring. We first compared the morphology of females from the two broods, as well as the nutrition they receive as larvae. Then we conducted a helper- removal experiment in the field to quantify the effects of the presence of helpers on colony survival and productivity. Finally, we reconstructed pedigree relationships of individuals using microsatellite markers in order to detect who reproduces in the nest and how much individuals drift between nests. We found that first brood females had a uniformly small size and low fat reserves, which may be caused by the restricted pollen and nectar provisions on which they develop. Colony survival and productivity was increased by the presence of a single helper, but the effect was small and mostly limited to small colonies. By inferring parentage within and across colonies, we could determine that females from the first brood rarely reproduce in their natal nests. However, foundresses are frequently replaced, and foundresses and females from the first brood occasionally move to and reproduce in foreign colonies. As a result, colonies often contain offspring from unrelated individuals, and the relatedness of females to the brood they rear is low. Overall, this thesis shows that the reproductive system of H. scabiosae is highly flexible. The production of helpers in the first brood is important for colony success and productivity, but there is a high colony failure rate and part of the first brood females drift and reproduce in foreign nests. Both foundresses and helpers appear to be constrained by harsh environmental conditions or social factors limiting reproduction and independent colony founding. - L'origine des insectes sociaux est un domaine fascinant pour la recherche. Pour comprendre les mécanismes et les conditions qui sont nécessaires pour l'évolution et le maintien de la vie en société, il est judicieux d'étudier des sociétés primitives d'insectes, où toutes les femelles ont conservé la capacité de se reproduire, même si leur rôle comportemental dans la colonie est d'aider sans se reproduire. Une des familles d'abeilles, les halictes, est idéale pour cette sorte de recherche, en raison de la grande variabilité dans leur comportement social. Dans cette thèse, j'ai étudié les stratégies reproductives des femelles de Halictus scabiosae pour mieux comprendre les mécanismes qui influencent l'évolution de la vie en société. Cette espèce produit deux cohortes de couvain par année. Les femelles du premier couvain restent souvent dans leur nid natal pour aider à élever le deuxième couvain, tandis que les femelles du deuxième couvain s'accouplent et hibernent pour devenir les nouvelles fondatrices au printemps suivant. Nous avons d'abord comparé la morphologie des femelles issues des deux couvains ainsi que leur nutrition au stade de larve. Puis, dans une expérience sur le terrain, nous avons quantifié l'apport d'une ouvrière pour la survie et la productivité de la colonie. Finalement, nous avons reconstruit des pedigrees en utilisant des marqueurs génétiques, pour savoir qui se reproduit dans la colonie et combien d'individus migrent entre colonies. Les résultats montrent que les femelles du premier couvain sont uniformément plus petites et plus maigres, ce qui indique que les fondatrices réduisent les provisions de nourriture pour leur premier couvain afin de les inciter à aider dans le nid au lieu de se reproduire indépendamment. Dans l'expérience sur le terrain, la survie et la productivité de la colonie augmentaient avec la présence d'une ouvrière additionnelle, mais l'effet était petit et limité aux petites colonies. Par la reconstruction de pedigrees, nous pouvions constater que les femelles du premier couvain pondent rarement dans leurs nids natals. Les fondatrices cependant sont souvent remplacées en cours de saison, et migrent fréquemment entre nids, tandis que les femelles du premier couvain pondent parfois des oeufs dans des nids étrangers. De ce fait, les colonies contiennent souvent des descendants d'individus étrangers, et la parenté génétique entre les femelles et le deuxième couvain est basse. Cette thèse démontre que le système reproductif de H. scabiosae est très flexible. La production d'ouvrières est importante pour la survie de la colonie et sa productivité, mais le taux d'échec est élevé et une partie des femelles du premier couvain migrent et pondent dans une colonie étrangère. Autant les fondatrices que les ouvrières semblent être contraintes par des conditions environnementales ou sociales qui limitent la reproduction et les nouvelles fondations de colonie. - Die Entstehung von sozialen Lebensformen ist eines der wichtigsten Entwicklungen in der Geschichte des Lebens. Um die Bedingungen oder Prozesse zu verstehen, welche bei der Entstehung und dem Erhalt von sozialen Merkmalen wichtig sind, sollte man Lebewesen untersuchen, welche je nach Umwelteinflüßen ihr soziales Verhalten flexibel ändern können. Furchenbienen (Halictidae) gehören dazu. Diese weisen nämlich ein breites Spektrum verschiedener sozialer Organisationsformen auf, oftmals sogar innerhalb der einzelnen Arten. In meiner Doktorarbeit befasste ich mich mit den Fortpflanzungsstrategien der Weibchen der Skabiosen-Furchenbiene Halictus scabiosae. Diese Art produziert zwei Brüten pro Jahr. Die Weibchen der ersten Brut bleiben dabei meist als Arbeiterinnen in ihrem Geburtsnest, wohingegen die Weibchen der zweiten Brut nach der Paarung überwintern, um im nächsten Frühling neue Kolonien zu gründen. In einem ersten Schritt verglichen wir die beiden Brüten bezüglich der Grösse und der Fettreserven der Weibchen sowie der Pollen-Nektar-Vorräte für die Larven. Dann bestimmten wir in einem Feldexperiment, wieviel eine zusätzliche Arbeiterin zum Überleben und zur Produktiviät der Kolonie beiträgt. Schliesslich ermittelten wir durch genetische Tests die Verwandtschaftsbeziehungen zwischen den Bienen, um herauszufinden, wer in den Kolonien tatsächlich die Eier legt und ob und wieviel die Bienen zwischen verschiedenen Nestern wandern. Wir stellten fest, dass die Weibchen von der ersten Brut einheitlich kleiner sind und weniger Fettreserven besitzen. Das weist daraufhin, dass die Nestgründerin die erste Brut unterernährt, um die Wahrscheinlichkeit zu erhöhen, dass diese Weibchen als Arbeiterinnen im Nest bleiben anstatt sich unabhängig fortzupflanzen. Schon eine einzelne zusätzliche Arbeiterin verbesserte die Überlebenschancen und Produktivität der Kolonie, der Effekt war allerdings klein und auf kleine Kolonien beschränkt. Die Verwandtschaftsanalysen zeigten, dass die Arbeiterinnen nur sehr selten ein Ei in ihr Geburtsnest legen. Erstaunlicherweise wanderten die Nestgründerinnen oft zwischen verschiedenen Nestern. Einige Weibchen der ersten Brut wanderten auch in ein fremdes Nest und produzierten dort Nachkommen. Diese Doktorarbeit zeigt, dass die Fortpflanzungsstrategien der Skabiosen-Furchenbiene tatsächlich sehr flexibel sind. Die Anwesenheit von Arbeiterinnen ist wichtig für das Überleben und die Produktivität der Kolonie. Die Misserfolgsraten bleiben jedoch hoch, und ein Teil der Weibchen der ersten Brut pflanzt sich in fremden Nestern fort. Sowohl die Nestgründerinnen als auch die Weibchen der ersten Brut scheinen durch Umweltsbedingungen oder durch soziale Faktoren in der Wahl ihrer Fortpflanzungs¬strategie eingeschränkt zu sein.

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El principal objetivo de este proyecto es realizar un aplicativo web que utilice API’s para que, a partir de un conjunto de rutas almacenadas en el sistema, éste sea capaz de generar nuevas rutas a partir de éstas, de modo que dicho sistema no se comporte como un mero "almacén" de rutas introducidas por los usuarios para poder ser utilizadas por los demás posteriormente, sino que podamos ser nosotros mismos los que decidamos ciertos aspectos de la ruta que deseamos que el sistema nos proporcione. Así, el aplicativo desarrollado, partiendo de un conjunto previo de rutas, será capaz de generar nuevas rutas pasando lo más cerca posible de un conjunto de puntos definidos por el usuario, pudiendo ser calculadas siguiendo diferentes parámetros de optimización tales como el menor número de rutas utilizadas en el cálculo o el menor número de intersecciones entre ellas. Estas rutas, posteriormente, pueden visualizarse en la aplicación mediante el API de Google Maps, o pueden ser descargadas para utilizarlas en nuestro dispositivo GPS portátil.

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Eusociality is taxonomically rare, yet associated with great ecological success. Surprisingly, studies of environmental conditions favouring eusociality are often contradictory. Harsh conditions associated with increasing altitude and latitude seem to favour increased sociality in bumblebees and ants, but the reverse pattern is found in halictid bees and polistine wasps. Here, we compare the life histories and distributions of populations of 176 species of Hymenoptera from the Swiss Alps. We show that differences in altitudinal distributions and development times among social forms can explain these contrasting patterns: highly social taxa develop more quickly than intermediate social taxa, and are thus able to complete the reproductive cycle in shorter seasons at higher elevations. This dual impact of altitude and development time on sociality illustrates that ecological constraints can elicit dynamic shifts in behaviour, and helps explain the complex distribution of sociality across ecological gradients.

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In some ants, bees, and wasps, workers kill or "police" male eggs laid by other workers in order to maintain the reproductive primacy of the queen. Kin selection theory predicts that multiple mating by the queen is one factor that can selectively favor worker policing. This is because when the queen is mated to multiple males, workers are more closely related to the queen's sons than to the sons of other workers. Earlier work has suggested that reproductive patterns in the German wasp Vespula germanica may contradict this theory, because in some colonies a large fraction of the adult males were inferred to be the workers' sons, despite the effective queen mating frequency being greater than 2 (2.4). In the present study, we reexamine the V. germanica case and show that it does support the theory. First, genetic analysis confirms that the effective queen mating frequency is high, 2.9, resulting in workers being more related to the queen's sons than to other workers' sons. Second, behavioral assays show that worker-laid eggs are effectively killed by other workers, despite worker-laid eggs having the same intrinsic viability as queen-laid ones. Finally, we estimate that approximately 58.4% of the male eggs but only 0.44% of the adult males are worker derived in queenright colonies, consistent with worker reproduction being effectively policed.

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The study of sex allocation in social Hymenoptera (ants, bees, and wasps) provides an excellent opportunity for testing kin-selection theory and studying conflict resolution. A queen-worker conflict over sex allocation is expected because workers are more related to sisters than to brothers, whereas queens are equally related to daughters and sons. If workers fully control sex allocation, split sex ratio theory predicts that colonies with relatively high or low relatedness asymmetry (the relatedness of workers to females divided by the relatedness of workers to males) should specialize in females or males, respectively. We performed a meta-analysis to assess the magnitude of adaptive sex allocation biasing by workers and degree of support for split sex ratio theory in the social Hymenoptera. Overall, variation in relatedness asymmetry (due to mate number or queen replacement) and variation in queen number (which also affects relatedness asymmetry in some conditions) explained 20.9% and 5% of the variance in sex allocation among colonies, respectively. These results show that workers often bias colony sex allocation in their favor as predicted by split sex ratio theory, even if their control is incomplete and a large part of the variation among colonies has other causes. The explanatory power of split sex ratio theory was close to that of local mate competition and local resource competition in the few species of social Hymenoptera where these factors apply. Hence, three of the most successful theories explaining quantitative variation in sex allocation are based on kin selection.

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Ecologically and evolutionarily oriented research on learning has traditionally been carried out on vertebrates and bees. While less sophisticated than those animals, fruit flies (Drosophila) are capable of several forms of learning, and have an advantage of a short generation time, which makes them an ideal system for experimental evolution studies. This review summarizes the insights into evolutionary questions about learning gained in the last decade from evolutionary experiments on Drosophila. These experiments demonstrate that Drosophila have the genetic potential to evolve substantially improved learning performance in ecologically relevant learning tasks. In at least one set of selected populations the improved learning generalized to another task than that used to impose selection, involving a different behavior, different stimuli, and a different sensory channel for the aversive reinforcement. This improvement in learning ability was associated with reduction in other fitness-related traits, such as larval competitive ability and lifespan, pointing out to evolutionary trade-offs of improved learning. These trade-offs were confirmed by other evolutionary experiments where reduction in learning performance was observed as a correlated response to selection for tolerance to larval nutritional stress or for delayed aging. Such trade-offs could be one reason why fruit flies have not fully used up their evolutionary potential for learning ability. Finally, another evolutionary experiment with Drosophila provided the first direct evidence for the long-standing ideas that learning can under some circumstances accelerate and in other slow down genetically-based evolutionary change. These results demonstrate the usefulness of fruit flies as a model system to address evolutionary questions about learning.

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Projecte de recerca elaborat a partir d’una estada a l’Oriental Institute de la University of Oxford, Regne Unit, entre juliol i octubre de 2007. Durant l’estada s’ha analitzat la documentació demòtica datada del regnat d’Alexandre el Gran com a faraó d’Egipte (332-323 aC). El conjunt de fonts que examinat està constituït per sis papirs (actes notarials que recullen diversos tipus de contractes o acords entre dues parts), un òstrakon fragmentari i una sèrie d’esteles provinents de la Necròpolis d’Animals de Saqqara Nord, en concret de la Catacumba de les Mares d’Apis. Aquesta documentació és fonamental perquè permet extreure conclusions importants sobre diversos aspectes relacionats amb l’administració i la religiositat egípcies en els moments inicials de la dominació grega d'Egipte. Cadascun d’aquests documents ha estat traduït, analitzat en profunditat i degudament contextualitzat històricament. D’una banda, en l’àmbit de l’administració, he pogut constatar la continuïtat existent amb el període històric immediatament anterior, és a dir, amb la Segona Dominació Persa del país; mentre que de l'altra, des del punt de vista religiós, l’anàlisi d’aquestes fonts m’ha permès verificar l'existència de tota una sèrie de canvis substancials, estretament vinculats a la voluntat expressa de la nova elit dirigent d'origen grec de distanciar-se dels seus predecessors aquemènides i de marcar amb força l’obertura d’una nova era que es caracteritzarà pel respecte a les tradicions autòctones i per la potenciació dels cultes nacionals.