Orientador: Luiz Carlos Forti / Coorientador: Juliane Floriano Lopes Santos / Banca: Pedro Leite Ribeiro / Banca: Sandra Verza da Silva / Resumo: O forrageamento é uma atividade central à vida animal e, portanto, um mecanismo delineador das diferentes estratégias comportamentais exibidas e evolutivamente selecionadas para as espécies. O uso de trilhas químicas e físicas, as estratégias de recrutamento, o compartilhamento de informações e o polietismo são mecanismos freqüentemente relacionados ao sucesso do forrageamento para formigas cortadeiras garantindo sua ampla distribuição nas regiões neotropicais. Buscando investigar a transferência de informações durante a atividade de forrageamento em Atta bisphaerica, foram verificadas a utilização temporal e espacial das trilhas físicas por operárias que trafegavam tanto em direção a fonte de recurso quanto em direção ao ninho. As operárias apresentaram organização temporal, formando grupos de deslocamento entre indivíduos que seguem na mesma direção, bem como organização espacial de acordo com o transporte ou não de carga vegetal, favorecendo a ocorrência de colisões funcionais que influenciam nas taxas de aporte de recursos à colônia. Operárias que transportam carga se mantêm nas áreas centrais juntamente com operárias que saem do ninho em direção a fonte de recursos, enquanto que operárias sem carga são observadas nas partes laterais da trilha. promovendo a troca de informações sobre a qualidade e localização de recursos disponíveis. Manipulações impostas de modo a estreitar trilhas físicas demonstraram que operárias foram hábeis em ajustar a utilização espacial das trilhas. Embora tenha ocorrido um aumento inicial de colisões não-funcionais ocasionadas pelo estreitamento, os dados obtidos demonstram o ajuste do fluxo de operárias, permitindo a manutenção da taxa de aporte de recursos e, consequentemente, da eficiência ergonômica da colônia. Visando obter... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Foraging is a central activity for the animal life, and so a mechanism that delineates the different behavioral strategies exhibited and evolutionarily selected for the species. The use of chemical and physical trails, the recruitment strategies, information sharing and the polyethism are the mechanisms often related with the foraging success for leafcutting ants, ensuring by this way their wide distribution in the neotropics. Investigating the information transfer during foraging in Atta bisphaerica, we verified a temporal and spatial organization of workers that transited from and to the nutritional sources and nest. Workers showed a temporal organization by forming displacement groups among those that move at the same direction. Spatial organization was verified in function of they are transporting or not leaves fragments, what favored the occurrence of functional collision and so the rate of resource delivery to the colony. Loaded workers walks preferentially at central lanes altogether with workers that leaves the colony, while unloaded workers were at the lateral lanes, promoting the information sharing about the quality and location of the resources. Manipulations for narrowing the physical trails demonstrated that workers were able to spatially adjust themselves over the trail, ensuring resources delivery rates and so the ergonomic efficiency of the colony. Aiming to obtain data to differentiate a specialized caste of scouts workers, dry body mass of workers recruited for new food sources was measured. We didn't find significant differences between the average dry body mass of workers samples at the trail and at the new sources, but the first workers that arrived at the nearest offered food were the lighter ones, what probably facilitates the displacement velocity and chemical trail marking. He present study... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:30:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T21:00:29Z : No. of bitstreams: 1 silva_mb_me_botib.pdf: 406170 bytes, checksum: e78dbe0dc8b2882f264db3ca73da8a81 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O forrageamento é uma atividade central à vida animal e, portanto, um mecanismo delineador das diferentes estratégias comportamentais exibidas e evolutivamente selecionadas para as espécies. O uso de trilhas químicas e físicas, as estratégias de recrutamento, o compartilhamento de informações e o polietismo são mecanismos freqüentemente relacionados ao sucesso do forrageamento para formigas cortadeiras garantindo sua ampla distribuição nas regiões neotropicais. Buscando investigar a transferência de informações durante a atividade de forrageamento em Atta bisphaerica, foram verificadas a utilização temporal e espacial das trilhas físicas por operárias que trafegavam tanto em direção a fonte de recurso quanto em direção ao ninho. As operárias apresentaram organização temporal, formando grupos de deslocamento entre indivíduos que seguem na mesma direção, bem como organização espacial de acordo com o transporte ou não de carga vegetal, favorecendo a ocorrência de colisões funcionais que influenciam nas taxas de aporte de recursos à colônia. Operárias que transportam carga se mantêm nas áreas centrais juntamente com operárias que saem do ninho em direção a fonte de recursos, enquanto que operárias sem carga são observadas nas partes laterais da trilha. promovendo a troca de informações sobre a qualidade e localização de recursos disponíveis. Manipulações impostas de modo a estreitar trilhas físicas demonstraram que operárias foram hábeis em ajustar a utilização espacial das trilhas. Embora tenha ocorrido um aumento inicial de colisões não-funcionais ocasionadas pelo estreitamento, os dados obtidos demonstram o ajuste do fluxo de operárias, permitindo a manutenção da taxa de aporte de recursos e, consequentemente, da eficiência ergonômica da colônia. Visando obter... / Foraging is a central activity for the animal life, and so a mechanism that delineates the different behavioral strategies exhibited and evolutionarily selected for the species. The use of chemical and physical trails, the recruitment strategies, information sharing and the polyethism are the mechanisms often related with the foraging success for leafcutting ants, ensuring by this way their wide distribution in the neotropics. Investigating the information transfer during foraging in Atta bisphaerica, we verified a temporal and spatial organization of workers that transited from and to the nutritional sources and nest. Workers showed a temporal organization by forming displacement groups among those that move at the same direction. Spatial organization was verified in function of they are transporting or not leaves fragments, what favored the occurrence of functional collision and so the rate of resource delivery to the colony. Loaded workers walks preferentially at central lanes altogether with workers that leaves the colony, while unloaded workers were at the lateral lanes, promoting the information sharing about the quality and location of the resources. Manipulations for narrowing the physical trails demonstrated that workers were able to spatially adjust themselves over the trail, ensuring resources delivery rates and so the ergonomic efficiency of the colony. Aiming to obtain data to differentiate a specialized caste of scouts workers, dry body mass of workers recruited for new food sources was measured. We didn’t find significant differences between the average dry body mass of workers samples at the trail and at the new sources, but the first workers that arrived at the nearest offered food were the lighter ones, what probably facilitates the displacement velocity and chemical trail marking. He present study... (Complete abstract click electronic access below)

Orientador: Luiz Carlos Forti / Banca: Odair Correa Bueno / Banca: Ivone Paschoal Garcia / Abstract: The objective of this paper was to have a better understanding of plant-ant-symbiotic fungus interaction focusing on foraging behavior of Atta sexdens rubropilosa workers during plant selection. Physical and chemical substrate factors were approached which can have a role on foraging material selection for symbiotic fungus cultivation besides defoliating localization in artificial plants. Tested hypothesis was that besides chemical characteristics physical stimulus and leaves localization in a plant also play a very important role in substrate selection by A. sexdens rubropilosa workers. Different shape and thickness material was used (different leaves, paper leaves with different shapes and thickness impregnated in plant extract and artificial plants). The aim was to verify the existence of physical and chemical resistance, leaf palatability and defoliating localization. Wood plants Actinostemon communis, Alchornea triplinervea, Croton floribundus, Faramea cyanea, were offered to workers and evaluated 4 according to mechanical resistance of cut and palatability. Each plant was offered individually in big disc shape (2,5cm diameter), small disc shape (0,5cm diameter) and whole leaves. Other studies were carried out for detecting physical and chemical stimulus through simulated cuts and impregnation of plant extract in paper leaves with different thickness making it possible to evaluate the combinations between physical and chemical substrate characteristics. Defoliating localization in plants was studied when offering artificial plants with four levels where either wood plant or Ligustrum sp. leaves was attached. Defoliating intensity was measured by the number of fallen leaves by ants. In order to study wood plant attractiveness small disc shaped leaves (0,5cm diameter) were offered at the same time for ants in laboratory. The end of the experiment was determined either by the carrying... (Complete abstract, click electronics address below). / Mestre

Orientador: Luiz Carlos Forti / Coorientador: Roberto da Silva Camargo / Banca: Nadia Caldato / Banca: Ivone Paschoal Garcia / Resumo: As formigas cortadeiras Atta (saúvas) e Acromyrmex (quenquéns) são apontadas como as principais pragas de ecossistemas florestais e agrícolas, em razão dos prejuízos que causam ao cortarem as folhas das plantas para o cultivo do fungo simbionte. Esse material vegetal selecionado é transportado para a câmara de fungo, onde passa por várias fases de processamento, desde o corte, à incorporação no jardim do fungo. Tal seleção feita pelas operárias forrageiras é influenciada pelas necessidades nutricionais do jardim de fungo e/ou a ausência de substâncias potencialmente nocivas a colônia. Conhecimento este, evidenciado em estudos que observaram a rejeição de plantas palatáveis quando essas apresentaram substâncias nocivas a colônia, como a cicloheximida (CHX), substância conhecida como fungicida em estudos realizados com formigas cortadeiras. As formigas não são capazes de detectar tal fungicida, mas observa-se uma rejeição retardada, quando o fungicida é incorporado ao jardim de fungo. Esse reconhecimento retardado, hipotetizou que um semioquímico emitido pelo jardim de fungo regula a seleção de plantas por operárias, sendo interpretado como uma comunicação entre o fungo simbionte e as operárias de formigas cortadeiras. Assim, alguns questionamentos são importantes como: as operárias respondem a ação do fungicida alterando seus comportamentos dentro da colônia e quais são? Qual o efeito ocasionado pela a CHX em formigas cortadeiras? Existe uma comunicação através de um volátil s... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Leaf-cutting ants Atta (saúvas) and Acromyrmex (quenquéns) are indicated as the main pests of forest and agricultural ecosystems, due to the damage they cause when cutting the leaves of the plants for the cultivation of the symbiotic fungus. This selected plant material is transported to the fungus chamber, where it goes through various stages of processing, from the cutting, incorporation into the fungus garden. Such selection made by forage workers is influenced by the nutritional needs of the fungus garden and / or the absence of substances potentially harmful to the colony. This knowledge, evidenced in studies that observed the rejection of palatable plants when they presented substances harmful to the colony, such as cycloheximide (CHX), a substance known as fungicide in studies with leaf cutting ants. Ants are not able to detect such fungicide, but a delayed rejection is observed when the fungicide is incorporated into the fungus garden. This delayed recognition hypothesized that a semiochemical emitted by the fungus garden regulates the selection of plants by fodder, being interpreted as a communication between the symbiotic fungus and the workers of cutter ants. Thus, some questions are important as: the workers respond to the action of the fungicide by changing their behavior within the colony and what are? What effect does CHX have on leaf cutting ants? Is there a communication through a volatile semiochemical released by the fungus to promote substrate rejection by... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-10Bitstream added on 2014-06-13T20:37:43Z : No. of bitstreams: 1 noronhajunior_nc_me_botfca.pdf: 814511 bytes, checksum: f0ba517a59245727f01aed36f56871ba (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Empresa Privada / The objective of this paper was to have a better understanding of plant-ant-symbiotic fungus interaction focusing on foraging behavior of Atta sexdens rubropilosa workers during plant selection. Physical and chemical substrate factors were approached which can have a role on foraging material selection for symbiotic fungus cultivation besides defoliating localization in artificial plants. Tested hypothesis was that besides chemical characteristics physical stimulus and leaves localization in a plant also play a very important role in substrate selection by A. sexdens rubropilosa workers. Different shape and thickness material was used (different leaves, paper leaves with different shapes and thickness impregnated in plant extract and artificial plants). The aim was to verify the existence of physical and chemical resistance, leaf palatability and defoliating localization. Wood plants Actinostemon communis, Alchornea triplinervea, Croton floribundus, Faramea cyanea, were offered to workers and evaluated 4 according to mechanical resistance of cut and palatability. Each plant was offered individually in big disc shape (2,5cm diameter), small disc shape (0,5cm diameter) and whole leaves. Other studies were carried out for detecting physical and chemical stimulus through simulated cuts and impregnation of plant extract in paper leaves with different thickness making it possible to evaluate the combinations between physical and chemical substrate characteristics. Defoliating localization in plants was studied when offering artificial plants with four levels where either wood plant or Ligustrum sp. leaves was attached. Defoliating intensity was measured by the number of fallen leaves by ants. In order to study wood plant attractiveness small disc shaped leaves (0,5cm diameter) were offered at the same time for ants in laboratory. The end of the experiment was determined either by the carrying... (Complete abstract, click electronics address below).