• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 185
  • 152
  • 32
  • 17
  • 13
  • 13
  • 13
  • 12
  • 7
  • 6
  • 5
  • 4
  • 3
  • 3
  • 2
  • Tagged with
  • 461
  • 104
  • 81
  • 62
  • 54
  • 40
  • 38
  • 36
  • 34
  • 32
  • 32
  • 31
  • 28
  • 27
  • 26
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Biologia, arquitetura de ninhos e coleta de substratos no cerrado por formigas cultivadoras de fungo, Trachymyrmex holmgreni Wheeler, 1925 (Hymenoptera, Formicidae, Attini) /

Lizidatti, Conceição Silva. January 2006 (has links)
Resumo: O pouco estudado gênero Trachymyrmex Forel (1893) é composto por formigas geralmente pequenas, de comportamento críptico, e ninhos geralmente com aberturas especializadas. A taxonomia do gênero ainda é precária: muitos espécimes não estão identificados devido à complexidade taxonômica dos grupos. As revisões recentes de Mayhé-Nunes e Brandão (2002; 2005) têm contribuído para o conhecimento desse gênero, mas muitas espécies ainda necessitam ser descritas. A biologia de muitas espécies, como a coleta de substratos para o cultivo do fungo e a arquitetura dos ninhos, é desconhecida, principalmente tratando-se das espécies do Cerrado. O estudo foi realizado em uma parte da Reserva Legal da Fazenda do Lageado, fragmento de cerrado strictu sensu, situada a 10 Km da cidade de Jataí, GO (17° 52’ 57" S e 51º 38’ 10" O). Foram encontrados 10 ninhos de T. holmgreni, em uma área de 1.280 m2. Esta espécie tem ampla distribuição geográfica no centro e sudeste do Brasil, mas foi considerada rara na área de estudo, onde seus ninhos apresentaram densidade equivalente a 0,008 ninhos /mø. Seis ninhos foram marcados para o monitoramento das colônias de julho a dezembro de 2004 e quatro escavados para coleta de dados sobre arquitetura e análise populacional. Os ninhos de T. holmgreni apresentam cratera, entrada guarnecida por torre de fragmentos vegetais (torre de palha) e um fosso escavado nas proximidades. Além da biologia de T. holmgreni foram listadas outras 4 espécies de Trachymyrmex coletadas no fragmento de cerrado strictu sensu. O material coletado pertence a três grupos distintos. Trachymyrmex grupo Iheringi (T. holmgreni), que exibe lobo projetado próximo à base do escapo antenal, Trachymyrmex grupo opulentus (T. dichrous), caracterizado pela fina pubescência especialmente visível nos fêmures posteriores e Trachymyrmex grupo urichi (T. fuscus)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Trachymyrmex Forel 1893, a not well studied genus, is generally composed by small ants with cryptic behavior, and nests that usually have specialized openings. The taxonomy of the genus is still precarious: many specimens are not yet identified due to the taxonomic complexity of the groups. Recent revisions by Mayhé-Nunes and Brandão have been contributing to the knowledge of the genus, but several species need to be described. The biology of the most species, as the collection of substrata for fungi cultivation and nest architecture, is unknown, especially those species from Brazilian savanna. The study was performed in a Legal Reserve from "Fazenda Lageado", a fragment of strictu sensu Brazilian savanna, placed 10 km from Jataí city, GO (17° 52 ' 57 " S and 51st 38 ' 10 " W). It was found 10 nests of T. holmgreni, in an area of 1.280 m2. This species has a wide geographical distribution between central and southeastern Brazil, but was considered rare in the study area where their nests presented density equivalent to 0,008 nests /mø. Six nests were marked for colony monitoring, from July to December 2004, and four of them were dug for data collection on nest architecture and population structure. The nests of T. holmgreni present a crater, an entrance garnished by tower of vegetable fragments (tower of straws) and a ditch, dug in the proximities. Besides the biology of T. holmgreni, it was found other 4 species of Trachymyrmex, collected in the Brazilian savanna fragment. The collected material belonged to three different groups: the group Iheringi (T. holmgreni), that exhibits a projected lobe close to the base of the antennal escape, the group opulentus (T. dichrous), characterized by the fine pubescence especially visible in the posterior femurs and the group urichi (T. fuscus), for presenting angular projections in the occipital sides... (Complete abstract, click electronic address below) / Orientador: Jorge Luís Machado Diniz / Coorientador: Fernando Barbosa Noll / Banca: Antônio José Mayhé Nunes / Banca: Denise de Cerqueira Rossa Feres / Mestre
292

Caracterização de duas linhagens simpátricas de Atta laevigata /

Bezerra, Cintia Maria Santos. January 2013 (has links)
Orientador: Mauricio Bacci Junior / Coorientador: Luíz Carlos Forti / Banca: Marco Antonio del Lama / Banca: Fabio de Melo Sene / Banca: Sergio Russo Matioli / Banca: Patricia Pasquali Parise Maltempi / Resumo: As formigas da tribo Attini apresentam um mutualismo com fungos basidiomicetos. Entre as attíneas, uma das mais derivadas é a formiga cortadeira Atta laevigata, que se apresenta com ampla distribuição na América do Sul e dividida em duas linhagens mitocondriais. Esta cortadeira já foi classificada em até três subespécies ou mesmo em duas espécies distintas, mas atualmente é considerada uma única espécie com grande variação morfológica. No presente trabalho, foram analisados indivíduos de 84 ninhos de A. laevigata em duas áreas na região Sudeste do Brasil. Nessas áreas foram encontrados indivíduos em ambas as linhagens mitocondriais, denominadas de linhagem I e II. Os machos da linhagem I se apresentaram distintos dos machos da linhagem II, com relação ao peso, dimensões do abdômen e estruturas da genitália. A congruência entre os marcadores morfológicos e mitocondriais sugere que as duas linhagens simpátricas de A. laevigata estão reprodutivamente isoladas, caracterizando um processo de especiação em andamento. Ninhos de ambas as linhagens de A. laevigata contiveram o mesmo fungo mutualista, Leucoagaricus gongylophorus, em três grupos gênicos distintos. Portanto, o processo de especiação em A. laevigata não foi causado por uma especialização no cultivo de um determinado grupo de fungo. Indivíduos simpátricos de linhagens distintas puderam realizar o voo nupcial simultaneamente. No entanto, análises de quatro lócus mitocondriais e seis lócus microssatélites mostraram que cada fêmea em uma das linhagens é fecundada exclusivamente (ou ao menos predominantemente) por machos da mesma linhagem. Portanto, há uma barreira pré-zigótica levando ao isolamento reprodutivo entre indivíduos simpátricos de linhagens distintas. Esta barreira foi provavelmente causada pelas diferenças corpóreas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Ants of Attini tribe have a mutualism with basidiomycete fungi. Among Attini ants, one of the most derived species is the leafcutter ant Atta laevigata, which has a wide distribution in South America and split into two mitochondrial lineages. This leafcutter has been classified into three subspecies or even up into two distinct species, but nowadays is considered a single species with great morphological variation. In this study, we analyzed 84 individuals from nests of A. laevigata located in two areas of southeastern region of Brazil. Individuals from both mitochondrial lineages, called lineage I and II, were found in those areas. Males of lineage I were different from males of lineage II, concerning weight, dimensions of the abdomen, and genitalia structures. The congruence between morphological and mitochondrial markers suggests that the two sympatric lineages of A. laevigata are reproductively isolated, characterizing a speciation process in progress. Nests of both A. laevigata lineages contained the same mutualistic fungus, Leucoagaricus gongylophorus, in three distinct genetic groups. Therefore, A. laevigata speciation process was not caused by a specialization in the cultivation of a particular group of fungi. Sympatric individuals of distinct lineages could perform the nuptial flight simultaneously. However, analysis of four mitochondrial and six microsatellite locus showed that each female from a lineage is fertilized exclusively (or at least predominantly) by one to six males from the same lineage. Thus, there is a pre zygotic barrier leading to reproductive isolation between sympatric individuals of distinct lineages. This barrier was probably caused by physical differences of males (including the genitalia) that makes it... (Complete abstract click electronic access below) / Doutor
293

Ocorrência de espécies de Atta Fabricius, 1804 e Acromyrmex Mayr, 1865 em algumas regiões do Brasil /

Rando, Jael Simões Santos, 1959- January 2002 (has links)
Orientador: Luiz Carlos Forti / Resumo: Este trabalho é o resultado de coletas realizadas pelo profo Dr. Luiz Carlos Forti nos anos de 1993 e 1994 em vários municípios dos Estados de Santa Catarina, Paraná, São Paulo, Mato Grosso do Sul, Minas Gerais, Goiás, Mato Grosso, Rondônia, Acre, Amapá, Amazonas e também Guiana Francesa e Paraguai, com o objetivo de atualizar a distribuição geográfica das formigas cortadeiras de folhas dos gêneros Atta Fabricius, 1804 e Acromyrmex Mayr, 1865. Nos diversos municípios foram feitos transectos localizados ao acaso e, sempre que possível, coletou-se dados sobre densidade de colônias, tipos de vegetação e exemplares de formigas dos dois gêneros para posterior exame no laboratório de Insetos Sociais-Praga da FCA/UNESP, Botucatu-SP. Além dos dados relativos aos 11 Estados do Brasil, incluiu-se o resultado das identificações de exemplares recebidos de diversos locais e datas para o referido laboratório. Concluiu-se que A. laevigata e A. capiguara foram as espécies encontradas em maior número de municípios amostrados do Brasil. A. sexdens piriventris somente foi encontrada na região sul do Brasil, com grande predomínio nos Estados de Santa Catarina e Rio Grande do Sul. A região Sudeste se caracterizou pela ocorrência de A. capiguara e A. laevigata, nesta ordem, sendo que em Minas Gerais, a espécie de maior ocorrência foi A. laevigata. A. capiguara também se destacou no Estado do Paraná. A. capiguara predominou em áreas cobertas por gramíneas e A. laevigata não apresentou preferência destacada quanto a cobertura vegetal. A. laevigata ocorreu de forma generalizada nas regiões Centro-Oeste e Norte do Brasil. A. sexdens rubropilosa esteve presente em todas as regiões do Brasil, com predominância nos Estados do Paraná e Minas Gerais. ...(Resumo completo, clicar acesso eletrônico abaixo). / Abstract: This work is the result of collects, done by professor Luiz Carlos Forti between years 1993 and 1994, in many cities on States of Santa Catarina, Paraná, São Paulo, Mato Grosso do Sul, Minas Gerais, Goiás, Mato Grosso, Rondônia, Acre, Amapá, Amazonas in Brazil and also Guiana Francesa and Paraguay, with the purpose to obtain an up-to-date geographical distribution of leaf cutting ants from genus Atta Fabricius, 1804 and Acromyrmex Mayr, 1865. Among cities it were done, on randomized areas, when it was possible, data collections as: colony densities, kind of vegetation and ants specimens from both genus for later laboratory tests at Insetos Sociais-Praga da FCA/UNESP, Botucatu-São Paulo State. Beyond data, related to eleven states of Brazil, it were include yet, in this work, results of specimens identification from different places and dates, received for identifications to mentioned laboratory. It was conclude that A. laevigata Smith, 1858 e A. capiguara Gonçalves, 1944 were species found on higher number of randomized cities in Brasil. A. sexdens piriventris Santschi, 1919 was found only at South region in Brazil, in States of Santa Catarina and Rio Grande do Sul. In Southwest region were found A. capiguara and A. laevigata, by this order but, in Minas Gerais State, higher frequency was of A. laevigata. A. capiguara had detached in Paraná State too, higher on areas of grassland. A. laevigata had no detached preference of vegetal covering and occurred, as general way, at regions of Middle-West and North of Brazil. A. sexdens rubropilosa Forel, 1908 was found at all regions of Brasil, with supremacy at States of Paraná and Minas Gerais. It were observed at first time occurrences of A. laevigata in States of Amapá and Rio Grande do Sul. It was registered, at first time too, occurrence of A. opaciceps Borgmeier, 1939 in State of Alagoas...(Complete abstract, click electronic address below). / Doutor
294

Glândulas mandibulares de operárias de formigas Atta sexdens rubropilosa (Forel, 1908) : morfologia e expressão gênica (Hymenoptera: Formicidae) /

Porfirio, Lorena Favaro Pavon. January 2006 (has links)
Resumo: As glândulas mandibulares, dos insetos Hymenoptera, fazem parte do seu sistema salivar. São estruturas pares que se localizam uma em cada lado da cabeça, possuindo um ducto excretor abrindo na base da articulação da mandíbula, por onde eliminam a secreção produzida. São compostas por um reservatório associado às células secretoras, sendo que cada célula desemboca individualmente no reservatório através de canalículos. Embora as glândulas mandibulares estejam ligadas às peças bucais, utilizando seu produto glandular na ingestão e digestão de alimentos, essas glândulas evoluíram no sentido de se dissociarem da função digestiva para terem função comportamental. No presente estudo avaliou-se a morfo-histologia, citoquímica ultra-estrutural, dosagem e eletroforese de proteínas, além da expressão gênica das glândulas mandibulares das operárias mínimas, médias e soldados de formigas Atta sexdens rubropilosa, com o objetivo de fornecer informações sobre a dinâmica da produção, bem como a composição e origem da secreção dessas glândulas nas três castas desses insetos. A análise morfológica e ultra-estrutural evidenciou uma organização glandular saculiforme, constituída por uma porção secretora e um reservatório com um ducto excretor a ele conectado. A porção secretora é formada por células arranjadas em ácinos e o reservatório é constituído por um epitélio simples pavimentoso revestido pela íntima cuticular. Essas duas porções encontram-se interligadas por canalículos intra e extracitoplasmáticos. Tanto a histoquímica, quanto a citoquímica ultra-estrutural detectou lipídios, proteínas e polissacarídeos nas diferentes regiões das glândulas mandibulares nas três castas estudadas, inclusive em suas secreções, demonstrando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The mandibular glands, in the Hymenoptera insects, make up part of the salivary system. These glands are paired structures that are located one on each side of the head, containing an excretory duct, at the base of the mandible articulation, from which the secretion produced is eliminated. They contain a reservoir associated with the secretory cells, being that each cell opens individually in the reservoir through the canaliculi. Even though the mandibular glands are connected to the bucal parts, using its glandular product in the ingestion and digestion of food, these glands have evolved in the sense of being disassociated with the digestive function to having a behavioural function. In the present study the morpho-histology, ultrastructural cytochemistry, protein dosage and electrophoresis were evaluated, as well as the gene expression of the mandibular glands of the minima, media workers and soldiers of ants Atta sexdens rubropilosa, with the objective of providing information about the production dynamics, as well as the composition and origin of the secretion of these glands in the three castes of these insects. The morphological and ultrastructural analysis described a glandular organization consisting of sacs, formed by a secretory portion and a reservoir with a connected excretory duct. The secretory portion is formed by cells arranged in alveoli and the reservoir is constituted of a simple pavimentous epithelium covered by the cuticular intima. These two portions are interconnected by intra- and extra-cytoplasmic canaliculi. The histochemistry, as well the ultrastructural cytochemistry, highlighted lipids, proteins and polysaccharides in different regions of the mandibular glands in the three castes studied demonstrating... (Complete abstract, click electronic address below) / Orientador: Maria Izabel Camargo Mathias / Coorientador: Maurício Bacci Júnior / Banca: Odair Correa Bueno / Banca: Vanderlei Geraldo Martins / Banca: Roberta Cornélio Ferreira Nocelli / Banca: Márcia Regina Paes de Oliveira. / Doutor
295

Monitoramento da qualidade ambiental de áreas citrícolas utilizando formigas (Hymenoptera: Formicidae) como bioindicadores

Barbieri, Rafael Forti [UNESP] 27 February 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-27Bitstream added on 2014-06-13T20:20:30Z : No. of bitstreams: 1 barbieri_rf_me_botib.pdf: 3591122 bytes, checksum: b3589d57191f02cb4a0c79ee3650d890 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O uso de formigas como bioindicadores constitui-se de uma ferramenta poderosa para avaliação de mudanças na estrutura dos ecossistemas, podendo ser um elo de confiança entre as partes interessadas (governo, mercado e a sociedade civil) no direcionamento de políticas públicas, e em processos de certificação, garantindo um desenvolvimento sustentável. Para validar as formigas como bioindicadores de áreas citrícolas foram amostradas quatro áreas, duas áreas de cultivo convencional e duas áreas de cultivo orgânico, e dois fragmentos florestais próximos a duas das áreas cultivadas, uma orgânica e uma convencional. A amostragem da mirmecofauna foi realizada utilizando-se armadilhas de solo tipo pitfall traps e em coletas realizadas na copa das árvores de citros através de guarda-chuva entomológico (batimento). Com os dados obtidos em campo foram calculados índices faunísticos de riqueza de espécies (S), diversidade de Shannon (H), diversidade de Simpson (1-D) e equitabilidade (J) para cada área amostrada. As espécies foram ainda classificadas em grupos funcionais e submetidos a análise estatística de similaridade e de variância de Kruskal-Wallis, que quando apresentaram valores significativos (p<O.05), foram pareados dois a dois em teste de Student-Newman-Keuls. Segundo os dados estatísticos obtidos e integrados a análise de grupos funcionais, a área de cultivo orgânico apresentou maior similaridade com seu fragmento florestal quando comparado a similaridade apresentada pela área de cultivo convencional e seu respectivo fragmento florestal. Ponderando as relações de dominância e os dados estatísticos obtidos em análises entre os grupos funcionais as áreas de cultivo orgânico apresentam melhor qualidade ambiental quando comparadas as áreas de cultivo convencional / The use of ants as bioindicators consist in a powerful tool for evaluation of changes in the structure of ecosystems, being able to be a reliable link among stakeholders (government, market and the civil society) aiming public politics and certification's processes, guaranteeing a sustainable development. To validate ants as bioindicators of citrus orchards, four agricultural areas were sampled, two of them are organic and the other two, are conventional areas. Two forest fragments, next to both cultivated areas, one organic and one conventional, were also sampled. Two methods were used to collect the ants, on soil surface using pitfall traps, and collects on canopies' citrus trees using entomological umbrella. With the data obtained in field the following indexes were calculated: Species richness (S), Shannon diversity (H), Simpson diversity (1-D) and equitability (J) for each sampled area. All the collected species were classified by functional groups and submitted to similarity's analyses, and variance of Kruskal-Wallis, that when showed significant values (p<O.05) were submitted to pairwise test of Student-Newman-Keuls. According to statistical data and the functional group analyses, the organic culture showed a greater similarity with its forest fragment when compared to similarity showed between the conventional culture and its own forest fragment. Considering the statistical data and dominance between the ant's functional groups, organic cultures showed better environmental quality when compared to conventional cultures
296

Toxicidade de formicidas utilizados em pastagens sobre a formiga não-alvo Ectatomma brunneum (Hymenoptera, Formicidae, Ectatomminae) e seus efeitos na dinâmica populacional em condições de laboratório

Tofolo, Viviane Cristina [UNESP] 27 April 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-04-27Bitstream added on 2014-06-13T21:00:37Z : No. of bitstreams: 1 tofolo_vc_me_rcla.pdf: 520198 bytes, checksum: 81a305ec02da5170d24bfe930d1ea7be (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo deste trabalho foi procurar conhecer os efeitos de três substâncias químicas, sulfluramida, fipronil e clorpirifós, sobre a espécie de formiga não-alvo Ectatomma brunneum (Hymenoptera: Formicidae: Ectatomminae), respondendo às seguintes questões: as marcas comerciais de iscas formicidas granuladas utilizadas neste trabalho são atrativas a esta espécie de formiga não-alvo ou simplesmente repelentes? Sendo atrativas, qual o comportamento exercido pelas operárias? Elas ingerem as iscas no local ou carregam para o interior do ninho? Há devolução? Em condições de múltipla escolha alimentar, esta atratividade permanece ou ocorre somente na ausência do alimento convencional? No que acarreta o contato direto e indireto das formigas com as iscas? Ocorre mortalidade significativa? Qual dos ingredientes ativos é mais prejudicial? Os produtos são seletivos? Os resultados obtidos através dos testes em laboratório revelaram que, em condições normais de exposição, as operárias de E. brunneum não foram repelidas pelas iscas formicidas. No entanto, não houve atratividade suficiente para induzir o carregamento ou ingestão. Quando esse material foi umedecido, a atratividade aumentou significativamente, permitindo que porções das iscas fossem ingeridas na própria arena de forrageamento ou carregadas para o interior do ninho e distribuídas aos outros indivíduos, não sendo registrada, em nenhum dos tratamentos, a devolução total ou parcial das porções carregadas. Após 48 horas de exposição, os três ingredientes ativos foram tóxicos, de modo que a população foi reduzida em 35,56% no tratamento com clorpirifós, 31,11% com sulfluramida e 30% com fipronil ao final de 20 dias de observação. As iscas à base de fipronil foram mais atrativas que as de sulfluramida e clorpirifós... / This work aimed at contributing to a better knowledge on the effects of three chemical substances, sulfluramid, fipronil and chlorpyrifos, on the non-target species of ant Ectatomma brunneum (Hymenoptera: Formicidae: Ectatomminae), answering the following questions: are the brands of granulated insecticide baits employed in this work attractive to this species of non-target ant or are they just repellent? If attractive, what is the behavior exhibited by the workers? Do they ingest the baits in the spot or take them into the nest? Is there any devolution? Under conditions of multiple food choice, does this attractiveness remain or does it happen only in the lack of the conventional food? What is the outcome of direct or indirect contact between the ants and the baits? Is there significant mortality? Which of the active ingredients is the most harmful? Are the products selective? The results obtained from the tests in laboratory showed that, under conditions of normal exposure, the workers of E. brunneum were not repelled by the insecticide baits. Nevertheless, there was not enough attractiveness as to lead to transporting or ingesting. When the material was moistened, the attractiveness increased significantly, allowing portions of bait to be ingested at the very foraging arena or to be taken into the nest and distributed to the other individuals. Total or partial devolution of the portions carried was not observed in any of the treatments. After a 48 hour exposure the three active ingredients proved to be toxic, for the population was reduced in 35.56% in the treatment with chlorpyrifos, 31.11% with sulfluramid and 30% with fipronil at the end of 20 days of observation. The fipronil based baits were more attractive than the ones based on sulfluramid and chlorpyrifos...(Complete abstract click electronic access below)
297

Modelo arquitetônico de ninhos, biologia e divisão de trabalho de Pachycondyla striata Fr. Smith, 1858 (Hymenoptera : Formicidae : Ponerinae)

Silva-Melo, Adolfo da [UNESP] 09 May 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-09Bitstream added on 2014-06-13T19:18:47Z : No. of bitstreams: 1 silvamelo_a_me_rcla.pdf: 1461706 bytes, checksum: 6d2b178e0a49ad6fe5fb7d3bdbb7387a (MD5) / Universidade Estadual Paulista (UNESP) / o presente trabalho procura contribuir para o conhecimento da arquitetura dos ninhos, divisão de trabalho, polietismo temporal e tabela de vida da espécie Pacchycondyla striata. Os esquemas dos ninhos foram confeccionados aproximando-se do natural no campo, sugerindo uma arquitetura pouco elaborada, com as câmaras e túneis distribuídos superficialmente no subsolo, sendo similar ao padrão de outras espécies da subfamília Ponerinae. Os dados comportamentais foram obtidos usando o método scanning sample e etograma comparativo. 0 repertório comportamental de Pachycondyla striata apresentou 46 atos, exibindo diferenças significativas de comportamento entre rainhas e operárias. A postura de ovos na posição C das rainhas e operárias é considerado primitivo por assemelhar-se ao de vespas do gênero Eustenogaster. 0 comportamento de dominância registrado para esta espécie pode estar relacionado ao de recrutamento e reprodução. O repertório comportamental desta espécie monomórfica sugere que as tarefas realizadas estão fundamentadas na idade dos indivíduos. A tabela de vida das operárias foi calculada segundo o método de CAREY, (1993). Pachycondyla striata atinge uma longevidade média de 74,48 ± 48,31 dias (l - 463, N = 798), cujo valor é semelhante à expectativa de vida no primeiro dia de idade (ex = 73,32). Esta espécie apresentou alto índice de mortalidade dos indivíduos jovens. O valor da entropia em operárias de Pachycondyla striata é de H = 0,611. O número de operárias desta espécie na arena de forrageamento aumenta de acordo com a carência nutritiva da colônia. / This work seeks to contribute to the knowledge on nest architecture, division of labor, temporal polyethism and life table of the species Pacchycondyla striata. The nest designs were made in the field, indicating a poorly-elaborated architecture, with their chambers and tunnels distributed close to the horizontal surface of the ground, similar to the pattern of other species of the subfamily Ponerinae. The behavioral data were obtained using the scanning sample method and comparative ethogram. The behavioral repertoire of Pachycondyla striata showed 46 actions, with significant behavior differences between queens and workers. Laying eggs at the position c of the queens and workers is considered primitive, once it resembles those of the wasps of the genus Eustenogaster. The dominance behavior observed in this species may be related to the recruiting and reproduction behaviors. The behavioral repertoire of this monomorphic species suggests that tasks performed are based on the age of the individuals. The life table of the workers was calculated according to CAREY, (1993). Pachycondyla striata reaches an average longevity of 74.48 ± 48.31 days (l - 463, N = 798), whose value is similar to the life expectation on the first day of life (ex = 73.32). This species showed a high mortality rate among young individuals. The value of the entropy for the workers of Pachycondyla striata is H = 0.611. The number of workers of this species in the foraging arena increases with to the nutrition needs of the colony.
298

Understanding the Emerging Behaviors and Demands for the Colony Success of Social Insects: A Mathematical Approach

January 2018 (has links)
abstract: The most advanced social insects, the eusocial insects, form often large societies in which there is reproductive division of labor, queens and workers, have overlapping generations, and cooperative brood care where daughter workers remain in the nest with their queen mother and care for their siblings. The eusocial insects are composed of representative species of bees and wasps, and all species of ants and termites. Much is known about their organizational structure, but remains to be discovered. The success of social insects is dependent upon cooperative behavior and adaptive strategies shaped by natural selection that respond to internal or external conditions. The objective of my research was to investigate specific mechanisms that have helped shaped the structure of division of labor observed in social insect colonies, including age polyethism and nutrition, and phenomena known to increase colony survival such as egg cannibalism. I developed various Ordinary Differential Equation (ODE) models in which I applied dynamical, bifurcation, and sensitivity analysis to carefully study and visualize biological outcomes in social organisms to answer questions regarding the conditions under which a colony can survive. First, I investigated how the population and evolutionary dynamics of egg cannibalism and division of labor can promote colony survival. I then introduced a model of social conflict behavior to study the inclusion of different response functions that explore the benefits of cannibalistic behavior and how it contributes to age polyethism, the change in behavior of workers as they age, and its biological relevance. Finally, I introduced a model to investigate the importance of pollen nutritional status in a honeybee colony, how it affects population growth and influences division of labor within the worker caste. My results first reveal that both cannibalism and division of labor are adaptive strategies that increase the size of the worker population, and therefore, the persistence of the colony. I show the importance of food collection, consumption, and processing rates to promote good colony nutrition leading to the coexistence of brood and adult workers. Lastly, I show how taking into account seasonality for pollen collection improves the prediction of long term consequences. / Dissertation/Thesis / Doctoral Dissertation Applied Mathematics 2018
299

Metabolic and behavioral integration in social insect colonies

January 2012 (has links)
abstract: In social insect colonies, as with individual animals, the rates of biological processes scale with body size. The remarkable explanatory power of metabolic allometry in ecology and evolutionary biology derives from the great diversity of life exhibiting a nonlinear scaling pattern in which metabolic rates are not proportional to mass, but rather exhibit a hypometric relationship with body size. While one theory suggests that the supply of energy is a major physiological constraint, an alternative theory is that the demand for energy is regulated by behavior. The central hypothesis of this dissertation research is that increases in colony size reduce the proportion of individuals actively engaged in colony labor with consequences for energetic scaling at the whole-colony level of biological organization. A combination of methods from comparative physiology and animal behavior were developed to investigate scaling relationships in laboratory-reared colonies of the seed-harvester ant, Pogonomyrmex californicus. To determine metabolic rates, flow-through respirometry made it possible to directly measure the carbon dioxide production and oxygen consumption of whole colonies. By recording video of colony behavior, for which ants were individually paint-marked for identification, it was possible to reconstruct the communication networks through which information is transmitted throughout the colony. Whole colonies of P. californicus were found to exhibit a robust hypometric allometry in which mass-specific metabolic rates decrease with increasing colony size. The distribution of walking speeds also scaled with colony size so that larger colonies were composed of relatively more inactive ants than smaller colonies. If colonies were broken into random collections of workers, metabolic rates scaled isometrically, but when entire colonies were reduced in size while retaining functionality (queens, juveniles, workers), they continued to exhibit a metabolic hypometry. The communication networks in P. californicus colonies contain a high frequency of feed-forward interaction patterns consistent with those of complex regulatory systems. Furthermore, the scaling of these communication pathways with size is a plausible mechanism for the regulation of whole-colony metabolic scaling. The continued development of a network theory approach to integrating behavior and metabolism will reveal insights into the evolution of collective animal behavior, ecological dynamics, and social cohesion. / Dissertation/Thesis / Ph.D. Biology 2012
300

Egg Policing and Fertility Signaling Across Colony Development in the Ant Camponotus floridanus

January 2012 (has links)
abstract: Of all the signals and cues that orchestrate the activities of a social insect colony, the reproductives' fertility pheromones are perhaps the most fundamental. These pheromones regulate reproductive division of labor, a defining characteristic of eusociality. Despite their critical role, reproductive fertility pheromones are not evenly expressed across the development of a social insect colony and may even be absent in the earliest colony stages. In the ant Camponotus floridanus, queens of incipient colonies do not produce the cuticular hydrocarbons that serve as fertility and egg-marking signals in this species. My dissertation investigates the consequences of the dramatic change in the quantity of these pheromones that occurs as the colony grows. C. floridanus workers from large, established colonies use egg surface hydrocarbons to discriminate among eggs. Eggs with surface hydrocarbons typical of eggs laid by established queens are nurtured, whereas eggs lacking these signals (i.e., eggs laid by workers and incipient queens) are destroyed. I characterized how workers from incipient colonies responded to eggs lacking queen fertility hydrocarbons. I found that established-queen-laid eggs, incipient-queen-laid eggs, and worker-laid eggs were not destroyed by workers at this colony stage. Destruction of worker-laid eggs is a form of policing, and theoretical models predict that policing should be strongest in incipient colonies. Since there was no evidence of policing by egg-eating in incipient C. floridanus colonies, I searched for evidence of another policing mechanism at this colony stage. Finding none, I discuss reasons why policing behavior may not be expressed in incipient colonies. I then considered the mechanism that accounts for the change in workers' response to eggs. By manipulating ants' egg experience and testing their egg-policing decisions, I found that ants use a combination of learned and innate criteria to discriminate between targets of care and destruction. Finally, I investigated how the increasing strength of queen-fertility hydrocarbons affects nestmate recognition, which also relies on cuticular hydrocarbons. I found that queens with strong fertility hydrocarbons can be transferred between established colonies without aggression, but they cannot be introduced into incipient colonies. Queens from incipient colonies cannot be transferred into incipient or established colonies. / Dissertation/Thesis / Ph.D. Biology 2012

Page generated in 0.0545 seconds