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  • 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.
61

Comparison of Subterranean Termite (Rhinotermitidae: Reticulitermes) Gut Bacterial Diversity Within and Between Colonies and to Other Termite Species Using Molecular Techniques (ARDRA and 16S rRNA Gene Sequencing)

Fisher, Marc Lewis 01 May 2006 (has links)
Termites are known to harbor within their gut a diverse assemblage of symbiotic microorganisms. Little work has been done, however, to describe the diversity and function of the bacteria in the economically important eastern subterranean termite, Reticulitermes flavipes. The first object of this study was to characterize the bacterial diversity in the gut of R. flavipes using amplified rDNA restriction analysis (ARDRA) and 16S rRNA gene sequencing. It was determined that ARDRA was an effective technique for characterizing the diversity of the termite gut microbiota. Of the 512 clones analyzed in the ARDRA study, 261 different ARDRA profiles were found. Forty-two 16S rRNA gene sequences were also analyzed, resulting in 33 different ribotypes. Representatives from six major bacterial phyla, Proteobacteria, Spirochaetes, Bacteroidetes, Firmicutes, Actinobacteria, and the newly proposed "Endomicrobia," were discovered. Further analysis indicated that the gut of R. flavipes may harbor as many as 1,318 ribotypes per termite. The second objective was to determine if the gut bacterial diversity could be manipulated by changing the termite's food source. Using ARDRA analysis, I found no evidence that changing the food source affected the termite gut bacterial diversity. In addition, changing the food source did not induce aggression in nestmates fed on different food sources. The third objective was to search for patterns of coevolution between termites and their gut symbiotic bacteria. Using rRNA gene sequences from this study and sequences from public databases (1,450 sequences total), a neighbor-joining tree demonstrated strong evidence for coevolution of termites and their symbiotic bacteria, especially in the phyla Bacteroidetes, Actinobacteria, Spirochaetes, and "Endomicrobia." Many monophyletic clusters were entirely composed of phylotypes specific to Isoptera. / Ph. D.
62

Stratégies de reproduction et de dispersion chez deux termites humivores de Guyane, Embiratermes neotenicus et Silvestritermes minutus (Termitidae, Syntermitinae) / Reproductive and dispersive strategies in two soil-feeding termites, Embiratermes neotenicus and Silvestritermes minutus (Termitidae, Syntermitinae)

Fougeyrollas, Romain 16 December 2016 (has links)
Chez les insectes sociaux, les reproductrices doivent faire face à un dilemme entre coûts et bénéfices de la reproduction asexuée et sexuée. Récemment, il a été montré que les reines termites pouvaient résoudre ce dilemme en optant pour l’utilisation alternée de la reproduction asexuée et sexuée, en produisant des femelles secondaires néoténiques par parthénogenèse, et les ouvriers, soldats et futurs essaimants par reproduction sexuée. Cette stratégie, appelée AQS pour « Asexual Queen Succession », a été décrite chez trois termites souterrains xylophages de la famille des Rhinotermitidae. Deux espèces humivores appartenant à la famille des Termitidae et particulièrement abondantes en forêt néotropicale, Embiratermes neotenicus et Silvestritermes minutus (Syntermitinae), semblaient être des nouvelles candidates pour cette stratégie, car elles présentaient des nids menées par de nombreuses femelles néoténiques. Pour confirmer cette hypothèse et déterminer l’origine génétique de ces femelles, des castes stériles et des futurs essaimants, nous avons développé une banque de microsatellites spécifiques pour E. neotenicus et S. minutus, et génotypé une dizaine de colonies du site de Petit Saut en Guyane, pour chaque espèce. Nous avons confirmé que les castes stériles et les imagos étai ent issus pour la très grande majorité de reproduction sexuée, alors que les femelles néoténiques étaient issues de parthénogenèse avec fusion centrale, un mécanisme différent de celui décrit chez les Rhinotermitidae. La reconstruction détaillée du cycle de vie de S. minutus nous a permis de conclure que l’AQS, au-delà des bénéfices communs à toutes les espèces i.e. la succession de plusieurs générations de reproductrices sans dilution de la participation génétique de la reine fondatrice, l’augmentation du potentiel reproductif de la colonie et la prévention de la consanguinité chez les castes stériles et les imagos, permettait à cette espèce d’investir dans un seul évènement massif d’essaimage pendant un cycle de vie très court. D’autre part, nous avons réalisé une analyse de structuration génétique des colonies et des populations d’E. neotenicus et de S. minutus dans le but de comprendre les conséquences de la dispersion, des modalités d’appariement et de la participation des différents reproducteurs sur la consanguinité des colonies et la potentialité de colonisation de ces espèces. Pour environ 40 colonies de chaque espèce, nous avons montré que les reproducteurs fondateurs étaient très majoritairement non apparentés, et une absence de viscosité à une échelle locale (1 à 11 km), suggérant une dispersion importante des essaimants. De plus, seule une très faible structuration génétique a pu être détectée sur l’ensemble du site d’échantillonnage, indiquant des flux de gènes peu contraints / In social insects, reproductive females have to face a dilemma between costs and advantages of asexual and sexual reproduction. Recently, termite queens were shown to be able to solve this dilemma by using alternatively asexual and sexual reproduction, with the production of secondary neotenic females by parthenogenesis, and workers, soldiers and future alate reproductives by sexual reproduction. This strategy, called AQS for Asexual Queen Succession, was described in three subterranean xylophagous termites of the Rhinotermitidae family. Two soil-feeding species belonging to the Termitidae family, and particularly abundant in Neotropical forest, Embiratermes neotenicus and Silvestritermes minutus (Syntermitinae), seemed to be new candidates for this strategy since they showed colonies headed by numerous neotenic females. In order to confirm this hypothesis and determine the genetic origin of these females, of sterile castes and future imagoes, we developed specific microsatellite libraries for E. neotenicus and S. minutus, and genotyped about ten colonies for each species, on the site of Petit Saut in French Guiana. We confirmed that sterile castes and imagoes were mostly produced by sexual reproduction, while neotenic females were produced by parthenogenesis with central fusion, a mechanism different from that described in Rhinotermitidae species. The detailed reconstruction of S. minutus life cycle allowed us to conclude that AQS, in addition to advantages common to all species i.e. succession of queen generations with undiluted genetic input of the foundress, multiplication of reproductive potential of the colony and prevention of inbreeding in sterile castes and dispersers, would allow this species to optimize a single dispersal event within a very short life cycle. Otherwise, we realized an analysis of colony and population genetic structuration of both species in order to understand consequences of dispersion, mating strategies and parental allocation on inbreeding and colonization abilities of both species. For about 40 colonies of each species, we showed that most of founding reproductives were not related, and absence of genetic viscosity at a local scale (1 to 11 km) suggesting long dispersal flights of alates. Furthermore, only a weak genetic structuration was detected, indicating unfettered gene flows on the sampling site
63

Effects of an entomogenous nematode, Neoaplectana carpocapsae Weiser, on the Formosan subterranean termite, Coptotermes formosanus Shiraki, with ecological and biological studies on C. formosanus

Fujii, Jack K January 1975 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1975. / Bibliography: leaves 155-163. / xvi, 163 leaves ill. (some col.), map
64

Developmental flexibility and evolution of the worker caste in termites

Parmentier, Dominique January 2006 (has links)
Doctorat en Sciences / info:eu-repo/semantics/nonPublished
65

Field Survey of Native and Non-Native Subterranean Termites in Southeastern United States Forests

Blount, Nathan Allen 15 December 2012 (has links)
Subterranean termites are ecologically and economically important insects that play major roles in organic matter decomposition and nutrient cycling. The Formosan subterranean termite, Coptotermes formosanus Shiraki, is an invasive species known to cause significant damage in urban areas through aggressive consumption of wooden structures and infestations of living trees. Little is known about the presence and impact of C. formosanus in forested ecosystems of the southeastern U.S. as the majority of studies have taken place in urban settings. This study investigates the prevalence of C. formosanus in localized forests, as well as the utilization of living trees by C. formosanus and native subterranean termite species (Reticulitermes spp.). Recently harvested timber stumps were inspected for subterranean termite presence on sites throughout Mississippi and Louisiana. Alate light traps were utilized for further C. formosanus detection. Three sites yielded C. formosanus alate catches, while 7,413 stump inspections produced 406 Reticulitermes spp. infestations.
66

Morfofisiologia das castas e forrageamento do cupim de cerrado Velocitermes heteropterus (Isoptera: Termitidae) /

Haifig, Ives. January 2013 (has links)
Orientador: Ana Maria Costa Leonardo / Banca: Alexandre Vasconcellos / Banca: Hélida Ferreira da Cunha / Banca: Fabiana Elaine Casarin dos Santos / Banca: Eliana Marques Cancello / Capítulos 1 e 2 estão escritos em ingês e em formato de artigo / Resumo: Os cupins são insetos eussociais que apresentam divisão em castas entre os componentes das colônias. As castas apresentam adaptações morfofisiológicas para o melhor desempenho de determinadas funções e atividades comportamentais. A presente pesquisa objetivou analisar, do ponto morfológico, fisiológico e comportamental, as castas ápteras do cupim Velocitermes heteropterus que participam ativamente do forrageamento. No capítulo 1 deste volume é apresentado o estudo do polimorfismo da casta operária de V. heteropterus com duas subcastas, operários pequenos e grandes, baseado em caracteres morfométricos. Além disso, no capítulo 1 a rede de túneis escavadas por estes insetos foi caracterizada e as redes formadas por operários pequenos comparadas àquelas formadas por operários grandes e por grupos mistos dos dois tipos de operários. No capítulo 2 são apresentados os dados morfométricos dos outros componentes da linhagem áptera, ou seja, larvas e soldados, e também constam os dados de expressão gênica das celulases, os quais foram quantificados para ambos operários (pequenos e grandes) e soldados. Adicionalmente, no capítulo 2 é apresentado o sistema de desenvolvimento pós-embrionário da linhagem áptera de V. heteropterus. No capítulo 3 são apresentados dados sobre a dinâmica das trilhas de forrageamento de V. heteropterus. O fluxo de cupins saindo do ninho e retornando do alimento, a velocidade média individual e o número de colisões, bem como a distribuição espacial dos indivíduos nas trilhas, foram analisados durante as três primeiras horas desde o início do processo de forrageamento. A linhagem áptera de V. heteropterus apresenta um polimorfismo que está intimamente vinculado ao sexo e aos ínstares dos indivíduos. O polimorfismo dos componentes desta linhagem está relacionado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Termites are eusocial insects that exhibit a division in castes among the members of the colonies. The current research had the aim to analyze, on the morphological, physiological and behavioral points of view, the apterous castes of the termite Velocitermes heteropterus that actively participate in foraging. The castes show morpho-physiological adaptations to develop certain functions and behavioral activities. In the chapter 1 of this volume it is presented the study of the polymorphism in the worker caste of V. heteropterus with two subcastes, major and minor workers, based on morphometric characters. In addition, in the chapter 1, the tunnel network excavated by these insects is characterized and the networks excavated by minor workers are compared to those excavated by major workers and mixed groups containing the two types of workers. In the chapter 2, the morphometric data on the other apterous individuals are presented, i. e., larvae and soldiers, and it is shown the cellulase gene expression, which were quantified for both workers (minors and majors) and soldiers. Additionally, in the chapter 2, the post-embryonic developmental system of the apterous line in V. heteropterus is presented. In the chapter 3, it is exhibit data on foraging trail dynamics of V. heteropterus. The flow of termites leaving the nest and returning from the food, the individual speed and the number of collisions, as well as the spatial distribution of the individuals in the trails, were analyzed for the first three hours from the beginning of the foraging process. The apterous line exhibit a polymorphism intimately related to the sex and instars of the individuals. The polymorphism of the members of this line is related to a differential contribution of the subcastes in tunneling and foraging processes, but does not seem to influence the... (Complete abstract click electronic access below) / Doutor
67

Efeitos da ação de cupins sobre propriedades de um perfil de solo em uma vertente da Represa Billings - São Bernardo do Campo/SP / The termites as agents of the formation and functioning of the soil of a Represa Billings\'s hogback - São Bernardo do Campo/SP

Martins, Gustavo Mattos 30 January 2008 (has links)
Considerando a importância de cupins como agentes da formação e funcionamento do solo, foram estudados a morfologia, granulometria e alguns parâmetros químicos do solo de um ninho de cupins do gênero Conitermes e de suas adjacências, para identificar e discutir as ações destes animais sobre as suas características e propriedades, principalmente acões sobre a morfologia e a química do perfil. O estudo foi feito por meio de perfis de solo que passaram pelo monte externo de um cupinzeiro e adjacências. Nos perfis foram identificados e descritos os horizontes e suas transições, as propriedades do solo e as organizações (feições de origem biológica) ali existentes, como: canais, câmaras e microagregados A descrição morfológica contemplou os aspectos de cor, textura, macroestrutura e consistência do solo. A descrição química incluiu as determinações do pH, matéria orgânica, alumínio e cátions trocáveis (cálcio, magnésio, potássio e sódio). E a análise granulométrica contemplou as frações argila, silte e areia. Os resultados obtidos mostraram diferenças químicas apreciáveis entre o solo do monte do ninho e solo do entorno, principalmente para os seguintes atributos: conteúdo de matéria orgânica, concentração de alumínio e concentração de cátios trocáveis, principalemente o magnésio e o potássio. Foram encontradas uma série de feições, principalmente câmaras e canais verticais preenchidos, que demonstraram o trabalho realizado pelos cupins no perfil decorrentes dos hábitos construtores. Tais feições comprovaram que os cupins têm importante papel na pedoplasmação da alterita da rocha e na formação de domínios microagregados. / Considering the importance of termites as agents of the formation and functioning of the soil, were studied the morphology, particle size and some soil chemical parameters of a soil nest of termites of the genus Conitermes and its around, to identify and discuss the actions of these animals on their properties, mainly actions on the chemistry and morphology of the profile. The study was done through profiles of soil that passed through the hill of termites nest and around. In profiles were identified and described horizons and their transitions, the properties of the soil and organizations (features of biological origin) there, like: channels, chambers, and microgranular structure. The morphological description included the aspects of color, texture, structure and consistency of the soil. The chemical description included determinations of pH, organic matter, aluminum and cátions (calcium, magnesium, potassium and sodium) and the particle size analysis included the clay, silte and sand. The results showed chemicals appreciable differences between the soil of the hill nest and the surrounding soil, mainly for the following attributes: content of organic matter, aluminum concentration and concentration of cátions, mainly the magnesium and potassium. Was found a series of biological features, mainly filled chambers and vertical channels, which showed the work done by termites in the profile derived from the habits builders. Such features shown that termites have important role in pedoplasmation of saprolite zone and important role in the formation of microgranular structure.
68

Termite baiting system technology: utilization and evaluation for integrated management of Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) subterranean termite populations, with seasonal variation and spatial patterns exhibited in foraging strategies

Glenn, Grady J. 12 April 2006 (has links)
Commercial termite baiting systems were utilized and evaluated under real-world conditions in order to provide a comparison of efficacy in the management of subterranean termites. Three commercial termite baiting systems available for comparison included: FirstLine® (FMC Corp.), Sentricon® (Dow AgroSciences), and Terminate® (United Industries, Inc). The time required for foraging termites to locate and begin feeding on both the Sentricon® and the Terminate® bait stations was approximately one-half the time required to locate and begin feeding on the FirstLine® system, for both R. flavipes and C. formosanus. The time required for C. formosanus to locate and begin feeding on all termite baiting systems was approximately one-half the time required for R. flavipes. There were no significant differences in efficacy between the three baiting treatment systems against R. flavipes, with a mean of 84% efficacy for all systems. The Sentricon® system was able to achieve efficacy (88%) results with few additional residual liquid termiticide treatments. FirstLine® efficacy (80%) and Terminate® efficacy (84%) results required initial and subsequent multiple spot treatments with residual termiticide for comparable results. The Sentricon® baiting system yielded positive results in the management of C. formosanus, if utilized in an aggressive, active management program, involving multiple supplementary in-ground and above-ground bait stations at both points of active infestation and at areas with conditions conducive to infestation. Optimum results were achieved when monitoring of the bait stations occurred twice each month, rather than the standard monthly monitoring regime. The two termite baiting systems with Sulfluramid as the active ingredient required spot treatments with termiticides in order to protect the structures. Grids of bait stations were installed and termite activity and foraging strategies were monitored for a five-year period. Treatment with sulfluramid required 472 active ingredient tubes, over a 37-month period, in order to reduce subterranean termite populations. Observations of seasonal variation and spatial patterns of foraging by native subterranean termites, R. flavipes, in a typical urban/suburban setting provided information with direct application to an effective termite baiting system program.
69

Termite baiting system technology: utilization and evaluation for integrated management of Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) subterranean termite populations, with seasonal variation and spatial patterns exhibited in foraging strategies

Glenn, Grady J. 12 April 2006 (has links)
Commercial termite baiting systems were utilized and evaluated under real-world conditions in order to provide a comparison of efficacy in the management of subterranean termites. Three commercial termite baiting systems available for comparison included: FirstLine® (FMC Corp.), Sentricon® (Dow AgroSciences), and Terminate® (United Industries, Inc). The time required for foraging termites to locate and begin feeding on both the Sentricon® and the Terminate® bait stations was approximately one-half the time required to locate and begin feeding on the FirstLine® system, for both R. flavipes and C. formosanus. The time required for C. formosanus to locate and begin feeding on all termite baiting systems was approximately one-half the time required for R. flavipes. There were no significant differences in efficacy between the three baiting treatment systems against R. flavipes, with a mean of 84% efficacy for all systems. The Sentricon® system was able to achieve efficacy (88%) results with few additional residual liquid termiticide treatments. FirstLine® efficacy (80%) and Terminate® efficacy (84%) results required initial and subsequent multiple spot treatments with residual termiticide for comparable results. The Sentricon® baiting system yielded positive results in the management of C. formosanus, if utilized in an aggressive, active management program, involving multiple supplementary in-ground and above-ground bait stations at both points of active infestation and at areas with conditions conducive to infestation. Optimum results were achieved when monitoring of the bait stations occurred twice each month, rather than the standard monthly monitoring regime. The two termite baiting systems with Sulfluramid as the active ingredient required spot treatments with termiticides in order to protect the structures. Grids of bait stations were installed and termite activity and foraging strategies were monitored for a five-year period. Treatment with sulfluramid required 472 active ingredient tubes, over a 37-month period, in order to reduce subterranean termite populations. Observations of seasonal variation and spatial patterns of foraging by native subterranean termites, R. flavipes, in a typical urban/suburban setting provided information with direct application to an effective termite baiting system program.
70

Relations phylogénétiques chez les termites du genre Reticulitermes en Europe. Description d'une nouvelle espèce.

Uva, Paolo 08 November 2002 (has links) (PDF)
En Europe les termites du genre Reticulitermes (Isoptera : Rhinotermitidae) sont distribués dans la zone méditerranéenne, mais leur présence en milieu urbain est en cours d'expansion vers le Nord, et en dehors de leur aire de répartition naturelle.<br />Récemment un nouveau phénotype, R. sp. nov., a été identifié en milieu urbain en France et dans le Nord de l'Italie. La distribution ponctuelle des points de récolte et sa rareté en milieu naturel avaient suggéré une importation liée à l'activité humaine, comme cela est le cas pour de nombreuses espèces invasives. L'objectif de ce travail était de définir sa position systématique au sein du genre Reticulitermes et d'identifier son origine géographique.<br />Dans un premier temps, nous avons étudié les composés présents sur la cuticule des différentes espèces de termites Reticulitermes européens par chromatographie en phase gazeuse (GC) et GC couplée à la spectrométrie de masse. Nous avons montré l'existence d'un pattern original d'hydrocarbures pour ce phénotype, différent des autres espèces connues dans son aire de répartition, ainsi que de fortes similarités chimique et morphologique avec les populations de la région Est-méditerranéenne (Grèce, Israël, Turquie).<br />Nous avons également employé une approche moléculaire (séquençage de segments d'ADN mitochondrial et nucléaire) pour définir des relations phylogénétiques au sein du genre Reticulitermes, ce qui a permis de confirmer l'originalité du phénotype.<br />Les données moléculaires obtenues, en accord avec les données chimiques, à la fois par analyse séparée et combinée (évidence totale), suggèrent une origine des populations de R. sp. nov. à partir d'un refuge balkanique en suivant des routes de colonisation postglaciaires. Ceci nous permet donc d'élever ces populations à un statut spécifique, en proposant pour cette nouvelle espèce le nom de Reticulitermes urbis.

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