• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 4
  • 1
  • Tagged with
  • 17
  • 17
  • 6
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 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.
11

Seleção de ingredientes ativos para o controle do cupim subterrâneo Coptotermes gestroi (Isoptera: Rhinotermitidae)

Casarin, Fabiana Elaine [UNESP] 20 August 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-20Bitstream added on 2014-06-13T20:46:52Z : No. of bitstreams: 1 casarin_fe_dr_rcla.pdf: 759241 bytes, checksum: 803110f7a1a06bc31e843e1cad93a654 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O cupim exótico Coptotermes gestroi (Wasmann, 1896) é a principal praga responsável por danos econômicos nas áreas urbanas da região sudeste do Brasil. No presente estudo foram realizados testes laboratoriais e de campo para avaliar a eficiência dos ingredientes ativos sulfluramida, hidrametilnona, ácido bórico, fipronil, piriproxifen e ciromazina para uso em iscas de controle desse cupim. Inicialmente, foram realizados experimentos em placas de Petri com o objetivo de selecionar as melhores concentrações de baixa toxicidade e que não fossem repelentes ou inibissem a alimentação dos cupins. As concentrações selecionadas foram usadas em uma segunda etapa de testes, nos quais foram utilizados um número maior de cupins. Os experimentos laboratoriais permitiram a seleção das seguintes concentrações para testes em campo: 0,01 ppm de sulfluramida; 200 ppm de hidrametilnona; entre 12.500 e 15.000 ppm de ciromazina; entre 1.000 e 12.500 ppm de piriproxifen; entre 3.000 e 2.000 ppm de ácido bórico. Somente, o ingrediente ativo fipronil não se mostrou adequado para uso em isca, devido à alta mortalidade obtida em todos os experimentos. Previamente aos testes de campo, foram estimados os territórios e as populações forrageiras das colônias de C. gestroi das áreas escolhidas. Os resultados de campo obtidos para C. gestroi nas áreas I (P.S.), II (L.U.) e III (S.O.R.) mostraram que não ocorreu nenhuma repelência ou inibição do consumo do papelão impregnado com os princípios ativos sulfluramida à 0,1 ppm, hidrametilnona à 400 ppm e ciromazina à 15.000 ppm. Contudo, o número de iscas e as concentrações utilizadas destes produtos não foram suficientes para eliminar nenhuma das colônias estudadas. Os resultados também sugerem que, em colônias naturais, as diferentes fontes alimentares exploradas pelos cupins subterrâneos e a competição... / The subterranean termite Coptotermes gestroi (Wasmann, 1896) is a pest of major economic importance in the urban environments of southeastern Brazil. In this study, we performed laboratory and field experiments to evaluate the efficacy of sulfluramid, hydramethylnon, boric acid, fipronil, pyriproxyfen and cyromazine as active ingredients in bait. In the first experiment, we tested different concentrations of these active ingredients in Petri dishes, searching for the best slow-acting and non-repellent concentrations for this termite. Concentrations selected from the initial experiment were used in a second laboratory experiment using a large number of individuals. From the results of this second experiment we selected the following concentrations to be fieldtested: 0.01 ppm of sulfluramid; 200 ppm of hydramethylnon; between 12,500 and 15,000 ppm of cyromazine; between 1,000 and 12,500 ppm of pyriproxyfen; between 3,000 and 2,000 ppm of boric acid. The data displayed a fast mortality of termites exposed to fipronil, even in small concentrations, therefore demonstrating that it is not a suitable chemical to be used in baits against C. gestroi. For field experiments, we estimated population and territory size from three colonies of C. gestroi present at the experimental site. Field results showed no repellence for site I (P.S.), II (L.U.) and III (S.O.R.) using sulfluramid 0.1 ppm, hydramethylnon 400 ppm, and cyromazine 15,000 ppm. However, the number of baited used at the selected concentrations were not sufficient to totally eliminate the colonies. This result suggests that, in natural colonies of subterranean termites, different food resources and competition, in this case with the native species Heterotermes tenuis, could influence the success of the control programs.
12

Toxicidade de produtos sintetizados a partir de extratos de plantas e do bistrifluron para o cupim subterrâneo Coptotermes gestroi (Wasmann, 1896) (Isoptera; Rhinotermitidae) /

Nascimento, João Paulo Reato. January 2009 (has links)
Orientador: Odair Correa Bueno / Banca: Marcos Roberto Potenza / Banca: Fabiana Elaine Casarin / Resumo: O cupim subterrâneo Coptotermes gestroi (WASMANN, 1896) é uma das principais pragas responsável por danos econômicos em estruturas de madeira nas áreas urbanas do litoral e interior do sudeste brasileiro. A metodologia mais empregada no controle de cupins subterrâneos é a aplicação direta de inseticidas no solo, porém esse tipo de tratamento não é destinado à eliminação da colônia e sim a formar uma barreira química entre a fonte de alimento que está sendo consumida e a colônia dos cupins. Essa barreira química também não evita que alados infestem prédios na época da revoada, pois eles não terão contato com os inseticidas. Essas infestações podem continuar sendo subterrâneas em porões de edificações ou podem ser aéreas, onde os cupins nidificam em espaços entre os andares dos edifícios, pois estes locais oferecem o ambiente ideal para os cupins com água, abrigo e alimento. Uma estratégia alternativa que visa à eliminação da colônia dos cupins subterrâneos é a utilização da metodologia de isca. Nas iscas o ingrediente ativo é incorporado a substratos que contenham celulose, sendo assim, a quantidade de inseticida usado é mínima, pois ele não pode ser repelente e precisa ter ação lenta e as partes não consumidas das iscas podem ser removidas depois do tratamento. No presente estudo foram realizados bioensaios laboratoriais com C. gestroi para avaliar a toxicidade de cinco substâncias que foram sintetizadas tendo como modelo a molécula da sesamina, sendo duas amidas e três compostos piperonílicos. Adicionalmente, foi analisado um inibidor de síntese de quitina, representado pelo bistrifluron. Os resultados revelaram que para as duas amidas e composto piperonílico 1, apesar de serem tóxicos, seriam necessários novos bioensaios com concentrações acima de 10 000 ppm para verificar se ocorre o aumento da dose ingerida pelos cupins. / Abstract: The subterranean termite Coptotermes gestroi (WASMANN, 1896) is a major urban pest that attacks wooden structures throughout southeastern Brazil. The most widely employed method to control subterranean termites is the direct application of insecticides on soil, however this method does not eliminate the colonies, but creates a chemical barrier between termites and their food. Moreover, this chemical barrier does not preclude infestation of buildings by alate reproductives during the reproductive season as they don't come in contact with the insecticides. The infestation may remain underground at basements or in the spaces between the stories of the buildings, as these sites offer the ideal habitat for termites with water, protection and food. An alternative strategy eliminating subterranean termite's colonies is the use of baits. In baits the insecticide is embedded in cellulose substrates, thus minimizing, the amount of insecticide used, which can't be repellent and has to have slow mode of action, generating easily removable unconsumed wastes. In this study, we performed laboratory bioassays with C. gestroi to evaluate the toxicity of five substances that were synthesized with a model of the molecule of sesamine, being two amides and three piperonyl compounds. Additionally, was analyzed a chitin synthesis inhibitor, represented by bistrifluron. The results showed that the two amides and piperonyl compound 1, although toxic, would have to be tested at concentrations above 10 000 ppm to verify if there is an increase in the uptake of insecticide. Piperonyl compounds 3 and 5 shown to be effective at the concentration of 10 000 ppm, but new bioassays would be needed to confirm this results. Bistrifluron proved efficient to be used in baits, although causing a reduction in the intake of food by termites, but didn't influence the effect of the insecticide... (Complete abstract click electronic access below) / Mestre
13

Toxicidade de produtos sintetizados a partir de extratos de plantas e do bistrifluron para o cupim subterrâneo Coptotermes gestroi (Wasmann, 1896) (Isoptera; Rhinotermitidae)

Nascimento, João Paulo Reato [UNESP] 22 October 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-22Bitstream added on 2014-06-13T19:00:00Z : No. of bitstreams: 1 nascimento_jpr_me_rcla.pdf: 245177 bytes, checksum: 75cec65a1ce5a11f6c59a601556a2179 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O cupim subterrâneo Coptotermes gestroi (WASMANN, 1896) é uma das principais pragas responsável por danos econômicos em estruturas de madeira nas áreas urbanas do litoral e interior do sudeste brasileiro. A metodologia mais empregada no controle de cupins subterrâneos é a aplicação direta de inseticidas no solo, porém esse tipo de tratamento não é destinado à eliminação da colônia e sim a formar uma barreira química entre a fonte de alimento que está sendo consumida e a colônia dos cupins. Essa barreira química também não evita que alados infestem prédios na época da revoada, pois eles não terão contato com os inseticidas. Essas infestações podem continuar sendo subterrâneas em porões de edificações ou podem ser aéreas, onde os cupins nidificam em espaços entre os andares dos edifícios, pois estes locais oferecem o ambiente ideal para os cupins com água, abrigo e alimento. Uma estratégia alternativa que visa à eliminação da colônia dos cupins subterrâneos é a utilização da metodologia de isca. Nas iscas o ingrediente ativo é incorporado a substratos que contenham celulose, sendo assim, a quantidade de inseticida usado é mínima, pois ele não pode ser repelente e precisa ter ação lenta e as partes não consumidas das iscas podem ser removidas depois do tratamento. No presente estudo foram realizados bioensaios laboratoriais com C. gestroi para avaliar a toxicidade de cinco substâncias que foram sintetizadas tendo como modelo a molécula da sesamina, sendo duas amidas e três compostos piperonílicos. Adicionalmente, foi analisado um inibidor de síntese de quitina, representado pelo bistrifluron. Os resultados revelaram que para as duas amidas e composto piperonílico 1, apesar de serem tóxicos, seriam necessários novos bioensaios com concentrações acima de 10 000 ppm para verificar se ocorre o aumento da dose ingerida pelos cupins. / The subterranean termite Coptotermes gestroi (WASMANN, 1896) is a major urban pest that attacks wooden structures throughout southeastern Brazil. The most widely employed method to control subterranean termites is the direct application of insecticides on soil, however this method does not eliminate the colonies, but creates a chemical barrier between termites and their food. Moreover, this chemical barrier does not preclude infestation of buildings by alate reproductives during the reproductive season as they don’t come in contact with the insecticides. The infestation may remain underground at basements or in the spaces between the stories of the buildings, as these sites offer the ideal habitat for termites with water, protection and food. An alternative strategy eliminating subterranean termite’s colonies is the use of baits. In baits the insecticide is embedded in cellulose substrates, thus minimizing, the amount of insecticide used, which can’t be repellent and has to have slow mode of action, generating easily removable unconsumed wastes. In this study, we performed laboratory bioassays with C. gestroi to evaluate the toxicity of five substances that were synthesized with a model of the molecule of sesamine, being two amides and three piperonyl compounds. Additionally, was analyzed a chitin synthesis inhibitor, represented by bistrifluron. The results showed that the two amides and piperonyl compound 1, although toxic, would have to be tested at concentrations above 10 000 ppm to verify if there is an increase in the uptake of insecticide. Piperonyl compounds 3 and 5 shown to be effective at the concentration of 10 000 ppm, but new bioassays would be needed to confirm this results. Bistrifluron proved efficient to be used in baits, although causing a reduction in the intake of food by termites, but didn’t influence the effect of the insecticide... (Complete abstract click electronic access below)
14

Laboratory and Field Studies on Subterranean Termites Native to the Eastern United States

Little, Nathan Shook 01 May 2010 (has links)
This study investigates modifications to AWPA Standard E18-06 to develop an above-ground field test for subterranean termites native to the eastern United States. AWPA Standard E18-06 was modified in two stages to progressively increase optimum conditions for subterranean termite feeding. Modification II, which incorporated the use of house bricks and feeder strips with a solid ventilated cover, had an increase in termite attack with less variation between tests. This study also investigates the effects of adding antioxidants, both natural and synthetic, and analogues which lack antioxidant properties, to test wood blocks on feeding by Reticulitermes flavipes Kollar using AWPA Standard E1-09. Antioxidants had feeding deterrence and mortality properties to R. flavipes. Conversely, the non-antioxidant analogues, with the exception of the heterocyclic flavanone, had little effect on R. flavipes. It is concluded that R. flavipes instinctively avoids wood which contains high levels of antioxidants, such as heartwood with phenolic extractives.
15

Implications for the detection, utilization, and degradation of bark beetle-attacked southern pines by subterranean termites

Little, Nathan S 11 May 2013 (has links)
Bark beetles regulate forest succession by removing weakened or stressed trees and exposing understory species to light from canopy gaps. Subterranean termites are predominate decomposers of coarse woody debris in southern pine forests; however, little is known about their role in forest health and succession. Both groups of insects rely heavily on fungal symbioses to fill their respective ecological niches in southern pine forests. During recent inspections of southern pine timber, we observed that trees in the early stages of bark beetle attack often had subterranean termites in blue-stained portions of the trunk. The frequency of subterranean termite presence in blue-stained areas of trees increased proportionally to the stage of bark beetle attack. However, practically no research has undertaken the challenge of describing how woody resources created by bark beetles are identified and utilized by subterranean termites before any signs of stress are visible. Therefore, this study examined possible facilitative interactions between subterranean termites, bark beetles and their blue-stain fungal associates, and other invertebrates, and investigated the effect of blue-stain fungi on surface properties of wood. Both native (Reticulitermes spp.) and Formosan subterranean termites exhibited a higher feeding preference for blue-stained sapwood than for unstained sapwood in laboratory assays. Native subterranean termites also consumed blue-stained sapwood at a higher rate than decayed wood. This study was the first to demonstrate that wood containing a non-decay fungus could elicit a feeding response from subterranean termites greater than that observed for decayed wood. Additionally, the surface properties of bark beetle-attacked southern pine were initially reduced by blue-stain fungal infection; however, the process of kiln-drying reversed this effect, resulting in a surface that was more conducive to wood product manufacturing.
16

Directed Movement of Subterranean Termites to Electromagnetic Frequencies

Ragon, Kevin W 05 May 2007 (has links)
This dissertation defines electromagnetic properties that are responsible for directing subterranean termite foraging behavior. Research identified specific frequencies and intensities that can attract Coptotermes formosanus Shiraiki and Reticulitermes flavipes (Kollar) to the site where the electrical fields are generated and defined on repellant freuency and intensity for C. formosanus. US Patent Docket Number 2343-215 PCT and MSU disclosure 05-0606-163 were filed based on the results. Data showed that frequencies and intensities were different for attracting the two species. Future work will address new alternatives for addressing termite infestations that will reduce and change the amounts and use of current termiticides.
17

Aspects of Management of Subterranean Termites in Queensland

Peters, Brenton Charles Unknown Date (has links)
i ABSTRACT I investigated aspects of the management of subterranean termites in the field by evaluating the protective values of preservative treated softwoods and evaluating the potential of softwoods conditioned by decay fungi or heat to produce termite monitoring and aggregating devices. As part of the investigation, it was necessary to: · develop assay techniques suitable for research into the natural resistance of timbers, the efficacy of wood preservatives and termite biology and foraging behaviour; and quantify variation in termite responses to untreated softwoods in various situations in the field using these techniques. Field bioassays were conducted with two Australian Coptotermes species to determine protection of pine sapwood afforded by borate compounds (Chapter 2). Coptotermes lacteus (Froggatt) was examined in winter and C. acinaciformis (Froggatt) in winter, spring and summer at two localities in Queensland. Hoop-(Araucaria cunninghamii Ait ex D. Don) and slash-pine (Pinus elliottii Engelm.)-sapwood blocks were placed in plastic containers and attached to termite mounds or infested trees. Termite response was determined by mass losses over five weeks and modelled. Coptotermes lacteus was relatively benign in winter and for 1.0 and 2.5% mass losses of hoop-pine sapwood, borate retentions of 0.20 and 0.06% mass/mass (m/m) boric acid equivalent (BAE), respectively, were derived. With C. acinaciformis, for 1.0 and 5.0% mass losses of hoop-pine sapwood, borate retentions ranged from 0.49 and 0.25% BAE, respectively, in winter to 0.76 and 0.47% BAE, respectively, in late summer. For 1.0 and 5.0% mass losses of slash-pine sapwood in summer, borate retentions of 0.58 and 0.14% BAE, respectively, were derived for C. acinaciformis. These results support conclusions from earlier laboratory studies conducted elsewhere. Prevention of damage by field populations of termites was not achieved. Marked intercolony variation in response to borate compounds was demonstrated, highlighting the usefulness of this rapid technique. The need for long-term field exposure trials to calibrate the lunch-box technique and to facilitate technology transfer to industry, is indicated. For comparison, termite response to white cypress (Callitris glaucophylla Thompson and Johnson), a naturally termite resistant timber, is also reported. A field bioassay was conducted to evaluate responses of C. acinaciformis to untreated southern-yellow-pine (Pinus spp.), hoop-pine and slash-pine blocks (Chapter 3). Sapwood blocks were placed in plastic containers and attached to trees infested with the termites during summer. Containers with a test block of each of the timber species were prepared. These and other containers were exposed to termites for 10 weeks. Termite feeding response (“voracity”) was assessed for all blocks by determining the mass of wood consumed. Termite voracity differed among trees. Variation in termite responses to individual hoop-pine feeder-blocks within a container was appreciable and consistent between containers. Variation in termite responses to the test blocks was appreciable, with hoop pine being significantly more susceptible to termite attack than either slash pine or southern yellow pine. Southern yellow pine is a generic name for five species of pine which are difficult to separate reliably. Therefore, caution should be exercised when using “southern yellow pine” to ensure that samples are at least from the same species of pine and preferably from the same length of timber. The sensitivity of both the bioassay and the statistical tests was demonstrated. Of particular interest was the similar level of termite response to the test timbers in the two sections of the experiment. The usefulness of feeder-blocks to initiate reliable attack rather than to promote sustained attack, is worth further attention. Sapwood stakes of Australian-grown hoop pine, slash pine, radiata pine and North American-grown southern yellow pine were exposed to subterranean termite attack in an in-ground bioassay (Chapter 4). Stakes in bait containers and bare stakes were attacked by C. acinaciformis and Schedorhinotermes intermedius (Brauer). Susceptibility of these timbers was evaluated with regard to potential for termite monitoring and aggregation. Variation between timbers and difference between termite species are described. The relevance of these data to suppressing foraging populations of subterranean termites, in Australia, using insect growth regulators, is discussed. Four field bioassays were conducted using two species of Australian subterranean termites, C acinaciformis and C. lacteus (Chapter 5). Hoop-pine blocks decayed using 14 fungi for four weeks and for 10 weeks were subsequently conditioned using dry heating, freezing or moist heating, and then exposed to termites. Blocks decayed by Gloeophyllum abietinum [Persoon: Fries] Murrill, Trametes lilacino-gilva (Berkeley) Wright & Deschamps, Schizophyllum commune Fries and Rigidoporus undatus (Persoon) Donk and subsequently oven dried, were attacked the most. Oven drying generally enhanced termite feeding responses in these two field bioassays. In a third bioassay, blocks of five softwood timber species conditioned with two high temperature regimes were exposed to C. acinaciformis. Slash pine was attacked the least. Mean mass losses for hoop pine, Caribbean pine (Pinus caribaea Morelet), radiata pine and the interspecific F1 hybrid between Caribbean and slash pine were not significantly different. For C. lacteus, slash and hoop-pine blocks were attacked the least while radiata pine was attacked the most. Additional heating at 105°C increased the susceptibility of most timber species. Relationships between heating duration and the consumption of hoop-pine-sapwood blocks were determined using results from a fourth bioassay. Heating the timber increased feeding responses for both termite species. The selective and rapid response of the termites highlights the usefulness of this field technique for multiple-choice bioassays. The cyclodiene termiticides were withdrawn from use, in Australia, as from 30 June 1995. Implications for the management of subterranean termites in Queensland are discussed. Community perceptions of the use of chemical pesticides and cost do not favour the widespread use of preservative treated timber in buildings. An integrated pest management approach to termite control is the likely direction for the future in Australia. A range of building techniques, regular inspections, and attention to factors that predispose existing buildings to termite attack can reduce the risk of damage from termites, but do not eliminate that risk. There will be an increased need for reliable preventative and remedial treatments involving bait technology. Much more work is needed on termite biology, foraging behaviour and bait toxicants before a baiting system can be confidently commercialised in Australia. Directions for research in Queensland are discussed.

Page generated in 0.2022 seconds