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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.
11

Termite foraging interactions with a protective barrier system

Aaron Stewart Unknown Date (has links)
The current application of low persistence pesticides is unreliable for protecting wooden structures from termite attack. These applications may also pose an environmental and public health risk. Consequently, there is a need for the development of alternative systems to protect wooden structures from termites. Investigated here is the interaction between Australian termites, Coptotermes acinaciformis Froggatt, and to a lesser extent, Mastotermes darwiniensis Froggatt and Schedorhinotermes seclusus Hill, and a barrier system for protection of wooden structures. The aim was to develop an improved barrier for the protection of wooden structures that maximizes protection and minimizes environmental and health risks. Specifically, the performance of a barrier to protect wood against termite attack that incorporates a synthetic pyrethroid into polyurethane formulations is investigated. This research was conducted in parallel with other project contributors focusing on material science aspects of the research goals. A fundamental problem in assessing the value of termite barrier strategies lies in developing and interpreting laboratory assays that can deliver reasonable predictions of performance in the field. This is particularly the case with respect to the behaviour of termites over much longer periods in the field than can be undertaken in the laboratory. The approach to laboratory trials presented here is to define individual termite capabilities and, in combination with behavioural studies, to develop an understanding of factors which affect termite performance. The key experimental approach involved various laboratory based assays to evaluate termite foraging behaviour and performance against a range of barrier materials, progressing to field trials with the best performing material. Various species of termites; M. darwiniensis (Mastotermitidae), Cryptotermes primus (Hill) (Kalotermitidae), C. acinaciformis , Coptotermes frenchi Hill and S. seclusus (Rhinotermitidae), Microcerotermes serratus (Froggatt), Microcerotermes turneri (Froggatt) and Nasutitermes walkeri (Hill) (Termitidae) and Porotermes adamsoni (Froggatt) (Termopsidae); were investigated to determine the force that they can develop at their mandible tips. Larger termites can generate higher pressures on their mandible tips than smaller termites. By quantifying the mandible strength of a termite it was possible to contrast the capabilities of various economic termite species. Damage caused by an individual termite biting on synthetic materials was measured using electron microscope generated three dimensional models of indentations caused to the material. This was successful in quantifying the immediate capabilities of individual termites of different species. Most species were found to inflict a similar amount of damage to high density polyethylene. However M. darwiniensis caused much more damage than other species examined. Micro hardness testing was utilized to determine the relative hardness of pest termite mandibles. Termites were found to have mandibles much harder than any tested synthetic material. It was therefore found to be unrealistic to aim to develop barrier technology based on “harder than termite mandible material”. Trials using groups of termites in the laboratory demonstrated large differences in the performance of termites against various synthetic materials. There was a tendency for harder materials to suffer less damage. Mechanical properties of the barrier alone were found to be insufficient to stop termite damage. The resistance of polyurethane formulations incorporating insecticides to termite attack in the laboratory demonstrated a potential suitability for termite barrier technology. In behaviour trials, persistence of termite attack at the barrier face was found to be due not only to deterrent chemicals, but also to physical characteristics. Softer materials are not only easier for termites to remove but termites attack softer materials with greater tenacity, more termites spend more time attacking softer materials. Laboratory toxicity trials confirmed the bioavailability of Bifenthrin when incorporated within the barrier material and enabled the establishment of expected concentrations for effective protection. Termites were found to require direct contact with the barrier for mortality to occur. Trials designed to quantify repellence of the Bifenthrin in the barrier found that termites did not escape mortality by avoiding contact with the barrier material. As such pure Bifenthrin is shown to protect the barrier material directly by causing mortality rather than by repelling live termites away from the barrier. Field trials were conducted in northern Queensland where colonies of economic termites could be directly targeted. Wooden blocks were coated in polyurethane containing a range of Bifenthrin concentrations and trialed over an eight month period. Combination of the pyrethroid Bifenthrin in a polyurethane barrier at concentrations as low as 0.07% proved successful in preventing damage by the economically important termites M. darwiniensis and C. acinaciformis under high pressure field conditions. Only very small amounts of Bifenthrin migrated into adjacent soil, concentrations reached were in the order of 100 µg/kg of soil. For comparison the MLR for Bifenthrin in bananas for human consumption is 100 µg/kg. Bifenthrin in a polyurethane barrier could be used for the protection of houses and other wooden structures in the same manner as existing barrier film technology in order to minimise environmental and health risks associated with direct pesticide application techniques.
12

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.
13

Pontos polêmicos acerca do forrageamento de cupins subterrâneos (Isoptera: Rhinotermitidae): consumo de alimentos similares, reutilização de iscas e tunelamento em solos não uniformes

Lima, Juliana Toledo [UNESP] 27 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-27Bitstream added on 2014-06-13T20:46:52Z : No. of bitstreams: 1 lima_jt_dr_rcla.pdf: 1902367 bytes, checksum: 643e995723baa05601e16df2db548e28 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Coptotermes gestroi e Heterotermes tenuis são espécies de cupins pertencentes à família Rhinotermitidae consideradas importantes pragas urbanas no Brasil, sendo que a segunda também é encontrada em ambientes agrícolas. No ambiente urbano, tais espécies são encontradas consumindo várias fontes celulósicas, algumas até aparentemente similares. O processo de forrageamento dos cupins subterrâneos é dinâmico e muda ao longo do tempo. Contudo, devido aos seus hábitos crípticos, existem alguns pontos polêmicos que precisam ser esclarecidos, principalmente visando melhorar e embasar as novas estratégias de manejo, tais como a tecnologia de isca. Em vista do exposto, a presente pesquisa propôs analisar e comparar, por meio de bioensaios, as respostas comportamentais de C. gestroi e H. tenuis considerando diferentes formas de apresentação do alimento e frente a recursos alimentares equivalentes. Uma vez que uma colônia pode utilizar várias fontes alimentares, também foi observado o comportamento de busca por novos alimentos, verificando o forrageamento desses insetos frente a recursos alimentares previamente visitados por outros cupins. Para esses bioensaios foram utilizados diferentes tipos de arenas experimentais compostas por câmaras “ninho” e câmaras alimentares. Adicionalmente, foi observado o comportamento de tunelamento dos forrageiros em solos heterogêneos, acrescidos de pistas físicas, químicas e biológicas, simulando aqueles presentes em áreas urbanas. Para tanto, foram utilizadas arenas bidimensionais compostas por duas placas de vidro separadas por uma moldura, a qual delimitava a área de tunelamento disponível para os indivíduos. Todos os dados obtidos foram analisados gráfica e estatisticamente, sendo que o nível de significância (a) adotado foi igual a 0,05. De acordo com os resultados obtidos nos experimentos com diferentes formas de apresentação... / Coptotermes gestroi and Heterotermes tenuis, termites of the Rhinotermitidae family, are considered important urban pests in Brazil. The latter is also found in rural areas. In urban environments, these species consume many cellulose sources, some apparently similar. The foraging behavior of subterranean termites is dynamic and changes throughout time. However, due to their cryptic behavior, some questions still remain, especially regarding the construction of a framework and the improvement of new control strategies involving baits. The present study was aimed at analyzing and comparing the behavioral responses of C. gestroi and H. tenuis using bioassays involving different food presentations and equivalent food resources. Since a colony can feed on many food sources, the searching behavior of new food items was examined as well as foraging of food items previously visited by other termites. Bioassays consisted of different types of arenas with a “nest” and feeding chambers were carried out. Also, the tunneling behavior of foragers in heterogeneous soils and physical, chemical, and biological cues was examined, simulating those present in urban areas. Bioassyas consisted of two glass plates separated by a frame delimitating the tunneling area available for the termites were carried out. The results were analyzed and significance level was set at p = 0.05. Based on the results obtained in the experiments with different forms of presentation of the food item, both species had similar behavioral patterns, showing a bias toward food items completely buried in the substrate. Regarding the exploitation of equivalent food sources, no differences were observed between consumption and recruiting for the first food sources visited compared to other sources available. Thus, C. gestroi and H. tenuis did not concentrate their efforts in the consumption of the first food item found. In tenacity... (Complete abstract click electronic access below)
14

Comportamento higiênico em cupins com diferentes nidificações / Hygienic behavior in termites with different nesting

Silva, Luiza Helena Bueno da [UNESP] 03 August 2017 (has links)
Submitted by Luiza Helena Bueno da Silva null (bueno.luizah@gmail.com) on 2017-10-02T13:04:18Z No. of bitstreams: 1 Dissertação Luiza.pdf: 2492240 bytes, checksum: 760cbfcbde8b0aca71cdc95bd132254b (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-02T18:31:27Z (GMT) No. of bitstreams: 1 silva_lhb_me_rcla.pdf: 2492240 bytes, checksum: 760cbfcbde8b0aca71cdc95bd132254b (MD5) / Made available in DSpace on 2017-10-02T18:31:27Z (GMT). No. of bitstreams: 1 silva_lhb_me_rcla.pdf: 2492240 bytes, checksum: 760cbfcbde8b0aca71cdc95bd132254b (MD5) Previous issue date: 2017-08-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presença de cadáveres no interior dos ninhos dos insetos sociais pode propiciar a contaminação com patógenos e prejudicar a integridade da colônia. O comportamento higiênico frente a cadáveres é imprescindível na manutenção da homeostase do ninho, mas em cupins ainda é pouco conhecido. Assim, o objetivo do presente trabalho foi estudar o comportamento higiênico diante de cadáveres de diferentes origens em três espécies de cupins com distintos tipos de nidificação. O cupim de madeira seca Cryptotermes brevis vive no interior do próprio alimento, o cupim Cornitermes cumulans constrói ninhos epígeos e o cupim Coptotermes gestroi é subterrâneo e constrói ninhos polidômicos. Diferentes bioensaios foram realizados com colônias de C. brevis e C. cumulans, nas quais foram introduzidos cadáveres de operários da mesma colônia, de outra colônia e de outra espécie. Adicionalmente, bioensaios foram realizados com subcolônias de C. gestroi (grupos de 300 operários e 15 soldados), nas quais foram inseridos cadáveres de operários e soldados da mesma colônia, de outra colônia e de outra espécie mortos recentemente e há 24 horas. Os bioensaios foram filmados e as respostas comportamentais dos indivíduos próximos aos cadáveres foram registradas. O repertório comportamental de C. brevis diante de cadáveres incluiu antenação, agonismo, alarme, recuo, grooming e consumo dos mesmos. Ninfas e falsos-operários de C. brevis consumiram os cadáveres, independentemente, da origem dos mesmos, mas evitaram a ingestão das partes quitinosas da cabeça. Nesta espécie, o consumo de cadáveres, além de desempenhar função higiênica, parece ser uma estratégia de aquisição de nitrogênio e água. O casal real das colônias de C. brevis observadas não participou do comportamento higiênico. O repertório comportamental de C. cumulans incluiu diferentes atividades, tais como: antenação, agonismo, alarme, recuo, grooming, deposição de material fecal, enterro com solo e transporte do cadáver para o ninho. Nesta espécie, corpos de origem interespecífica e intercolonial foram cobertos com solo após grooming. Corpos de companheiros de ninho foram enterrados (60% das repetições), carregados para o ninho (30%) ou ignorados após serem submetidos ao grooming (10%), o que indica uma plasticidade comportamental em C. cumulans. Em subcolônias de C. gestroi o repertório comportamental incluiu atividades como: antenação, recuo, grooming, agonismo, alarme, deposição de solo e consumo integral ou parcial do cadáver. Soldados de grupos de C. gestroi não consumiram ou enterraram cadáveres. Corpos de operários de diferentes origens foram discriminados por subcolônias de C. gestroi, o que não aconteceu com cadáveres de soldados com tempo de post-mortem maior. Cadáveres de cupins de outras espécies e de outras colônias foram enterrados após grooming por grupos de C. gestroi, porém companheiros de ninho foram preferencialmente canibalizados. O caráter higiênico do comportamento de grooming em cadáveres juntamente com o isolamento físico por meio do enterro dos mesmos com solo colabora para a não dispersão de patógenos entre membros da colônia. Os resultados do presente trabalho mostram que os cupins realizam o comportamento higiênico em cadáveres de térmitas de diferentes origens, contudo este processo foi mais simples em C. brevis, cupim com nidificação do tipo “uma peça”. Nos cupins “múltiplas peças” tais como C. gestroi e C. cumulans, o comportamento higiênico foi mais complexo, com recrutamento de indivíduos, mostrando que o manejo de cadáveres é essencial para o desenvolvimento e homeostase destes ninhos. / The presence of dead individuals inside nests of social insects can be a risk of contamination with pathogens and damage the integrity of the colony. The hygienic behavior towards corpses is essential in maintaining nest homeostasis, but in termites it is still little known. Thus, the objective of the present study was to observe the hygienic behavior towards corpses from different origins in three species of termites with distinct types of nesting. The drywood termite Cryptotermes brevis lives inside its own food, Cornitermes cumulans builds mound nests and Coptotermes gestroi is a subterranean termite that builds polydomous nests. Different bioassays were performed with colonies of C. brevis and C. cumulans, in which corpses of workers of termites from the same colony, from another colony and from another species were introduced. Additionally, bioassays of subcolonies of C.gestroi were performed in which corpses of workers and soldiers from the same colony, from another colony and from another species freshly dead and dead for 24 hours were introduced. The bioassays were recorded and the behavioral responses from the different species were registered. The results showed that the behavioral repertoire of C. brevis towards corpses included: antenation, aggression, alarm, retreat, grooming and consumption. Nymphs and pseudergates of C. brevis consumed the corpses independently of their origin, but they avoided the chitinous parts of the head. In this species, consumption of dead individuals, besides performing a hygienic function, seems to be a strategy of nitrogen and water acquisition. The royal couple of C. brevis colonies observed did not participate of the hygienic behavior. The behavioral repertoire of C. cumulans towards corpses included activities, such as: antenation, agression, alarm, retreat, grooming, deposition of fecal material, entombment and transport of corpse to the nest. In this species, inter-specific and inter-colonial corpses were covered with soil after being groomed. Nestmate corpses were entombed (60% of replications), transported to the nest (30%) or ignored after being submitted to grooming (10%), which indicates the behavioral plasticity of the C. cumulans species. In subcolonies of C. gestroi the behavioral repertoire included activities such as: antenation, retreat, grooming, aggression, alarm, deposition of soil, integral or partial consumption of corpses. Soldiers of C. gestroi subcolonies never consumed or buried corpses. However, corpses of workers from different origins were discriminated by C. gestroi subcolonies, which did not occurred with corpses of soldiers with longer period of post-mortem. Termite corpses from another species or from another colony were buried after being groomed by C. gestroi groups, but nestmate corpses were preferably cannibalized. The hygienic character of grooming behavior in corpses along with the physical isolation through entombment with soil contributes to the non-dispersion of pathogens among colony members. The results of the present study indicate that termites perform hygienic behavior in termite corpses from different origins, however, this process was less elaborate in C. brevis, one-piece nesting termite. In multiple-pieces nesting termites, such as C. gestroi and C. cumulans, the hygienic behavior was more complex, with recruitment of individuals, showing that the management of corpses is essential for the development and homeostasis of the termite nests.
15

Estudo do cupim Coptotermes gestroi = análise de genes diferencialmente expressos entre castas e busca de genes de importância biotecnológica / Study of the termite Coptotermes gestroi : analysis of differentialy expressed genes between castes and search for genes with biotechnological applicability

Leonardo, Flávia Costa 17 August 2018 (has links)
Orientadores: Gonçalo Amarante Guimarães Pereira, Fernando Ferreira Costa / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-17T10:30:44Z (GMT). No. of bitstreams: 1 Leonardo_FlaviaCosta_D.pdf: 6145744 bytes, checksum: 199799932d8959740a6ec52e8963bcb8 (MD5) Previous issue date: 2010 / Resumo: Os cupins são insetos pertencentes à Ordem Isoptera, com mais de 3.000 espécies descritas. São importantes agentes de degradação de madeira e compostos celulósicos em geral. Entretanto, essas mesmas características tornam algumas das espécies danosas por destruírem estruturas de edificações, sendo responsáveis por prejuízos da ordem de milhões de dólares. Uma destas espécies-praga é o Coptotermes gestroi. Originária do sudeste asiático foi introduzida no Brasil no início do século XX, estabelecendo-se ao longo daregião costeira, mas com uma clara expansão para o interior do país. O ciclo de vida de C .gestroi inicia com a eclosão do ovo, a larva originada pode se transformar tanto em um operário (linhagem áptera) como em uma ninfa (linhagem ninfal), a qual pode originar um rei ou uma rainha. Além disso, o operário pode se transformar em soldado, sob indução do hormônio juvenil. Assim sendo, o objetivo do presente trabalho foi a avaliação da expressão gênica nas diversas castas e estágios de vida de C.gestroi visando a identificação de genes relacionados ao ciclo de vida e com possível aplicação biotecnológica. Para isso,foi deita a análise de uma biblioteca de cDNA de cabeça de operários previamente construída. Para melhor compreender genes diferencialmente expressos entre as castas,outras quatro bibliotecas subtrativas foram confeccionadas. Alguns dos genes identificados foram genes selecionados para a validação pelo método de PCR em tempo Real. O seqüenciamento de segunda geração (454) foi realizado com amostras de soldados e operários e mais de 110.000 transcritos foram identificados. Dentre eles destacam-se as Hexamerinas I e II, a epóxido hidroláse do hormônio juvenil e genes relacionados à musculatura. Quanto aos genes com potencial biotecnológico dezenove enzimas envolvidasna quebram da lignocelulose foram identificadas e serão investigadas para confirmar o papel destas neste processo. / Abstract: Termites are insects belonging to the Order Isoptera, with more than 3,000 describedspecies. These insects are important wood and cellulosic compounds degraders. However, these same characteristics make some of them harmful species to mankind, by destroying buildings, accounting for million dollars losses. One of these pest species is Coptotermesgestroi. Originated from Southeast Asia, it was introduced in Brazil in the early twentieth century, establishing colonies along the coastal region, but with a clear expansion into thecountry. The life cycle of C. gestroi works as follows: after hatching from the egg, thelarvae can become either a worker (apterous lineage) or a nymph (nymphal lineage), whichcan lead to a king or a queen. In addition, the worker can become a soldier, under inductionof juvenile hormone. Therefore, the purpose of this study was the evaluation of gene expression in different castes and developmental stages of C.gestroi in order to identifygenes related to different life cycles and biotechnological potential. To accomplish this, weanalized a workers head cDNA library previously prepared. To better understand genes differentially expressed between castes, other four subtractive libraries were constructed. Some of the genes identified were selected for validation by Real Time PCR. Secondgeneration sequencing (454) was performed with samples of workers and soldiers and morethan 110,000 transcripts were identified. Among them stand out Hexamerins I and II, thejuvenile hormone epoxide hydrolase and genes related to muscle formation. As for geneswith biotechnological potential, nineteen enzymes involved in lignocellulose's break downwere identified and will be investigated to confirm their role in this process. / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular
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

Evaluation of Parameters Specified in AWPA standard E1-97: Standard Method for Laboratory Evaluation to Determine Resistance to Subterranean Termites

Lindsey, Gary Brian 01 May 2010 (has links)
This research focuses on the evaluation of many aspects of the American Wood Protection Association (AWPA) Standard E1-97, “Standard Method for Laboratory Evaluation to Determine Resistance to Subterranean Termites.” This standard is used extensively for testing the efficacy of new products and preservative systems against subterranean termite species. Research was done to determine what changes, if any, are needed for testing against subterranean termite species such as Coptotermes formosanus (Shiraki) and species of native termite genus Reticulitermes (Holmgren), primarily R. flavipes (Kollar). Variables from the current standard were tested to determine effects of parameters such as moisture of sand substrate; size, type, and location of test material within a test bottle; and termite number and ratios of workers to soldiers per test bottle. Research also improved comprehension of termite biology in a laboratory setting, enabling researchers to develop new and safer control methods.
18

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.
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Biodeterioração, anatomia do lenho e análise de risco de queda de árvores de tipuana, Tipuana tipu (Benth.) O. Kuntze, nos passeios públicos da cidade de São Paulo, SP / Biodeterioration, wood anatomy and falling risk analysis of tipuana, Tipuana tipu (Benth.). O. Kuntze trees, in the sidewalks of São Paulo city, SP

Brazolin, Sérgio 28 August 2009 (has links)
Os objetivos do presente trabalho foram: avaliar o processo de biodeterioração do lenho das árvores de tipuana na cidade de São Paulo e relacionar as alterações da sua estrutura anatômica e propriedades físico-mecânicas com o seu risco de queda. Nos passeios públicos de regiões selecionadas da cidade, 1109 árvores de tipuana foram caracterizadas quanto às condições de entorno, estado geral, variáveis dendrométricas, biodeterioração externa e interna e o risco de queda, estimado com modelo de cálculo estrutural desenvolvido pelo IPT. A biodeterioração e os mecanismos de resistência das árvores foram avaliados ao nível macroscópico e microscópico. As alterações nas propriedades do lenho de tipuana foram analisadas por densitometria de raios X e pelos ensaios físico-mecânicos (densidade de massa aparente; resistência à flexão) e aplicado o método de elementos finitos para análise da distribuição de tensões no lenho. As árvores de tipuana de elevada idade não apresentaram sinais de declínio, embora com estado geral considerado como crítico, pelo plantio em locais indequados, manejo inapropriado e/ou ocorrência de injúrias. O lenho foi deteriorado por fungos apodrecedores, cupins-subterrâneos e brocas-de-madeira, sendo os fungos e cupins os principais organismos xilófagos, afetando a região do cerne; a associção entre os fungos, os cupins, as variáveis dendrométricas e o risco de queda foram estatisticamente significantes ao nível de 5 %. O cupim-subterrâneo Coptotermes gestroi ocorreu em elevados níveis de infestação nas árvores, sendo considerado, no entanto, como um organismo-praga secundário, fortemente associado com lenho previamente apodrecido por Ganoderma sp.. Os fungos apodrecedores ocorrentes foram classificados como de podridão branca e mole, sendo a primeira mais comum no cerne das árvores. Como mecanismo de resistência à biodeterioração observou-se a compartimentalização do lenho, caracterizada pelo acúmulo de extrativos nas células. Os fungos xilófagos causaram reduções significativas na densidade de massa aparente, tensão de ruptura à flexão estática e módulo de elasticidade em estágios incipiente e intenso de apodrecimento do lenho. Ruptura do tronco e o risco de queda das árvores de tipuana relacionaram-se, principalmente, com a intensidade da deterioração do lenho e com a sua dendrometria. A alteração da distribuição das tensões no lenho foi analisada em relação ao estágio, tamanho e localização da deterioração no tronco das árvores de tipuana. / The objectives of the present work were to evaluate the process of biodeterioration in the wood of tipuana trees in the city of São Paulo and to relate the alterations in the anatomical structures and physical and mechanical properties with there falling risk. In the sidewalks of selected regions of the city, 1109 trees were characterized taking into consideration aspects as surroundings, general conditions, dendrometric variables, external and internal biodeterioration and falling risk estimated by using a structural model developed by IPT. The biodeterioration and the resistance mechanisms of the trees were evaluated at a macro and microscopic levels. The alterations on the wood properties were analysed by X-rays densitometry and by performing physical and mechanical tests (specific gravity; bending resistance); the tension distribution in the wood was analyze by finite-elements method. The old aged trees encountered, did not show any sign of decline, eventhough, the general aspect of their surroundings was critical by the inadequate places they were planted; inappropriate management and/or occurrence of injuries. The trees had their trunks deteriorated by xylophagous organisms, mainly fungi and subterranean-termites, and some wood borer beetle too, which affected the heartwood. The association between the presence of the first two organinsms, the dendrometric variables and the risk of falling, was statistically significant at the 5% level. The infestation of the trees by the subterranean-termite Coptotermes gestroi was at high levels, however, it was considered as a secundary plague-organism, because its attack was strongly associated with the previously decayed heartwood by Ganoderma sp.. The decaying fungi observed were classified as white rot and soft rot, being the white rot more common in the heartwood of the trees. As a resistance mechanism of the trees against biodeterioration, it was observed the compartimentalization of the wood characterized by the accumulation of extractives in the cells. Decaying fungi caused significant reductions in the following wood properties: specific gravity, rupture strength to bending and modulus of elasticity either in incipient or intense decay. Trees trunk rupture and falling risk were associated mainly to biodeterioration intensity and dendrometric variables. The alteration of tension distribution in the wood was analyzed in relation to the stage, size and position of the deterioration in the wood of the trees.
20

Xylophagous Insects: developments in feeding assays

Peters, Brenton Charles Unknown Date (has links)
Xylophagous borers and termites that damage "timber-in-service" cause millions of dollars loss annually throughout mainland Australia. I developed field-based feeding assays with practical relevance to preventative action and remedial treatment of infestations of xylophagous insects in the built environment. Essential to this work is facilitating a high termite risk by maintaining an environment conducive to sustained foraging by termites. Feeding assays conducted in low termite risk areas are unduly prolonged, with inherently erratic termite feeding responses. I successfully developed feeding assays with a high termite risk. To establish whether a physical barrier, retrofitted as a sleeve, could prevent termites from damaging wooden poles, eighty poles were established within Beerburrum State Forest, south-east Queensland, Australia. Poles within sets were interconnected with buried timber to facilitate a high risk to Coptotermes acinaciformis (Froggatt). Mesh sleeves to a depth of 1.5m did not prevent termite damage to the poles. Hoop pine Araucaria cunninghamii Ait. ex D.Don dowels ("dip-sticks") were useful termite monitoring devices on the poles. The depth of foraging by termites has implications for the effectiveness of retrofitted physical and chemical barriers in general. Timber quantity and quality has a pivotal influence on the aggregation of large numbers of feeding termites necessary for baiting work and for producing efficacy data of relevance to the protection of timber-in-service from termites. Seasonal variation in termite foraging was examined. Both C. acinaciformis and Coptotermes lacteus (Froggatt) were more active feeding in summer than in autumn. In general, mass loss followed mean ambient temperature. Suppression of C. acinaciformis feeding responses relative to C. lacteus during summer, particularly during January, is thought to be due to excessive temperatures in the containers attached to infested trees. Termite foraging behaviour and responses to both varying masses of softwood timbers and varying exposure times were investigated. The rate of mass loss was independent of the number of test specimens and appeared linear. Colonies regulate the number of foragers directly according to the mass of susceptible timber available. This phenomenon was exploited throughout the remainder of the thesis. Of particular significance was the considerable intra- and inter-specific variation in susceptibility of softwoods to C. acinaciformis and Mastotermes darwiniensis Froggatt. The sapwoods tested were susceptible, but the heartwoods were generally resistant to damage by termites. These data confirm that termites are discriminating feeders, and some more so than others. A novel methodology, developed to maintain an environment conducive to sustained foraging by termites during field-testing, is presented. Consistency in timber acceptance and susceptibility to termites is considered to be important in determining the frequency of inspection and the success of bait systems. I evaluate the termiticidal activity of the bait toxicants hexaflumuron and chlorfluazuron for the management of the subterranean termite C. acinaciformis in the field. The Sentricon Colony Elimination System with Baitube-devices containing 0.1% and 1% mass/mass (m/m) hexaflumuron bait toxicant in dry wood flour (Recruit) was successful in eliminating field colonies of C. acinaciformis. Similarly, the Exterra Termite Interception and Baiting System with cellulose-acetate powder containing either 0.05% m/m or 0.25% m/m chlorfluazuron (Requiem) eliminated C. acinaciformis. Indicators (including "dip-sticks") used to monitor colony health were reliable. By using C. acinaciformis, which builds mounds (epigeous nests) in northern Australia, I was able to avoid the use of multiple mark-release schemes to verify the effects of the bait toxicant on the termite colonies. Problems with multiple mark-release schemes, used elsewhere in the world, are discussed. I continued the focus on bait quality and placement by evaluating termite responses to two aspects of treated stakes, their attractiveness and their susceptibility. Three experiments were undertaken near Townsville and at Beerburrum, with Coptotermes and Schedorhinotermes. Whilst there were no significant differences in the rate of location and foraging, with respect to treatments, differences in foraging, with respect to C. acinaciformis and Schedorhinotermes seclusus (Hill) were significant. Coptotermes acinaciformis displayed greater foraging site tenacity than S. seclusus at Beerburrum. Increased consumption of bait, due to the addition of a phagostimulant, needs to be observed in the field before an increase in the efficacy of baits in a termite management program can be claimed. In Australia, softwood timbers are extensively used in building construction and are generally highly susceptible to damage by termites. I focussed on field feeding assays to test efficacy of borate-treated softwoods against termites and to define "adequate" protection thresholds. Laboratory and field data reported in the literature were confusing with regard to what constitutes "adequate" protection thresholds. The confusion was compounded by differences in termite species, timber species used and test methodology. Laboratory data indicated a borate loading of 0.5% m/m boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to 5%. Field data generally suggested that borate loadings in excess of 0.5% m/m BAE were required. The main contribution of the work to increasing our understanding of management options for termites in the built environment was in resolving the confusion between laboratory and field data for borate wood-preservatives. These apparently conflicting results were explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, retention of 0.5% BAE provides adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions are required. Furthermore, the retentions required increase with increased amounts of susceptible material. Some termites, Nasutitermes sp. and M. darwiniensis, for example, are borate-tolerant and borate wood-preservatives are not a viable management option. The lack of uniform standards for termite-test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of wood preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed. Whilst the majority of the work involves subterranean termites ("termites"), I examine the question of how to define a hardwood timber species as "not susceptible" to lyctine beetle damage. Aspects of the biology, behaviour and management of Lyctus brunneus (Stephens) are reviewed and a novel field sampling and testing protocol to establish lyctine susceptibility of timber species is presented. A sound understanding of the biology and behaviour of xylophagous insects in the field is essential to ensure that management options implemented in the built environment have a strong ecological basis. The success of this study in achieving stated aims, the need for further work and the implications for test methodologies in the field with practical relevance to infestations of xylophagous insects in the built environment are discussed.

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