Thèse de doctorat : Génétique évolutive : Paris 12 : 2005. / Version électronique uniquement consultable au sein de l'Université Paris 12 (Intranet). Titre provenant de l'écran-titre. Bibliogr. : 213 réf.

Although termites serve the ecologically important function of converting dead trees into organic matter, they annually cause damage worth billions of dollars to human structures such as houses, power poles and bridges throughout the world. This led to the development of various chemical and physical measures that primarily aimed at preventing the termites from causing damage to wooden structures. While the adverse effects of the chemical methods on the environment and human health has made them widely unacceptable, physical methods are costly and difficult to implement. There is a specific need to develop an environment friendly, cost effective, easily applicable and durable alternative barrier that would effectively protect a wide range of wooden structures. This study aims at designing and developing an eco-friendly, robust and easy to apply barrier material to protect wooden structures. Ether polyurethane (EPU) was chosen as the base material considering its toughness, resilience, hydrolytic stability due to the presence of ether group and easy applicability on large, irregular surfaces. EPU was upgraded to a ‘termite effective’ material by the incorporation of a synthetic pyrethroid, Bifenthrin®. Bifenthrin® was chosen over other termiticides due to its less pervasive nature to the environment along with its repellent/ killer effect on termites. The EPU/ Bifenthrin® system incorporates the specific features of durability of the polymer and slow release of Bifenthrin®, making it more acceptable to the environment and public health. Termite damage resistance of EPU was analyzed by testing the polymer, along with various other polymers (HDPE, PP, PVC and Nylon), with Coptotermes acinaciformes and correlating the termite properties (mandibular force, hardness) with those of the polymeric materials (surface and tensile properties). EPU resisted termite damage, though its softer form incurred 5 times more material damage than the robust cast type. EPUs with high values of hardness incurred ~40% less damage than HDPE and were comparable with the damages on PP. The depth and width of termite damage on HDPE was 5 and 4 times, respectively, than that of PVC. This part of the study inferred that, although hardness of polymeric materials helps prevent termite damage, toughness and resilience too can make it difficult for termites to find a pathway through the material. XPS, FTIR, termite mortality bioassays in an applied setting and elusion tests of Bifenthrin® from EPU in water, acetone and soil were employed to understand the interaction of EPU with Bifenthrin®. Water and soil were chosen as test mediums due to their practical nature. These studies confirm that Bifenthrin® at concentrations as low as 0.5 wt% enriches the surface of EPU due to preferential migration of CF3 group to the surface of EPU. Furthermore, Bifenthrin® incorporated in EPU does not compromise its insecticidal activity and diffuses in a controlled manner at the rate of ~10–8 cm2 s–1 and ~10–7 cm2 s–1 when kept in water and soil media respectively. The durability of EPU/ Bifenthrin® system was analyzed by conducting degradation studies on EPU. The effect of Bifenthrin® on the ageing of EPU was also investigated. The studies involved ageing of the system in natural and accelerated conditions and validating the results by use of Arrhenius models. The sub-soil conditions do not degrade EPU beyond the oxidative levels as the activation energy required to cause changes in properties of EPU are unphysically small (0.02 kJ mol-1). It was found that EPU can sustain its physical integrity for 12 years at room temperature and Bifenthrin® may remain in a 5 mm thick barrier material for up to 10 years. The effect of Bifenthrin® on the tensile properties of EPU is negligible. Studies to analyze the performance of the barrier material, involved testing of timber coated with the EPU/ Bifenthrin® system under real-life conditions against termites in field trials located at two tropical locations in Northern Queensland. EPU/ Bifenthrin® system with nominal concentrations of Bifenthrin® incurred no damage when the concentration of Bifenthrin® was above 0.07 wt% in EPU. The degradation of Bifenthrin® under sub-soil conditions is unlikely. Given that favourable characteristics of EPU and Bifenthrin® the design and development an effective and long-lasting termite barrier material seems feasible.

Although termites serve the ecologically important function of converting dead trees into organic matter, they annually cause damage worth billions of dollars to human structures such as houses, power poles and bridges throughout the world. This led to the development of various chemical and physical measures that primarily aimed at preventing the termites from causing damage to wooden structures. While the adverse effects of the chemical methods on the environment and human health has made them widely unacceptable, physical methods are costly and difficult to implement. There is a specific need to develop an environment friendly, cost effective, easily applicable and durable alternative barrier that would effectively protect a wide range of wooden structures. This study aims at designing and developing an eco-friendly, robust and easy to apply barrier material to protect wooden structures. Ether polyurethane (EPU) was chosen as the base material considering its toughness, resilience, hydrolytic stability due to the presence of ether group and easy applicability on large, irregular surfaces. EPU was upgraded to a ‘termite effective’ material by the incorporation of a synthetic pyrethroid, Bifenthrin®. Bifenthrin® was chosen over other termiticides due to its less pervasive nature to the environment along with its repellent/ killer effect on termites. The EPU/ Bifenthrin® system incorporates the specific features of durability of the polymer and slow release of Bifenthrin®, making it more acceptable to the environment and public health. Termite damage resistance of EPU was analyzed by testing the polymer, along with various other polymers (HDPE, PP, PVC and Nylon), with Coptotermes acinaciformes and correlating the termite properties (mandibular force, hardness) with those of the polymeric materials (surface and tensile properties). EPU resisted termite damage, though its softer form incurred 5 times more material damage than the robust cast type. EPUs with high values of hardness incurred ~40% less damage than HDPE and were comparable with the damages on PP. The depth and width of termite damage on HDPE was 5 and 4 times, respectively, than that of PVC. This part of the study inferred that, although hardness of polymeric materials helps prevent termite damage, toughness and resilience too can make it difficult for termites to find a pathway through the material. XPS, FTIR, termite mortality bioassays in an applied setting and elusion tests of Bifenthrin® from EPU in water, acetone and soil were employed to understand the interaction of EPU with Bifenthrin®. Water and soil were chosen as test mediums due to their practical nature. These studies confirm that Bifenthrin® at concentrations as low as 0.5 wt% enriches the surface of EPU due to preferential migration of CF3 group to the surface of EPU. Furthermore, Bifenthrin® incorporated in EPU does not compromise its insecticidal activity and diffuses in a controlled manner at the rate of ~10–8 cm2 s–1 and ~10–7 cm2 s–1 when kept in water and soil media respectively. The durability of EPU/ Bifenthrin® system was analyzed by conducting degradation studies on EPU. The effect of Bifenthrin® on the ageing of EPU was also investigated. The studies involved ageing of the system in natural and accelerated conditions and validating the results by use of Arrhenius models. The sub-soil conditions do not degrade EPU beyond the oxidative levels as the activation energy required to cause changes in properties of EPU are unphysically small (0.02 kJ mol-1). It was found that EPU can sustain its physical integrity for 12 years at room temperature and Bifenthrin® may remain in a 5 mm thick barrier material for up to 10 years. The effect of Bifenthrin® on the tensile properties of EPU is negligible. Studies to analyze the performance of the barrier material, involved testing of timber coated with the EPU/ Bifenthrin® system under real-life conditions against termites in field trials located at two tropical locations in Northern Queensland. EPU/ Bifenthrin® system with nominal concentrations of Bifenthrin® incurred no damage when the concentration of Bifenthrin® was above 0.07 wt% in EPU. The degradation of Bifenthrin® under sub-soil conditions is unlikely. Given that favourable characteristics of EPU and Bifenthrin® the design and development an effective and long-lasting termite barrier material seems feasible.

Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-04-15Bitstream added on 2014-06-13T19:46:43Z : No. of bitstreams: 1 haifig_i_dr_rcla.pdf: 2054555 bytes, checksum: 803fbe5e3da776dfaa8be8546198a21a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / 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... / 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)

Orientador: Ana Maria Costa Leonardo / Banca: Maria Santina de Castro Morini / Banca: Ives Haifig / Resumo: 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 evitar... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: 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 ... (Complete abstract electronic access below) / Mestre

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.

Orientador: Ana Maria Costa Leonardo / Banca: Silvana Beani Poiani / Banca: Maria Santina de Castro Morini / Banca: Ives Haifig / Banca: Alexsandro Santana Vieira / Resumo: As colônias de insetos sociais constituem grupos de indivíduos que vivem juntos e se reproduzem como uma unidade, sendo a divisão de trabalho entre os companheiros de ninho uma das mais importantes características dessas colônias. A alocação de trabalho pode ser baseada em casta, sexo, tamanho ou idade dos indivíduos e este processo é denominado polietismo, que pode ser temporal e, nesse caso, o desenvolvimento da tarefa está ligado a idade e a fisiologia do indivíduo. O desenvolvimento de glândulas exócrinas está relacionado com essas atividades e tarefas. As lacunas existentes no conhecimento atual do polietismo em Isoptera dizem respeito a grande dificuldade de observar o comportamento dos cupins em ambientes naturais, devido ao hábito críptico destes insetos. Visando elucidar a divisão de trabalho de reis e rainhas na parte de cuidados com os ovos e larvas na espécie exótica Coptotermes gestroi e na espécie nativa Cornitermes cumulans foram realizados estudos comportamentais e estudos morfológicos das glândulas salivares em diferentes fases da vida destes reprodutores. Estes estudos morfológicos envolveram histologia, histoquímica e morfometria dos ácinos das glândulas salivares de reis e rainhas. O cuidado biparental é uma importante estratégia para a sobrevivência dos insetos e representa um avanço na adaptação ao ambiente. Nos insetos sociais, como os cupins, o cuidado com ovos e a alimentação dos imaturos é tarefa dos operários, no entanto, no início da fundação de um... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Colonies of social insects constitute groups of individuals which live together and reproduce as a superorganism, and the most important characteristic of such colonies is a complex division of labor among nestmates. The task allocation may be based on the caste, sex, size and the age of the individuals, and this process is termed polyethism, which may be temporal and, in this case, the task development is associated to the age and physiology of the individual. The development of exocrine glands is associated to these colonial activities and tasks. The current knowledge gaps concerning the polyethism in Isoptera are consequences of the difficulty in observing the behavioral repertories performed by termites under natural conditions, especially due their cryptic habit. Aiming to elucidate the division of labor between kings and queens related to eggs and larval care in the exotic species Coptotermes gestroi and in the native species Cornitermes cumulans, behavioral bioassays and morphological studies of the salivary glands were performed on different life phases of these reproductives. These morphological studies involved histology, histochemistry and morphometry of the salivar acini of kings and queens. The biparental care is an important strategy for insect survival and represent an advance during the adaptation to the environment. Among the social insects, case of the termites, workers care for eggs and feed the immatures, although these tasks are performed by the royal cou... (Complete abstract click electronic access below) / Doutor

The overall aim of this study was to provide new and updated information about subterranean termite morphology and digestive physiology. Scanning electron microscopy was used to obtain high resolution images of morphological features of the termite cuticle not discernable by light microscopy. In addition, digital scanning electron micrographs clearly show the appearance of wood particles recovered from the termite digestive tract at different stages of digestion. The ability of termites to obtain and conserve nitrogen in their diet was demonstrated by establishing whether the insect can digest chitin, as well as from determination of levels of soluble proteins and uric acid in the feces. Finally, a technique for determining the efficiency of cellulosic food digestion was tested. Scanning electron microscope images of alate abdomens showed similar appearance of cuticular structures between two subterranean termite species. In addition, the high magnification of electron microscopy allowed for identification of a pair of cuticular structures in the vicinity of the female genitalia that had not been reported from previous light microscope studies. Scanning electron microscopy also revealed the appearance of wood undergoing degradation as it traverses worker termite digestive tract, showing detail not possible from light microscope images. Adult workers of a native termite species were found to produce the enzymes needed to digest chitin, a nitrogen containing polysaccharide ingested by termites. Specific activity of chitinase was subsequently determined to establish the efficiency of chitin digestion for the termite species tested. As termites are coprophagous, significant levels of proteins measured from the feces demonstrated an additional potential dietary nitrogen source. Uric acid was generally found to be absent from termite feces, however. Digestive efficiency of wood cellulose could not be determined for Formosan termites due to the inability to obtain sufficient feces for quantification of undigested food contained in it. Previous studies of Formosan termite digestive efficiency did not address difficulty in obtaining feces for assay. Therefore, interpretation of data from earlier studies of Formosan termite digestive efficiency should be viewed with caution.

No description available.

Reticulitermids were significantly more likely to discover subterranean baits connected by physical guidelines than freestanding baits under both laboratory and field conditions. In the laboratory, subterranean termites built significantly longer tunnels adjacent to cellulosic guidelines than plastic guidelines. In the field, all guideline materials were equally effective at directing tunneling activity. Reticulitermes spp. workers were tested to determine their preferred substrate temperature. The preferred range for Reticulitermes spp. workers was found to be 18 to 27 degrees C. A laboratory bioassay was performed to determine if Reticulitermes spp. aggregates within thermal shadows. Significantly more Reticulitermes spp. workers aggregated within cool thermal shadows than control areas. In a multiple choice bioassay, mean consumption was higher for paper baits treated with fructose, galactose, glucose, raffinose, sucrose, trehalose and uric acid than for control baits. In a multiple choice bioassay, mean consumption was significantly lower for baits treated with arbutin, and most amino acids than for control baits. In the no-choice bioassay, the amount of paper bait consumed did not differ significantly for any of the treated baits tested and control baits. / Ph. D.