Made available in DSpace on 2014-06-11T19:34:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-01-26Bitstream added on 2014-06-13T20:25:39Z : No. of bitstreams: 1 rosa_jmo_me_botfca.pdf: 472277 bytes, checksum: 14a0b218861a6342b7c87ff0e0657503 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No Brasil, Cornitermes cumulans é uma das espécies de cupim mais freqüentes, principalmente nas regiões sul, sudeste e centro-oeste do país. Causam danos diretos e indiretos em várias culturas agrícolas. Os nematóides das famílias Steinernematidae e Heterorhabditidae têm sido considerados agentes promissores no controle biológico de pragas, inclusive para cupins. Com a finalidade de avaliar a possibilidade de utilização desses nematóides no controle de Cornitermes cumulans, a presente pesquisa teve como objetivo verificar a suscetibilidade de C. cumulans a diferentes isolados de Steinernema e Heterorhabditis. De acordo com os resultados obtidos na primeira fase, S. carpocapsae foi o isolado mais patogênico às castas de C. cumulans. Na segunda fase da pesquisa, a patogenicidade desse isolado à C. cumulans foi estudada em colônias artificiais, nas concentrações de 133, 166, 267, 332 e 533 juvenis infectivos (JI)/inseto, e duas formas de exposição (substrato e alimento). Nesta fase também foi conduzido um experimento em placas de Petri utilizando as concentrações de 2.000 e 4.000 JI/inseto. O isolado S. carpocapsae foi patogênico a C. cumulans, em todos os experimentos, proporcionando 100% de mortalidade dos insetos. / In Brazil, Cornitermes cumulans is one of the most frequent termite species, mainly in the south, southeast and center-west of country. They cause direct and indirect loss many crops. The nematodes of Steinernematidae and Heterorhabditidae families have been considered promising agents for the biological control of pests, including for termites. With the purpose of evaluating the possibility of use those nematodes for the Cornitermes cumulans control, this research had the objective to verify the susceptibility of C. cumulans to different isolates of Steinernema and Heterorhabditis. According to the results obtained in the first phase, S. carpocapsae was the most pathogenic one to C. cumulans castes. In the second phase of the research, the effect action of this nematode to C. cumulans was investigated in artificial colonies, in different concentrations (133, 166, 267, 332 and 533 juveniles infectives (JI)/insect), and two exhibition forms (substratum and food). An experiment in Petri dishes was also conducted with two concentrations (2.000 and 4.000 JI/insect). The S. carpocapsae isolate was pathogenic to C. cumulans, for all experiments, providing 100% mortality of insects.

Chez de nombreuses espèces d'insectes sociaux, le nid joue un rôle central dans la survie de la colonie. Une fonction supposée du nid est d'assurer une protection contre les fluctuations climatiques importantes. Il est donc nécessaire d'étudier la façon dont les nids construits par les animaux régulent les facteurs abiotiques et réciproquement comment ces facteurs modulent le comportement constructeur et en conséquence l'architecture de ces nids. Pour toutes ces questions, des réponses partielles et fragmentaires existent dans la littérature. Le premier objectif de cette thèse consiste à étudier les propriétés thermorégulatrices supposées des nids de termites. Nous avons choisi comme modèles d'étude deux espèces de termites du cerrado brésilien, Cornitermes cumulans et Procornitermes araujoi. Ces deux espèces sympatriques construisent toutes les deux des nids composés d'une partie hypogée et d'une partie épigée. Si les nids de ces deux espèces offrent une morphologie externe similaire, les architectures internes diffèrent nettement et les parois externes semblent également posséder des propriétés différentes. Nous avons exploré si ces différences de structure étaient liées à des différences dans leurs propriétés thermorégulatrices. Nous avons enregistré les températures dans les nids de ces deux espèces et proposé une méthodologie pour étudier la dynamique de diffusion de la chaleur en leur sein. Des mesures de l'humidité relative, plus difficiles à traiter, sont également discutées. En complément de ces travaux de terrain, nous avons testé la survie des termites soumis à différentes conditions de température et d'hygrométrie. Ces expériences ont permis de tester l'hypothèse d'adaptation des individus aux conditions abiotiques potentiellement différentes, en relation avec les milieux de vie de ces deux espèces. Le second objectif de cette thèse vise à apprécier l'effet des facteurs abiotiques, notamment de la température, dans les processus de construction du nid. En effet, les facteurs abiotiques sont connus pour affecter les comportements des insectes, aussi bien au niveau individuel que collectif. Pour aborder ce sujet, nous avons travaillé avec la fourmi Lasius niger dont le comportement constructeur, analogue à celui des termites, a déjà été modélisé. Cette espèce de fourmi très commune dans l'hémisphère nord, construit un nid également composé d'une partie sous-terraine et d'une partie épigée, comme les deux espèces de termites étudiés. En laboratoire, les ouvrières de L. niger construisent en quelques heures des piliers qu'elles finissent par recouvrir de plafonds formant les premières bases de la construction. Nous avons étudié le comportement de construction des fourmis sous différentes conditions de températures afin de mesurer l'effet de ce paramètre abiotique sur l'architecture des structures émergentes. Une analyse quantitative et qualitative de l'architecture a été réalisée après avoir scanner ces structures à l'aide d'un scanner de surface et d'un tomographe à rayon X. Avant d'étudier le comportement constructeur, nous avons préalablement réalisé une expérience visant à étudier le préférendum thermique des fourmis. Nos résultats indiquent que la régulation des températures dans les nids suit l'équation classique de la chaleur où l'architecture pourrait jouer un rôle sur la dynamique de diffusion dans le nid. Les facteurs abiotiques étudiés ont un effet sur la survie des termites, la distribution des fourmis et l'architecture émergente, en accord avec les prédictions d'un modèle de construction précédemment établi. Cependant, nous restons loin d'une compréhension globale de l'interaction entre la régulation des facteurs abiotiques par le nid, leur effet sur l'architecture de ce dernier et leur influence sur les traits d'histoire de vie des individus qui l'occupent. / For many social insects, the nest is a central element for the colony's survival. A presumed function of the nest is to ensure protection against climatic fluctuations of the environment. One has to ask how the nests achieve to regulate such abiotic factors, and whether this factors modulate the construction behavior and thus the architecture of the nests. For all these questions only partial and fragmentary answers exist in the literature. The first aim of this thesis was to investigate the putative thermo regulating property of termite nests. We focused on two termite species found in the Brazilian cerrado: Cornitermes cumulans and Procornitermes araujoi. These two sympatric species both build nests consisting of an hypogeous and of an epigeous part. If these structures might seem similar, the internal architecture and the nest composition are quite different. We first aim to investigate whether these differences between the two structures influence their thermo regulating property. To do so, we monitored the temperatures inside the nests of the two species and we proposed a methodology to study the heat diffusion dynamics inside the structures. We also monitored the relative humidity, a factor that is essential for termite survival but that proved to be more complicated to understand. To complement this field work, we tested the survival of the two termite species in different conditions of temperature and relative humidity to test whether they present some adaptations to resist to such conditions related to their living environment. The second aim of this thesis was to study the effects of abiotic factors and more precisely temperature on the nest construction process. In fact, abiotic factors are known to affect insects' behavior, as much on the individual than on the collective level. Here we used the ant Lasius niger in which the construction behavior had already have modelled. This really common species of the northern hemisphere build a nest also made of an hypogeous and of an epigeous part. In the lab, the workers quickly build pillars that they covered by caps and thereby established the first basis of the structure. We performed an experiment where we constrained ants to build under different temperature conditions to test the effect of this abiotic factor on the emerging architecture. It is then possible to establish a quantitative and qualitative description of the architecture by scanning the structure thanks to a surface scanner or with X-ray tomography. Before studying the construction behavior, we first did an experiment to study the ants thermal preferendum. We found temperature regulation in the nest to follow the common heat equation where architecture only modifies the speed of heat diffusion in the nest. The studied environmental factors had complex effects on termite survival, ant distribution and the emerging ant architectures, the latter in agreement with the predictions of the construction model. However, we are still far from a coherent understanding of the interplay between the regulation of abiotic factors by the nest, their effect on his architecture architecture, and their influence on the animal's life history parameters.

Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-10-03T13:39:14Z No. of bitstreams: 1 texto completo.pdf: 16340145 bytes, checksum: ca5e3dfd61690ddf655c96a0e55b1549 (MD5) / Made available in DSpace on 2017-10-03T13:39:14Z (GMT). No. of bitstreams: 1 texto completo.pdf: 16340145 bytes, checksum: ca5e3dfd61690ddf655c96a0e55b1549 (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Uma resposta comum de animais sociais à pressão de predação é alocar alguns indivíduos para a função de defesa. Em cupins, a evolução da casta de soldados, parece ter ocorrido como uma resposta extrema a predação, uma vez que são morfofisiologicamente adaptados à defesa, estéreis e incapazes de se alimentarem sozinhos. No entanto, Vários estudos têm mostrado a participação ativa da casta de soldados em tarefas de exploração do espaço como forrageio. Ditas observações são relevantes pois a alta contribuição dos operários em defesa sugere que os soldados tem um grau de redundância nas colônias de cupins. Tal redundância parece ocorrer em Cornitermes cumulans, no qual os operários são mais participativos que os soldados na defesa do ninho. Aqui nós hipotetizamos que uma forma de diminuir o custo da casta de soldados é que eles sejam capazes de fazer mais do que só defender. Especificamente, prevemos que tal contribuição deve ser otimizar estratégias de busca. No experimento de caminhamento com C. cumulans encontramos que a velocidade média de deslocamento dos operários cresce não-linearmente com a presença de sol- dados. Esse resultado e a presença de padrões de movimento altamente coerentes com vôo de Lévy sugerem que os soldados reforçam a capacidade exploratória dos operários em C. cumulans. A eficiência na exploração do espaço na presença de soldados pode estar contribuindo na entrada de recursos na colônia e na diminuição da mortalidade. Assim, nossos resultados mostram uma vantagem intrínseca de ter soldados na colônia, o que pode diminuir o custo dos soldados nas colônias de cupins. / A common response to predation pressure in social animals has been to allocate some individuals to defence tasks. In termites, the evolution of soldier caste was the most extreme anti-predatory response, because they are highly specialized in defence, sterile and incapable of perform self-maintenance. However, many studies have shown the active role of soldiers in tasks of space exploration like foraging. Such observations are important because the high contribution of workers in defence suggest some redundancy rate of soldier caste in termite colonies. The redundancy seems occurs in Cornitermes cumulans, where the workers being more responsive to threats than soldiers. Here we hypothesized that one way to diminish the cost of soldiers is that they are capable to do more than only defence. Specifically, we anticipate that soldiers are capable to optimize the search strategy of the workers. In the walking experiment with C. cumulans we find that the mean speed of the workers increases nonlinear with the number of soldiers. This result and the pre- sence of patterns highly coherent with Lévy flight motion suggests that the soldiers strengthen the exploratory capacity of workers in C. cumulans. In doing so, soldiers are expected to provide significant contributions to the intake of resources and to decreasing mortality in the colony. Then, our results propose an intrinsic advantage of have soldiers in the colony, and this may diminish the cost of soldiers in termite colonies.

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.