Orientador: Ana Maria Costa Leonardo / Coorientador: Alberto Arab / Banca: Francis de Morais Franco Nunes / Banca: Tiago Fernandes Carrijo / Resumo: O bioma Cerrado possui uma das termitofaunas mais diversas do mundo. Cornitermes cumulans é um cupim neotropical conhecido pela construção de ninhos em montículos e por armazenar alimento no núcleo celulósico do ninho. Apesar de ser considerado uma espécie-chave do Cerrado, aspectos básicos da biologia deste cupim não estão esclarecidos, principalmente em relação à fisiologia da sua alimentação e seu comportamento de forrageamento. A simbiose entre cupins superiores e bactérias é considerada essencial para a sobrevivência destes insetos, pois tem papel fundamental na digestão do alimento consumido por estes insetos. No entanto, os ninhos de cupins também possuem uma grande variedade de microrganismos presentes nas paredes destas estruturas, os quais podem estar ou não diretamente associados com a digestão lignocelulósica. Atualmente, análises moleculares têm relevado novas informações sobre os mecanismos de digestão da lignocelulose no intestino de cupins. Contudo, esses estudos não consideram os microrganismos associados ao alimento armazenado no interior dos ninhos e seu papel na biologia de cupins. Em vista do exposto, a presente pesquisa investigou aspectos da coleta do alimento e dinâmica do forrageamento de C. cumulans sob condições laboratoriais por meio de bioensaios. Adicionalmente buscou-se comparar morfologicamente e morfometricamente uma população de operários coletada no interior do ninho com uma população forrageira, levando-se em conta principalmente o desgast... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Cerrado biome has one of the most diverse termitofaunas in the world. Cornitermes cumulans is a neotropical termite known for building nests in mounds and store food in the cellulosic core nest. Although it is considered a key species of the Cerrado, basic aspects of the biology of this termite are not clarified, mainly in relation to the physiology of its feeding and its foraging behavior. The symbiosis between upper termites and bacteria is considered essential for the survival of these insects, since it plays a fundamental role in the digestion of the food consumed by these insects. However, termite nests also have a wide variety of microorganisms present on the walls of these structures, which may or may not be directly associated with lignocellulosic digestion. Currently, molecular analyzes have revealed new information on the mechanisms of digestion of lignocellulose in the intestine of termites. However, these studies do not consider the microorganisms associated with food stored inside the nests and their role in termite biology. In view of the above, the present study investigated aspects of food gathering and foraging dynamics of C. cumulans under laboratory conditions using bioassays. In addition, we sought to compare morphometrically and morphometrically a population of workers collected inside the nest with a forage population, taking into account mainly the wear of the jaws. Additionally, prosente study aimed to understand the food storage for Cornitermes cu... (Complete abstract click electronic access below) / Mestre

Thèse de doctorat : Écologie microbienne : Paris Est : 2008. / Titre provenant de l'écran-titre.

Tsavo National Park lies in an area of very dry country in South Eastern Kenya. Elephants live there in large numbers and in the early 2 1970's, they had a mean population density of about 1 km^-2 . They have inflicted widespread destruction on the woodlands which originally covered the Park, leading to a complete change in the appearance of the habitat. This caused considerable anxiety about the future of the Park and all its animal populations so research was begun to try to elucidate the root causes of the "elephant problem" and to predict its consequences. The purpose of the present study was to find out what happens to dead wood in Tsavo and to gauge the importance of termites in the ecology of the area. Section 1 gives a brief introduction to the history of Tsavo and sets out the main questions posed when this study was begun. In Section 2 the environment of the study area is described in terms of its topography and geology, the soils and their origins, the floristic and structural composition of the vegetation during this study, the climate and its variations in time and space and the role of fire in shaping the habitat. The species of termites found in the study area are listed in Section 3, followed by brief descriptions of their natural history. Section 4 contains all the information on the turnover of dead wood. The standing crop and rates of wood fall and removal were measured directly at one site and extended by means of an index to measure consumption of dead wood by termites at other sites. Consumption is found to be related to rainfall. The results are discussed in relation to similar studies made elsewhere. A model is constructed relating the consumption of dead wood by termites to rainfall and comparing this with the consumption of grass and browse by large herbivorous mammals. A method is described for measuring the relative importance of different termite species as consumers of dead wood.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 82-86). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 82-86). Also available on the Internet.

Resumo: 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... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: 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. / Orientador: Ana Maria Costa Leonardo / Coorientador: Odair Correa Bueno / Banca: Maria Santina de Castro Morini / Banca: José Eduardo Marcondes de Almeida / Banca: Ana Eugenia de C. Campos Farinha / Banca: Alexandre de Sene Pinto / Doutor

Esta dissertação trata da revisão taxonômica do gênero sul-americano Spinitermes Wasmann, 1897 (Isoptera, Termitidae, Termitinae). Estudei um total de 399 amostras, incluindo todas as do MZUSP e as de outras instituições, das quais solicitei material emprestado. As espécies deste gênero ocorrem no solo e em ninhos epígeos de outras espécies de cupins, principalmente do gênero Cornitermes (Termitidae, Syntermitinae), e alimentam-se de material orgânico em decomposição. De acordo com os caracteres morfológicos, separei as seis espécies já descritas e três espécies novas em três grupos: Grupo allognathus, com Spinitermes allognathus, S. sp. A, sp.n. e S. sp. B, sp.n., Grupo robustus, com S. robustus e Grupo trispinosus, que ainda dividi em dois subgrupos, de acordo com as características das válvulas entéricas, com Subgrupo de V.E. lisa (S. longiceps, S. nigrostomus, S. trispinosus e S. sp. C, sp.n.) e Subgrupo de V.E. rugosa (S. brevicornutus). Fiz as descrições de todas as castas dos três grupos e diagnoses para as espécies e subgrupos. Ilustrei o soldado de todas as espécies e os imagos conhecidos. Também ilustrei os seguintes caracteres dos operários de cada um dos grupos: pronoto, mandíbulas, gálea, lacínia, tubo digestivo in situ, válvula entérica e moela. Apresento uma chave dicotômica para identificação das espécies baseada em soldados e mapas de distribuição geográfica para todas as espécies. / This is the taxonomic revision of the South American genus Spinitermes Wasmann, 1897 (Isoptera, Termitidae, Termitinae). I studied 399 samples including all those from MZUSP and others from institutions that I requested material as loans. The species of this genus feed on decomposed organic matter and occurs in both the soil and in the epigeal nests constructed, mainly, by species of the genus Cornitermes (Termitidae, Syntermitinae). Using morphological characters, mainly from soldiers, I clustered the six species already known and the three new ones into three groups: Grupo allognathus: Spinitermes allognathus, S. sp. A, new species and S. sp. B, n.sp.; Grupo robustus: S. robustus; and Grupo trispinosus, that I subdivided, accordantly to the enteric valves characteristics, into two subgroups: Subgrupo de V.E. lisa: S. longiceps, S. nigrostomus, S. trispinosus and S. sp. C, n.sp., and Subgrupo de V.E. rugosa: S. brevicornutus. I described all castes of the three groups and made diagnoses for the species and subgroups; I also made illustrations of the soldier and imago, when presents, for all species and the pronote, mandibles, galea, lacinia, digestive tube in situ, enteric valve and crop from workers of the three groups. In addition, I present a dicotomic key for identification of the species using soldiers and geographic distributions maps for all species.

In this study we wanted to investigate the community ecology of African termites and uncover possible mechanisms structuring these species communities. Termites are important ecosystem engineers, crucial for the maintenance of tropical biodiversity and ecosystem functioning, therefore we wanted to show how anthropogenic disturbance influences these termite communities. Using a cross-sectional approach, we studied termite community composition along a disturbance gradient from fields to 12-year-old fallows in a West African savannah. We could show that disturbance was associated with environmental filtering of termites from the regional species pool, maybe via its effect on vegetation type. The most heavily disturbed sites were characterized by a subset of termite species which are well-known pests of crop. This supports a model in which strong anthropogenic disturbance selects for termite pest species. Additionally, we comparatively studied termite communities in the two major West African ecosystems, savannah and forest, both under natural settings and along disturbance gradients. Overall we found 33 species in the forest and 22 in the savannah. However, alpha diversity per site did not differ between both ecosystems with on average around ten species. For both ecosystems, species diversity did not decrease along the studied disturbance gradient but encounter rates did. In general, we found little evidence for strong community structuring mechanisms such as environmental filtering or interspecific competition in the natural habitats. Most local communities did not differ significantly from random assemblages of the regional species pool. Interestingly, only the disturbed sites in the savannah showed some sign of phylogenetic structuring, the teak plantation sites did not. By using stable isotope analysis we could investigate how so many termite species with very similar feeding niches can coexist in an African savannah. We discovered that closely related species either differed in their δ15N and /or δ13C signatures, providing support for our hypothesis that fine-scaled differentiation of the feeding niche exists between termites in the studied area that formerly have been classified as feeding on the same dead plant material. We were able to distinguish feeding groups with stable isotope analysis, as each feeding group had a specific δ15N and δ13C signature, supporting the classification of Donovan et al. (2001). Comparatively, we tested whether southern African termite communities show signs of environmental filtering and / or competition along a rainfall gradient in Namibia. There was a regional species pool of 11 species and we found no evidence for phylogenetic structuring at the local scale. Rather, our results suggest that the assembly of the studied termite communities has as strong random component on the local scale, but that species composition changes along the climatic gradient. Interestingly, species richness and species composition was different to West African termite communities.

The main objectives of this study were to investigate the applicability of chitosan as an effective wood preservative against subterranean termites, conduct metagenomic analysis of the bacterial hindgut community of Reticulitermes flavipes exposed to chitosan-treated wood, and perform chitosanase activity assay of metagenomics suggested bacterial species potentially responsible for chitosan breakdown. Chitosan showed termiticidal effects on subterranean termites at varying retention levels. Termite mortality increased when exposed to samples treated with higher chitosan concentration solutions. Approximately 40 - 100% of chitosan retained in treated-wood was leached depending on the initial retention. Post-leaching results indicate chitosan is not suitable for protection against both subterranean termites in outdoor conditions, but should be effective in non-leaching/indoor applications. For metagenomic analysis of the bacterial hindgut community of Reticulitermes flavipes, two methods were used for sequence data interpretation. The Illumina BaseSpace program identified twenty-six bacteria phyla with significant differences in abundance between the chitosan-treated and control groups. The second method, mothur, identified fifteen bacterial phyla also with significant differences in abundance between both treatment groups. Similar bacterial taxa were uniquely assigned to samples from termites fed on chitosan-treated wood using both methods. These results suggest a treatment driven effect on the hindgut bacteria diversity. While majority of the bacterial taxa were common to both methods, inconsistencies detected using the BaseSpace program suggests that the Greengenes database in its present state is not reliable for 16S rRNA gene sequence analysis. As for chitosanase activity of bacterial species with significance abundance from chitosan-treated wood exposed termites, three bacteria species, Lactococcus raffinolactis, Lactococcus lactis, and Dysgonomonas gadei, were examined. After culturing on chitosan media plates and broth, no conclusive activity could be detected from all three species. Further studies need to be conducted to understand the mechanism of chitosan toxicity to termites and insects in general and to prevent chitosan leaching from treated wood. A comparative metatransciptomic study needs to be implemented to supplement the metagenomic study performed herein, so as to elucidate the exact bacteria species involved in chitosan breakdown and the enzymes produced. Also, other bacterial species suggested by the metagenomic data to possess chitosanase activity should be investigated.

This dissertation aimed to assess whether tannins were able to prevent boron leaching using heat treatment. First, to understand tannin behavior under high temperatures a pilot test was performed. Tannin powder from the Quebracho tree was dissolved into deionized water (DW). Southern yellow pine (SYP) and yellow-poplar (YP) woods were impregnated with tannins under a full cell process. Heat treatment under N2 atmosphere at 190/195/210°C was evaluated for four hours for both species. Mass loss due to heat treatment for wood and tannin as well as radial and tangential shrinkage were calculated. FT-IR spectroscopy and scanning electron microscopy were performed to understand the phenomena. Results indicated that at temperatures above 190°C there was an excessive tannin mass loss with collapse formation on SYP tannin-treated samples as well as changes in the in the spectra. The detailed study used 80 g of tannins and 12 g of DOT into 800 g of DW to attempt preventing boron leaching. SYP and YP samples were impregnated through full cell process and heat treated under N2, at 190°C for four hours. Samples were leached for 15 days. Anti-swelling efficiency was calculated. The resistance of the woods was tested against Gloeophyllum trabeum and Trametes versicolor fungi as well as the subterranean termite Reticulitermes flavipes for leached and unleached samples. The mass loss due to heat treatment was higher in YP than in SYP. The color changed for both woods, turning into much darker after tannin impregnation and heat treatment. All treatments for both species had lower volumetric shrinkage when compared to control as an effect of heat treatment, leading to improvement in dimensional stability. When mixed with tannins and heat treated, DOT remained in wood with leaching reduction of 46.5% and 34.5% for SYP and YP, respectively. After 15 days leaching HT T/DOT samples were classified as resistant (SYP) and highly resistant (YP) to the attack of decay fungi. Heat treated wood had improvement in durability against R. flavipes. HT DOT leached samples had 20.6% mass loss, whereas HT T/DOT 13.8%. Future work with amine-tannin solution should be tested to improve the leaching reduction.