Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-06-30T13:08:52Z No. of bitstreams: 1 ELVIRA BEZERRA PESSOA - DISSERTAÇÃO PPGEA 2004..pdf: 25315444 bytes, checksum: 5be953c0f57dcad2cd5d4fb9e7795cdb (MD5) / Made available in DSpace on 2018-06-30T13:08:52Z (GMT). No. of bitstreams: 1 ELVIRA BEZERRA PESSOA - DISSERTAÇÃO PPGEA 2004..pdf: 25315444 bytes, checksum: 5be953c0f57dcad2cd5d4fb9e7795cdb (MD5) Previous issue date: 2004-04 / Dentre as pragas associadas às sementes e grãos armazenados no Brasil, o gorgulho, Sitophilus zeamais, destaca-se como um dos principais responsáveis na queda da produção, devido as perdas e danos provocado por este inseto praga. Com bases nessas considerações e dentro de um alinhamento ecológico, realizou-se o presente trabalho, objetivando avaliar a eficácia de sete extratos vegetais, com propriedades inseticidas, no controle do inseto na fase imatura (ovo) e a mortalidade do inseto adulto. Os extratos hidroálcoolicos foram obtidos pelo método de extração a frio por percolação. Os trabalhos foram realizados no Laboratório de Armazenamento e Processamento de Produtos Agrícolas do DEAg da UFCG e no Laboratório de Farmacotécnica (LF) do Departamento de Farmácia e Biologia do CCBS da UEPB, ambos sediados em Campina Grande, PB. Inicialmente, realizou-se a multiplicação do inseto a partir de exemplares coletados em grãos armazenados. Posteriormente, foram aplicados, pelo método do vapor, aos insetos adultos contidos em recipientes plásticos na dose estabelecida para cada tratamento (4, 8, 12 e 16 ml). Em uma segunda fase, selecionou-se os quatros melhores extratos e as duas doses que mataram os insetos adultos na primeira fase, os quais foram levados aos carunchos, previamente inoculados em uma massa de milho pipoca, pelo método do vapor e diretamente sobre as sementes, que depois de homogeneizadas eram secas a sombra por 24 horas. Em uma terceira etapa, testou-se os dois melhores extratos, aplicados diretamente sobre as sementes de milho pipoca, contendo ovos do S. zeamais, na dose de 16 ml, para a avaliação da eficácia dos mesmos sobre a emergência do inseto depois de 40 dias da instalação dos ensaios. Em um quarto experimento, avaliou-se o efeito desses mesmos extratos e dose, empregados na etapa anterior, sobre a eficácia dos mesmos no controle do S. zeamais e seus efeitos na germinação, teor de umidade e sementes infestadas. Tendo sido constatado, mediante os resultados de cada bioensaio, que os insetos adultos de Sitophilus zeamais são controlados igualmente com os extratos de Citrus cinensis (98,62%), Cymbopogon citratus (97,87%) e Nicotiana tabacum (96,50%), em todas as doses testadas e aplicadas pelo método do vapor. Os extratos de Nicotiana tabacum e Cymbopogon citratus, demonstraram ação ovicida, controlando esta fase imatura do gorgulho em 96,55 e 95,07%, respectivamente, e que a qualidade fisiológica da semente de milho pipoca não foi afetada pelos extratos, durante o período de armazenamento. / Among the pests associated with seeds and grains stored in Brazil, the weevil, Sitophilus zeamais, stands out as one of the main responsible in the fall of the production, due to the losses and damages caused by this insect pest. Based on these considerations and within an ecological alignment, the present work was carried out, aiming to evaluate the efficacy of seven plant extracts, with insecticidal properties, in the control of the insect in the immature phase (egg) and adult insect mortality. The hydroalcoholic extracts were obtained by the cold extraction method by percolation. The work was carried out at the Laboratory of Storage and Processing of Agricultural Products of the DEAg of the UFCG and in the Laboratory of Pharmacotechnics (LF) of the Department of Pharmacy and Biology of CCBS of UEPB, both based in Campina Grande, PB. Initially, the insect multiplication was performed from specimens collected in stored grains. Subsequently, they were applied by the steam method to adult insects contained in plastic containers at the dose established for each treatment (4, 8, 12 and 16 ml). In a second phase, the four best extracts were selected and the two doses that killed the adult insects in the first phase were selected, which were then fed to the weevils previously inoculated in a popcorn mass by the steam method and directly on the seeds , which after homogenates were dried in the shade for 24 hours. In a third step, the two best extracts were applied directly to the seeds of popcorn, containing eggs of S. zeamais, in the dose of 16 ml, for the evaluation of their efficacy on the emergence of the insect after 40 days of installation of the tests. In a fourth experiment, the effect of these same extracts and dose, employed in the previous stage, on the efficacy of the same in the control of S. zeamais and its effects on germination, moisture content and infested seeds were evaluated. It was observed that adult insects of Sitophilus zeamais are also controlled with extracts of Citrus cinensis (98.62%), Cymbopogon citratus (97.87%) and Nicotiana tabacum (96.50% ), at all doses tested and applied by the steam method. The extracts of Nicotiana tabacum and Cymbopogon citratus demonstrated ovicidal action, controlling this immature stage of the weevil in 96.55 and 95.07%, respectively, and that the physiological quality of the seed of popcorn corn was not affected by the extracts during the period of storage.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-04T14:09:16Z No. of bitstreams: 1 NILENE RODRIGUES DOS SANTOS - DISSERTAÇÃO PPGEA 2003..PDF: 9864701 bytes, checksum: d75a590a50b67444833851b131a9e950 (MD5) / Made available in DSpace on 2018-07-04T14:09:16Z (GMT). No. of bitstreams: 1 NILENE RODRIGUES DOS SANTOS - DISSERTAÇÃO PPGEA 2003..PDF: 9864701 bytes, checksum: d75a590a50b67444833851b131a9e950 (MD5) Previous issue date: 2003-06-18 / CNPq / A presença de praga em milho armazenado é um dos fatores limitantes a manutenção da viabilidade dessas sementes, sendo uma das principais responsáveis na queda da produção, devido ao grande número de perdas e danos nas sementes armazenadas. Com base nessas considerações, este trabalho busca alternativas no controle do Sitophilus zeamais, na fase adulta e de ovo mediante o emprego de seis espécies vegetais por conter em sua composição substâncias com propriedades inseticidas e por os extratos dessas plantas poder configurar-se numa alternativa aos produtos químicos comerciais com vantagens ecológicas bastante interessantes, devido à baixa agressividade ao ambiente e ao homem. O trabalho foi conduzido no período de agosto/2001 a maio/2003, no LAPPA da UFCG. Os extratos foram obtidos pelo método de extração a frio por percolação. O delineamento experimental utilizado nos bioensaios foi o inteiramente casualizado com os tratamentos distribuídos em esquema fatorial, exceto na terceira etapa onde não se empregou a distribuição fatorial, sendo utilizado na primeira etapa, regressão na análise de variância para os fatores estudados de acordo com o número que se apresentavam em cada ensaio (extratos, doses, forma de aplicação e período de armazenamento) e as variáveis de respostas (mortalidade de adultos, estágio de ovo, sementes infestadas, perda do peso, viabilidade de sementes e teor de umidade). Com base nos resultados de cada bioensaio, tem-se que a aplicação dos extratos diretamente sobre as sementes foi o método que melhor controlou os Sitophilus zeamais presente na massa de sementes, sendo os extratos de Calopogonium caeruleum e Ruta graveolens os mais eficientes em seu controle, tanto na fase adulta como de ovo e a melhor dose foi a de 12 ml. A qualidade fisiológica da semente de milho não foi afetada pela aplicação dos extratos, sendo estes considerados eficazes na manutenção da qualidade fisiológica das sementes durante os 90 dias de armazenamento e os extratos de Calopogonium caeruleum e Ruta graveolens que atuaram com maior eficiência em matar os insetos, possuem grupos químicos: alcalóides, flavonóides e taninos, com propriedadesinseticidas que justificam essa ação. / The plague presence in stored corn is one of the factors limits the maintenance of the viability of those seeds, being responsible one of the main ones in the fali of the producrion, due to the great number of losses and damages in the stored seeds. With base in those considerations, this work search alternatives in the control of the Sitophilus zeamais, in the adult phase and of egg by means of the employment of six vegetable species for containing in its composition substances with insecticide properties and for the extracts of those plants to configure in an alternative to tiie commercial chemical products with quite interesting ecological advantages, due to the low aggressiveness to the atmosphere and the man. The work was driven in the period august/2001 to may/2003, in the Department of Agricultural Engineering of UFCG. The extracts were obtained by the extraction method to cold for percolação. The experimental lineation used in the biopractices was it entirely casualty with the treatments distributed in outline factorial, except in the third stage where the distribution factorial was not used, being used being used in the first stage, regression in the variance analysis for the factors studied in agreement with the number that you/they carne each rehearsal (extracts, doses, application form and storage period) and the variables of answers (adults' mortality, egg apprenticeship, infested seeds, loss of the weight, viability of seeds and humidity text). With base in the results of biopractices each, it is had that the application of the extracts directly on the seeds the method that best controlled Sitophilus zeamais present in the mass of seeds was, being the extracts of Calopogonium caeruleum and Ruta graveolens the most efficient in the control of the S. zeamais, so much in the adult phase as of egg and the best dose was the one of 12 ml. The physiologic quality of the corn seed was not affected by the application of the extracts, being these considered effective in the maintenance of the physiologic quality of the seeds during the 90 days of storage and the extracts of Calopogonium caeruleum and Ruta graveolens that acted with larger efficiency in killing the insects, they possess chemical groups: alkaloids, flavonóides and tannins, with insecticide properties tiiat justify that action.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-03-06T18:51:46Z No. of bitstreams: 1 texto completo.pdf: 1908347 bytes, checksum: 79b4c5cb22e232cf6c475ec549d90a35 (MD5) / Made available in DSpace on 2017-03-06T18:51:46Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1908347 bytes, checksum: 79b4c5cb22e232cf6c475ec549d90a35 (MD5) Previous issue date: 2004-02-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Em decorrência das perdas qualitativas e quantitativas que ocorrem durante o período de armazenamento de grãos, objetivou-se com este trabalho avaliar a deterioração dos grãos de milho em função da perda de matéria seca, sob diferentes condições de armazenamento e quantificar a perda de matéria seca dos grãos de milho armazenados e infestados ou não com Sitophilus zeamais, em diferentes condições de temperatura do ar ambiente, através da determinação da taxa respiratória pela produção de CO 2 . Para esta avaliação, grãos da variedade BRS 3060, colhidos com teor de umidade em torno de 14,5% b.u. foram infestados ou não com o inseto-praga na proporção de 10 insetos por quilo de produto. Logo em seguida as amostras correspondentes a cada tratamento foram colocadas em câmara do tipo BOD nas temperaturas de 20, 25, 30, 35 e 40 °C. Para a determinação da produção de CO 2 e conseqüente perda de matéria seca, nos intervalos de zero, 30, 45, 60, 90, 120 e 150 dias os grãos de cada tratamento foram distribuídos em frascos de vidro, com volume de 800 mL, e mantidos hermeticamente fechados por 24 h. Após este intervalo, 5 mL de ar intergranular foi removido do interior dos frascos e injetado em um analisador de fluxo bissegmentado com detecção condutimétrica. Através da leitura obtida, da porosidade da massa de grãos, da curva padrão do sistema e da equação dos gases perfeitos foram determinadas a taxa respiratória e a perda de matéria seca dos grãos de milho. Para avaliação da qualidade do milho armazenado utilizou-se o teste de condutividade elétrica da solução que contém os grãos. A análise dos dados e a interpretação dos resultados obtidos nas condições específicas deste trabalho permitiram concluir que: o sistema em uso (analisador em fluxo bissegmentado) forneceu dados que permitiram o acompanhamento da taxa respiratória dos grãos e mostrou ser sensível para tal; a umidade dos grãos e a temperatura de armazenamento influenciam diretamente na taxa respiratória; o tempo máximo que os grãos precisam ficar hermeticamente fechados, para se determinar a produção de CO 2 e conseqüente perda de matéria seca durante o armazenamento, é de 24 h; a taxa respiratória dos grãos na ausência do inseto-praga se manteve discreta ao longo do armazenamento, enquanto que na presença deles aumentou cerca de 10 e 15 vezes em apenas 30 dias para as temperaturas de 25 e 30 °C, respectivamente; as maiores taxas respiratórias foram observadas para os grãos armazenados nas condições em que o inseto-praga melhor se desenvolve, ou seja, para as temperaturas de 20, 25 e 30 °C; as maiores perdas de matéria seca devido a respiração dos grãos foram obtidas também nas condições em que o inseto- praga se desenvolve; pode existir uma relação entre a perda de qualidade e a taxa respiratória dos grãos, pelo fato que nas temperaturas em que os insetos melhor se desenvolveram (25 e 30 o C) é que se obteve as maiores médias de condutividade elétrica e as maiores produções de CO 2 ; a condutividade elétrica da solução que contém os grãos aumenta com o período de armazenamento, com a elevação da temperatura ambiente e com a presença de inseto-praga, demonstrando maior perda de qualidade do produto. / Due to the qualitative and quantitative losses that happen during the period of storage of grains, it was aimed at with this work to evaluate the deterioration of the corn grains in function of the loss of dry matter, under different storage conditions and to quantify the loss of dry matter of the corn grains stored and infested or not with Sitophilus zeamais, in different conditions of temperature of the environment air, through the determination of the breathing rate by the production of CO 2 . For this evaluation, grains of the variety BRS 3060, picked with humidity content around 14,5% were infested or not with the insect-plague in the proportion of 10 insects per kilo of product. Soon after, the samples corresponding to each treatment were placed in a camera type BOD, in the temperatures of 20, 25, 30, 35 and 40 °C. For the determination of the production of CO 2 and consequent loss of dry matter, in the zero intervals, 30, 45, 60, 90, 120 and 150 days the grains of each treatment were distributed in glass flasks, with volume of 800 mL, and maintained tightly closed for 24 h. After this interval, 5 mL of intergranular air was removed from the interior of the flasks and injected in a bissegmented flow analyzer with condutimetric detection. Through the obtained reading of the grains mass porosity, of the system curve pattern and of the equation of the perfect gases, were determined the breathing rate and the loss of dry matter of the corn grains. For evaluation of the quality of the stored corn it was used the test of electric conductivity of the solution that contains the grains. The analysis of the data and the interpretation of the results obtained in the specific conditions of this work allowed to conclude that: the system in use (analyzer in bissegmented flow) supplied data that allowed the accompaniment of the breathing rate of the grains and it showed to be sensitive for such; the humidity of the grains and the storage temperature influence directly in the breathing rate; the maximum time that the grains need to be tightly closed, to be determined the production of CO 2 and consequent loss of dry matter during the storage, is of 24 h; the breathing rate of the grains in the absence of the insect-plague stayed discreet along the storage, while in their presence it increased about 10 and 15 times in only 30 days for the temperatures of 25 and 30 °C, respectively; the largest breathing rates were observed for the grains stored in the conditions in which the better insect-plague grows, in other words, for the temperatures of 20, 25 and 30 °C; the largest matter losses due to breathing of the grains were also obtained in the conditions in which the insect-plague grows; a relationship can exist between the quality loss and the breathing rate of the grains, for the fact that in the temperatures in which the insects better grew (25 and 30 oC) was obtained the largest averages of electric conductivity and the largest productions of CO 2 ; the electric conductivity of the solution that contains the grains increases with the storage period, with the elevation of the environment temperature and with the insect-plague presence, demonstrating larger loss of quality of the product. / Tese importada do Alexandria

Submitted by (edna.saturno@ufrpe.br) on 2016-12-02T12:15:37Z No. of bitstreams: 1 Rodrigo Lenadro Braga Coitinho.pdf: 431687 bytes, checksum: 3510e17dbd6224b39b136428e9bf81c4 (MD5) / Made available in DSpace on 2016-12-02T12:15:37Z (GMT). No. of bitstreams: 1 Rodrigo Lenadro Braga Coitinho.pdf: 431687 bytes, checksum: 3510e17dbd6224b39b136428e9bf81c4 (MD5) Previous issue date: 2009-02-02 / The essential oils are promising alternative for the management of Sitophilus zeamais in stored maize. In this investigation, toxicity, repellency and persistence of essential oils in stored maize were evaluated using S. zeamais. The oil’s LC50s from leaves of Piper hispidinervum, Eugenia uniflora, Cinnamomum zeylanicum, eugenol compound, Piper marginatum, Schinus terebinthifolius and Melaleuca leucadendron and green fruits of S terebinthifolius, in the tests of contact and ingestion were estimated at 1.0; 11.6; 14.2; 14.8; 21.1; 57.7, 75.8 and 98.8 μL/40g maize, respectively. In fumigation tests for adults, the LC50s ranged from 94.7 to 0.53 μL/L of air and the toxicity ratios ranged from 178.7 to 2.0. In the fumigation for larvae with 7 to 14 days of age, only eugenol did not differ from control concerning number of adults emerged. In larvae with 7 to 21 days, the oils of green fruits from S. terebinthifolius and P. hispidinervum showed the best performance in relation to the control. Percentages of repellency varied between 97.4 (P. marginatum and C. zeylanicum) to 81% (P. hispidinervum). In the initial storage period (after impregnation), mortality of S. zeamais ranged between 93.8 (P. hispidinervum, Melaleucaleucadendron and eugenol) to 100% (E. uniflora, green fruits of S. terebinthifolius and P. marginatum). From 30 days, mortality generally decreased, except for P. marginatum (92.2%). According to the regression equations adjusted for the number of S. zeamais emerged throughoutthe storage period, there was no statistical significance for the oils of S. terebinthifolius and P. marginatum and control. For the average, the oil from P. marginatum was the most persistent, providing emergency of only 0.30 insects differing from the other oils and the control. / Os óleos essenciais constituem alternativa promissora para o manejo de Sitophilus zeamais em milho armazenado. Neste trabalho avaliou-se a toxicidade, a repelência e a persistência de óleos essenciais em milho armazenado, utilizando-se S. zeamais. As CL50s dos óleos de folhas de Piper hispidinervum, Eugenia uniflora, Cinnamomum zeylanicum, composto eugenol, Piper marginatum, Schinus terebinthifolius, e Melaleuca leucadendron e de frutos verdes de S terebinthifolius, nos testes de contato e ingestão, foram estimadas em 1,0; 11,6; 14,2; 14,8; 21,1; 57,7; 75,8 e 98,8 μL/40g de milho, respectivamente. Nos testes de fumigação para adultos, as CL50s variaram entre 94,7 a 0,53 μL/L de ar e as razões de toxicidade estiveram entre 178,7 a 2,0. Na fumigação para larvas de 7 a 14 dias de idade, apenas o eugenol não diferiu da testemunha, quanto ao número de adultos emergidos. Em larvas com 7 a 21 dias, os óleos de frutos verdes de S. terebinthifolius e de P. hispidinervum apresentaram o melhor desempenho, em relação à testemunha. As percentagens de repelência variaram entre 97,4 (P. marginatum e C. zeylanicum) a 81% (P. hispidinervum). No período inicial de armazenamento (logo após a impregnação), asmortalidades de S. zeamais variaram entre 93,8 (P. hispidinervum, Melaleuca leucadendron e eugenol) a 100% (E. uniflora, frutos verdes de S. terebinthifolius e P. marginatum). A partir dos 30 dias, as mortalidades, de um modo geral, decresceram, com exceção de P. marginatum(92,2%). De acordo com as equações de regressão ajustadas para o número de S. zeamais emergidos em todo o período de armazenamento, não houve significância estatística para os óleos de S. terebinthifolius e de P. marginatum e testemunha. Em relação à média geral, o óleo de P. marginatum foi o mais persistente, proporcionando emergência de apenas 0,30 insetos, diferindo dos demais óleos e da testemunha.

Plusieurs insectes se développant dans des milieux nutritionnellement déficients vivent en symbiose durable avec des bactéries intracellulaires (endosymbiotes) qui complémentent leur alimentation et améliorent leur pouvoir adaptatif. Alors que ces associations ont été largement étudiées sur les plans physiologiques et évolutifs, peu de travaux se sont consacrés à l’étude des mécanismes impliqués dans la tolérance et le contrôle des endosymbiotes par l’hôte. L’objectif de cette thèse est d’étudier, chez les charançons des céréales du genre Sitophilus, les particularités moléculaires et immunitaires du bactériome, un organe que l’insecte développe pour héberger les symbiotes et les isoler de sa réponse immunitaire systémique. Le bactériome du charançon exprime une réponse immunitaire modulée : des études transcriptomiques ont montré que les effecteurs de l’immunité sont peu exprimés dans cet organe, à l’exception d’un gène codant un peptide antimicrobien, la coléoptéricine A. Cette dernière interagit avec les endosymbiotes et participe à leur confinement intracellulaire. Dans une première partie, j’ai montré avec une approche d’interférence à l’ARN que l’expression du gène colA serait contrôlée par un système original qui impliquerait les gènes relish et tollip. Cette régulation « interne » au bactériome semble assurer le maintien des endosymbiotes et l’homéostasie de l’organe. Afin de comprendre comment le bactériome répond à une infection par les bactéries exogènes, j’ai suivi par RT-qPCR l’expression de gènes effecteurs de l’immunité dans le bactériome après injection systémique de bactéries à Gram positif ou négatif. Ceci a mis en évidence une réponse « externe », induite en cas d’infection, et qui aurait un rôle de protection des endosymbiotes contre les bactéries exogènes. Enfin, je me suis consacré à l’étude des changements de régulation accompagnant le passage du stade larvaire au stade adulte, marqué par une symbiose très dynamique. Le nombre d’endosymbiotes augmente fortement pendant les premiers jours de vie imaginale, puis diminue jusqu’à leur élimination complète par recyclage autophagique. Une analyse RNAseq a permis d’identifier les voies de signalisation dont l’activité accompagne cette dynamique. Une approche de RT-qPCR a également montré que l’immunité du bactériome est maintenue à un faible niveau d’activation pendant tout le processus de recyclage. Ce travail montre qu’au cours de leur évolution, les insectes ont sélectionné plusieurs stratégies pour assurer le maintien et l’ajustement de leur charge endosymbiotique en fonction de leurs besoins physiologiques : une signalisation immunitaire assurerait le confinement intracellulaire des endosymbiotes, et un ensemble de processus cellulaires incluant l’apoptose et l’autophagie semble être en associé aux voies métaboliques pour assurer le contrôle de la dynamique bactérienne et garantir le compromis bénéfice/coût de la symbiose. / Many insect species living on nutritionally unbalanced media depend on intracellular mutualistic bacteria, called obligatory endosymbionts, for their development and reproduction. Endosymbionts are housed in specialized host cells called bacteriocytes, that group together to form the bacteriome organ. Although such associations have been widely investigated on a physiological and evolutionary point of view, little is known about the mechanisms involved in the tolerance and the control of endosymbionts by the host. This work aims at deciphering the molecular and immune specificities of the bacteriome using the model system Sitophilus oryzae, the cereal weevil, and its obligate endosymbiont Sodalis pierantonius. The weevil bacteriome expresses a modulated immune response: transcriptomic studies showed that immune effector genes were lowly expressed despite the massive bacterial presence, with the exception of colA, a gene encoding for Coleoptericin A, an antimicrobial peptide. Coleoptericin A interacts with endosymbionts and participates in their intracellular seclusion. In a first chapter, I used RNA interference to demonstrate that colA gene expression may be controlled by an original system involving the genes relish and tollip. This “internal” regulation for endosymbiont control seems to maintain bacteriome homeostasis. In a second chapter, in order to understand how the bacteriome responds to an infection by exogenous bacteria, I followed up by RT-qPCR the expression of immune effector genes in the bacteriome after injection of Gram positive and Gram negative bacteria. This highlighted an “external” immune response, inducible upon infections, which may enable endosymbiont protection against exogenous intruders. In a third and last chapter, I focused on the regulation changes that accompany the switch from the larval stage to the imaginal stage, the latter being characterized by a very dynamic symbiosis. Endosymbiont load drastically increases during the first days of imaginal life, then rapidly decreases until complete elimination of the bacteria by autophagic recycling. RNAseq analysis allowed the identification of signaling pathways linked to this dynamic. A complementary RT-qPCR approach also showed that bacteriome immunity was laid low during the whole recycling process. This work shows that several strategies have been selected during host-symbiont coevolution to ensure the maintenance of the endosymbionts and the adjustment of their population depending on the insects physiological needs: immunity allows the intracellular seclusion in the bacteriocytes, and cell processes including autophagy and apoptosis are associated to metabolic pathways to control the endosymbiotic dynamics and secure the cost and benefit trade-off of symbiosis.

MSCAGR / Department of Plant Production

Algunas plagas causan daños importantes en productos y granos almacenados, lo cual conlleva consecuentemente a pérdidas de producción y calidad en estos productos.Las principales plagas del arroz almacenado en España son, Sitophilus oryzae L. (Coleoptera Curculionidae), Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), y Cryptolestes pusillus Schönherr (Coleoptera: Cucujidae). Las dos primeras son plagas primarias que atacan directamente el grano y resultan bastante destructivas debido a que sus larvas se alimentan y desarrollan dentro de él. C.pusillus es, sin embargo, una plaga secundaria que se beneficia de granos que ya están dañados y rotos.Actualmente, el uso de fumigantes e insecticidas de síntesis sigue siendo el principal método de lucha para controlar las plagas de almacén, si bien recientemente (dadas las continuas restricciones al uso de agroquímicos) existe un gran interés en la utilización de otras alternativas tales como el control biológico, el almacenamiento a bajas temperaturas, o los tratamientos con calor entre otros.Igualmente muchos productos obtenidos principalmente de plantas y que derivan del metabolismo secundario de las mismas ofrecen una fuente de bioinsecticidas que podrían representar una alternativa ecológica frente a los insecticidas de síntesis ya que su uso masivo e indiscriminado ha ocasionado problemas tales como la aparición de resistencias en determinadas especies de insectos frente a diferentes materias activas, desequilibrios ecológicos y problemas medioambientales sin olvidar el riesgo que entrañan para la salud humana.Con este trabajo se ha pretendido estudiar la actividad plaguicida de los aceites esenciales extraídos de tres plantas: Coriandrum sativum L. (Umbelliferae), Carum carvii L. (Umbelliferae) y Ocimum basilicum L. (Labiatae) y su posterior fraccionamiento para identificar dentro de estos aceites los compuestos químicos responsables de esta actividad insecticida sobre tres plagas de almacén de arroz (S. oryzae, R.dominica y C.pusillus).Del estudio de estos monoterpenoides, linalol, S-carvona y estragol resultaron tener una alta actividad insecticida sobre estas plagas. Sin embargo el E-anetol fue más selectivo para R.dominica y C.pusillus, así como el limoneno, γ-terpineno, geraniol y eucaliptol sólo resultaron activos frente a C.pusillus.Algunos monoterpenoides podrían actuar de sinergistas potenciando la actividad de otros, como podría ser el caso del alcanfor, acetato de geranilo y E-anetol con linalol en R.dominica y C.pusillus, o el caso del metoxicinamaldehido, p-anisaldehido y linalol que pueden tener efecto sinergista sobre el estragol.Este trabajo también abarcó el estudio de un posible modo de acción de estos monoterpenoides, la inhibición de la acetilcolinesterasa, para alcanzar un mayor entendimiento del comportamiento de estas sustancias en el interior del insecto.Así se pudo observar como la mayoría de monoterpenoides estudiados inhibían en cierta medida esta enzima, siendo fenchona, S-carvona y linalol los monoterpenoides que mayor inhibición originaron.Del mismo modo se observó como fenchona, γ-terpineno, geraniol y linalol inhibían competitivamente la acetilcolinesterasa, mientras que S-carvona, estragol y alcanfor producían una inhibición mixta para esta enzima.Sin embargo no se observó inhibición de la acetilcolinesterasa por parte del E-anetol a las concentraciones de monoterpenoides ensayadas.Para completar este trabajo se examinó de igual forma la capacidad que tenían estos bioinsecticidas de generar resistencia en estas tres plagas así como el mecanismo de resistencia implicado en el desarrollo de este proceso. Para ello se fueron seleccionando las poblaciones de insectos mediante la aplicación de los diferentes monoterpenoides a dosis crecientes durante 7 generaciones. De este modo se pudo calcular el factor de resistencia en cada una de las plagas y para cada uno de los monoterpenoides comparando las concentraciones letales 50 de las poblaciones seleccionadas con las poblaciones iniciales (sensibles).A continuación se analizaron tres posibles sistemas de detoxificación enzimáticos gracias al uso de sinergistas para estudiar el mecanismo de resistencia que podría estar involucrado.De tal forma se observó como estos monoterpenoides inducían lentamente resistencias resultando ventajosos en un futuro para el control de estas plagas.Esta Tesis ha englobado un estudio íntegro y profundo de estos insecticidas ecológicos desde la extracción de los aceites esenciales, seguido de la identificación de compuestos puros (CG-EM) con actividad insecticida junto con el estudio de un modo de acción de estos insecticidas, la selección de resistencia en las poblaciones de insectos y los posibles mecanismos de resistencia que pudieran estar implicados en este proceso. / Some pests cause serious damage to stored grains and stored products and consequently production and quality losses in these products.The rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), the lesser grain borer, Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae) and Cryptolestes pusillus Schönherr (Coleoptera: Cucujidae) were the main damaging pests found in stored rice in Spain.S.oryzae and R.dominica are primary pests attacking directly the intact grain and are quite destructive because their larvi feed and develop inside the grain whereas C.pusillus is a secondary pest which benefits from grains previously damaged.At the present time, organic synthetic pesticides are still the main method to control stored grain pests, however, recently (due to restriction in agrochemicals use) there is a great interest in using other altenatives such as biological control, storage at low-temperatures, or heat treatment.Likewise, many products obtained mainly from plants and derived from secondary metabolism have insecticidal activity against insects, such as monoterpenoids, which present a broad variety of bioinsecticide products which could turn out to be an ecologic alternative to synthetic pesticides since the majority of alternative products are not harmful for the human healthy and they become less environmentally damaging, exhibiting a low impact on the environment.In addition, it cannot be ignored the different difficulties related to resistance due to several active compounds from organic pesticides found in some species of insects.With this work, we have considered remarkable to study the insecticide activity of essential oils extracted from three plants: Coriandrum sativum L. (Umbelliferae), Carum carvii L. (Umbelliferae) and Ocimum basilicum L. (Labiatae) and carry out a bioassay-guided fractionation of their essential oils to identify which compounds were responsible for the volatile toxicity shown on three stored rice pests (S. oryzae, R. dominica and C. pusillus).Linalool, S-carvone and estragole turned out to have a high insecticide activity on these pests. Nevertheless E-anetol was more selective to R. dominica and C. pusillus, being only active on C. pusillus limonene, γ-terpinene, geraniol and eucalyptol.Some monoterpenoids were found as synergists, increasing the activity of the other ones, like for instance, camphor, geranyl acetate and E-anethole with linalool in R.dominica and C.pusillus or metoxycinnamaldehyde, p-anysaldehyde and linalool which could activate to estragole.In this work, the inhibition of acetylcholinesterase as a posible mode of action was studied as well, to reach a clear understanding about the action of these products inside the insects.The majority of monoterpenoids inhibited the enzyme acetylcholinesterase being fenchone, S-carvone and linalool the monoterpenoids that produced a higher inhibition.Furthermore, it was observed how fenchone, γ-terpinene, geraniol and linalool showed a competitive inhibition whereas S-carvone, estragole and camphor produced a mixed inhibition for this enzyme. However the enzyme acetylcholinesterase was not inhibited by E-anethole.To finish up this work, the selection for monoterpenoid resistance on these pests as well as the metabolic mechanisms implicated was studied.The resistant strains were selected from susceptible insect populations and survivors were reared separately for each monoterpenoid and successive generations were treated with higher concentrations. These populations were selected until seven times.As a result we could calculate the resistance factor on each pest (comparing lethal concentration 50 values of susceptible and resistant strains).Next, three enzymatic systems detoxifying these monoterpenoids were analysed to study the metabolic mechanism implicated.In this way we could realize that all monoterpenoids induced resistance slowly, concluding that these pesticides will be appropriated to control these pests in the future.This Thesis has concerned a study in depth about ecological insecticides from extraction of essential oils, identification of compounds (GC-MS) with insecticide activity, mode of action and study of resistance and mechanism of insecticide resistance involved in this process.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The maize weevil (Sitophilus zeamais) is one of the stored grain pests of major importance in the world. The indiscriminate use of conventional insecticides has led to the selection of populations of resistant S. zeamais. Although the essential oils (EO) of plants are considered an alternative to conventional insecticides, their range of use due to insect populations with different capacities resistance has not been determined. We examined the toxicity of the EO of Pogostemon cablin and its nanoemulsion on nine populations of S. zeamais from different regions of Brazil. For that were performed bioassays topical application, contact, fumigation, and repellency effects on population growth. Fifteen compounds were identified the EO of P. cablin, and patchoulol was major component (55.04%). The EO of P. cablin showed average activity against the nine populations of S. zeamais when applied topically. The time required to cause 50% mortality of the population was 33.4 hours. The nine populations of S. zeamais responded similarly to EO of P. cablin. The lethal dose to kill 50% of the population resulted in low toxicity index (<2). The population of Viçosa-MG was more susceptible the EO of P. cablin, with LD50 of 9.17 and 8.01 μg mg-1 after 48 and 72 hours exposure respectively. The greater tolerance of EO P. cablin was detected in the population of Sete Lagoas, Minas Gerais, which increased the LD50 of 1.77 and 1.53 times. The concentration the EO of P. cablin required to cause 50% mortality of the population by contact and fumigation ranged from 0.34 to 0.43 μl ml-1 and from 28.6 to 33.5 μl l-1, respectively. Already the nanoemulsion P. cablin showed LC50 ranging from 1.28 to 8.84 μl ml-1 and from 32.7 to 39.5 μl l-1. There was an increase in toxicity by contact and fumigation (LC50) of the nanoemulsion of P. cablin from 48 to 72 hours of exposure. Toxicity (LC50) for contact and fumigation on populations of Viçosa-MG and Sete Lagoas-MG after 48 and 72 hours of exposure to EO P. cablin was in most cases greater than the toxicity caused by nanoemulsion of P. cablin. The EO and the nanoemulsion of P. cablin were LC50 and LC70 repellents in at all times of exposure for the population of Viçosa-MG. The same occurred with the population of Sete Lagoas, Minas Gerais, except for LC50 after 4, 6 and 8 hours of exposure and the LC70 after 24 hours of exposure to nanoemulsion of P. cablin. For the population of Viçosa-MG, there was no difference in repellency caused by EO and nanoemulsion of P. cablin. As for the population of Sete Lagoas, Minas Gerais, EO P. cablin caused greater repellency to this population compared to this oil nanoemulsion. Increasing concentrations of nanoemulsion of P. cablin resulted in reduction and consumption of grains of the two populations. Populations of Viçosa-MG and Sete Lagoas-MG entered decline (ri <0) using concentrations of 50.15 and 67.29 μl kg-1, respectively. / O gorgulho do milho (Sitophilus zeamais) e uma das pragas de graos armazenados de maior importancia no mundo. O uso indiscriminado de inseticidas convencionais tem levado a selecao de populacoes de S. zeamais resistentes. Apesar dos oleos essenciais (OE) de plantas serem considerados uma alternativa ao uso de inseticidas convencionais, sua amplitude de utilizacao frente as populacoes de insetos com capacidades distintas de resistencia ainda nao foi determinada. Neste trabalho analisamos a toxicidade do OE de Pogostemon cablin e da nanoemulsao a base desse OE sobre nove populacoes de S. zeamais provenientes de diferentes regioes do Brasil. Para isso foram realizados bioensaios de aplicacao topica, contato, fumigacao, repelencia e efeitos sobre o crescimento populacional. Foram identificados quinze compostos no OE de P. cablin, sendo o patchoulol o componente majoritario (55,04%). O OE de P. cablin demonstrou atividade inseticida sobre as nove populacoes de S. zeamais quando aplicado topicamente. O tempo necessario para causar 50% de mortalidade das populacoes foi em media 33,4 horas. As nove populacoes de S. zeamais responderam de modo semelhante ao OE de P. cablin. As doses letais para matar 50% das populacoes resultaram em baixas razoes de toxicidade (<2). A populacao de Vicosa-MG foi a mais susceptivel ao OE de P. cablin, com DL50 de 9,17 e 8,01 Êg mg-1 apos 48 e 72 horas de exposicao, respectivamente. A maior tolerancia ao OE de P. cablin foi detectada na populacao de Sete Lagoas-MG, que apresentou aumento na DL50 de 1,77 e 1,53 vezes. A concentracao do OE de P. cablin necessaria para causar 50% de mortalidade das populacoes por contato e fumigacao variou de 0,34 a 0,43 Êl ml-1 e 28,6 a 33,5 Êl l-1, respectivamente. Ja a nanoemulsao de P. cablin apresentou CL50 que variaram de 1,28 a 8,84 Êl ml-1 e 32,7 a 39,5 Êl l-1. Houve aumento da toxicidade por contato e fumigacao (CL50) da nanoemulsao de P. cablin de 48 para 72 horas de exposicao. A toxicidade (CL50) por contato e fumigacao sobre as populacoes de Vicosa-MG e Sete Lagoas-MG apos 48 e 72 horas de exposicao ao OE de P. cablin foi, na maioria das vezes, maior do que a toxicidade causada pela nanoemulsao de P. cablin. O OE e a nanoemulsao de P. cablin foram repelentes nas CL50 e CL70 em todos os tempos de exposicao para a populacao de Vicosa-MG. O mesmo ocorreu com a populacao de Sete Lagoas-MG, excecao para a CL50 apos 4, 6 e 8 horas de exposicao e para a CL70 apos 24 horas de exposicao a nanoemulsao de P. cablin. Para a populacao de Vicosa-MG, nao houve diferenca na repelencia causada pelo OE e nanoemulsao de P. cablin. Ja para a populacao de Sete Lagoas-MG, o OE de P. cablin causou maior repelencia a esta populacao se comparado a nanoemulsao deste OE. Concentracoes crescentes da nanoemulsao de P. cablin resultaram em reducao do ri e do consumo de graos das duas populacoes. As populacoes de Vicosa-MG e Sete Lagoas-MG entraram em declinio (ri<0) a partir das concentracoes de 50,15 e 67,29 Êl kg-1, respectivamente.

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