A utilização de plantas transgênicas expressando proteínas inseticidas de Bacillus thuringiensis (Bt) tem sido a principal estratégia para o controle da lagarta-do-cartucho Spodoptera frugiperda (J.E. Smith) no Brasil. A resistência de S. frugiperda à proteína Vip3Aa20 foi recentemente isolada e caracterizada em condições de laboratório, a partir de uma população proveniente de Correntina-BA. Para subsidiar programas de Manejo da Resistência de Insetos (MRI), foram realizados estudos para entender a distribuição geográfica da resistência de S. frugiperda à proteína Vip3Aa20 no Brasil, mediante uso de métodos fenotípicos (proteína purificada e folhas de milho Bt) e genotípicos (F1 e F2 screen), além da elucidação da presença custo adaptativo associado à resistência a partir de uma linhagem resistente quase-isogênica. Para o monitoramento com proteína purificada, as médias de sobrevivência na dose discriminatória de 3600 ng Vip3Aa20/cm2 para 10 populações/safra de S. frugiperda das principais regiões produtoras de milho do Brasil, tiveram um aumento em número, no decorrer das safras, para as populações que diferiram da sobrevivência da linhagem SUS, por não sobreposição do I.C. (95%). As larvas sobreviventes deste monitoramento morreram quando transferidas para folhas de milho Bt expressando Vip3Aa20. Não houve sobreviventes no monitoramento da resistência utilizando folhas de milho Bt, para todas as populações avaliadas. As médias de frequência alélica da resistência estimadas pelo método F1 screen foram de 0,0069, 0,0051 e 0,0041 para as populações avaliadas na 2ª safra/2016, entressafra/2016 e 1ª safra/2017 respectivamente. Pelo método F2 screen, as médias de frequência alélica foram de 0,0030, 0,0036, 0,0054 e 0,0042 para as populações da 2ª safra/2016, entressafra/2016, 1ª safra/2017 e 2ª safra/2017 respetivamente. Foram selecionadas 3 linhagens resistentes a Vip3Aa20 pelo método F2 screen, a partir de populações provenientes de Peabiru-PR, São João da Boa Vista-SP e Casa Branca-SP. Pelo teste de complementaridade, o mesmo alelo da resistência que havia sido inicialmente isolado da região de Correntina-BA, foi verificado nestas novas linhagens resistentes selecionadas. Não foi verificada a presença de custo adaptativo associado à resistência de S. frugiperda a Vip3Aa20, além de um maior valor adaptativo de indivíduos heterozigotos mediante avaliação de parâmetros de tabela de vida e fertilidade. Os resultados do presente trabalho comprovaram que o alelo da resistência de S. frugiperda para a proteína Vip3Aa20 está amplamente distribuído nas principais regiões produtoras de milho no Brasil. Este fato aliado à ausência de custo adaptativo da resistência reforçam a necessidade de implementação de estratégias eficientes de MRI para retardar a evolução da resistência de S. frugiperda à Vip3Aa20 no Brasil. / The use of transgenic plants expressing Bacillus thuringiensis (Bt) insecticidal proteins has been the main strategy to control the fall armyworm Spodoptera frugiperda (J.E. Smith) in Brazil. The resistance of S. frugiperda to Vip3Aa20 protein was recently isolated and characterized in laboratory conditions from a Correntina-BA population. In order to subsidize Insect Resistance Management (IRM) programs, studies were carried out to understand the geographical distribution of S. frugiperda resistance to Vip3Aa20 protein in Brazil, through the use of phenotypic (purified protein and Bt maize leaves) and genotypic methods (F1 and F2 screen), in addition, the elucidation of fitness-cost presence associated with resistance from a near-isogenic resistant strain. For the purified protein monitoring, the mean survival at the diagnostic concentration of 3,600 ng Vip3Aa20/cm2 for 10 populations/season of S. frugiperda from the main maize producing regions of Brazil, had an increase in the number of populations with significant difference by non-overlap in the confidence interval (95 %) in relation with our reference of susceptibility. The surviving larvae of this monitoring died when transferred to leaves of Bt maize expressing Vip3Aa20. There were no survivors in resistance monitoring using Bt maize leaves for all populations evaluated. The mean frequency of resistance alleles estimated by the F1 screen method were 0.0069, 0.0051 and 0.0041 for the populations evaluated in the 2nd/2,016, the offseason/2,016 and the 1st/2,017 crop seasons, respectively. By the F2 screen method, the means of allele frequency were 0.0030, 0.0036, 0.0054 and 0.0042 for the populations of the 2nd/2,016, offseason/2,016, 1st/2,017 and 2nd/2,017 crop seasons, respectively. Three Vip3Aa20 resistant strains were selected by the F2 screen method from populations from Peabiru-PR, São João da Boa Vista-SP and Casa Branca-SP. By the complementarity test, the same resistance allele that had been initially isolated from the Correntina-BA region was verified in these new selected resistant strains. The presence of the adaptive cost associated to the resistance of S. frugiperda to Vip3Aa20 was not verified, besides a higher adaptive value of heterozygous individuals through evaluation of life table parameters and fertility. The results of the present work proved that the resistance allele of S. frugiperda for the Vip3Aa20 protein is widely distributed in the main maize producing regions in Brazil. This fact, coupled with the lack of adaptive cost of resistance, reinforces the need to implement efficient IRM strategies to delay the evolution of S. frugiperda resistance to Vip3Aa20 protein in Brazil.

O objetivo deste estudo é identificar e analisar os impactos que o desenvolvimento da resistência de pragas à tecnologia do milho Bt tem sobre a cultura do milho para o agricultor, como forma de incentivar, pelo aspecto econômico, o uso de práticas adequadas à gestão da resistência, de modo a postergar sua evolução. A justificativa da escolha deste tema está não só no grande impacto econômico e social da resistência de pragas às culturas Bt no Brasil e no mundo, capaz de causar sérias perdas aos agricultores, mas também à indústria biotecnológica e aos próprios consumidores. Ademais, embora a eficácia das plantas Bt no controle de pragas agrícolas seja comprovada e seu uso seja frequente no Brasil, há necessidade de difusão sobre a importância da adequação de medidas de manejo de resistência (MRI) pelo agricultor. Medidas como a adoção das áreas de refúgio dentro dos programas de Manejo Integrado de Pragas (MIP), visando, pelo menos, retardar a evolução da resistência das pragas aos cultivos Bt, garantindo que essa tecnologia permaneça viável por mais tempo. A hipótese deste trabalho é que a evolução da resistência de pragas ao cultivo Bt reduz a probabilidade de obtenção de lucro pelo agricultor. Isto porque, com a exigência de maior número de aplicações inseticidas para complementar a ineficiência de controle do cultivo Bt, há elevação dos custos com pulverizações, aos quais se somam os altos custos da semente Bt, tornando os custos de produção superiores à receita bruta obtida pelo produtor. Assim, com a finalidade de realizar alguma quantificação de impactos, conduz-se como estudo de caso, a análise de viabilidade econômica da produção de milho Bt, sob condições de evolução da resistência de Spodoptera frugiperda (lagarta do cartucho) ao milho Bt. Para tanto, desenvolve-se um método para a análise de risco, avaliando dois índices econômicos, o VPL (Valor Presente Líquido) e a relação B/C (Benefício Custo), e utilizando o método de Monte Carlo para gerar simulações das variáveis de risco, preço e produtividade do milho. Foram analisados dados do fluxo de caixa da produção do milho Bt e convencional, coletados da base do Cepea, obtidos por meio de painéis, informações sobre propriedades modais de Rio Verde (GO), relativas ao período de 2009/10 a 2015/16. Adotou-se o conceito de Custo Operacional Efetivo na análise. Os resultados indicaram que, de fato, a resistência possui um impacto negativo sobre o lucro do produtor rural no médio e longo prazo, confirmando a hipótese do estudo. Evidenciou-se que a produção de milho Bt, na ausência da evolução da resistência de pragas é o cenário com maior viabilidade econômica, devido ao menor risco de um VPL negativo na atividade produtiva e de uma relação B/C menor que 1. Todavia quando é inevitável conter a evolução da resistência, e à medida que a frequência de pragas resistentes ao cultivo Bt se eleva, os riscos de a produção do milho transgênico se tornar inviável economicamente são maiores, diante de uma maior probabilidade de ocorrência de VPL negativo e de uma relação B/C inferior a um. / The purpose of this study is to identify and analyze the impacts that the development of pest resistance to the Bt corn technology has on the corn crop for the farmer, as a way to encourage the use of appropriate practices for the management of resistance, so that it can delay its evolution. The justification for choosing this subject is not only in the great economic and social impact of pest resistance to Bt crops in Brazil and in the world, which can cause serious losses to farmers, the biotechnology industry and consumers themselves. Moreover, although the effectiveness of Bt plants in the control of agricultural pests is proven and their use is frequent in Brazil, it is necessary to disseminate the importance of the adaptation of measures of resistance management (IRM) by the farmer. Measures such as the adoption of the areas of shelter within the Integrated Pest Management (IPM) programs, objectifying to at least delay the evolution of pest resistance to Bt crops, ensuring that this technology remains accessible longer. The hypothesis of the present work is that the evolution of pest resistance to Bt crop decreases the probability of obtaining profit to the farmer. This is because with the requirement of a greater number of insecticide applications to add to the control inefficiency of the Bt crop, there is an increase in spraying costs which adds up to the high Bt seed costs, making production costs higher than the relevant income obtained by the producer. Thus, in order to perform some quantification of the impacts, the economic viability analysis of the Bt maize production is carried out under conditions of evolution of the resistance of Spodoptera frugiperda to Bt corn. To do so, a method for risk observance was developed evaluating two economic indices, the NPV and the B / C ratio and using the Monte Carlo method to generate simulations of corn risk, price and productivity variables. Bt and conventional maize production cash flow data were collected from the Cepea base, acquired through panels, information on modal properties of Rio Verde (GO). The concept of Effective Operational Cost was adhered to in the analysis. The results indicated that, in fact, the resistance has a negative impact on the rural producers\' profit in the medium and long term, confirming the hypothesis of the study. It was evidenced that the production of Bt corn, without occurrence of the evolution of pest resistance is the circumstance that presents greater economic viability, due to the lower risk of a negative NPV in the productive activity and a B / C ratio lower than 1. However, when it is inevitable to contain the evolution of resistance and as it increases the frequency of pests resistant to Bt cultivation, there will be a greater risk that the production of transgenic maize will become economically unviable, due to a higher probability of negative NPV occurrence and of a B / C ratio of less than one.

Genetically modified (GM) cotton expressing Cry1Ac proteins was released in South Africa in 1997 for control of the bollworm complex on this crop. No reports of the failure of Bollgard® cotton to control these pests have yet been made. Throughout the world there are concerns about the development of resistance of target pests to Bt cotton due to the use of only one Bt gene. The aim of this study was to determine if Helicoverpa armigera (Lepidoptera: Noctuidae) and Diparopsis castanea (Lepidoptera: Noctuidae) developed resistance to Bt cotton in South Africa. To determine if H. armigera developed resistance, laboratory experiments were conducted to determine the levels of larval survival and development time when feeding on Bt and non–Bt cotton. Bollworm populations were collected on maize and cotton at different sites in South Africa and reared on Bt and non–Bt cotton under laboratory conditions. Results showed that some populations survived on Bt cotton and that a significant proportion of the individuals successfully completed their life cycles on Bt cotton. Surveys were also conducted amongst cotton farmers to determine the levels of compliance to the refuge strategy that has to be implemented by farmers as an insect resistance management (IRM) strategy to delay resistance development. The levels of compliance to refugia requirements were low and farmers generally only started planting refugia several years after they planted Bt cotton for the first time. The development of resistance of H. armigera to Bt cotton in South Africa can possibly be ascribed to non–compliance to the prescribed refuge requirements. No conclusions can be made on resistance of D. castanea to Bt cotton but the relatively long time to mortality of larvae could indicate development of tolerance to Cry1Ac proteins. The new generation Bollgard II® cotton, expressing both Cry1Ac and Cry2Ab2 proteins, has been released in South Africa during the 2010/11 growing season and field observations showed effective control of the bollworm complex at several sites in the country. Monitoring of refuge compliance levels as well as resistance development in the bollworm complex to Bollgard II® cotton is necessary to ensure the future success of GM cotton. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2012.

Genetically modified (GM) cotton expressing Cry1Ac proteins was released in South Africa in 1997 for control of the bollworm complex on this crop. No reports of the failure of Bollgard® cotton to control these pests have yet been made. Throughout the world there are concerns about the development of resistance of target pests to Bt cotton due to the use of only one Bt gene. The aim of this study was to determine if Helicoverpa armigera (Lepidoptera: Noctuidae) and Diparopsis castanea (Lepidoptera: Noctuidae) developed resistance to Bt cotton in South Africa. To determine if H. armigera developed resistance, laboratory experiments were conducted to determine the levels of larval survival and development time when feeding on Bt and non–Bt cotton. Bollworm populations were collected on maize and cotton at different sites in South Africa and reared on Bt and non–Bt cotton under laboratory conditions. Results showed that some populations survived on Bt cotton and that a significant proportion of the individuals successfully completed their life cycles on Bt cotton. Surveys were also conducted amongst cotton farmers to determine the levels of compliance to the refuge strategy that has to be implemented by farmers as an insect resistance management (IRM) strategy to delay resistance development. The levels of compliance to refugia requirements were low and farmers generally only started planting refugia several years after they planted Bt cotton for the first time. The development of resistance of H. armigera to Bt cotton in South Africa can possibly be ascribed to non–compliance to the prescribed refuge requirements. No conclusions can be made on resistance of D. castanea to Bt cotton but the relatively long time to mortality of larvae could indicate development of tolerance to Cry1Ac proteins. The new generation Bollgard II® cotton, expressing both Cry1Ac and Cry2Ab2 proteins, has been released in South Africa during the 2010/11 growing season and field observations showed effective control of the bollworm complex at several sites in the country. Monitoring of refuge compliance levels as well as resistance development in the bollworm complex to Bollgard II® cotton is necessary to ensure the future success of GM cotton. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2012.

This thesis looks at the divergent policy decisions on the commercial release of two genetically modified (GM) crops in India. Bt cotton was introduced in India in 2002, and has spread widely across the country, though not without controversy. In 2010, the first GM food crop – Bt Brinjal (eggplant) – was put forward for approval. In contrast to the Bt cotton decision, and following heated debate and a series of public consultations across the country, an indefinite moratorium was placed on the crop. In this thesis, I unpack the various factors that shaped both decisions and the politics that accompanied them. To facilitate this analysis, I use a conceptual framework that combines four key forces that are often the focus of food governance analysis, but which are not always considered together. I argue that the divergence in outcomes can be explained by a confluence of shifts in key elements of the policy process. These dimensions of influence can be understood in four related categories: corporate actors, institutional mechanisms, science and science networks, and discursive elements. Changes that took place in each of these dimensions in the period between the two decisions align to explain divergent outcomes that no individual influence could. The conceptual framework I develop in this thesis presents a useful structure to analyse the often-complex and multi-causal processes and outcomes related to food and environmental issues. The results of this research have implications for the future direction of agricultural GMO policy in India, as well as in other countries in the global South.

This thesis looks at the divergent policy decisions on the commercial release of two genetically modified (GM) crops in India. Bt cotton was introduced in India in 2002, and has spread widely across the country, though not without controversy. In 2010, the first GM food crop – Bt Brinjal (eggplant) – was put forward for approval. In contrast to the Bt cotton decision, and following heated debate and a series of public consultations across the country, an indefinite moratorium was placed on the crop. In this thesis, I unpack the various factors that shaped both decisions and the politics that accompanied them. To facilitate this analysis, I use a conceptual framework that combines four key forces that are often the focus of food governance analysis, but which are not always considered together. I argue that the divergence in outcomes can be explained by a confluence of shifts in key elements of the policy process. These dimensions of influence can be understood in four related categories: corporate actors, institutional mechanisms, science and science networks, and discursive elements. Changes that took place in each of these dimensions in the period between the two decisions align to explain divergent outcomes that no individual influence could. The conceptual framework I develop in this thesis presents a useful structure to analyse the often-complex and multi-causal processes and outcomes related to food and environmental issues. The results of this research have implications for the future direction of agricultural GMO policy in India, as well as in other countries in the global South.

O objetivo deste estudo é identificar e analisar os impactos que o desenvolvimento da resistência de pragas à tecnologia do milho Bt tem sobre a cultura do milho para o agricultor, como forma de incentivar, pelo aspecto econômico, o uso de práticas adequadas à gestão da resistência, de modo a postergar sua evolução. A justificativa da escolha deste tema está não só no grande impacto econômico e social da resistência de pragas às culturas Bt no Brasil e no mundo, capaz de causar sérias perdas aos agricultores, mas também à indústria biotecnológica e aos próprios consumidores. Ademais, embora a eficácia das plantas Bt no controle de pragas agrícolas seja comprovada e seu uso seja frequente no Brasil, há necessidade de difusão sobre a importância da adequação de medidas de manejo de resistência (MRI) pelo agricultor. Medidas como a adoção das áreas de refúgio dentro dos programas de Manejo Integrado de Pragas (MIP), visando, pelo menos, retardar a evolução da resistência das pragas aos cultivos Bt, garantindo que essa tecnologia permaneça viável por mais tempo. A hipótese deste trabalho é que a evolução da resistência de pragas ao cultivo Bt reduz a probabilidade de obtenção de lucro pelo agricultor. Isto porque, com a exigência de maior número de aplicações inseticidas para complementar a ineficiência de controle do cultivo Bt, há elevação dos custos com pulverizações, aos quais se somam os altos custos da semente Bt, tornando os custos de produção superiores à receita bruta obtida pelo produtor. Assim, com a finalidade de realizar alguma quantificação de impactos, conduz-se como estudo de caso, a análise de viabilidade econômica da produção de milho Bt, sob condições de evolução da resistência de Spodoptera frugiperda (lagarta do cartucho) ao milho Bt. Para tanto, desenvolve-se um método para a análise de risco, avaliando dois índices econômicos, o VPL (Valor Presente Líquido) e a relação B/C (Benefício Custo), e utilizando o método de Monte Carlo para gerar simulações das variáveis de risco, preço e produtividade do milho. Foram analisados dados do fluxo de caixa da produção do milho Bt e convencional, coletados da base do Cepea, obtidos por meio de painéis, informações sobre propriedades modais de Rio Verde (GO), relativas ao período de 2009/10 a 2015/16. Adotou-se o conceito de Custo Operacional Efetivo na análise. Os resultados indicaram que, de fato, a resistência possui um impacto negativo sobre o lucro do produtor rural no médio e longo prazo, confirmando a hipótese do estudo. Evidenciou-se que a produção de milho Bt, na ausência da evolução da resistência de pragas é o cenário com maior viabilidade econômica, devido ao menor risco de um VPL negativo na atividade produtiva e de uma relação B/C menor que 1. Todavia quando é inevitável conter a evolução da resistência, e à medida que a frequência de pragas resistentes ao cultivo Bt se eleva, os riscos de a produção do milho transgênico se tornar inviável economicamente são maiores, diante de uma maior probabilidade de ocorrência de VPL negativo e de uma relação B/C inferior a um. / The purpose of this study is to identify and analyze the impacts that the development of pest resistance to the Bt corn technology has on the corn crop for the farmer, as a way to encourage the use of appropriate practices for the management of resistance, so that it can delay its evolution. The justification for choosing this subject is not only in the great economic and social impact of pest resistance to Bt crops in Brazil and in the world, which can cause serious losses to farmers, the biotechnology industry and consumers themselves. Moreover, although the effectiveness of Bt plants in the control of agricultural pests is proven and their use is frequent in Brazil, it is necessary to disseminate the importance of the adaptation of measures of resistance management (IRM) by the farmer. Measures such as the adoption of the areas of shelter within the Integrated Pest Management (IPM) programs, objectifying to at least delay the evolution of pest resistance to Bt crops, ensuring that this technology remains accessible longer. The hypothesis of the present work is that the evolution of pest resistance to Bt crop decreases the probability of obtaining profit to the farmer. This is because with the requirement of a greater number of insecticide applications to add to the control inefficiency of the Bt crop, there is an increase in spraying costs which adds up to the high Bt seed costs, making production costs higher than the relevant income obtained by the producer. Thus, in order to perform some quantification of the impacts, the economic viability analysis of the Bt maize production is carried out under conditions of evolution of the resistance of Spodoptera frugiperda to Bt corn. To do so, a method for risk observance was developed evaluating two economic indices, the NPV and the B / C ratio and using the Monte Carlo method to generate simulations of corn risk, price and productivity variables. Bt and conventional maize production cash flow data were collected from the Cepea base, acquired through panels, information on modal properties of Rio Verde (GO). The concept of Effective Operational Cost was adhered to in the analysis. The results indicated that, in fact, the resistance has a negative impact on the rural producers\' profit in the medium and long term, confirming the hypothesis of the study. It was evidenced that the production of Bt corn, without occurrence of the evolution of pest resistance is the circumstance that presents greater economic viability, due to the lower risk of a negative NPV in the productive activity and a B / C ratio lower than 1. However, when it is inevitable to contain the evolution of resistance and as it increases the frequency of pests resistant to Bt cultivation, there will be a greater risk that the production of transgenic maize will become economically unviable, due to a higher probability of negative NPV occurrence and of a B / C ratio of less than one.

Dans cette étude, des aspects importants du rapport entre pesticides et abeilles domestiques (Apis mellifera L.) ont été traités. Dans la première partie, les effets de l’exposition des abeilles aux poussières contaminées avec trois neonicotinoides et le fipronil ont été étudiés. En fait, des quantités considérables de ces pesticides, utilisés pour l’enrobage des semences, sont dispersées pendant le semis du mais, et peuvent donc représenter une voie d’exposition des abeilles.En particulier, une voie spécifique d’exposition, le contact indirect, a été pris en compte. Les effets létaux et sub-létaux (mortalité aigue, butinage, développement des colonies, capacité d’orientation) des poussières ont été évalués en laboratoire, en tunnel et en plein champ. La dispersion réelle des poussières pendant le semis avait été évalué précédemment.Les résultats ont montré un effet significatif, sur la mortalité, de l’exposition aux poussières contaminées avec neonicotinoides et fipronil, en laboratoire et en tunnel. Par contre, la capacité d’orientation des abeilles n’a été pas influencée par l’exposition aux concentrations testées.Dans la deuxième partie de la recherche, on a étudié l’impact de différentes pesticides (chimiques et biologiques) sur les changements biochimiques et physiologiques des abeilles exposées. Ces paramètres on été évalué pour différentes façons et durées d’exposition. En particulier, trois expérimentations ont été effectuées en combinant les spores de Bacillus thuringiensis avec la deltamethine, les spores de Bt avec le fipronil et le traitement avec deltamethrine et le fongicide difenoconazole. Certains enzymes impliqués dans la détoxification, le stress oxydant et le métabolisme énergétique (GST, ALP, SOD, CAT, G6PDH, GAPDH) ont été sélectionnés pour évaluer les variations de leur activité suite à l’exposition aux pesticides. L’analyse des différents indicateurs biochimiques, comme le GST et le ALP, a mis en évidence des variations physiologiques qui peuvent être liés à l’exposition aux pesticides. Cette méthodologie pourrait donc représenter un nouvel aspect de l’évaluation des effets sub-létaux des pesticides chez l’abeille. / In this study, some important aspects of the relationship between honey bees (Apis mellifera L.) and pesticides have been investigated. In the first part of the research, the effects of the exposure of honey bees to neonicotinoids and fipronil contaminated dusts were analyzed. In fact, considerable amounts of these pesticides, employed for maize seed dressing treatments, may be dispersed during the sowing operations, thus representing a way of intoxication for honey bees. In particular, a specific way of exposure to this pesticides formulation, the indirect contact, was taken into account. To this aim, we conducted different experimentations, in laboratory, in semi-field and in open field conditions in order to assess the effects on mortality, foraging behaviour, colony development and capacity of orientation. The real dispersal of contaminated dusts was previously assessed in specific filed trials. The results showed a significant effect on mortality of neonicotinoids and fipronil contaminated dusts, both in laboratory and in semi-field trials. However, no effects were evidenced in honey bees orientation capacity.In the second part, the impact of various pesticides (chemical and biological) on honey bee biochemical-physiological changes, was evaluated. Different ways and durations of exposure to the tested products were also employed. Three experimentations were performed, combining Bt spores and deltamethrin, Bt spores and fipronil, difenoconazole and deltamethrin. Several important enzymes (GST, ALP, SOD, CAT, G6PDH, GAPDH) were selected in order to test the pesticides induced variations in their activity. In particular, these enzymes are involved in different pathways of detoxification, oxidative stress defence and energetic metabolism. The analysis of different biochemical indicators highlighted some interesting physiological variations that can be linked to the pesticide exposure. We therefore stress the attention on the possibility of using such a methodology as a novel toxicity endpoint in environmental risk assessment.

Orientador: Marcelo da Costa Ferreira / Resumo: O algodão (Gossypium hirsutum L.) tem grande relevância para a economia mundial. Dentre os principiais fatores limitantes da produção estão os problemas fitossanitários, que ocorrem em todas as fases da cultura. O inseto Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) é importante devido a sua capacidade de causar danos nas folhas e maçãs do algodoeiro, muitas vezes requerendo a aplicação frequente de inseticidas para o seu controle. Em geral são utilizados inseticidas químicos. Entretanto, o uso de bioinseticidas têm aumentado consistentemente, principalmente aqueles à base de Bacillus thuringiensis, chamados de Bt bioinseticidas. Fatores abióticos como a chuva também interferem na eficiência de aplicações de Bt bioinseticidas e consequentemente no controle do organismo alvo. Uma alternativa que pode dar proteção ao Bt mediante chuva é a adição de adjuvantes a calda. Porém, pouco se sabe o quanto a associação do Bt com adjuvantes afeta no crescimento vegetativo, esporulação e persistência da bactéria e o controle. Portanto é de extrema importância à compreensão das interações físico-químicas e biológicas da mistura de Bt bioinseticidas e adjuvantes. Neste contexto, objetivou-se avaliar o efeito da adição de adjuvantes nas características físico-química e biológicas dos Bt bioinseticidas nas formulações Dipel® WP e Dipel® SC submetidas à chuva artificial para o controle de S. frugiperda em plantas de algodão. Para simular a chuva, foram utilizadas as lâminas de chuv... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cotton (Gossypium hirsutum L.) has great relevance to the world economy. Among the main limiting factors of production are the phytosanitary problems that occur at all stages of the crop. The insect Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) is important because of its ability to cause damage to cotton leaves and apples, often requiring insecticides to be applied frequently for its control. In general, chemical insecticides are used. However, the use of bioinsecticides has consistently increased, especially those based on Bacillus thuringiensis, called Bt bioinsecticides. Abiotic factors such as rain also interfere with the efficiency of Bt applications and consequently in the control of the target organism. An alternative that can protect Bt in the rain is the addition of adjuvants to the syrup. However, little is known about how the association of Bt with adjuvants affects vegetative growth, sporulation and bacterial persistence and control. Therefore, it is extremely important to understand the physicochemical and biological interactions of the mixture of Bt bioinsecticides and adjuvants. In this context, the objective of this study was to evaluate the effect of the addition of adjuvants on the physicochemical and biological characteristics of Bt bioinsecticides in the formulations Dipel® WP and Dipel® SC submitted to artificial rain to control S. frugiperda in cotton plants. To simulate the rain, the 20mm artificial rain blades applied one hour after the ap... (Complete abstract click electronic access below) / Doutor

No description available.