O cultivo sucessivo de soja em grandes áreas agrícolas contribuíram significativamente para o aumento da incidência de pragas nessa cultura. Os percevejos sugadores são responsáveis por significativas perdas de rendimento, qualidade e potencial germinativo, além de causar a retenção foliar. Sendo assim, os objetivos deste trabalho foram i) avaliar a adaptabilidade e estabilidade em progênies de soja com excelente desempenho agronômico e resistência ao complexo de percevejos em três ambientes; e ii) explorar a viabilidade do uso de diferentes métodos de melhoramento para no desenvolvimento de progênies resistentes ao complexo de percevejos. Para a compreensão da interação genótipo por ambiente, 28 progênies e cinco testemunhas foram avaliados em três ambientes, e os resultados foram submetidos à análise de GGE Biplot. Os caracteres avaliados foram: número de dias para a maturidade, período de granação, produtividade de grãos, peso de cem sementes, retenção foliar e peso sementes boas. A análise gráfica biplot demonstrou que existe interação do tipo complexa entre as progênies avaliadas, e as progênies 7, 9, 8 e 23 foram as que tiveram a maior estabilidade nos três ambientes. Para a análise de viabilidade dos métodos genealógico e MSD (descendência de múltiplas sementes), foram avaliadas duas populações de soja, respectivamente à cada método. Ambas populações são oriundas do cruzamento entre as cultivares IAC-100 (fonte de resistência ao complexo de percevejos) e CD- 215 (suscetível). Os caracteres utilizados para essa análise foram a produtividade de grãos e peso de sementes boas. Foram realizadas análises descritiva de cada método e uma análise de modelos mistos para a verificação da diferença entre eles. A maior média e variabilidade genética foi encontrada na população oriunda do método MSD. Todavia, o método genealógico apresentou 10 progênies maiores que a média da melhor testemunha. Os resultados foram influenciados pela presença da interação genótipo por ambiente, e a diferença entre os métodos foi detectada pelo teste Wald-F. Ambos os métodos foram eficientes para a geração de progênies com alto potencial agronômico e com resistência ao complexo de percevejos. Com isso, é necessário submeter as melhores progênies à ensaios de competição para um futuro lançamento de novas cultivares de soja que reúnam alta produtividade e resistência ao complexo de percevejos. / The continuous cultivation of a given crop in large areas contributes significantly to the increased incidence of pests. One such pest are the sucking insects that can cause significant losses. Stink bugs will feed on developing soybean seeds by piercing and immature pods, causing seed damage and reductions in yield, quality and germination potential, in addition to causing leaf retention. Thus, the objectives of this study were i) to evaluate the adaptability and stability in soybean progenies with excellent agronomic performance and resistance to stink bugs in three environments; and ii) to study the viability to use different breeding methods for development of resistant progeny to stink bugs. To evaluate the genotype-byenvironment interaction, 28 progenies and five experimental checks were evaluated in three environments, and the results submitted to analysis of GGE Biplot. The following traits were evaluated in the field: number of days to maturity, grain filling period, grain yield, weight of one hundred seeds, leaf retention, and weight of healthy seeds. The graphical biplot analysis showed that there is complex interaction between progenies, and the progenies 7, 9, 8 and 23 were those that had the highest stability in all three environments. To analyze the feasibility of pedigree and multiple seeds descent (MSD) methods were evaluated two soybean populations respectively for each method. Both populations were from the cross between IAC-100 (resistance source to stink bug complex) and CD-215 (susceptible). The traits used for this analysis were grain yield and weight of healthy seeds. Descriptive analyses of each method and a mixed model analysis were made to verify the difference between them. The highest average and genetic variability was found in the MSD method derived from the population. However, the pedigree method showed 10 progenies higher than the average of the best experimental check. The results were influenced by the presence of genotype-by-environment and the difference between the methods was detected by the Wald-F test. Both methods were efficient to generated progenies with high agronomic potential and resistance to stink bugs. Thus, it is necessary to submit the best progeny to competition tests for a future release of new soybean cultivars with high productivity and resistance.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-03-15T18:48:21Z No. of bitstreams: 2 Dissertação - Humberto Oliveira Guimarães - 2014.pdf: 1535284 bytes, checksum: 045806a0a1f7bc2c0c290dd980ed680c (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-16T11:29:57Z (GMT) No. of bitstreams: 2 Dissertação - Humberto Oliveira Guimarães - 2014.pdf: 1535284 bytes, checksum: 045806a0a1f7bc2c0c290dd980ed680c (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-16T11:29:57Z (GMT). No. of bitstreams: 2 Dissertação - Humberto Oliveira Guimarães - 2014.pdf: 1535284 bytes, checksum: 045806a0a1f7bc2c0c290dd980ed680c (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-25 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / During 2011/2012 and 2012/2013, soybean fields were sampled in all stages. In this case objective of describing the population dynamics of the main species of phytophagous stink bugs and to determine the spatial distribution within field level to understand how is the stink bugs colonize soybean field. Five commercial fields submitted to different management practices were monitored. Sampling surveys to describe the spatial and probability distribution were conducted using regular sampling grids with equidistance of 50 m between sampling points. Fields were sampled weekly for stink bugs in all crop stages. The sampling method used was ground cloth, trough coutn nymphs and adults. The data were subjected to descriptive statistical analysis for better understanding of population dynamics. To verify the statistical distribution to the population of stinkbugs best adjusted of the null hypothesis test. Maps representing the localization of samples of stink bugs in soybean fields were constructed. Euschistus heros was the predominant species, representing 91% of all stink bugs sampled. The stink bug population fluctuation showed an early colonization of the soybean fields, which in the past was restricted to pod formation. Our results indicate that E. heros best fits the negative binomial and occurs randomly distributed in soybean fields what allows to conclude that sampling should be done in the hole field. / Durante as safras de 2011/2012 e 2012/2013 campos de soja foram amostrados em diversos estádios fenológicos da planta. Neste caso objetivou-se conhecer a flutuação populacional das principais espécies de percevejos fitófagos e determinar a sua distribuição espacial na lavoura com o intuito de analisar como ocorre a colonização nos campos de soja. Foram monitoradas cinco lavouras comerciais submetidas a diferentes condições de manejo. Para tanto confeccionou-se malhas regulares de amostragem com pontos equidistantes de 50 metros, as quais foram amostradas semanalmente com o auxílio do GPS a partir da emissão dos primeiros trifólios até próximo à colheita. O método de amostragem utilizado foi o do pano de batida, através da contagem de ninfas e adultos dos percevejos em um metro linear. Os dados obtidos foram submetidos às análises estatísticas descritivas, para melhor entendimento da flutuação populacional. Para verificação da distribuição estatística a que a população de percevejos melhor se ajustou foi utilizado o teste de hipótese de nulidade. Mapas representativos da localização dos percevejos no campo foram confeccionados. Euschistus heros foi a espécie predominante, compondo 91% dos percevejos encontrados. As flutuações populacionais demonstraram a presença precoce dos percevejos nos cultivos de soja. A distribuição de E. heros nos campos de soja se ajustou melhor à Binomial Negativa e ocorreu de forma aleatória, asssim amostras devem ser realizadas em toda a área.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-05-23T11:58:33Z No. of bitstreams: 1 texto completo.pdf: 664042 bytes, checksum: 760ba21f1908906030a13daa97304915 (MD5) / Made available in DSpace on 2017-05-23T11:58:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 664042 bytes, checksum: 760ba21f1908906030a13daa97304915 (MD5) Previous issue date: 2017-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A grande extensão de área com cultura de soja intensificoua ocorrência de diversas pragas, dentre elas, o percevejo-marrom, Euschistus heros (Fabricius, 1798) (Pentatomidae). Os danos desta praga vêm se tornando cada vez mais expressivos, devido ao seu aumento populacional, manejo inadequado e resistência a inseticidas, o que resulta em perda de produtividade. As plantas apresentam mecanismos de defesa contra os insetos e, por sua vez, estes tentam burlar estas defesas. Estudos sobre a interação inseto/planta têm sido realizados analisando a via de defesa da planta e/ou enzimas digestivas das pragas. Entretanto, não há relatos sobre enzimas digestivas presentes no intestino e nas glândulas salivares do percevejo- marrom após interação com a soja, ao longo do tempo. Assim, este estudo teve como objetivo avaliar o perfil das enzimas presentes no intestino médio e nas glândulas salivares após serem alimentados com as cultivares IAC 24 (resistente) e IAC Foscarin 31 (susceptível). Sendo este o início dos estudos em relação ao controle desta praga com base em aspectos bioquímicos. Plantas, no estágio R5, foram infestadas com machos do percevejo. As avaliações foram realizadas em diferentes tempos de alimentação (0, 24, 48, 72 e 96 horas). Após cada tempo, retirou-se os intestinos e as glândulas salivares. As atividades das enzimas proteolíticas, amilase e lipase, foram realizadas de acordo com protocolos específicos. Tanto no intestino como nas glândulas salivares não foi detectada atividade de cisteíno proteases. No intestino médio, a atividade de proteases totais apresentou diferença para tempo, cultivar e interação cultivar x tempo. A amilase foi diferente somente para o tempo e lipase diferiu no tempo e na interação. Nas glândulas salivares, a atividade de proteases totais apenas diferiu em relação às cultivares analisadas. A amilase mostrou significância tanto para o tempo quanto para a interação e lipase foi significativa para as três fontes de variações avaliadas. Assim, observou- se o comportamento das enzimas responsivo a alimentação com os distintos cultivares. Estudos mais aprofundados são necessários para entender o porquê das oscilações registradas nas condições analisadas. / Great extension of soybean crop intensified the occurrence of several pests, including the brown stink bug Euschistus heros, which is considered one of the main soybean pests. Pest damage has become increasingly significant due to its population increase, inadequate management and resistance to insecticides, resulting in soybean productivity losses. Plants have defense mechanisms against insects, and these latter in turn try to cheat these defenses. Plant-insect interaction studies have been performed by analyzing plants defense-signaling pathways and/or pest’s digestive enzymes. However, digestive enzymes present in the gut and salivary glands of the stink bugafter his interaction with soybeans over the time has not been reported. Thus, the aim of this study was to assess the enzymatic profile present in the midgut and salivary glands of the stink bug after feeding with IAC 24 (resistant) and IAC Foscarin 31 (susceptible) soybean crop. This being the beginning of the studies in relation to the control of this pest based on biochemical aspects. Plants at the R5 stage were infected with male stink bug. Assessments were performed at different feeding times (0, 24, 48, 72 and 96 hours). After each time, midgut and salivary glands were removed. The proteolytic enzyme assays, amylase and lipase were performed according to specific protocols. Cysteine proteases activities were not detected in the midgut and salivary glands. In the midgut, total proteases activity presented difference for time, cultivar and cultivar x time interaction. Amylase activity was different only in time, meanwhile lipase differed in time and interaction. In the salivary glands, total proteases activity differed only in relation to the cultivars analyzed. Amylase activity showed significance for time and in interaction, while lipase was significant for the three sources of variations assessed. Thus, the behavior of the enzymes responsive to feeding with the different cultivars was observed. Further studies are needed to understand why the oscillations recorded under the conditions analyzed.

Submitted by EDER LICIERI GROLI (elicierigroli@gmail.com) on 2016-11-11T11:58:29Z No. of bitstreams: 1 Dissertação_Eder_Original_Final.pdf: 843789 bytes, checksum: a378dddd9748a608509cdc09ff7afc91 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO null (luizaromanetto@hotmail.com) on 2016-11-17T13:02:01Z (GMT) No. of bitstreams: 1 groli_el_me_jabo.pdf: 843789 bytes, checksum: a378dddd9748a608509cdc09ff7afc91 (MD5) / Made available in DSpace on 2016-11-17T13:02:01Z (GMT). No. of bitstreams: 1 groli_el_me_jabo.pdf: 843789 bytes, checksum: a378dddd9748a608509cdc09ff7afc91 (MD5) Previous issue date: 2016-09-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A soja apresenta grande importância econômica para o Brasil, sendo considerada a principal cultura do sistema agrícola brasileiro. No entanto, está sujeita a grandes interferências externas durante todo o seu ciclo, as quais podem afetar consideravelmente seu desempenho produtivo. O ataque de insetos pragas se caracteriza como um dos principais problemas a ser solucionado, em especial, o chamado complexo de percevejos, o qual ataca diretamente às sementes durante o período de enchimento e maturação, depreciando a qualidade das mesmas. Assim sendo, este trabalho teve como objetivo avaliar linhagens de soja obtidas a partir de hibridações artificiais entre cultivares de soja com resistência ao complexo de percevejos e elevado potencial agronômico, buscando identificar possíveis genótipos que apresentem simultaneamente os bons atributos de ambos os genitores, além de identificar quais os caracteres que melhor auxiliam na seleção de genótipos resistentes ao complexo de percevejos. O trabalho foi desenvolvido no ano agrícola 2014/15, em delineamento experimental alfa-látice 16x16, utilizando 256 genótipos de soja sob infestação natural do complexo de percevejos. Foram avaliados os caracteres altura de planta na maturidade, altura de inserção da primeira vagem, número de dias para a maturação, valor agronômico, retenção foliar, produtividade de grãos, peso de sementes boas, porcentagem de sementes boas, peso de cem sementes, número de ramos por planta, número de vagens por planta e número de nós reprodutivos. Trinta e três genótipos apresentaram resistência moderada ao complexo de percevejos e bom desempenho para caracteres de interesse agronômico. Os caracteres produtividade de grãos, peso de sementes boas, porcentagem de sementes boas, retenção foliar e peso de cem sementes podem ser utilizados na seleção indireta para resistência ao complexo de percevejos. / Soybean has great agricultural and economic importance to Brazil, being the main culture of the Brazilian agricultural system. However, the productive performance of soybean is greatly affected by external interferences throughout the production cycle. The attack of pests is characterized as one of the main problems to be solved, especially the stink bug complex, which directly attacks the seeds during the filling and maturation, lowering soybean quality. Thus the aim of this study was to evaluated soybean lines derived from artificial crosses between soybean cultivars with resistance to stink bug complex and high agronomic potential, aiming to identify possible genotypes that inherited the good traits of both parents, and which traits best assist in the selection of genotypes resistant to stink bug complex. The experiment was carried out in the 2014/15 growing season, using an alpha-lattice experimental design 16x16 and 256 genotypes of soybean naturally infested with the stink bug complex. The agronomic traits evaluated were: plant height at maturity, height of the first pod insertion, number of days to maturity, agronomic value, leaf retention, grain yield, good seeds weight, good seed percentage, one hundred-seeds weight, number of branches per plant, number of pods per plant and number of reproductive nodes. Thirty-three genotypes were resistant to the stink bug complex and performed well regarding agronomically important traits. The traits grain yield, good seed weight, good seed percentage, leaf retention and one hundred-seeds weight can be used for indirect selection of genotypes resistant to the stink bug complex.

Stink bugs are major pests of agricultural crops throughout Virginia and much of the United States. Knowledge of the biology, the species complex, and insecticide susceptibility can improve management. A survey was conducted in Virginia to determine the species complex in soybean and cotton and to monitor for nonnative species. Seven stink bug species were identified. Acrosternum hilare (Say) and Euschistus servus (Say) were the most common. Two sampling methods, the sweep net and the beat sheet, were assessed in soybean and cotton. There was less variability with the sweep net method compared to the beat sheet method. Laboratory bioassays and field trials were conducted to evaluate the toxicity and efficacy of selected conventional and organic insecticides against A. hilare and E. servus. In bioassays with conventional insecticides, A. hilare adults and nymphs were susceptible to all pyrethroids tested. Generally, the neonicotinoids, dinotefuran and clothianidin, were more toxic to A. hilare, while thiamethoxam and acetamiprid were more toxic to E. servus. In soybean field efficacy trials, dinotefuran performed comparably to the organophosphates and pyrethroids. Laboratory bioassays with organic insecticides resulted in moderate to high levels of mortality, and in antifeedant and repellency responses. Likewise, soybean field trials indicated that a single application can reduce stink bug numbers for up to two days after treatment; however in tomato field trials multiple weekly applications did not result in significant reductions in stink bug damage. A weather model to predict abundance of A. hilare adults was developed using weekly black light trap catch data collected from 1990 to 2007 at a single location. The two weather variables that resulted in a significant model were days below freezing and mean monthly precipitation from January to April. The model was validated by correlating five independent data sets to predicted weekly trap catch. Mean trap catch plotted over time showed three peaks. In accordance with A. hilare developmental rates, the peaks indicated that two generations and a partial third occur in Virginia. Cumulative trap catch estimated from the 18-yr trap catch mean showed that 10, 50, and 90% of the total seasonal catch should occur by 153, 501, and 1066 degree days, respectively. / Ph. D.

Stink bugs, including native brown stink bug (Euschistus servus) and invasive brown marmorated stink bug (Halyomorpha halys), cause damage to a variety of crops including field corn (Zea mays). Frequency and size of stink bug infestations have increased in corn fields in the Mid-Atlantic U.S., and there are growing concerns that these infestations may contribute to reductions in grain quality including increased mycotoxin concentrations. Prior research on native and invasive stink bugs has focused on understanding their biology, the damage they cause, and elucidating effective and economic management strategies. However, few studies examined the potential for stink bugs to facilitate fungal infection and mycotoxin contamination of corn grain. Thus, the objectives of this research were to: 1) assess the relationship between invasive brown marmorated stink bug (H. halys) feeding injuries and fumonisin contamination of field corn in the Mid-Atlantic U.S., 2) determine if stink bugs are a vector for mycotoxigenic Fusarium spp. in corn, and 3) evaluate the efficacy of pesticides for mitigating stink bug feeding injury and associated mycotoxin contamination in field corn. A correlation between H. halys feeding injury and fumonisin concentrations was identified, and the ability of H. halys to increase F. verticillioides infection and fumonisin concentrations in corn was demonstrated in field experiments. Fusarium species including fumonisin-producing F. verticillioides and F. proliferatum were isolated from field-collected stink bugs, and in laboratory experiments, E. servus was able to transmit F. verticillioides to non-infected corn ears after feeding on F. verticillioides-infected corn. In field studies, both fungicide and insecticide reduced stink bug-associated mycotoxin concentrations in corn, but levels of control were inconsistent. Thus, additional tactics that target both the stink bug and Fusarium should be implemented to mitigate risks of mycotoxin contamination in corn. / Doctor of Philosophy / Native and invasive stink bugs can severely damage crops including field corn. Frequency and size of stink bug infestations in Mid-Atlantic U.S. corn fields have increased, and there is growing concern that this may contribute to reductions in grain quality. Insect feeding injury is a risk factor for fungal infection and mycotoxin contamination in corn. Mycotoxins are toxic chemicals produced by certain fungi that have detrimental health effects on animals including livestock and humans. The relationship between stink bug feeding injuries and mycotoxin contamination in corn grain is not well understood, and management strategies to minimize the risk of mycotoxin contamination in corn need to be identified. The main goal of this research was to characterize interactions between stink bugs and mycotoxin-producing fungi and identify tactics for controlling both the insect pest and pathogen. Specific objectives were to: 1) assess the relationship between invasive brown marmorated stink bug (H. halys) feeding injuries and fumonisin contamination of field corn in the Mid-Atlantic U.S., 2) determine if stink bugs are a vector for mycotoxin-producing Fusarium spp. in corn, and 3) evaluate the efficacy of pesticides for mitigating stink bug feeding injury and associated mycotoxin contamination in field corn. Results from this work indicated that stink bugs have the ability to cause feeding injuries which facilitate invasion of mycotoxin-producing Fusarium species, leading to increases in mycotoxin concentrations in corn grain. Studies also demonstrated that stink bugs can vector Fusarium species during feeding and increase Fusarium infection of corn resulting in subsequent mycotoxin contamination. Field studies indicated that pesticide applications targeting both the stink bugs and mycotoxigenic fungi may be needed to minimize risk of mycotoxin contamination in corn. However, under low pest pressure, application of pesticides is unlikely to be profitable.

Dissertação (Mestrado) / A dinâmica de insetos, associados à soja, depende dos fatores como clima, transgenia e pulverização de inseticidas que influenciam na fenologia, distribuição e abundância dos organismos, tamanho das populações de insetos. Populações de lagartas e percevejos podem variar com a região de cultivo, cultivar (transgênica ou convencional), inimigos naturais e características da espécie e manejo da cultura. O novo cenário agrícola com cultivos transgênicos, cultivares precoces, mudança na arquitetura de plantas, aumento da população de plantas/ha e cultivares adaptados a diferentes regiões requerem informações sobre a sazonalidade das pragas. Objetivou-se estudar os fatores que determinam o ataque de lagartas e percevejos em plantios de soja nos municípios de Rio Paranaíba e Lagoa Formosa na região do Alto Paranaíba, Minas Gerais, Brasil. O estudo foi conduzido nas safras de 2013/2014 e 2014/2015 com as cultivares RR (Syn 1059 e P97R01) e RR2 (Monsoy 7110 IPRO). Em dois talhões de 10 ha, com 50 pontos de avaliação/talhão. As avaliações foram realizadas com batida de pano branco de 1 metro. Abundância dos insetos foi relacionada por análise de redundância (RDA) com dados climáticos e variações sazonais. Os elementos climáticos e pulverização de inseticidas são fatores que afetam a dinâmica populacional dos insetos-praga e inimigos naturais. Lagartas da subfamília Plusiinae atingiram maiores populações, seguidas de Helicoverpa armigera e Anticarsia gemmatalis com maiores populações em ambos os anos na fase reprodutiva da soja. Fatores como temperatura do ar, precipitação pluviométrica, pulverização de inseticidas e velocidade do vento afetam a população desses insetos. Euschistus heros foi o percevejo mais abundante, seguido de Piezodorus guildinii e Nezara viridula. Sendo que a temperatura do ar e radiação solar afetam diretamente as ninfas e indiretamente os adultos. Inimigos naturais foram pouco abundantes em ambos os locais, sendo em Lagoa Formosa teve menor quantidade. Coccinelídeos foram afetados negativamente e indiretamente pelas pulverizações de inseticidas. O fator Bt não influenciou a dinâmica e os surtos populacionais de pragas de soja.