Doctor of Philosophy / Department of Grain Science and Industry / Subramanyam Bhadriraju / Filter cake and Triplex are powdered by-products of aluminum sulfate and soap factories, respectively. Studies were designed to determine elemental composition of these two powders and evaluate the efficacy against stored product insect species on concrete surfaces and commodities. Elemental composition of the powders was determined using conjugated scanning electron microscopy and Energy-dispersive X-ray spectroscopy. No heavy metals were found in both powders, and the dominant elements found were silicon and oxygen in the form of silicon dioxide. The efficacy of filter cake and Triplex against the maize weevil, Sitophilus zeamais Motschulsky; rice weevil, Sitophilus oryzae (Linnaeus); lesser grain borer, Rhyzopertha dominica Fabricius; red flour beetle, Tribolium castaneum (Herbst); saw-toothed grain beetle, Oryzaephilus surinamensis (Linnaeus); and Indian meal moth, Plodia interpunctella (Hübner), was determined using a range of concentrations and exposure times. On concrete surfaces ≥ 7.5 g/m² of filter cake produced more than 99% mortality of S. zeamais and S. oryzae adults within 12–24 h, whereas more than three times the concentration of filter cake was required to achieve similar mortality of both species in Triplex treatments. At 3 g/m² of filter cake, 99% mortality S. zeamais and S. oryzae adults was achieved within 22–27 h of exposure. The corresponding exposure time at 9 g/m² of Triplex was 39 h to achieve 99% mortality of both species. For both powders, lower concentrations and exposure times were required to achieve complete suppression of progeny production, percentage of insect damaged kernels, and percentage of grain weight loss compared to the concentrations and exposure times required for 00% mortality. Filter cake treated wheat at concentrations above 0.7 g/kg produced more than 99% mortality of S. zeamais and S. oryzae adults. Similarly, filter cake concentrations above 2 g/kg on wheat produced more than 99% mortality of R. dominica, T. castaneum, and O. surinamensis adults. However, on maize ≥ 3 g/kg of filter cake concentration was required to achieve similar mortality of R. dominica, T. castaneum, and O. surinamensis. Higher concentrations of Triplex were required to achieve similar mortalities of tested species on maize and wheat. Reduction in progeny production was greater when adults were exposed to higher concentrations than lower concentrations. Complete suppression of live larvae and adult emergence of P. interpunctella was achieved after exposure of eggs for 21 and 42 d to ≥ 2 g/kg of filter cake treated maize and to ≥ 0.5 g/kg of filter cake treated wheat. Similarly, complete suppression of live larvae and adult emergence was achieved when eggs were exposed to ≥ 6 g/kg of Triplex treated maize and to 3g/kg of Triplex treated wheat. In general, our study consistently showed that filter cake was more efficacious compared to Triplex against all tested species on both surfaces and commodities. Filter cake and Triplex should be recommended for protecting grain stored by smallholder farmers in Ethiopia to discourage farmers from using dangerous chemical insecticides. However, field studies should be done using both powders against stored product insects in smallholder farmers’ traditional storages structures in Ethiopia to determine concentrations that are practical under field conditions. The effective duration of protection offered by these powders should also be investigated.

Made available in DSpace on 2014-06-11T19:34:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-10-23Bitstream added on 2014-06-13T19:44:39Z : No. of bitstreams: 1 dantas_im_dr_jabo.pdf: 1564795 bytes, checksum: b13a33d6084828753dd2f2e94108f7e3 (MD5) / A distribuição do minador-dos-citros, Phyllocnistis citrella Stainton, foi estudada em pomares comerciais de laranjeira 'Pêra-Rio' (Citrus sinensis), com três e dez anos de idade, durante os anos de 2000 e 2001, nos municípios de Taiúva e Jaboticabal, São Paulo, Brasil. No estudo da distribuição na planta, constatou-se que os ovos e as lagartas de P. citrella encontram-se distribuídos por toda a planta, podendo ser realizadas amostragens tanto nas partes inferior e superior, quanto nos quatro quadrantes da planta. Esse inseto preferiu ovipositar na face inferior das folhas mais novas, localizadas no ápice dos brotos, medindo até três centímetros. Constatou-se que a concentração de lagartas no broto aumenta no sentido da extremidade para a base, como também das folhas menores para as maiores. Entre plantas constatou-se que na maioria das amostragens, os índices estudados (Razão variânciaImédia, índice de Morisita, Índice de Green, kcomun da distribuição binomial negativa, b de Taylor e ß da regressão de aglomeração média de Iwao) indicaram que a P. citrella apresenta distribuição agregada. Entre as três distribuições estudadas: binomial negativa, binomial positiva e Poisson, a distribuição binomial negativa foi o modelo que melhor ajustou-se à distribuição da lagarta do minador dos citros em pomares de laranjeira 'Pêra-rio'. Foram desenvolvidos planos de amostragem seqüencial e construídas tabelas para levantamento em campo. / The distribution of the citrus leafminer, Phyllocnistis citrella (Stainton), was studied at 'Pêra-Rio'orange (Citrus sinensis) commercial orchards, with three and ten years old, during the years of 2000 and 2001, at Taiúva and Jaboticabal county, São Paulo State, Brazil. In the study of distribution in the plant, as the eggs and larvae of P. citrella are distributed by the whole plant, samplings in the plant could be accomplished both in the inferior or superior part as in the four quadrants. This insect has preference for oviposition on the inferior face of newest leaves, located at the apex of sprout, measuring up to three centimeters. It was verified that the concentration of larvae in the sprout increases from the apex to the basis, as well as from the smallest to the largest leaves. Among plants, it was verified that in most of the samplings, the studied indexes (Reason variance/mean ratio, Morisita's index, Green's dispersion coefficient, kcommon of the negative binomial distribution, b of Taylor's power law and ß of the Iwao's patchiness regression) indicated aggregated spatial arrangement. Among the three studied indexes, binomial, negative binomial and Poisson, the negative binomial distribution, was the best model to fit the spatial distribution of the citrus leafminer in 'Pêra-Rio' orange orchards. Sequential sampling plans were developed and tables for field monitoring were built.

<p>  </p> <p>Spotted-wing Drosophila (SWD), <em>Drosophila suzukii</em> (Matsumura), is an economically-important pest of small fruits worldwide. Currently, timing of management is based on morphological identification of adult flies captured in baited monitoring traps; however, distinguishing SWD from other native drosophilids in traps is a time-consuming process that requires magnification. And a degree-day model that could help small fruit growers understand and predict the seasonal activity of this pest has not been developed for Indiana. Due to the low tolerance for maggots in fruit market, most small fruit growers rely on intensive, insecticide applications on a calendar-based schedule without guidance on the activity levels of SWD. </p> <p>A total of 6,051 SWD adults were monitored weekly using commercial Scentry traps at three highbush blueberry orchards during May to August. I applied the published SWD developmental thresholds of 7.2 °C (lower) and 31.5 °C (upper) and the single-sine method to calculate accumulated degree days in the year of 2021 and 2022. A predictive model from two years of data at three locations exhibited an S-shaped curve, with 5%, 25%, and 50% of adults detected at ~907, 1,293, and 1,523 CDD, respectively. By examining infestations in three varieties, ‘Bluecrop’, ‘Blueray’, and ‘Elliot’, I found that blueberry infestation rate increased as the trap captures increased. The use of early-ripening highbush blueberry varieties can reduce infestation and regardless of variety, as berries became softer, the number of SWD egg scars in berries increased.</p> <p>DNA-based diagnostic methods, like loop-mediated isothermal amplification (LAMP), have the potential to improve SWD detection by replacing morphological identification with DNA-based identification. Positive results of the LAMP assay are based on a visible color change from pink to yellow when focal DNA is present. I tested the reliability of LAMP results using SWD DNA and then evaluated the sensitivity of LAMP in discriminating between SWD and two native drosophilids common captured in monitoring traps in Indiana, <em>Drosophila affinis</em> and <em>D. simulans</em>. I found the LAMP assay can quickly and accurately identify SWD with as little as 0.1 ng/μl of DNA. Following optimization, the assay also suggested success in discriminating between SWD and these two native species: it only requires an individual fly, DNA extraction is not necessary. </p> <p>By better predicting seasonal SWD activity and optimizing DNA-based diagnostics for this pest, this study can help improve the timely detection of SWD and the management in small fruit systems. </p>

The demand for locally sourced hops from Northeastern microbreweries began the recent resurgence in local hop production. The farming community has increased acreage and improved the quality of hops grown and processed in the Northeast region over the past five years. There was a sharp increase in the number of Northeast hop producers from six in 2009 to over 175 in 2014. Hop growers in the Northeast are new to the crop and have limited experience with pest identification and management. This dissertation encompasses three research projects that were conducted over the 2012-2014 growing seasons. These projects were the first critical steps taken to develop arthropod integrated pest management (IPM) tactics for Northeastern hop growers. First, the arthropod community in seven Vermont hop yards was evaluated. The objectives of Chapter 2 are to 1) present current hop pest biology and management strategies, 2) report the phenology of arthropod pests observed over three growing seasons, 3) report abundance and peak date for each pest, and 4) document natural enemy abundance in Vermont hop yards. The survey indicates that in cool, wet seasons hop aphid (Phorodon humuli Schrank) is expected to be a pest of concern. Two-spotted spider mite (Tetranychus urticae Koch) is expected to be a pest of concern in hot, dry conditions. Potato leafhopper (Empoasca fabae Harris) is an unpredictable pest of special concern for first year hop plants. When hop aphid or potato leafhopper are sprayed for with broad-spectrum insecticide, two-spotted spider mite secondary outbreak can be expected. Second, the abundance of major arthropod pests and their natural enemy groups were evaluated under drive row flowering cover crop treatments. The objectives of this study were to 1) measure the effect of cover crops on natural enemy group abundance, 2) measure the effect of cover crops on the three major Northeastern hop pests, and 3) measure the effect of cover crop presence on hop yield and quality. Natural enemy groups and pests were positively correlated yet cover crop treatments had no significant effect on natural enemy abundance. Red clover cover crop treatments served as a trap crop for potato leafhopper. No significant difference in hop yield or quality was observed between flowering cover crop treatments. Finally, potato leafhopper is a documented but understudied regional pest of hops. The objectives of this study were to 1) measure the physiological response of eight hop cultivars to adult potato leafhopper feeding and 2) measure hop leaf recovery from potato leafhopper injury. Gas exchange (net photosynthesis and transpiration) and chlorophyll content were measured to quantify injury by adult potato leafhopper to first year hop leaves in field and greenhouse studies. Cultivars did not vary significantly in their physiological response to potato leafhopper feeding. Injury significantly reduced gas exchange measures in the field (P < 0.05) and greenhouse (P < 0.05) and when leafhoppers were removed, gas exchange was restored.

Spodoptera frugiperda is one of the main insect pests of the New World, and causes extensive damage to economically important crops such as cotton and corn. One of the most common control strategies is the use of Bt plants; however, their intense and indiscriminate use has led to the evolution of resistance in some populations. The establishment of a refuge can be a viable option to delay this process. Refuges consist of areas where non-Bt crops are planted, in order to provide susceptible insects to the population. In this study, I initially developed a model to describe the evolution of resistance of fall armyworm populations in different refuge configurations (seed mixture, blocks, and strips) and sizes (20% - 50%), considering the larval movement. I demonstrated that with a seed mixture, in most cases, the higher the rate of larval movement, the higher the proportion of resistant insects in the population, regardless of the type of resistance tested; meanwhile, strip configurations showed the opposite trend. In the second part of this study, I obtained data to validate the proposed model. The development of the fall armyworm on corn leaves was determined at five constant temperatures ranging from 14°C to 30°C. These data were also used to estimate the number of generations of fall armyworms at 42 locations in the state of Florida, from 2006 to 2016, which were interpolated and represented on maps, using GIS (Geographic Information System). I observed that counties farther south had the highest numbers of generations, and that fall armyworms should be able to overwinter as far north as ~29°N. Using the data obtained in the experiment, a new model was proposed, covering a wider range of conditions and allowing the user to define the crop area, the thermal requirements of the population studied, the viability and oviposition functions, the migration rate, the rate of larval movement and the frequency of alleles for resistance. The model was verified with monitoring data collected in a crop area in Florida from 2012 - 2015, only 70 km from the area that provided the population for the experiment. I also used the model to estimate the number of adults for 2016 and for two hypothetical situations that considered possible scenarios involving global warming (mean temperatures in 2016 + 1°C and + 2°C). The model succeeded in fitting the monitoring data, and indicated that the simulated increases in mean temperature could produce outbreaks nearly twice as large as the levels of fall armyworm estimated for 2016. The model can be used to estimate the population dynamics of S. frugiperda in a particular area, according to the crop composition and disposal, to investigate the effects of temperature changes on the levels of fall armyworm populations, to define appropriate refuge areas in order to manage the evolution of insect resistance, and to define the best periods for plantation and harvesting during the year to reduce pest populations, among others. / Spodoptera frugiperda é um dos principais insetos-praga do hemisfério ocidental, causando diversos danos a cultivos de interesse econômico, como milho e algodão. Uma das estratégias mais comuns de controle é o uso de plantas Bt, contudo sua aplicação intensa e indiscriminada levou à evolução de resistência em algumas populações. O estabelecimento de refúgio pode representar uma opção viável para atrasar esse processo. Refúgios são áreas nas quais cultivos não-Bt são plantados de forma a fornecerem insetos suscetíveis para a população. Neste estudo, eu desenvolvi inicialmente um modelo para descrever a evolução de resistência de populações de S. frugiperda em diferentes configurações de refúgio (mistura de sementes, blocos e faixas) e tamanhos (20 - 50%), considerando o movimento larval. Eu demonstrei que para a mistura de sementes, na maioria dos casos, maiores taxas de movimentação larval implicavam em maiores proporções de insetos resistentes na população, independente do tipo de resistência testada, enquanto áreas com configurações em faixas apresentaram tendência oposta. Na segunda parte deste trabalho, eu obtive dados para validar o modelo proposto. O desenvolvimento de S. frugiperda em folhas de milho foram determinadas em 5 temperaturas constantes variando de 14°C a 30°C. Estes dados também foram utilizados para estimar o número de gerações do inseto em 42 localizações no estado da Flórida de 2006 a 2016, que foram interpolados e representados em mapas, utilizando SIG (Sistema de Informações Geográficas). Eu observei que condados mais ao sul apresentaram maior número de gerações e que S. frugiperda é capaz de passar o inverno abaixo de latitudes ~29°N. Utilizando os dados obtidos no experimento, um novo modelo foi proposto, considerando um intervalo maior de condições e permitindo ao usuário definir a área de cultivo, as exigências térmicas da população estudada, as funções de oviposição e viabilidade, a taxa de migração, a taxa de movimentação larval e a frequência do alelo de resistência. O modelo foi verificado com dados de monitoramento de 2012 a 2015, coletados em uma área de cultivo localizada na Flórida, distante apenas 70 km da área que forneceu a população para o experimento laboratorial. Eu também utilizei o modelo para estimar o número de adultos para 2016 e para duas situações hipotéticas que consideraram possíveis cenários envolvendo o aquecimento global (médias de temperaturas de 2016 + 1°C e + 2°C). O modelo se ajustou aos dados de monitoramento com sucesso e indicou que os aumentos simulados na temperatura média poderiam produzir surtos quase duas vezes maiores que os níveis de S. frugiperda estimados para 2016. O modelo pode ser usado para estimar a dinâmica populacional de S. frugiperda em uma determinada área de acordo com a composição e disposição dos cultivos, investigar os efeitos das mudanças de temperatura nos níveis populacionais, definir áreas de refúgio apropriadas para o manejo da evolução de resistência, definir os melhores períodos para plantação e colheita durante o ano de forma a reduzir a população da praga, entre outros.

Der Wiederaustrieb beernteter Pappeln in Kurzumtriebsplantagen erfolgt nicht selten stark verzögert. Ob und inwieweit hierbei der Große Rote Pappelblattkäfer eine Rolle spielt, wurde in einem Versuch mit zwei unterschiedlichen Dichten des Schadinsekts untersucht.

Orientador: José Carlos Barbosa / Banca: Pedro Takao Yamamoto / Banca: Décio Barbin / Banca: Antonio Carlos Busoli / Banca: Francisco Jorge Cividanes / Resumo: A distribuição do minador-dos-citros, Phyllocnistis citrella Stainton, foi estudada em pomares comerciais de laranjeira 'Pêra-Rio' (Citrus sinensis), com três e dez anos de idade, durante os anos de 2000 e 2001, nos municípios de Taiúva e Jaboticabal, São Paulo, Brasil. No estudo da distribuição na planta, constatou-se que os ovos e as lagartas de P. citrella encontram-se distribuídos por toda a planta, podendo ser realizadas amostragens tanto nas partes inferior e superior, quanto nos quatro quadrantes da planta. Esse inseto preferiu ovipositar na face inferior das folhas mais novas, localizadas no ápice dos brotos, medindo até três centímetros. Constatou-se que a concentração de lagartas no broto aumenta no sentido da extremidade para a base, como também das folhas menores para as maiores. Entre plantas constatou-se que na maioria das amostragens, os índices estudados (Razão variânciaImédia, índice de Morisita, Índice de Green, kcomun da distribuição binomial negativa, b de Taylor e ß da regressão de aglomeração média de Iwao) indicaram que a P. citrella apresenta distribuição agregada. Entre as três distribuições estudadas: binomial negativa, binomial positiva e Poisson, a distribuição binomial negativa foi o modelo que melhor ajustou-se à distribuição da lagarta do minador dos citros em pomares de laranjeira 'Pêra-rio'. Foram desenvolvidos planos de amostragem seqüencial e construídas tabelas para levantamento em campo. / Abstract: The distribution of the citrus leafminer, Phyllocnistis citrella (Stainton), was studied at 'Pêra-Rio'orange (Citrus sinensis) commercial orchards, with three and ten years old, during the years of 2000 and 2001, at Taiúva and Jaboticabal county, São Paulo State, Brazil. In the study of distribution in the plant, as the eggs and larvae of P. citrella are distributed by the whole plant, samplings in the plant could be accomplished both in the inferior or superior part as in the four quadrants. This insect has preference for oviposition on the inferior face of newest leaves, located at the apex of sprout, measuring up to three centimeters. It was verified that the concentration of larvae in the sprout increases from the apex to the basis, as well as from the smallest to the largest leaves. Among plants, it was verified that in most of the samplings, the studied indexes (Reason variance/mean ratio, Morisita's index, Green's dispersion coefficient, kcommon of the negative binomial distribution, b of Taylor's power law and ß of the Iwao's patchiness regression) indicated aggregated spatial arrangement. Among the three studied indexes, binomial, negative binomial and Poisson, the negative binomial distribution, was the best model to fit the spatial distribution of the citrus leafminer in 'Pêra-Rio' orange orchards. Sequential sampling plans were developed and tables for field monitoring were built. / Doutor

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-05-18T11:36:06Z No. of bitstreams: 1 arquivototal.pdf: 10156219 bytes, checksum: b07b75a7a10dfb56dd494879971fa975 (MD5) / Made available in DSpace on 2016-05-18T11:36:06Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 10156219 bytes, checksum: b07b75a7a10dfb56dd494879971fa975 (MD5) Previous issue date: 2009-03-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Among the methods of controlling insect pests, the use of pesticides has been reduced in negative consequences on the beneficial fauna and the environment, so it is therefore necessary to search for alternatives that minimize the adverse effects of pesticides on the environment. As alternatives to control pests, are being studied, several other techniques, which includes the use of origin plant substances because they have low toxicity to humans and animals, and for presenting performance against several species of pests, which assumes increasing importance in programs of integrated pest management (MIP), especially at a time when it discusses very integrated production towards sustainable agriculture. The insects belonging to the order Dermaptera, are still not well known and the information in the literature, characterized as predatory bodies with good ability. Among the biological agents with characteristics suitable for this purpose, the dermápteros have attracted great attention because predators are greedy, that is, with high ability to attack and feeding on different prey, particularly of eggs and immature stages insects of the orders Lepidoptera, Hemiptera, Coleoptera and Diptera. Considering the potential use of preying on programs for biological control, studies related to their biology and their selectivity in plant extracts become indispensable. Thus, the aim of this work was to study the biological aspects of Euborellia annulipes fed on Spodoptera frugiperda and Hyadaphis foeniculi and selectivity of this predator to products of plant origin in laboratory conditions. / Dentre os métodos de controle de insetos-praga, o uso de agrotóxicos vem sendo reduzido, em conseqüências negativas sobre a fauna benéfica e sobre o ambiente, fazendo-se, portanto, necessário a busca de alternativas que minimizem os efeitos adversos dos agrotóxicos sobre o meio ambiente. Como alternativas ao controle de pragas, estão sendo estudadas, várias outras técnicas, nas quais se inclui o uso de substâncias de origem vegetal, por terem baixa toxicidade ao homem e animais, e por apresentarem eficiência contra várias espécies de pragas, que assume importância cada vez maior em programas de manejo integrado de pragas (MIP), principalmente em um momento em que se discute muito a produção integrada rumo a uma agricultura sustentável. Os insetos pertencentes à ordem Dermaptera, ainda não são bem conhecidos e as informações existentes na literatura, os caracterizam como organismos com boa capacidade predatória. Dentre os agentes biológicos com características adequadas a esta finalidade, os Dermápteros têm despertado grande atenção, pois são predadores vorazes, isto é, com alta capacidade de ataque e que se alimentam de diversas presas, particularmente, de ovos e fases imaturas de insetos das ordens Lepidoptera, Hemiptera, Coleoptera e Diptera. Considerando-se o potencial de uso desse predador em programas de controle biológico, os estudos relacionados a sua biologia e a sua seletividade a extratos vegetais tornam-se imprescindíveis. Diante disso, o objetivo desse trabalho foi de estudar os aspectos biológicos de Euborellia annulipes alimentada com Spodoptera frugiperda e Hyadaphis foeniculi, e a seletividade desse predador a produtos de origem vegetal em condições de laboratório.

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-09-28T13:49:59Z No. of bitstreams: 2 Mayara_Silva_2018.pdf: 701671 bytes, checksum: a7eb1cb0ed47b21bf1e3990cb4f2bd09 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-09-28T13:49:59Z (GMT). No. of bitstreams: 2 Mayara_Silva_2018.pdf: 701671 bytes, checksum: a7eb1cb0ed47b21bf1e3990cb4f2bd09 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-20 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The cultivation of soybeans occupies a large area of land in Brazil, but pest attack, despite all the technology already developed, especially in relation to chemical insecticides, remains a determining factor for the success of the crop, since such substances, when bad used as a single tactic, become inefficient and pose a danger to the environment and health. In this context, the objective of this work was to verify the use of a compound of mineral origin in the control of E. heros, the main pest of the soybean crop, as an alternative to the conventional method. To this end, suspensions of 0, 4, 8 and 16% of the FertP® product in aqueous suspension were prepared along with 0.01% Tween, which were sprayed onto E. heros eggs up to 24 hours old. The incubation period and number of hatched insects were evaluated. First-instar nymphs, recently hatched, were also submitted to spraying, evaluating the mortality and duration of the instar. To verify the longevity and reproductive capacity of adults, couples with up to 48h of ecdise were immersed in suspensions and transferred to cages, being evaluated daily for 32 days regarding longevity, number of eggs and eggs viability. After compiling and analyzing the collected data, it was concluded that the product under study did not present any significant effect on any of the biological parameters of the soya-brown bug / O cultivo da soja ocupa grande extensão de terra no Brasil, porém, o ataque de pragas, apesar de toda tecnologia já desenvolvida, principalmente em relação aos inseticidas químicos, continua sendo fator determinante do sucesso da lavoura, uma vez que tais substâncias, quando mal utilizadas e como tática única, se tornam ineficientes e um perigo ao ambiente e a saúde. Neste contexto, o objetivo deste trabalho foi verificar o emprego de um composto de origem mineral no controle de E. heros, principal praga da cultura da soja, como um método alternativo ao convencional. Para isso, foram preparadas suspensões de 0, 4, 8 e 16% do produto FertP® em suspensão aquosa, juntamente a 0,01% de Tween, as quais foram pulverizadas sobre ovos de E. heros com até 24 horas de idade. Avaliaram-se o período de incubação e número de insetos eclodidos. Ninfas de 1º instar, recém-eclodidas, também foram submetidas à pulverização, sendo avaliada a mortalidade e duração do instar. Para verificação da longevidade e capacidade reprodutiva de adultos, casais com até 48h de ecdise, foram imersos nas suspensões e transferidos para gaiolas, sendo avaliados diariamente, durante 32 dias, quanto à longevidade, número de ovos ovipositados e viabilidade dos ovos. Após compilação e analise dos dados coletados concluiu-se que o produto em estudo não apresentou efeito significativo sobre nenhum dos parâmetros biológicos do percevejo-marrom-da-soja aqui avaliados.

Spodoptera frugiperda is one of the main insect pests of the New World, and causes extensive damage to economically important crops such as cotton and corn. One of the most common control strategies is the use of Bt plants; however, their intense and indiscriminate use has led to the evolution of resistance in some populations. The establishment of a refuge can be a viable option to delay this process. Refuges consist of areas where non-Bt crops are planted, in order to provide susceptible insects to the population. In this study, I initially developed a model to describe the evolution of resistance of fall armyworm populations in different refuge configurations (seed mixture, blocks, and strips) and sizes (20% - 50%), considering the larval movement. I demonstrated that with a seed mixture, in most cases, the higher the rate of larval movement, the higher the proportion of resistant insects in the population, regardless of the type of resistance tested; meanwhile, strip configurations showed the opposite trend. In the second part of this study, I obtained data to validate the proposed model. The development of the fall armyworm on corn leaves was determined at five constant temperatures ranging from 14°C to 30°C. These data were also used to estimate the number of generations of fall armyworms at 42 locations in the state of Florida, from 2006 to 2016, which were interpolated and represented on maps, using GIS (Geographic Information System). I observed that counties farther south had the highest numbers of generations, and that fall armyworms should be able to overwinter as far north as ~29°N. Using the data obtained in the experiment, a new model was proposed, covering a wider range of conditions and allowing the user to define the crop area, the thermal requirements of the population studied, the viability and oviposition functions, the migration rate, the rate of larval movement and the frequency of alleles for resistance. The model was verified with monitoring data collected in a crop area in Florida from 2012 - 2015, only 70 km from the area that provided the population for the experiment. I also used the model to estimate the number of adults for 2016 and for two hypothetical situations that considered possible scenarios involving global warming (mean temperatures in 2016 + 1°C and + 2°C). The model succeeded in fitting the monitoring data, and indicated that the simulated increases in mean temperature could produce outbreaks nearly twice as large as the levels of fall armyworm estimated for 2016. The model can be used to estimate the population dynamics of S. frugiperda in a particular area, according to the crop composition and disposal, to investigate the effects of temperature changes on the levels of fall armyworm populations, to define appropriate refuge areas in order to manage the evolution of insect resistance, and to define the best periods for plantation and harvesting during the year to reduce pest populations, among others. / Spodoptera frugiperda é um dos principais insetos-praga do hemisfério ocidental, causando diversos danos a cultivos de interesse econômico, como milho e algodão. Uma das estratégias mais comuns de controle é o uso de plantas Bt, contudo sua aplicação intensa e indiscriminada levou à evolução de resistência em algumas populações. O estabelecimento de refúgio pode representar uma opção viável para atrasar esse processo. Refúgios são áreas nas quais cultivos não-Bt são plantados de forma a fornecerem insetos suscetíveis para a população. Neste estudo, eu desenvolvi inicialmente um modelo para descrever a evolução de resistência de populações de S. frugiperda em diferentes configurações de refúgio (mistura de sementes, blocos e faixas) e tamanhos (20 - 50%), considerando o movimento larval. Eu demonstrei que para a mistura de sementes, na maioria dos casos, maiores taxas de movimentação larval implicavam em maiores proporções de insetos resistentes na população, independente do tipo de resistência testada, enquanto áreas com configurações em faixas apresentaram tendência oposta. Na segunda parte deste trabalho, eu obtive dados para validar o modelo proposto. O desenvolvimento de S. frugiperda em folhas de milho foram determinadas em 5 temperaturas constantes variando de 14°C a 30°C. Estes dados também foram utilizados para estimar o número de gerações do inseto em 42 localizações no estado da Flórida de 2006 a 2016, que foram interpolados e representados em mapas, utilizando SIG (Sistema de Informações Geográficas). Eu observei que condados mais ao sul apresentaram maior número de gerações e que S. frugiperda é capaz de passar o inverno abaixo de latitudes ~29°N. Utilizando os dados obtidos no experimento, um novo modelo foi proposto, considerando um intervalo maior de condições e permitindo ao usuário definir a área de cultivo, as exigências térmicas da população estudada, as funções de oviposição e viabilidade, a taxa de migração, a taxa de movimentação larval e a frequência do alelo de resistência. O modelo foi verificado com dados de monitoramento de 2012 a 2015, coletados em uma área de cultivo localizada na Flórida, distante apenas 70 km da área que forneceu a população para o experimento laboratorial. Eu também utilizei o modelo para estimar o número de adultos para 2016 e para duas situações hipotéticas que consideraram possíveis cenários envolvendo o aquecimento global (médias de temperaturas de 2016 + 1°C e + 2°C). O modelo se ajustou aos dados de monitoramento com sucesso e indicou que os aumentos simulados na temperatura média poderiam produzir surtos quase duas vezes maiores que os níveis de S. frugiperda estimados para 2016. O modelo pode ser usado para estimar a dinâmica populacional de S. frugiperda em uma determinada área de acordo com a composição e disposição dos cultivos, investigar os efeitos das mudanças de temperatura nos níveis populacionais, definir áreas de refúgio apropriadas para o manejo da evolução de resistência, definir os melhores períodos para plantação e colheita durante o ano de forma a reduzir a população da praga, entre outros.