Commercial sugarcane in South Africa is a monoculture, and therefore lacks vegetation diversity, which is instrumental in increasing associated faunal diversity. Diverse habitats tend to support more stable populations of herbivorous and predacious animals. It is hypothesised that lack of this diversity in sugarcane was partially responsible for the existence of Eldana saccharina infestation levels that are higher than is commercially acceptable. Amongst the available E. saccharina control strategies, is habitat management. This has been developed with the view of increasing and enhancing predator foraging activity. Through increasing arthropod predator abundance and activity, it is believed that E. saccharina control may be enhanced. In this study, habitat diversity was increased through intercropping beans within sugarcane. Arthropod populations were monitored throughout the sugarcane-growing period, to determine what effect this intercropping had on known potential arthropod predator populations of E. saccharina. The study site was divided into two plots: the intercrop (beans planted within sugarcane rows: sugarcane-bean intercrop) and sole sugarcane: control plot. At monthly intervals, epigeal arthropods were sampled with pitfall traps, while foliage associated arthropods were sampled with a suction trap. Predator activity at the base of the sugarcane stalk, where E. saccharina lays its eggs was monitored with sticky traps. Sampling took place in the sugarcane-bean intercrop and control plots as well as in the roadway bordering the study site. Epigeal predator habitat preference was assessed by randomly placing pitfall traps in the sugarcane rows, bean rows, interrows between sugarcane rows, interrows between sugarcane and bean rows and the roadway. Corresponding with monthly trapping, an E. saccharina infestation and damage survey was conducted. Environmental factors such as weather, light intensity, plant (beans and sugarcane) phenology and weed density were measured, and their effect on E. saccharina potential arthropod predators examined. At harvest, sugarcane stalks were sampled for sucrose yield analysis. Potential E. saccharina predators that were captured included species of the orders and/or families Acarina, Blattidae, Formicidae (Pheidole megacephala and Dorylus helvolus) and Araneida (Lycosidae, Oxyopidae, Thomisidae and Salticidae). P. megacephala and species of Acarina were the only predators caught with all three trapping techniques, thus indicating that they occurred both on the ground and foliage. D. helvolus and Acarina were the only predators caught in significantly higher numbers in the intercrop, suggesting that increased habitat management had positively affected their population sizes. D. helvolus were captured both on the ground and length of sugarcane stalk, while species of Acarina were captured on the ground, foliage and at the base of sugarcane stalk, indicating that they forage at the base of the stalk, where E. saccharina activity is concentrated. Specific ground habitats preferred by D. helvolus included the sugarcane rows and bean rows, while Acarina preferred the interrows between sugarcane and bean rows. Despite the generally low E. saccharina infestation levels during this study, significantly higher levels of infestation occurred in the intercrop when compared to sole sugarcane. As expected with high infestation, higher (although not statistically significant) damage occurred in the intercrop. Surprisingly, sucrose yield and sugarcane stalk mass were slightly higher in the intercrop. The implications of the observations made during this study are discussed in the context E. saccharina management. / Thesis (M.Sc.)-University of Durban-Westville, 1998.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 76-84).

Orientador: Daniela Carvalho dos Santos / Banca: Daniela Pinheiro / Banca: Eliani Rodrigues da Silva / Resumo: A Diatraea saccharalis possui uma grande importância econômica e é considerada uma das pragas que mais afeta da cultura canavieira. Em Lepidoptera, o polimorfismo espermático está presente e envolve a produção de espermatozóides apirenes (anucleados) e eupirenes (nucleados), os quais são morfologicamente e funcionalmente diferentes. Este estudo teve como objetivo descrever o processo da espermatogênese envolvido no polimorfismo espermático. Testículos de larvas de último instar e de adultos de D. saccharalis foram processados convencionalmente para microscopia de luz e microscopia eletrônica de transmissão. As análises permitiram a identificação de um par de testículos com formato riniforme, limitado externamente por uma túnica celular, em larvas. Cada testículo possui quatro folículos que estão divididos através de septos de túnica interna. Em adultos há somente um único testículo, fundido e esférico dividido em oito folículos e constituído principalmente por feixes de espermatozóides. Os cistos de espermatogônias e espermatócitos estão localizados na região apical do folículo, e os cistos de espermátides e espermatozóides estão localizados na região basal do folículo. Dentro dos cistos, as células da linhagem germinativa se desenvolvem sincronicamente e contém somente espermatozóides apirenes ou eupirenes, nunca contém ambos. A extremidade anterior do espermatozóide apirene consiste em um capuz denso ao invés de núcleo. O espermatozóide eupirene possui um núcleo e acrossoma. Ambos os tipos de espermatozóides apresentam um axonema com padrão microtubular do tipo "9+9+2" e dois derivados mitocondriais na região do flagelo. Somente células eupirenes apresentaram apêndices laciniados e reticulares prorrogados a partir da membrana plasmática. O processo da espermatogênese é similar ao encontrado em outros insetos da ordem Lepidoptera / Abstract: The Diatraea saccharalis has a great economic importance and is considered the most destructive pest attacking sugarcane culture. In Lepidoptera, the sperm polymorphism is present and involves the production of apyrene (enucleate) and eupyrene (nucleate) spermatozoa, which are morphologically and functionally different. This investigation aimed to describe the spermatogenesis process involved in this sperm polymorphism. The testis from last larval instar and from adults of D. saccharalis was processed conventionally for light and transmission electron microscopy. The analysis allowed the identification of paired testis, with kidney-shaped, limited externally by tunica cells, in larvae. Each testis contains four follicles that are divided by internal tunica septa. In adult there is only a single, fused and spherical testis that is divided into eight follicles mainly constituted by spermatozoa bundles. The spermatogonia and spermatocyte cysts are located at the apical region and the spermatids and spermatozoa cysts are located at the basal region of the follicle. Within the cysts, sperm cells developed synchronously and contained either apyrene or eupyrene spermatozoa, never both. The anterior end of apyrene consisted of an electron dense cap instead of the nucleus. The eupyrene contained a nucleus and acrosome. Both sperm types present a 9+9+2 axoneme and two mitochondrial derivatives in the tail region. Only eupyrene cells showed lacinate and reticular appendages extended from the plasma membrane. The process of spermatogenesis is similar to that found in other insects of the order Lepidoptera / Mestre

Orientador: Sergio Antonio De Bortoli / Banca: José Eudes de Morais Oliveira / Banca: Silvio Rogério Viel / Banca: Roberto Marchi Goulart / Banca: Ana Carolina Pires Veiga / Resumo: O Brasil é considerado o maior produtor de cana-de-açúcar do mundo e por utilizar grandes áreas de cultivo várias pragas atacam a cultura, entre elas larvas de lepidópteros, particularmente da família Crambidae, sendo que o maior prejuízo econômico é causado por Diatraea saccharalis, popularmente conhecida como broca-da-cana. O controle químico é de baixa eficiência contra essa praga, devido ao hábito "broqueador" das lagartas, por isso, a alternativa de controle, para essa praga, é o uso do parasitoide Cotesia flavipes. A criação desse inseto em laboratório foi aprimorada ao longo dos anos, com início nos anos de 1970, existindo atualmente no Brasil, várias biofábricas e laboratórios de usinas açucareiras que produzem massalmente esses parasitoides. Apesar de serem produzidos em grandes quantidades, não existe um protocolo para o controle de qualidade do material produzido, ou quando existe normalmente é incipiente, resultando, muitas vezes, em insetos com baixa qualidade ou que não são capazes de efetuar seu papel de controlador biológico, bem como lotes com diferentes características tanto morfológicas como biológicas. Nesse sentido, presente estudo buscou comparar a qualidade de C. flavipes de diferentes regiões do Brasil, avaliando-se as características biológicas e morfológicas, parasitismo em campo, além da realização de análise molecular comparando as sequências da região do DNA mitocondrial, "Citochrome C Oxidase subunit I", dos insetos produzidos no Brasil, com exem... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is considered the largest sugarcane producer worldwide and because of the big cultivated areas, many pests rise to attack the culture. Among these pests are the lepidopterans larvae, especially from the Crambidae family and the major economic damage is caused by Diatraea saccharalis, known as sugarcane borer. Chemical control is inefficient against this pest; because the larvae has the habit to drill the sugarcane, for that reason the alternative to control this pest is the use of the parasitoid Cotesia flavipes. The rearing of this parasitoid in laboratory had been improved since 1970; nowadays, in Brazil, many biofactories and laboratories have been installed to produce this parasitoid on the sugarcane mills. Although these wasps have been mass-produced there isn't a protocol that regulates the quality of these insects. In many cases the protocol followed is not enough and could result in production of bad insects with no capacity to perform their role as a biological control agent, even with varied batches that presents different biological and morphological characteristics. Therefore, this study aimed to compare four different batches of wasps produced by biofactories from different Brazilian states Mato Grosso, Goiás, Alagoas and São Paulo. We performed tests to compare the biological and morphological characteristics, the range of parasitism on field and a molecular analysis from the DNA region Cytochrome C Oxidase Subunit I using insects produced in Brazil and insects collected in Pakistan. Our results allows us to conclude that: wasps from Campo Novo do Parecis-MT, Quirinópolis-GO, Coruripe-AL e Promissão-SP showed morphological differences; the insects produced by these biofactories are biologically different from each other; the batches produced are not uniform; the len... (Complete abstract click electronic access below) / Doutor

Orientador: Regiane Cristina Oliveira de Freitas Bueno / Coorientador: Dirceu Pratissoli / Banca: Paulo Cesar Bogorni / Banca: Carolina Reigada Montoya / Banca: Carlos Frederico Wilcken / Banca: Marcelo de Almeida Silva / Resumo: O sucesso na utilização de parasitoides no campo está diretamente relacionado à capacidade de busca do hospedeiro, que pode ser afetada por alterações nas características biológicas, morfológicas, comportamentais ou pela presença de patógenos dos insetos. Por isso, objetivou-se avaliar a qualidade dos parasitoides Cotesia flavipes Cameron (Hymenoptera: Braconidae), Trichospilus diatraeae (Cherian & Margabandhu) e Palmistichus elaeisis (Delvare & LaSalle) (Hymenoptera: Eulophidae) multiplicados em Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). Para isso, foram realizadas avaliações das características biológicas, morfológicas, comportamento de voo e identificação molecular de microsporídios em populações de C. flavipes obtidas em seis biofábricas do Estado de São Paulo (A, B, C, D, E e F) e de quatro biofábricas do Brasil (São Paulo, Paraná, Minas Gerais e Alagoas). Nos parasitoides T. diatraeae e P. elaeisis foi realizada a identificação molecular de microsporídios. As populações (A, B, C, D, E e F) diferiram nos parâmetros avaliados. As populações A, C, E e F apresentaram predominância de parasitoides fêmeas com razão sexual acima de 0,65, enquanto que as populações B e D apresentaram alta frequência de machos, média de 0,34. A população E destacou-se com tempo de sobrevivência mediana de 150 horas, no entanto, as fêmeas das populações B e C tiveram a menor sobrevivência, com tempo médio de 49 e 26 horas, respectivamente. Nos testes de voo houve predominância de ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The success in the use of parasitoids in the field is directly related to the capacity of search of the host, which can be affected by changes in the biological, morphological, behavioral characteristics or by the presence of insect pathogens. Therefore, the objective was to evaluate the quality of parasitoids Cotesia flavipes Cameron (Hymenoptera: Braconidae), Trichospilus diatraeae (Cherian & Margabandhu) and Palmistichus elaeisis (Hymenoptera: Eulophidae) multiplied in Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). For this, evaluations of the biological parameters, morphological, flight behavior and molecular identification of microsporids in populations of C. flavipes obtained from six biofactories of the State of São Paulo (A, B, C, D, E and F) and four biofactories in Brazil (São Paulo, Paraná, Minas Gerais and Alagoas). In the T. diatraeae and P. elaeisis parasitoids, molecular identification of microsporidium was performed. The populations (A, B, C, D, E and F) differed in the parameters evaluated. Populations A, C, E and F had a predominance of female parasitoids with sex ratio above 0.65, while populations B and D presented a high frequency of males, mean of 0.34. Population E stood out with a median survival time of 150 hours, however, the females of populations B and C had the lowest survival, with an average time of 49 and 26 hours, respectively. In the flight tests, there was a predominance of parasitoid walkers in all populations, however, population D presented 37% of flying insects, differing from the others. The parasitoids from biofactories installed in the States of São Paulo, Paraná, Minas Gerais and Alagoas presented biological and morphological characteristics considered appropriate for the biological control agent. There was a predominance of parasitoid walkers in all populations. PCR analysis revealed intracellular parasites related to Filo Microsporidia ... / Doutor

Made available in DSpace on 2014-06-11T19:31:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-16Bitstream added on 2014-06-13T19:21:14Z : No. of bitstreams: 1 carvalho_js_dr_jabo.pdf: 697726 bytes, checksum: 0785c6c16f6a2531f403eacf0b663f5b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os objetivos desse trabalho foram: avaliar a distribuição espacial de lagartas de D. saccharalis em duas áreas de cana-de-açúcar, uma com alta e outra com baixa intensidade de infestação, visando à construção de um plano de amostragem sequencial para ser empregado em programas de manejo integrado desta praga e avaliar influência das duas linhas e do comprimento dessas linhas no método de levantamento amostral. Os levantamentos foram realizados em áreas com baixa infestação (variedade CTC3) e alta infestação (variedade RB92579) durante três estágios de desenvolvimento da planta: 4,0, 6,5 e 9,0 meses nos municípios de Jaboticabal/SP e Quatá/SP, respectivamente, durante o período de julho/2008 a março/2009. Foram analisados índices de agregação para melhor descrição da distribuição da praga e o ajuste dos dados à um modelo probabilístico de distribuição de frequência, como Poisson e Binomial Negativa. Os índices da razão variância/média, índice de Morisita, Coeficiente de Green e parâmetro k da binomial negativa indicaram distribuição agregada das lagartas de D. saccharalis em ambas as áreas avaliadas, assim como os dados se ajustaram à distribuição binomial negativa, rejeitando-se, a aleatoriedade. Foi desenvolvido um plano de amostragem sequencial de lagartas de D. saccharalis, e o número máximo de amostras esperadas para tomada de decisão foi de sete unidades amostrais independente do tamanho da área. A comparação entre os métodos de amostragens indicou que é necessário avaliar as duas linhas paralelas de cana-de-açúcar, mas que o comprimento de 1 metro linear é suficiente para uma amostragem representativa / The aims of this study were: to evaluate the spatial distribution of D. saccharalis larvae in two sugarcane areas, one high and another low infestation intensity, as support for the construction of a sequential sampling plan to be used in integrated pest management of this pest and to evaluate the influence of two lines and the length lines in the method of sample surveys. The surveys were conducted in low infestation intensity area (CTC3 variety) and high infestation intensity area (RB92579 variety) during three development stages of the plant: 4.0, 6.5 and 9.0 months in the cities of Jaboticabal/SP and Quatá/SP, respectively, during the period from March/2009 to July/2008. Were analyzed rates of aggregation for a better description of the pest distribution, as well as the adjustment to a probabilistic model of frequency distribution such as Poisson and Negative Binomial Distributions. The variance/mean relationship index, index of Morisita, the Green coefficient and the k exponent of negative binomial indicated aggregate distribution of D. saccharalis larvae in both areas evaluated, as well as the data were adjusted to the negative binomial distribution rejecting itself, the randomness. Sequential sampling plans have been developed to D. saccharalis larvae and the maximum number of expected samples to making decision was seven sampling units. The comparison between the sample methods indicated that it is necessary to evaluate the two lines of sugarcane, but only 1 meter of length is enough for a representative sample

Made available in DSpace on 2014-06-11T19:27:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-04-20Bitstream added on 2014-06-13T20:16:33Z : No. of bitstreams: 1 bovi_ecv_me_sjrp.pdf: 5979263 bytes, checksum: 0251f66437659527ac6203a77bed11fc (MD5) / A broca da cana-de-açúcar é considerada como uma das principais pragas da cultura, cujo controle químico não tem sido muito eficaz. O controle biológico com Cotesia flavipes, em função da expansão do plantio, não será suficiente para o controle em áreas de alta infestação. O clima quente e úmido das regiões Noroeste de São Paulo e Centro-Oeste potencializam a utilização dos fungos Beauveria bassiana e Metarhizium anisopliae para o controle desta praga. O presente trabalho teve como objetivo estudar as variações dentre as populações de B. bassiana e M. anisopliae provenientes de diferentes regiões do Brasil e hospedeiros associadas ao controle da Diatraea saccharalis e identificar microrganismos com potencial de uso como agentes para o controle desta praga. Neste sentido, foram realizados isolamentos de fungos de amostras de solos de diferentes culturas e regiões do Brasil e hospedeiros. Destas amostras, após análises morfológicas, foram obtidos 55 isolados de B. bassiana e 14 isolados de M. anisopliae. Isolados provenientes de Institutos de Pesquisa e Empresas privadas foram fornecidos para serem utilizados como referencias, totalizando 73 isolados de B. bassiana e 68 isolados de M. anisopliae. Os isolados foram inicialmente caracterizados quanto ao potencial de patogenicidade, sendo avaliados quanto a capacidade de infectividade sobre todas as fases de desenvolvimento da D. saccharalis. Os resultados do presente estudo demonstraram que ovos, lagartas, crisálidas e adultos de D. saccharalis são suscetíveis à infecção por diversos isolados de M. anisopliae e B. bassiana. Foi possível ainda caracterizar a patogenidade de diversos isolados de M. anisopliae e B. bassiana, comprovando que estes entomopatogênicos apresentam potencial de controle sobre todas as fases de desenvolvimento deste inseto-praga. Em seguida... / The sugarcane borer is considered a major crop pest, whose chemical control has not been very effective. Biological control with Cotesia flavipes, due to the expansion of the plantation will not be enough to control in areas of high infestation. The hot and humid climate of Northwest region of São Paulo and the Midwest potentiate the use of Beauveria bassiana and Metarhizium anisopliae to control this pest. The present work aimed to study the variations among populations of B. bassiana and M. anisopliae from different regions of Brazil and hosts associated with the control of Diatraea saccharalis and identify microorganisms with potential use as agents to control this pest. In this sense, fungal isolations were made of soil samples from different cultures and regions of Brazil and hosts. From these samples, after morphological analysis, we obtained 55 isolates of B. bassiana and 14 isolates of M. anisopliae. Isolates from research institutes and private companies were provided for use as references, totaling 73 isolates of B. bassiana and 68 isolates of M. anisopliae. The isolates were initially characterized for their pathogenic potential and they were evaluated for their ability to infectivity on all phases of development of D. saccharalis. The results of this study show that eggs, larvae, pupae and adults of D. saccharalis are susceptible to infection by several isolates of M. anisopliae and B. bassiana. It was also possible to characterize the pathogenicity of different isolates of M. anisopliae and B. bassiana, confirming that these entomopathogenics have potential control over all stages of development of this pest insect. Then, we sought to investigate the genetic diversity of these isolates, to evaluate the spatial distribution of genotypes, to know the genetic relationship between isolates from different regions of Brazil, different... (Complete abstract click electronic access below)

Orientador: Jose Carlos Barbosa / Banca: Enrico de Beni Arrigoni / Banca: Alexandre de Sene Pinto / Banca: Arlindo Leal Boiça Júnior / Banca: Júlio César Galli / Resumo: Os objetivos desse trabalho foram: avaliar a distribuição espacial de lagartas de D. saccharalis em duas áreas de cana-de-açúcar, uma com alta e outra com baixa intensidade de infestação, visando à construção de um plano de amostragem sequencial para ser empregado em programas de manejo integrado desta praga e avaliar influência das duas linhas e do comprimento dessas linhas no método de levantamento amostral. Os levantamentos foram realizados em áreas com baixa infestação (variedade CTC3) e alta infestação (variedade RB92579) durante três estágios de desenvolvimento da planta: 4,0, 6,5 e 9,0 meses nos municípios de Jaboticabal/SP e Quatá/SP, respectivamente, durante o período de julho/2008 a março/2009. Foram analisados índices de agregação para melhor descrição da distribuição da praga e o ajuste dos dados à um modelo probabilístico de distribuição de frequência, como Poisson e Binomial Negativa. Os índices da razão variância/média, índice de Morisita, Coeficiente de Green e parâmetro k da binomial negativa indicaram distribuição agregada das lagartas de D. saccharalis em ambas as áreas avaliadas, assim como os dados se ajustaram à distribuição binomial negativa, rejeitando-se, a aleatoriedade. Foi desenvolvido um plano de amostragem sequencial de lagartas de D. saccharalis, e o número máximo de amostras esperadas para tomada de decisão foi de sete unidades amostrais independente do tamanho da área. A comparação entre os métodos de amostragens indicou que é necessário avaliar as duas linhas paralelas de cana-de-açúcar, mas que o comprimento de 1 metro linear é suficiente para uma amostragem representativa / Abstract: The aims of this study were: to evaluate the spatial distribution of D. saccharalis larvae in two sugarcane areas, one high and another low infestation intensity, as support for the construction of a sequential sampling plan to be used in integrated pest management of this pest and to evaluate the influence of two lines and the length lines in the method of sample surveys. The surveys were conducted in low infestation intensity area (CTC3 variety) and high infestation intensity area (RB92579 variety) during three development stages of the plant: 4.0, 6.5 and 9.0 months in the cities of Jaboticabal/SP and Quatá/SP, respectively, during the period from March/2009 to July/2008. Were analyzed rates of aggregation for a better description of the pest distribution, as well as the adjustment to a probabilistic model of frequency distribution such as Poisson and Negative Binomial Distributions. The variance/mean relationship index, index of Morisita, the Green coefficient and the k exponent of negative binomial indicated aggregate distribution of D. saccharalis larvae in both areas evaluated, as well as the data were adjusted to the negative binomial distribution rejecting itself, the randomness. Sequential sampling plans have been developed to D. saccharalis larvae and the maximum number of expected samples to making decision was seven sampling units. The comparison between the sample methods indicated that it is necessary to evaluate the two lines of sugarcane, but only 1 meter of length is enough for a representative sample / Doutor

Thesis (PhD(Agric))--Stellenbosch University, 2012. / The sugarcane borer, Eldana saccharina Walker (Lepidoptera: Pyralidae) is the most limiting factor in the South African sugar industry with losses to this insect pest estimated to be at least ZAR60 million per annum. Because of its cryptic nature as well as the fact that E. saccharina is both indigenous to Africa and occurs on several host plants, attempts to control or eradicate it using several available methods have not been very successful. However, the sterile insect technique (SIT) is one of the newer control methods that can be incorporated into an area-wide integrated pest management (AW-IPM) programme to achieve better control or eradication. The implementation of the SIT program needs to go through a series of well-researched phases in order to be successful. In the first of this multi-phase project, it was determined that E. saccharina is susceptible to ionizing radiation, and is thus a suitable candidate for the SIT development against it and that a sub-sterilizing dose of 200 Gy is sufficient to induce F1(inherited) sterility in male and complete sterility in female moths respectively. The results presented here are discussed in the context of further development of the SIT as an addition to the arsenal of tactics in an AW-IPM programme against E. saccharina. Based on these initial findings, the study examined the lek and mating behavior of male moths subjected to three radiation doses (150, 200, 250 Gy) against normal non-irradiated/fertile moths. Both mass-rearing and irradiation of E. saccharina led to a quantitative departure of male mating behavior away from that exhibited by their wild counterparts. However, treated males are still able to form leks and mate with wild females. Male E. saccharina irradiated at all three doses tested were found to be as active and competitive as wild males, but in some of the traits measured, performance diminished significantly with an increase in the radiation dosage. In general, the performance of moths treated at 200 Gy did not differ significantly from that of moths treated at 150 Gy and therefore the former dose is ideal for SIT development since it results in a lower residual F1 fertility than the latter. The level of mating competitiveness and compatibility was assessed under both laboratory and semi-field conditions in pairwise comparisons consisting of laboratory reared vs. wild (L-W), 200 Gy irradiated vs. wild (S-W) and laboratory reared vs. irradiated moths (L-S). Based on the results from the more robust field cage assays, the mating indices generated indicated that the mass-reared E. saccharina strain produced in South Africa has not yet evolved sexual behaviours suggestive of incipient pre-mating isolation barriers with local wild strains. Wild moths did not discriminate against either the partially sterile or laboratory reared moths and most importantly, the irradiated males mated significantly more than their wild counterparts regardless of the type of female. The irradiated insects could therefore achieve the purpose for which they are intended upon release into the field. Third, the critical thermal limits (CTLs) to activity at high and low temperatures (i.e. critical thermal maxima “CTmax” and minima “CTmin”) of different E. saccharina strains/treatments were investigated under standard experimental conditions. The effect of laboratory rearing and increasing radiation dosage on thermal tolerance of the adult stage of E. saccharina was explored. There were highly significant differences between the laboratory-reared and wild strain and also between non-irradiated and irradiated strains in both CTmax and CTmin. Laboratory reared E. saccharina moths were more heat tolerant compared to wild moths for both genders while in the case of CTmin, the reverse was true. Irradiation had a negative effect on both CTmax and CTmin. Moths treated at the lowest radiation dose were more cold and heat tolerant than those treated at higher dosages thereby reinforcing the importance of lower dosages rather than those that induce full sterility against E. saccharina. In general, gender effects on the CTLs were non-significant. Pilot sterile male releases in shade house trials to measure the impact of sustained releases of partially sterile adult males at an over-flooding moth ratio of 10T: 1U (treated to untreated),were conducted to measure their efficacy to stop E. saccharina incursions and suppress populations prior to testing in pilot studies under true season-long and area wide conditions. Results from the current study demonstrated that releasing partially irradiated (200 Gy) adult male moths at the afore mentioned release rate significantly reduced sugarcane stalk damage as well as lowered the number of fertile progeny from F1to succeeding generations in a stable E. saccharina population initiated in a cage house. There were more damaged internodes per stalk in the control than in the sugarcane receiving regular releases of partially sterile male moths. Overall, there were significantly more undamaged stalks in the treated sugarcane than the untreated control. Furthermore, there were significantly more larvae per stalk retrieved from the control compared to the treated sugarcane suggesting that the sustained release of steriles was efficacious in reducing emergence of fertile larvae in the succeeding generations. The results of this study indicate that there is considerable scope for the SIT against E. saccharina.

Orientador: Odair Aparecido Fernandes / Coorientador: Cláudia Pio Ferreira / Banca: Leila Luci Dinardo Miranda / Banca: Daniel Junior de Andrade / Resumo: A broca-da-cana, Diatraea saccharalis, é considerada uma das principais pragas da cana-de-açúcar e tem causado sérios prejuízos em novas fronteiras agrícolas brasileiras que abrangem o oeste do estado de São Paulo e a região centro-oeste do país. Desta forma, este trabalho teve por objetivo avaliar a dinâmica populacional de adultos de Diatraea saccharalis em diferentes regiões canavieiras e sua relação com os fatores meteorológicos, bem como estabelecer modelo de previsão de ocorrência com base em graus-dia e equações de diferenças. Os adultos foram avaliados semanalmente durante duas safras (2013/2014 e 2014/2015) em cultivos localizados nos estados de São Paulo (Pradópolis e Valparaíso) e Goiás (Quirinópolis). Em cada localidade foram utilizados um ou dois talhões de 25 ha, próximos (< 2 km) a estações climáticas. Em uma área central (1 a 1,5 ha) de cada talhão foram instaladas quatro armadilhas delta contendo fêmeas virgens e piso colante para captura dos adultos. O número de adultos coletados e os dados climáticos foram submetidos à análise de regressão múltipla e correlação. Modelos matemáticos baseados em graus-dia e equações de diferenças foram elaborados. Verificou-se maior ocorrência de adultos no período das chuvas, principalmente, de janeiro a abril. Não houve correlação entre os fatores climáticos e a flutuação populacional; com exceção de Quirinópolis, onde a umidade foi fator abiótico limitante para o crescimento populacional desta espécie. Os modelos de graus-... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The sugarcane borer, Diatraea saccharalis, is considered one of the main pest of sugarcane and has caused serious losses in new Brazilian agricultural frontiers including the western region of São Paulo state and the Midwest region of the country. Thus, this study aimed to assess the population dynamics of D. saccharalis adults in different sugarcane regions and its relationship with meteorological factors, as well as to establish a forecasting model based on degree days and difference equations. The adults were evaluated weekly for two growing seasons (2013/2014 and 2014/2015) in areas located in the states of São Paulo (Pradópolis and Valparaiso) and Goiás (Quirinópolis). In each location we used one or two plots of 25 ha, near (<2 km) to meteorological stations. In a central area (1 to 1.5 ha) of each block, four delta traps with virgin females and sticky floor were installed to capture adults. The number of collected adults and weather data were submitted to analysis of multiple regression and correlation. Mathematical models based on degree days and difference equations were developed. A higher occurrence of adults was observed during the rainy season, mainly from January to April. There was no correlation between climatic factors and population dynamics; except for Quirinópolis where the relative humidity was a limiting abiotic factor for population growth of this species. Models of degree days and difference equations are complementary and have shown effectiveness in f... (Complete abstract click electronic access below) / Mestre