Doctor of Philosophy / Department of Entomology / Larry L. Buschman / Kun Yan Zhu / Genomic information for lepidopteran insects, particularly agricultural pest species, is very limited but urgently needed due to their economic importance and biodiversity. The huge economic losses ($ 1-2 billons / year) caused by the European corn borer (Ostrinia nubilalis, Hübner, ECB) makes this insect species one of the major pests of corn in the United States and western world. Management of ECB by conventional methods is limited but has had a great success by transgenic Bt (Bacillus thuringiensis) corn, which targets insect gut. However, the widespread use of Bt corn may lead to the development of Bt resistance in ECB. Knowledge of genes expressed in the insect gut is considered crucial for understanding basic physiology of food digestion, their interactions with Bt toxins and pathogens, and for discovering new targets for pest management. A large database of 15,000 expressed sequence tags (ESTs) was established from the ECB larval gut. To our knowledge, this database represents the largest gut-specific EST database from a lepidopteran pest. Analysis of 10 aminopeptidase-like genes between Cry1Ab–resistant and –susceptible ECB larvae revealed that aminopeptidase P-like (OnAPP) gene is a strong candidate for its role in Bt toxicity and resistance. The RNA interference mediated reduction in the transcript level of OnAPP gene in ECB larvae resulted in their reduced susceptibily to Cry1Ab. Analysis of the chitinase-like gene (OnCht) revealed its essential role in regulating chitin content of peritrophic membrane (PM). Our results suggest that OnCht may influence food digestion, nutrient absorption or movement of digestive enzymes through the PM and can be an important target for insect management. We also identified and characterized six genes involved in the innate immune defense response in ECB and showed that the expression of these genes were induced when challenged with bacteria. In addition to these results, this research generated significant genomic information for the development of microarray from the larval gut of ECB. The establishment of the feeding-based RNA interference technique could potentially help in delivering dsRNA orally to ECB for high throughput screening of effective genes to be targeted for insect pest management.

No description available.

When coring thick-barked trees, increment cores often become compressed and jammed inside the narrow region of the borer shaft. These jams can be problematic for two reasons: first, it often leaves the core unusable; second, the jam may be so tightly compressed in the borer that removal is difficult, especially in the field. Although procedures to evacuate these jams are documented in the literature, methods of prevention are not. Here, a modified manual method of increment boring that can reduce the likelihood of jams and, in addition, decrease the number of deformed core samples is described. Traditional and modified boring methods were randomly assigned to 40 Douglas-fir trees (80 cores) at a research site along the Oregon coast. Results show that jams were associated with traditional boring over six times more than with the proposed modified technique.

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

Typescript. / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

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

In some areas the effect of pathogenicity of microorganisms upon the European corn borer have been explored. The microorganisms studied were: Nosema, pyraustae, Nosema necatrix, and Bacillus thuringlensis var, thuringiensie. Most studies have been limited to either laboratory or field work. In this thesis, a comparative study of mortality, percent infection, and tune intervals in which infection occurs have been explored, in the field and the laboratory studies.It is concluded: (1) field recovered borers at different day intervals showed interaction between the experimental microorganisms and time intervals (2) that the microorganisms used in the field, especially N. necatrix, may be used as effective microbial control agents against Ostrinia nubilalis.Ball State UniversityMuncie, IN 47306

Thesis (M.S.)--Oregon State University, 1998. / Typescript (photocopy). Includes bibliographical references (leaves 40-43). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 72-79). Also available on the Internet.