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

Thesis (M.S.)--Humboldt State University, 2007. / Includes bibliographical references (leaves 27-31). Also available via Humboldt Digital Scholar.

Doctor of Philosophy / Department of Physics / Thomas W. Phillips / The emergence of heritable high-level resistance to the fumigant gas phosphine in stored-product insects is of grave concern to many grain growing countries around the world. The research reported in this dissertation was designed to determine the presence of phosphine resistance in 34 field collected populations of Rhyzopertha dominica (F.) from the United States and Canada, the potential to control resistant R. dominica populations utilizing high dose and longer exposure time strategies, and to develop a rapid assay for phosphine resistance detection. Using a discriminatory dose assay called the FAO number 16 method, adult R. dominica were sampled and subjected to a phosphine dose of 20 ppm for a fumigation exposure period of 20 h to distinguish a susceptible R. dominica adult by death from a resistant beetle that survives the treatment. Results from the study showed that 32 out of the 34 geographic populations surveyed had beetles resistant to phosphine, and the frequency of resistance varied from 97% in a population from Parlier, California to 0% in beetles from both Carnduff, Saskatchewan and Starbuck, Manitoba. A 20-hour dose response assay was used to characterize the level of resistance by calculating the resistance ratio factors using beetles from a laboratory susceptible strain and those from five of the populations sampled. This resistance ratio (RR) was based on the ratio of LC50 (estimate for the concentration to kill 50% of a test group) in the sampled population to the LC50 for the susceptible strain. The highest RR for the five resistant populations was nearly 596-fold in beetles from Belle Glade, Florida, which represented the “strong” resistance phenotype, whereas the lowest RR in that group was 9-fold in Wamego, Kansas, representing the “weak” resistance phenotype. Manipulation of concentration and exposure periods can be utilized to manage strongly resistant R. dominica populations. The effect of several phosphine concentrations and fumigation exposure periods were assessed on progeny of mixed life stage colonies of the strongly resistant R. dominica. A 48 hours dose response assay was carried out on these two strongly resistant populations to re-characterize their levels of resistance. Results from this assay showed that a phosphine dose of 730-870 ppm could control all resistant adult R. dominica. Additionally, phosphine concentrations ranging from 400-800 ppm phosphine for 96 hours completely killed mixed life stage colonies of strongly resistant lesser grain borers from the two populations studied. Lastly, fumigations done beyond 4 days at phosphine concentrations between 450-700 ppm controlled all phosphine resistant populations of lesser grain identified from our previous work. Phosphine applied at high concentrations is known to elicit a knockdown effect that can vary between susceptible and resistance grain insects. Using 18 of the 34 R. dominica populations this study sought to determine among three knockdown time (KT) techniques which method had potential to be utilized in an effective rapid assay for phosphine resistance in R. dominica. Adult R. dominica were exposed to a high concentration of phosphine (3000 ppm) to assess the time to knockdown 50%, 100% of a group of ten insects and that of single insects from the 18 geographically distinct populations vis a vis the resistance frequencies using the FAO method. KT100 quick test was better than the KT50 and Ktsingle, because bioassays were able to clearly distinguish among susceptible, weak and strong resistant individuals. Time for KT100 from susceptible populations did not exceed 30 minutes, while resistant populations had KT100 times above 30 min, with strong-resistant populations times longer than 100 min.

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

Doctor of Philosophy / Department of Grain Science and Industry / Subramanyam Bhadriraju / The lesser grain borer, Rhyzopertha dominica (F.), females lay eggs loosely outside of wheat kernels. Larvae hatching from eggs enter wheat kernels to complete immature development. Four laboratory experiments were conducted to understand the wheat kernel infestation by first instars of R. dominica at 28°C and 65% r.h. The first experiment compared different kernel to first instar ratios on sound hard red winter (HRW) wheat class, probability of successful infestation, and subsequent adult development as affected by site of feeding on the kernels. Infested kernels were dissected 21 d after infestation to determine stage of development and larval weight. Development of larvae to adulthood was monitored for 50 d from time of infestation. Different kernel to first instar ratios did not affect probability of infestation, entry site preferences, larval development and weight, and days to adult emergence. In the second experiment one first instar was placed with a kernel on each of seven different wheat classes. Wheat kernels were artificially-damaged with a microdrill at the germ, endosperm, and brush end, and the sound kernels served as the controls. At 21 d, 82-90% of artificially-damaged HRW wheat kernels were infested by larvae versus 12% for sound kernels. Five times fewer hard white (HW) wheat sound kernels were infested by larvae compared with infestation in soft white (SW) wheat kernels. Sound kernels of durum, soft red winter (SRW), hard red spring (HRS), and hard white spring (HWS) wheat classes were more resistant to larval infestation than artificially-damaged kernels. Majority of first instars preferred germ as the entry site on HRW, HWW, SRW, and HWS wheat classes. Germ entry promoted faster larval development, leading to heavier larvae, and higher kernel weight losses. Adult emergence was earlier by 3-7 d compared with other sites across all 6 wheat classes, except for SWW class, where adult emergence was nil at 50 d. In the third experiment, speed of larval development on artificially-drilled HRW wheat kernels on different kernel sites. Three-hundred kernels each were drilled near the germ, endosperm, and brush end, and one first instar was placed per kernel in a glass vial. Kernels from glass vials were dissected every 3 d for 30 d and larval head capsule was measured. Larval development was fastest on the germ, followed by endosperm, and brush end. In the fourth experiment short-term feeding by R. dominica adults on infestation by first instars on sound wheat kernels was determined. Two laboratory tests were conducted with single and grouped (10) kernels using either two adults or two first instars per kernel. Signs of feeding were monitored for 21 d in single kernels and 7 d in grouped kernels. There was a significant association between adult feeding and larval infestation responses in single and group kernel tests. In conclusion, understanding factors that contribute to first instar establishment in wheat kernels will have impacts in breeding varieties that could be resistant and designing grain-handling equipment to minimize grain damage to mitigate R. dominica infestation of wheat.

No description available.

The European Corn Borer (ECB), Ostrinia nubilalis, is an agricultural pest which bores small holes in the rind of maize stalks and then proceeds to consume the pith. Because most of the damage to the stalk is internal, it is difficult to quantify the damage to an individual stalk without time-consuming, manual examination. This work explored the hypothesis that internal damage could be detected and quantified using non-destructive, electromagnetic measurements. Laboratory experiments and numerical simulation studies predicted changes in capacitance of stalks due to hollow core ECB damage. A guarded probe device to measure electrical impedance from 500 Hz to 100 kHz was designed and constructed for data collection. A field test with the measurement device was conducted and frequency-swept impedance measurements were taken on field-grown plants with and without ECB damage. Field measurements demonstrated that statistically significant capacitance changes associated with ECB damage could be detected in agreement with numerical simulations of stalk damage. Numerical, laboratory, and field test results all supported the hypothesis that electromagnetic impedance measurements, in particular, capacitance, provide a promising new avenue for ECB damage evaluation. While further research will be needed to further refine this concept, this measurement approach is non-destructive, thus allowing measurements to be performed without sacrificing the infested plants.

No description available.