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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Potencial inseticida das proteínas Cry1Ca e Cry2Ac de Bacillus thuringiensis Berliner para populações de Plutella xylostella (L.) (Lepidoptera : Plutellidae) em laboratório. /

Cardoso, Camila Pires January 2019 (has links)
Orientador: Sergio Antonio de Bortoli / Resumo: O cultivo intensivo de Brassicaceae favorece o aparecimento de algumas pragas como Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae), a traça-das-crucíferas, cujos danos podem comprometer seriamente a produção. Esse inseto-praga pode ser controlado tanto com inseticidas sintéticos, como com biológicos, sendo, no entanto, usualmente utilizados os sintéticos em seu combate. A traça-das-crucíferas foi a primeira espécie de inseto a ser constatada resistência a inseticidas biológicos, com o uso indiscriminado de inseticidas sintéticos para o seu controle contribuindo também para a seleção de indivíduos tolerantes ou resistentes, além de causar a mortalidade de organismos não alvos. Sendo assim, este trabalho teve por objetivo avaliar a atividade inseticida e os efeitos subletais de duas toxinas lepidóptero-ativas de Bacillus thuringiensis, Cry1Ca e Cry2Ac, em três populações de traças-das-crucíferas, sendo uma delas suscetível (PC) e duas consideradas resistentes (Bt e NO-QA) a toxinas de B. thuringienis, em condições de laboratório. Foram realizados bioensaios de suscetibilidade com as três populações e as toxinas Cry1Ca e Cry2Ac, estimando-se a concentração letal (CL50) e os seus efeitos subletais. A toxina Cry2Ac não causou mortalidade nas lagartas das três populações, então os testes subletais foram realizados apenas com a toxina Cry1Ca que provocou mortalidade. Os parâmetros biológicos avaliados foram: período e peso pupal, sobrevivência larval e pupal, longevi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Intensive brassics cultivation favors appearing of some pests as Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae), diamondback moth (DBM), whose damage can seriously compromise production. This insect-pest can be controlled either synthetic insecticides as biological insecticides, but synthetics are usually used to combat. Diamondback moth was the first insect species to be verified resistance to biological insecticides, with indiscriminate use of synthetic insecticides for its control, also contributing to selection of tolerant or resistant individuals, as well as causing mortality on non-target organisms. Therefore, the objective of this work was to evaluate insecticide activity and sublethal effects of two lepidopteran-active toxins of Bacillus thuringiensis, Cry1Ca and Cry2Ac, on three DBM populations, one of them susceptible (PC) and two considered as resistant (Bt and NO-QA) to B. thuringiens toxins under laboratory conditions. Susceptibility bioassays were performed on the three populations and toxins Cry1Ca and Cry2Ac, estimating lethal concentration (LC50) and its sublethal effects. Cry2Ac toxin did not cause mortality on the caterpillars from the three populations, so the sublethal tests were performed only with Cry1Ca toxin. The biological parameters evaluated were: pupal period and weight, caterpillar and pupal survival, male and female longevity and fecundity. The populations showed susceptibilities to Cry1Ca toxin, with statistically equal behavio... (Complete abstract click electronic access below) / Mestre
232

Otimização da criação de Anagasta kuehniella (Zeller, 1879), hospedeiro alternativo de Trichogramma sppa., baseando-se na temperatura, densidade larval e concentração de dióxido de carbono / Optimization of the rearing of Anagasta kuehniella (Zeller, 1879), factitious host for Trichogramma spp., based on temperature, larval density and carbon dioxide concentration

Coelho Junior, Aloisio 27 January 2011 (has links)
O objetivo do trabalho foi estabelecer as condições ótimas para criação massal de Anagasta kuehniella (Zeller, 1879), definindo a densidade larval por recipiente de criação, associando-a com temperatura e concentração de CO2, produzidos pelo metabolismo larval. Para que este objetivo fosse atingido, foram avaliados: 1) o efeito da temperatura no ciclo evolutivo (ovo-adulto) de A. kuehniella para determinação das suas exigências térmicas; 2) efeito da temperatura nas fases imaturas e nos adultos de A. kuehniella sobre a reprodução, estudando-se o efeito de diferentes temperaturas (na faixa de 18 a 32°C) desde a fase de ovo até a morte dos insetos; efeito de diferentes temperaturas (18 a 32ºC) durante as fases larval e pupal em adultos transferidos para 25°C e o efeito de diferentes temperaturas (18 a 32°C) nos adultos provenientes de imaturos mantidos a 25°C; 3) otimização do número de insetos por recipiente, para criações massais de A. kuehniella, avaliando-se o efeito da densidade de ovos no incremento térmico dos recipientes e na postura, bem como a relação entre incremento térmico x densidade populacional x temperatura de criação na postura de A. kuehniella; 4) produção de dióxido de carbono (CO2) por bandeja de criação de A. kuehniella e o efeito do CO2, na viabilidade do período ovo-adulto e na postura de A. kuehniella. A condição ótima de criação de A. kuehniella foi obtida quando as lagartas no interior das bandejas foram mantidas na temperatura de 25° C. Assim, considerandose o incremento térmico entre 7 e 9°C, gerado pelo metabolismo larval, a temperatura das salas de criação deve ser mantida com temperaturas mais baixas durante o 4° e 5° ínstares do desenvolvimento larval de A. kuehniella. A concentração máxima de CO2, no interior da sala de criação, deve ser inferior a 1.200 ppm, sala esta contendo bandejas com 1 Kg de dieta (97% de farinha de trigo integral e 3% de levedura) inoculadas com 7.200 ovos, pois esta densidade proporcionou uma viabilidade satisfatória do período ovo-adulto (78%), produzindo ainda uma maior quantidade de ovos por bandeja e ovos de A. kuehniella mais pesados. / The objective of this research was to establish the optimum conditions for mass rearing of Anagasta kuehniella (Zeller, 1879), defining the larval density for rearing container, associating it with temperature and concentration of the CO2 produced by the larval metabolism. For this purpose, it was evaluated: 1) the effect of temperature on the life cycle (egg to adult) of A. kuehniella to determine the thermal requirements; 2) effect of temperature in the immature and adults stages of A. kuehniella on reproduction, studying the effect of different temperatures (from 18 to 32°C) from the egg stage until the death of the insects and effect of different temperatures (18 to 32ºC) during the larval and pupal in adults transferred to 25°C and the effect of different temperatures (18 to 32°C) in adults emerging from immature kept at 25°C; 3) optimizing the number of insects per container, for mass rearing of A. kuehniella, evaluating the effect of egg density on temperature increment of containers and oviposition, as well as the relationship between increased temperature X population density X rearing temperature in oviposition of A. kuehniella, 4) carbon dioxide production (CO2) per tray of rearing of A. kuehniella and the effect of CO2 on the viability of the egg-adult and oviposition of A. kuehniella. The optimum condition of rearing A. kuehniella was obtained when the larvae inside the trays were kept at 25°C. Thus, considering the temperature increment between 7 and 9°C, generated by larval metabolism, the temperature in rearing rooms should be kept at lower temperatures during the 4th and 5th instars of the larval development of A. kuehniella. The maximum CO2concentration inside the rearing room should be lower than 1,200 ppm, this room containing trays with 1 kg of diet (97% of whole wheat flour and 3% of yeast) inoculated with 7,200 eggs, as this density provided satisfactory feasibility in the egg-adult period (78%), producing an even greater number of eggs per tray and heavier eggs of A. kuehniella.
233

Efeitos da ingestão de carboidratos com reguladores de crescimento de insetos na reprodução de Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) / Effects of the ingestion of carbohydrates with insect growth regulators on the reproduction of Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)

Alexandre Luis Jordão 02 April 2009 (has links)
O presente trabalho foi subdividido em quatro capítulos com os seguintes objetivos: (i) apresentar revisão bibliográfica abordando as principais referências presentes na literatura sobre a cultura da batata, Solanum tuberosum L. (Solanaceae), os aspectos bioecológicos da traça-da- -batatinha, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), os hormônios no desenvolvimento dos lepidópteros e a atuação de alguns reguladores de crescimento de insetos (RCIs); (ii) avaliar a ingestão dos carboidratos por adultos de P. operculella e sua influência na reprodução da espécie; (iii) testar parâmetros reprodutivos devido à ingestão de alguns ingredientes ativos presentes em RCIs; (iv) avaliar a ingestão de carboidratos aplicados sobre plantas de batata de maneira a ser possível a aplicação de RCIs como método de redução populacional da praga. Inicialmente, para comprovação da ingestão dos carboidratos, foi utilizada a técnica de marcadores coloridos, em que se ofereceu, por capilaridade via rolete dental, solução de mel a 10% contendo corante líquido artificial de coloração azul anis. Os insetos foram confinados em um recipiente cilíndrico construído com tubo de PVC rígido. Após três dias de oferecimento da alimentação, analisou-se a presença do corante no sistema digestivo dos insetos. Para verificação da ingestão de carboidrato em condições mais próximas ao ambiente das culturas agrícolas, foi realizada nova avaliação em recipientes com diferentes dimensões: 0,0018; 0,054 e 9,6 m3. Posteriormente, simulando um borrifamento na cultura, foi realizada uma terceira avaliação no ambiente de 9,6 m3, na qual a solução de mel foi oferecida aos insetos em gotas grandes no limbo foliar de plantas de batata. Para análise da influência dos carboidratos na reprodução da espécie, foram verificados os seguintes parâmetros reprodutivos: ritmo de postura, fecundidade, viabilidade dos ovos e índice de ovigenia. Para análise dos efeitos dos RCIs, foram utilizados quatro compostos com diferentes ingredientes ativos: azadiractina, lufenurom, metoxifenozida e piriproxifem. Estes compostos foram oferecidos aos insetos em solução de mel a 10%, nas concentrações de 5, 10 e 20 ppm. Durante 10 dias após o acasalamento, foram analisados os parâmetros reprodutivos. O corante colorido mostrou-se adequado para os estudos visuais do sistema digestivo de P. operculella. A ingestão dos carboidratos pelos insetos ocorreu somente quando estes foram confinados em ambientes menores, 0,0018 e 0,054 m3. No ambiente maior, de 9,6 m3, a ingestão ocorreu somente quando a solução foi oferecida via gotas em plantas de batata. Quanto aos efeitos dos RCIs, verificou-se diminuição significativa na fecundidade das fêmeas de P. operculella que ingeriram solução de mel contendo azadiractina e lufenurom à concentração de 5 ppm e piriproxifem à concentração de 20 ppm. Quanto aos parâmetros viabilidade dos ovos e período embrionário não foram verificadas diferenças significativas entre os tratamentos. Este fato sugere que a fertilidade não foi alterada, demonstrando que os RCIs não afetam os machos. A comprovação da ingestão dos carboidratos oferecido via gotas no limbo foliar de plantas de batata e os resultados obtidos na redução da fecundidade de P. operculella indicaram que esta técnica pode ser utilizada em programas de manejo integrado da traça-da-batatinha. / The present work has been subdivided into four chapters, with the following objectives: (i) to present a bibliographic review of the main aspects related to the potato crop, Solanum tuberosum L. (Solanaceae), the bioecological aspects of potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), the hormones related to lepidopterans development and the role of some insect growth regulators (IGRs); (ii) to evaluate the carbohydrate intake by P. operculella adults and its influence on the species reproduction; (iii) to test the effects of active ingredients of IGRs on reproductive parameters; (iv) to evaluate the ingestion of carbohydrates applied on potato plants, in order to allow IGRs application as a population reduction strategy for this pest. Initially, confirmation of carbohydrate consumption was by a means colored marker technique, which offers a 10% honey solution containing an artificial liquid food dye, blue anise, by capillarity via a dental roll wick. The insects were caged in a cylindrical container made of a rigid PVC tube. After three days of food offering, dye presence was analyzed within the insects digestive system. For confirmation of carbohydrate intake under simulated field conditions, an additional evaluation was conducted in containers with different sizes: 0.0018, 0.054 and 9.6 m3. Later, a third evaluation was carried out in the 9.6 m3 container, in which the honey solution was offered to insects as big drops applied on the leaf blade of potato plants, simulating a spray application. To analyze carbohydrate influence on species reproduction, the following reproductive parameters were assessed: oviposition rate, fertility, egg viability and ovigeny index. Four compounds with different active principles were utilized to analyze IGR effects: azadirachtin, lufenuron, methoxyfenozide and pyriproxyfen. These compounds were offered to the insects in a 10% honey solution at concentrations of 5, 10 and 20 ppm. During 10 days after mating the reproductive parameters were evaluated. The colored dye method proved to be efficient for visual studies of P. operculellas digestive system. Carbohydrate ingestion by the insects occurred only when they were caged in small environments, 0.0018 and 0.054 m3. In larger ones 9.6 m3, feeding occurred when the solution was offered by dripping over potato plants. Results showed a significant reduction of P. operculella fertility among females that ingested the honey solution containing azadirachtin and lufenuron, at 5 and 20 ppm, respectively. Regarding egg viability and embrionary period, no significant differences were found between the treatments. This fact suggests that fertility was not affected, thus demonstrating that IGRs did not affect males. Confirmation of carbohydrate ingestion offered by dripping over potato leaf blades and the results of fertility reduction in P. operculella, indicated that this technique may be utilized in integrated management programs against the potato tuber moth.
234

Fire Ants

Riha, Joyce Marie 09 May 1996 (has links)
Loss is a fundamental part of the human experience, from the loss of security and innocence that comes with the necessary separation of child from parent to the ultimate loss of life. Along the way, there are the losses of jobs, of incomes, of homes; the losses of friendships, of family members, of lovers; the losses of direction, of control, of hope. As cognitive and caring beings, humans struggle to cope with these losses, to greater and lesser degrees of success. This is the theme at the heart of this thesis. Fire Ants is composed of ten short stories, fictive works, which differ in specific subject matter, yet deal unilaterally with issues of loss. Like the venomous creatures that threaten to eat B. D. Packard alive in the title story, life eats away at a number of characters in the collection who are deficient. The narrators in "Aftermath" and "Hues," for example, suffer psychological -- if not physical -- deaths. But not all of the characters lack coping mechanisms, unhealthy as they may sometimes be. As the stories unfold, some characters begin to gain small degrees of perspective and understanding, to learn that while life is full of loss, it is not always entirely bleak. As demonstrated in "Cross Creek," good exists, though it is not always where one might expect it. And life can be full despite loss, as depicted in "Stitches."
235

Development and evaluation of automated radar systems for monitoring and characterising echoes from insect targets

Dean, Timothy J., Physical, Environmental & Mathematical Sciences, Australian Defence Force Academy, UNSW January 2007 (has links)
This thesis describes the construction of a mobile Insect Monitoring Radars (IMR) and investigations of: the reliability of IMRs for observing insect migration in inland Australia; possible biases in IMR migration estimates; the relation between an insect???s size and its radar properties; radar discrimination between insect species; the effect of weather on the migrations of Australian plague locusts and of moths; the scale of these migrations; and here IMRs are best located. The principles of entomological radar design, and the main features of insect migration in inland Australia, are reviewed. The main procedures used in the study are: calculation of radar performance and of insect radar cross sections (RCSs); reanalysis of a laboratory RCS dataset; statistical analysis of a fouryear dataset of IMR and weather observations; and a field campaign using both two existing fixed IMRs and the new mobile unit. Statistical techniques used include correlation, multiple regression, discriminant analysis, and principal components analysis. The original results of this work include design details of the mobile IMR, extension of radar performance calculations to IMRs and evaluation of flight speed biases, a holistic approach to IMR design, the relation of insect RCS magnitudes and polarization patterns to morphological variables, an estimate of the accuracy of the retrieved parameters, evaluations of three approaches (oneparameter, theory-based, and a novel two-stage method) to target identification, and verification of inferred target identities using results from nearby light traps. Possible sites for future IMRs are identified. The major conclusions are that: a mobile IMR can be built with a performance equal to that of a fixed IMR but at half the cost; significant biases in the signal processing results arise from insect speed; locusts and moths can be distinguished if all RCS parameters are used; IMRs can be designed to match particular requirements; weather has a significant effect on insect migration, the best single predictor of insect numbers being temperature; moonlight has no effect; the spatial correlation of migration properties falls to 50% at a separation of 300 km; and migrating insects can be carried by the wind for 500 km in a single night
236

Selection and Floral Evolution in <i>Platanthera bifolia</i> and <i>P. chlorantha</i> (Orchidaceae)

Maad, Johanne January 2002 (has links)
<p>Natural selection mediated by pollinators has influenced the evolution of floral diversity of the flowering plants (angiosperms). The scope of this thesis was to study: 1) phenotypic selection, 2) mating systems, and 3) floral shifts involved in plant speciation. Model plant species were <i>Platanthera bifolia</i> and <i>P. chlorantha</i> (Orchidaceae). These orchids are moth-pollinated, strictly co-sexual (bisexual flowers), and produce a spike that displays 10-20 white flowers.</p><p>I explored the influence of characters on plant fitness by using multiple linear regressions. Pollen removal (male fitness) and fruit set (female fitness) increased with more flowers per plant in three <i>P. bifolia</i> populations. There was selection towards longer spurs in a dry year when average spur length was shorter than in normal-wet years. Female function was sensitive to drought, which enabled an application of the male function hypothesis of floral evolution (Bateman's principle). The results show that selection may vary between populations, years, and sex-functions.</p><p>I examined inbreeding by estimating levels of geitonogamy (self-pollination between flowers of an individual) with an emasculation method in two <i>P. bifolia</i> populations. Geitonogamy did not vary with inflorescence size. Levels of geitonogamy was 20-40% in the smaller, but non-significant in the larger population. This may relate to lower number of possible mates and pollinator activity in the smaller population.</p><p><i>Platanthera bifolia</i> exhibits the ancestral character state of tongue-attachment of pollinia on the pollinator. Its close relative <i>P. chlorantha</i> attaches its pollinia onto the pollinator's eyes. To explore the mechanism of a floral shift, pollination efficiency and speed was compared between the two species. The results showed no differences in pollination efficiency, but <i>P. chlorantha</i> had faster pollen export and import. Efficiency of pollination in terms of speed may cause floral shifts, and thus speciation.</p>
237

Selection and Floral Evolution in Platanthera bifolia and P. chlorantha (Orchidaceae)

Maad, Johanne January 2002 (has links)
Natural selection mediated by pollinators has influenced the evolution of floral diversity of the flowering plants (angiosperms). The scope of this thesis was to study: 1) phenotypic selection, 2) mating systems, and 3) floral shifts involved in plant speciation. Model plant species were Platanthera bifolia and P. chlorantha (Orchidaceae). These orchids are moth-pollinated, strictly co-sexual (bisexual flowers), and produce a spike that displays 10-20 white flowers. I explored the influence of characters on plant fitness by using multiple linear regressions. Pollen removal (male fitness) and fruit set (female fitness) increased with more flowers per plant in three P. bifolia populations. There was selection towards longer spurs in a dry year when average spur length was shorter than in normal-wet years. Female function was sensitive to drought, which enabled an application of the male function hypothesis of floral evolution (Bateman's principle). The results show that selection may vary between populations, years, and sex-functions. I examined inbreeding by estimating levels of geitonogamy (self-pollination between flowers of an individual) with an emasculation method in two P. bifolia populations. Geitonogamy did not vary with inflorescence size. Levels of geitonogamy was 20-40% in the smaller, but non-significant in the larger population. This may relate to lower number of possible mates and pollinator activity in the smaller population. Platanthera bifolia exhibits the ancestral character state of tongue-attachment of pollinia on the pollinator. Its close relative P. chlorantha attaches its pollinia onto the pollinator's eyes. To explore the mechanism of a floral shift, pollination efficiency and speed was compared between the two species. The results showed no differences in pollination efficiency, but P. chlorantha had faster pollen export and import. Efficiency of pollination in terms of speed may cause floral shifts, and thus speciation.
238

The effects of gypsy moth defoliation and climatic conditions on radial growth of deciduous trees /

Naidoo, Robin. January 1997 (has links)
I investigated the effect of defoliation by the gypsy moth, Lymantria dispar L. (Lepidoptera: Lymantriidae) on the radial growth of tree species that differ in their acceptability as hosts for gypsy moth larvae. Annual growth rings were measured from 1950 to 1992 on increment cores taken from three species: red oak (Quercus rubra L.), a preferred species, sugar maple (Acer saccharum Marsh.), an acceptable species, and white ash (Fraxinus americana L.), an avoided species. The number of gypsy moth larvae on these same individual trees had already been recorded from 1979 to 1992. To remove the potentially-confounding effects of climate on radial growth, I developed regression models of growth on climate in a pre-gypsy moth period (1950 to 1975), and then used these models to predict growth in a post-gypsy moth period (1978 to 1992). The residuals from these growth models were then examined with respect to gypsy moth numbers. (Abstract shortened by UMI.)
239

Development and evaluation of automated radar systems for monitoring and characterising echoes from insect targets

Dean, Timothy J., Physical, Environmental & Mathematical Sciences, Australian Defence Force Academy, UNSW January 2007 (has links)
This thesis describes the construction of a mobile Insect Monitoring Radars (IMR) and investigations of: the reliability of IMRs for observing insect migration in inland Australia; possible biases in IMR migration estimates; the relation between an insect???s size and its radar properties; radar discrimination between insect species; the effect of weather on the migrations of Australian plague locusts and of moths; the scale of these migrations; and here IMRs are best located. The principles of entomological radar design, and the main features of insect migration in inland Australia, are reviewed. The main procedures used in the study are: calculation of radar performance and of insect radar cross sections (RCSs); reanalysis of a laboratory RCS dataset; statistical analysis of a fouryear dataset of IMR and weather observations; and a field campaign using both two existing fixed IMRs and the new mobile unit. Statistical techniques used include correlation, multiple regression, discriminant analysis, and principal components analysis. The original results of this work include design details of the mobile IMR, extension of radar performance calculations to IMRs and evaluation of flight speed biases, a holistic approach to IMR design, the relation of insect RCS magnitudes and polarization patterns to morphological variables, an estimate of the accuracy of the retrieved parameters, evaluations of three approaches (oneparameter, theory-based, and a novel two-stage method) to target identification, and verification of inferred target identities using results from nearby light traps. Possible sites for future IMRs are identified. The major conclusions are that: a mobile IMR can be built with a performance equal to that of a fixed IMR but at half the cost; significant biases in the signal processing results arise from insect speed; locusts and moths can be distinguished if all RCS parameters are used; IMRs can be designed to match particular requirements; weather has a significant effect on insect migration, the best single predictor of insect numbers being temperature; moonlight has no effect; the spatial correlation of migration properties falls to 50% at a separation of 300 km; and migrating insects can be carried by the wind for 500 km in a single night
240

Vliv působení trávicího procesu zavíječe voskového (Galleria mellonella) na spory původce moru včelího plodu (Paenibacillus larvae).

MRÁZ, Petr January 2017 (has links)
This diploma thesis deals with a serious honey bee (Apis mellifera) disease, the American foulbrood (AFB), and with possibilities of its control. The thesis is divided into two parts, the theoretical and the experimental. The theoretical part is written as a research and contains two big chapters. The first one describes American foulbrood disease and its causative agent, bacteria Paenibacillus larvae. The second part deals with the wax moth (Galleria mellonella). The experimental part then combines above mentioned themes in an effort to find the relationship between the wax moth caterpillars and bacteria P. larvae that could possibly help to control the AFB. The aim of this work was to determine whether the wax moth can disrupt resistant layers of P. larvae spores thanks to its well adapted digestive tract and whether it could change their germination.

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