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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.
81

Zoneamento ecológico de Anastrepha fraterculus e Ceratitis capitata (Diptera: Tephritidae) em dois cenários climáticos no Brasil / Ecological zoning for Anastrepha fraterculus and Ceratitis capitata (Diptera, Tephritidae) in two climatic scenarios in Brazil

Wyratan da Silva Santos 28 February 2008 (has links)
O zoneamento ecológico exploratório de Anastrepha fraterculus e de Ceratitis capitata foi baseado nos dados climáticos de 497 estações meteorológicas de todo o Brasil para o clima recente (1961 - 1990) e nos dados climáticos previstos pelo IPCC para o clima futuro (2080 no cenário A2). Com esses dados, foram confeccionados evapluviogramas para calcular o índice de desenvolvimento das duas espécies, com base em suas necessidades térmicas e de umidade de solo. Os índices de desenvolvimento foram espacializados pelo sistema de informações geográficas SPRING 4.1.1 e divididos em cinco classes. As localidades mais propícias ao desenvolvimento de A. fraterculus, no clima recente, localizam-se nas regiões Sudeste e Sul. Essas regiões apresentam temperaturas médias mensais dentro da faixa mesotérmica de desenvolvimento da espécie e período curto de estiagem. Por outro lado, as localidades com condições menos favoráveis estão no semi-árido da região Nordeste, onde as temperaturas ficam sempre acima da temperatura-limite de desenvolvimento da mosca-das-frutas sul-americana e as condições hídricas são inadequadas ao desenvolvimento da fase de pupa. Com o aumento da temperatura, devido ao aquecimento global previsto para 2080 (cenário A2), as regiões Norte, Nordeste e Centro-Oeste serão completamente desfavoráveis ao desenvolvimento de A. fraterculus. Na região Sul e parte da Sudeste, a temperatura ficará dentro da faixa mesotérmica de desenvolvimento de A. fraterculus, mesmo com o aumento da temperatura, mas em alguns meses, excederá a temperatura-limite superior de desenvolvimento. No entanto, as condições hídricas serão desfavoráveis em grande parte do ano. No cenário do clima recente, as regiões Norte e Nordeste, com as temperaturas elevadas, são desfavoráveis ao desenvolvimento de C. capitata durante o ano todo. No Nordeste, também as condições hídricas só são favoráveis em curto período do ano. Na região Centro-Oeste, de março a agosto, parte do Mato Grosso do Sul e de Goiás são desfavoráveis ao desenvolvimento de C. capitata, em razão da precipitação pluvial baixa. Na região Sudeste, o período de setembro a março é favorável ao desenvolvimento, em razão da temperatura e condição hídrica adequadas. Na região Sul, apenas em maio e junho, quando ocorrem as menores temperaturas, o período é desfavorável ao desenvolvimento de C. capitata. Na previsão para 2080, devido principalmente ao aumento da temperatura causado pelo aquecimento global, apenas nos estados de Santa Catarina e do Rio Grande do Sul, haverá condições climáticas apropriadas ao desenvolvimento da mosca-do-mediterrâneo. Portanto, as mudanças climáticas previstas serão menos favoráveis ao desenvolvimento de C. capitata (espécie exótica) do de A. fraterculus (espécie nativa). / Exploratory ecological zoning for the South American fruit fly, Anastrepha fraterculus, and the medfly, Ceratitis capitata, were established based on data of 497 meteorological stations throughout Brazil, considering recent (1961 - 1990) and future climate forecast by IPPC (2080, A2 scenario). Climograms were used to estimate the South American fruit fly and medfly development indexes (Id) based on their thermal and soil moisture requirements. The development index was divided into five classes and spacialized by using the SPRING 4.1.1 geographical information system. Based on development index the Southwest and South regions were the most suitable for Anastrepha fraterculus in the recent climate. These regions have average monthly temperatures within the mesothermic range of A. fraterculus development and a short period of drought, while the unfavorable localities were situated in the semi-arid of the Northwest region, where temperatures are always above the threshold temperature of development and soil moisture are unsuitable for the pupa stage. For the increase of temperature due to global warming foreseen for 2080 (scenario A2), the North, Northwest and Center-West regions will become entirely unsuitable for the South American fruit fly development. Temperatures within the mesothermic range of development will still be available in part of Southwest region and in the South region, even with the increase of the temperature. However, the hydric conditions will be unfavorable for most of the year, and the upper temperature threshold will be exceeded in warmer months. For Ceratitis capitata, the recent climate of the North and Northwest regions were unsuitable for its development due to the high temperatures year-round. In the Northwest region, the hydric conditions will be favourable for a short period of the year. The low rainfall from March to August will make part of the state of Mato Grosso do Sul and Goiás unfavorable for medfly development in the Center-West region. In the Southwest region, temperature and hydric conditions from September to March are inadequate for medfly development. In the South region, conditions will be unfavorable to medfly development only during the months of May and June, when low temperatures occur. In the prediction for 2080, due to the temperature increase, only Santa Catarina and Rio Grande do Sul states will have adequate climatic conditions to allow for C. capitata development. Therefore, the foreseen climate changes will be more unfavorable for the development of C. capitata (exotic species) than A. fraterculus (native species).
82

La technique des insectes stériles comme méthode de lutte contre la drosophile à ailes tachetées (Drosophila suzukii)

Lanouette, Geneviève 07 1900 (has links)
Cette recherche a été réalisée grâce à l'aide financière du Programme Innov'action agroalimentaire de l'entente Cultivons l'Avenir 2 conclue entre le Ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec (MAPAQ) et Agriculture et Agri-Food Canada. / La drosophile à ailes tachetées s’avère être un ravageur exotique particulièrement dommageable pour les cultures de petits fruits puisqu’elle s’attaque aux fruits en murissement. Depuis son invasion des continents américain et européen en 2008, ses populations sont contrôlées majoritairement avec des insecticides chimiques. L’objectif de cette étude était d’explorer le potentiel de la technique des insectes stériles (TIS) comme approche de lutte à la drosophile à ailes tachetées, d’abord en irradiant des pupes à différentes doses pour identifier la dose optimale pour la stérilisation des mâles et, par la suite, en évaluant les capacités reproductives de ces mâles irradiés. En premier lieu, il a été observé que l’irradiation n’avait pas d’effet significatif sur l’émergence, la malformation et la longévité des adultes à chacune des doses testées. Suite à l’accouplement de mâles irradiés avec des femelles saines, deux équations ont été obtenues permettant d’établir une relation entre la dose d’irradiation et un taux d’éclosion des œufs et leur survie jusqu’au stade adulte. Ces résultats ont permis de choisir la dose de 120 Gy comme dose d’irradiation pour la drosophile à ailes tachetées dans un contexte de TIS. Les capacités reproductives des mâles irradiés à cette dose ont ensuite été comparées à celles des mâles non-irradiés. Les mâles irradiés se sont révélés significativement aussi efficaces que les mâles non-irradiés pour accoupler et transmettre du sperme aux femelles en absence de compétition. En conditions de compétition, le succès d’accouplement par le mâle irradié a été de 37,5% et de 62,5% par le mâle non-irradié, mais sans différence significative. Puis, une expérience sur le ré-accouplement des femelles a conclu que celui-ci était peu fréquent et n’était pas influencé significativement par l’irradiation des mâles. / Spotted wing drosophila is an exotic pest especially damaging to berry crops because of its ability to lay eggs inside ripening fruits. Since its invasion of North America and Europe in 2008, its populations are controlled mainly with chemical insecticides. The objective of this study was to explore the potential of the sterile insect technique (SIT) as a control method for the spotted wing drosophila, first by irradiating pupae at different doses to identify the optimum dose for male sterilization, and secondly by evaluating the reproductive capacities of these irradiated males. First, it was observed that irradiation had no significant effect on emergence, malformation and longevity of adults at any of the doses tested. Following mating of irradiated males with healthy females, two equations were obtained to establish a relation between the irradiation dose and the egg hatch rate, and the survival rate to the adult stage. These results made it possible to choose the dose of 120 Gy as the irradiation dose for the spotted wing drosophila in an SIT context. The reproductive capacities of males irradiated at this dose were later compared with those of non-irradiated males. Irradiated males were shown to be significantly as effective as non-irradiated males to mate and transfer sperm to females in absence of competition. In competitive conditions however, the success of irradiated males was of 37.5% and of 62.5% for the non-irradiated males, but without significant difference. Then, an experiment on the re-mating of the females concluded that it was infrequent and was not significantly influenced by the irradiation of the males.
83

Fitnesskomponenter hos honor av Drosophila melanogaster : Med alternativa alleler av en potentiell sexuellt antagonistisk gen / Fitness components in female Drosophila melanogaster : With alternativ alleles of a potentially sexually antagonistic gene

Högström, Maja January 2023 (has links)
Anisogami och sexuella konflikter kan vara grunden till flera fall av könslig dimorfism. Intralokus sexuell konflikt uppstår när alleler vid ett genetiskt lokus har en antagonistisk effekt på fitness hos hanar och honor. Helgenomstudier har pekat ut flera sexuellt antagonistiska kandidatgener hos Drosophila melanogaster. En av dem, CG15170, har återskapats med hjälp av genediteringstekniken CRISPR/Cas9. Den här genen är intressant då populationer med en viss allel, A1, inte förlorar balanser kromosomen, förmodligen på grund av negativ fitnesspåverkan från den återskapade allelen A1. I den här studien undersöktes om fertiliteten hos honor och ägg-till-vuxen överlevnaden är negativt påverkad. Detta gjordes genom att antalet lagda ägg och proportionen av lagda ägg som utvecklades till vuxna individer hos honor av D. melanogaster homozygota för A1 eller A2 alleler mättes. Resultatet från de statistiska tester som utfördes visade ingen signifikant skillnad mellan honor med A1 och A2 alleler varken för antalet lagda ägg eller proportionen av ägg som utvecklades till vuxna. Däremot upptäcktes en signifikant skillnad mellan de två allelerna i antalet vuxna honor som överlevde parningen i den första delen av försöket. Denna studie kan inte påvisa att fekunditeten hos honorna och den tidiga överlevnadsgraden hos deras avkommor skulle vara olika för honor med A1 respektive A2 alleler. Det bör i stället vara någon annan del av livscykeln som påverkas av att A1 inte förlorar balanser kromosomen men vilken kan ej fastställas utifrån den här studien. / Anisogamy and sexual conflict may be the basis of several cases of sexual dimorphism. Intralocus sexual conflict occurs when alleles at a genetic locus have an antagonistic effect on the fitness of males and females. Genome wide association studies have pointed out several candidate genes for sexual antagonism in Drosophila melanogaster. One of them, CG15170, has been recreated with the gene editing technique CRISPR/Cas9. This gene is interesting because populations with one particular allele, A1, do not lose the balancer chromosome, probably because of negative effects off the allele on fitness. In this study, the fertility and egg-to-adult survival of eggs laid by females was investigated to see if these traits were adversely affected by the recreated allele A1.  This was done by measuring the number of eggs laid by females of D. melanogaster, homozygous for A1 or A2 alleles, and also by measuring the proportion of eggs that developed to adults. The results of the statistical tests that were performed showed no significant difference between females with A1 and A2 alleles, not for the number of eggs laid nor the proportion of eggs that developed into adults. However, a significant difference was detected between the two alleles in the number of adult females that survived the first courtship and mating part of the experiment. Probably some other part of the life cycle is affected by A1 not losing the balancer chromosome, but which cannot be determined by this study.
84

Why is Nature Able to Mold Some Phenotypes More Readily than Others? Investigating the Structure, Function and Evolution of ßeta-2 Tubulin in Drosophila Melanogaster

Golconda, Sarah Rajini 31 May 2018 (has links)
No description available.
85

Eficiência de dietas larvais para produção massal de Ceratitis capitata e Anastrepha fraterculus (Diptera: Tephritidae) / Efficiency of larval diets for mass rearing of Ceratitis capitata and Anastrepha fraterculus (Diptera: Tephritidae)

Maset, Bruno Aguiar 22 February 2019 (has links)
Várias espécies de moscas-das-frutas têm sido alvo de investigações visando sua criação massal, incluindo Ceratitis capitata (Wiedemann) (mosca-do-Mediterrâneo ou medfly) e, mais recentemente, Anastrepha fraterculus (Wiedemann) (mosca-das-frutas sul americana), sendo as espécies de maior importância econômica e quarentenária em várias áreas produtoras de frutas do Brasil, Uruguai, Argentina e Peru. Um dos fatores determinantes para que a Técnica do Inseto Estéril (TIE) seja aplicada contra uma determinada praga é a existência de métodos de criação massal da espécie. Para se alcançar a criação em larga escala dessas espécies de moscas-das-frutas, é necessário, inicialmente, o preparo de uma dieta larval adequada. Como a dieta de criação pode oferecer uma quantidade enorme de substâncias nutritivas, as larvas criadas artificialmente amadurecem mais cedo do que as selvagens, o que acelera a sucessão de gerações. Essas mudanças detectadas durante o estágio larval podem formar adultos com maiores reservas nutritivas, atingindo a maturidade sexual mais cedo. Existem várias biofábricas de mosca-das-frutas no mundo capazes de produzir machos estéreis que são utilizados para a erradicação ou supressão populacional em área-ampla. Visando-se diminuir os custos de produção dos insetos, pesquisas voltadas para a otimização e desenvolvimento de novas dietas não podem parar. Portanto, os objetivos deste trabalho foram determinar a adequação e densidade larval ideal das moscas C. capitata e A. fraterculus em novas dietas à base de farinha de milho (FM), bagaço de cana-de-açúcar (BC), pó de cenoura liofilizada (PC) e carragenina (MC), escolhendo a dieta mais eficiente e viável economicamente para produção de cada uma dessas espécies com base na quantidade e qualidade de insetos produzidos e no custo de produção. As densidades larvais ideais para a criação de C. capitata nas dietas larvais FM, BC e PC foram, respectivamente, 0,5; 2,0; e 1,0 mL de ovos/kg de dieta. A dieta larval com maior produtividade foi a dieta BC, produzindo uma média de 6.514 pupas/kg de dieta, seguida das dietas FM e PC, que produziram, respectivamente, uma média de 5.018 e 4.135 pupas por kg de dieta. A ordem decrescente de viabilidade econômica entre as três dietas larvais para C. capitata foi a mesma (BC>FM>PC), sendo necessário um investimento médio de R$ 471,29; R$ 482,26; e R$ 1.085,85, respectivamente, para a produção de 1 milhão de pupas. Os resultados com A. fraterculus mostraram que as densidades larvais ideais nas dietas FM e MC foram de 2,0/kg de dieta e 1,5 mL de ovos/L de dieta, respectivamente. A dieta larval PC foi considerada inviável devido à baixa produtividade e peso de pupas. Em termos de produtividade, a dieta larval MC (produção média de 22.451 pupas/L de dieta), foi mais eficiente do que a FM (6.688 pupas/kg de dieta). Quanto à viabilidade econômica, a dieta larval MC foi mais vantajosa, demandando um investimento médio de R$ 312,67 para a produção de 1 milhão de pupas, enquanto que a dieta FM custou R$ 1.266,36 para produzir a mesma quantidade de pupas / Several species of fruit flies have been the subject of research for their mass rearing, including Ceratitis capitata (Wiedemann) (Mediterranean fruit fly or medfly) and, more recently, Anastrepha fraterculus (Wiedemann) (South American fruit fly), being these species the ones with most economic and quarantine importance in several fruit producing areas of Brazil, Uruguay, Argentina and Peru. One of the requirements for the Sterile Insect Technique (SIT) is the existence of mass rearing methods of the target species. In order to achieve the large-scale rearing of these species of fruit flies, it is necessary initially to develop a suitable larval diet. As the rearing diet can offer a huge amount of nutrients, artificially reared larvae mature earlier than wild ones, what accelerates the succession of generations. These changes during the larval stage may form adults with higher nutritional reserves and they can reach sexual maturity earlier. There are several mass-rearing facilities for fruit flies in the world capable of producing sterile males that are used for population eradication and suppression in area-wide. In order to reduce insect production costs, the optimization or development of new diets cannot stop. Therefore, the objectives of this study were to determine the adequacy and optimal larval density of C. capitata and A. fraterculus flies in new diets based on corn flour (FM), sugarcane bagasse (BC), lyophilized carrot powder (PC) and carrageenan (MC), choosing the most efficient and less costly diet for the production of each of the species, based on the quantity and quality of insects reared and production costs. The optimal larval densities for C. capitata in larval diets FM, BC and PC were, respectively, 0.5; 2.0 and 1.0 mL of eggs/kg of diet. The larval diet that reached the highest productivity was the BC diet, giving an average of 6,514 pupae/ kg of diet, followed by FM and PC diets, which produced an average of 5,018 and 4,115 pupae per kg of diet, respectively. The decreasing order of economic viability among the three larval diets used was the same (BC>FM>PC), requiring a mean investment of R$ 471.29; R$ 482.26; and R$ 1,085.85, respectively, for the production of 1 million pupae. The results with A. fraterculus showed that the ideal larval densities in FM and MC diets were 2.0 eggs/kg of diet and 1.5 mL of eggs/L of diet, respectively. The PC larval diet was considered infeasible based on the low production and weight of pupae. In terms of productivity, the MC larval diet, which resulted in an average of 22,451 pupae produced per L of diet, was more efficient than FM, which produced a mean of 6,688 pupae per kg of diet. Considering the economic costs, the MC larval diet was also superior, requiring R$ 312,67.00 for the production of 1 million pupae, while the FM diet required R$ 1,266.36 to produce the same amount of pupae
86

Turning flies into nurse bees: Developing a Drosophila-based ectopic expression system to functionally-characterize the honey bee Major Royal Jelly Proteins

Stephanie Renee Hathaway (13164312) 28 July 2022 (has links)
<p>Across the tree of life, novel genes are thought to be a source of much of the unique behaviors and adaptions between the different taxa. This is especially true in the social insects where novel genes are proposed to contribute to novel social behaviors. In the honey bee (Apis mellifera L.), a group of novel genes called the major royal jelly proteins (MRJPs) are proposed to be important to the expression of novel social behaviors, particularly those related to nursing versus foraging tasks. Unfortunately, identifying the functional role of novel genes is often not possible due to a lack of functional genomic tools in non-model species such as the honey bee. Here I have developed a novel ectopic expression system in Drosophila melanogaster and used it to elucidate how the MRJPs contribute to behavioral and transcriptional changes in the insect brain. I found that the MRJPs regulated the expression of hundreds of genes in Drosophila, and these overlap with genes regulated differentially between nursing and foraging honey bees. Furthermore, I found that MRJP expression impairs or negatively regulated phototaxis. My results demonstrate the MRJPs play a role in behavioral plasticity and highlight that the MRJPs may have a much larger role in the nurse-forager transition than previously thought.</p>

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