Thesis (Ph.D.)--York University, 2006. Graduate Programme in Mathematics and Statistics. / Typescript. Includes bibliographical references (leaves 126-132). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR19847

Made available in DSpace on 2015-03-03T11:52:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-28Bitstream added on 2015-03-03T12:06:09Z : No. of bitstreams: 1 000810574_20160728.pdf: 555774 bytes, checksum: a1eafb543fd960c6eb728f54e4d8d4fa (MD5) Bitstreams deleted on 2016-07-29T12:53:57Z: 000810574_20160728.pdf,. Added 1 bitstream(s) on 2016-07-29T12:54:50Z : No. of bitstreams: 1 000810574.pdf: 619509 bytes, checksum: 02da17d2039311135a8a7eb0b12e2091 (MD5) / A dengue, doença infecciosa aguda, causada por um vírus da família Flaviviridae e transmitida aos humanos pela picada dos mosquitos do gênero Aedes, é considerada um dos principais problemas de saúde pública no mundo. O Aedes aegypti é o único vetor conhecido nas Américas e no Brasil está presente nos 26 estados e no distrito federal. A indisponibilidade de uma vacina que imunize a população contra os quatro sorotipos da dengue restringe a prevenção da doença ao controle do vetor. Isto é feito por aplicações de inseticidas químicos, porém o uso frequente em altas doses tem selecionado populações resistentes do mosquito. Diante dessa situação há necessidade de se buscar produtos alternativos que tenham efeito nestas populações. Diversos estudos demonstraram que os óleos essenciais de Syzygium aromaticum e Citrus sinensis apresentam pronunciada atividade larvicida, assim, este trabalho teve por objetivo avaliar o potencial destes produtos como alternativa de controle larvicida para populações de A. aegypti resistentes ao organofosforado temephos e verificar o efeito da associação deste inseticida aos óleos essenciais sobre a atividade larvicida. Avaliou-se também, a influência dos óleos essenciais na oviposição do vetor quando presentes nos sítios de postura. A comparação da atividade larvicida nas populações resistentes e suscetíveis foi realizada por meio das concentrações letais obtidas em ensaios de dose-resposta, seguindo metodologia proposta pela Organização Mundial da Saúde. Para avaliar o efeito da associação dos óleos essenciais ao temephos comparou-se a atividade larvicida das associações com a do temephos e o efeito no comportamento de oviposição foi avaliado pela comparação do número de ovos colocados nos sítios de postura, contendo soluções dos óleos essenciais em relação aos contendo somente água. Os resultados revelaram que os óleos essenciais exerceram atividade ... / Dengue fever an acute infectious disease caused by Flaviviridae family virus, transmitted to humans by the mosquitoes bite of Aedes genus. It is considered one of the most public health problems in the world. The Aedes aegypti is the only known vector in the Americas and in Brazil is present in 26 states and the federal district. The unavailability of a vaccine to immunize people against the four dengue serotypes restricted the disease prevention to the vector control. The control is done by chemical insecticides application, but the frequent use in high doses, have selected resistant mosquito populations. In front of this situation, it is necessary to seek for alternative products that have effect on these populations. Several studies demonstrated that Syzygium aromaticum and Citrus sinensis essential oils have larvicidal activity, so the aim of this study was to evaluate the potential of the essencial oils as an alternative to control A. aegypti larvae resistant to the organophosphate temephos and analyze the effect of this insecticide and essencial oils association on the larvicidal activity. It was evaluated too the influence of essencial oils on vector oviposition, when present on the posture sites. The larvicidal activity was assessed by dose-response tests, according to the methodology proposed by the World Health Organization. To evaluate the effect of essential oils associatiate with temephos, the larvicidal associations activity was compared with the temephos. The effect on oviposition behavior was evaluated comparing the number of eggs in laying sites containing essential oils in relation to the number of eggs in laying sites containing only water. The results demonstrated that essential oils had larvicidal activity in resistant and susceptible to temephos populations, being an alternative to resistance management. The association of temephos and essential oils had an antagonist ...

Orientador: João Tadeu Ribeiro Paes / Banca: Maria de Lourdes da Graça Macoris / Banca: Francisco Anaruma Filho / Resumo: A dengue, doença infecciosa aguda, causada por um vírus da família Flaviviridae e transmitida aos humanos pela picada dos mosquitos do gênero Aedes, é considerada um dos principais problemas de saúde pública no mundo. O Aedes aegypti é o único vetor conhecido nas Américas e no Brasil está presente nos 26 estados e no distrito federal. A indisponibilidade de uma vacina que imunize a população contra os quatro sorotipos da dengue restringe a prevenção da doença ao controle do vetor. Isto é feito por aplicações de inseticidas químicos, porém o uso frequente em altas doses tem selecionado populações resistentes do mosquito. Diante dessa situação há necessidade de se buscar produtos alternativos que tenham efeito nestas populações. Diversos estudos demonstraram que os óleos essenciais de Syzygium aromaticum e Citrus sinensis apresentam pronunciada atividade larvicida, assim, este trabalho teve por objetivo avaliar o potencial destes produtos como alternativa de controle larvicida para populações de A. aegypti resistentes ao organofosforado temephos e verificar o efeito da associação deste inseticida aos óleos essenciais sobre a atividade larvicida. Avaliou-se também, a influência dos óleos essenciais na oviposição do vetor quando presentes nos sítios de postura. A comparação da atividade larvicida nas populações resistentes e suscetíveis foi realizada por meio das concentrações letais obtidas em ensaios de dose-resposta, seguindo metodologia proposta pela Organização Mundial da Saúde. Para avaliar o efeito da associação dos óleos essenciais ao temephos comparou-se a atividade larvicida das associações com a do temephos e o efeito no comportamento de oviposição foi avaliado pela comparação do número de ovos colocados nos sítios de postura, contendo soluções dos óleos essenciais em relação aos contendo somente água. Os resultados revelaram que os óleos essenciais exerceram atividade ... / Abstract: Dengue fever an acute infectious disease caused by Flaviviridae family virus, transmitted to humans by the mosquitoes bite of Aedes genus. It is considered one of the most public health problems in the world. The Aedes aegypti is the only known vector in the Americas and in Brazil is present in 26 states and the federal district. The unavailability of a vaccine to immunize people against the four dengue serotypes restricted the disease prevention to the vector control. The control is done by chemical insecticides application, but the frequent use in high doses, have selected resistant mosquito populations. In front of this situation, it is necessary to seek for alternative products that have effect on these populations. Several studies demonstrated that Syzygium aromaticum and Citrus sinensis essential oils have larvicidal activity, so the aim of this study was to evaluate the potential of the essencial oils as an alternative to control A. aegypti larvae resistant to the organophosphate temephos and analyze the effect of this insecticide and essencial oils association on the larvicidal activity. It was evaluated too the influence of essencial oils on vector oviposition, when present on the posture sites. The larvicidal activity was assessed by dose-response tests, according to the methodology proposed by the World Health Organization. To evaluate the effect of essential oils associatiate with temephos, the larvicidal associations activity was compared with the temephos. The effect on oviposition behavior was evaluated comparing the number of eggs in laying sites containing essential oils in relation to the number of eggs in laying sites containing only water. The results demonstrated that essential oils had larvicidal activity in resistant and susceptible to temephos populations, being an alternative to resistance management. The association of temephos and essential oils had an antagonist ... / Mestre

Mosquitoes are the deadliest animal on the planet killing about a million people a year. These insects are competent vectors of multiple pathogens (e.g., Plasmodium sp, filarial worms, and arboviruses). In most species, females are blood feeders, and must consume a blood meal to complete a gonotrophic cycle. Extensive research has been conducted on hematophagy and host-seeking behaviors, but relatively little is known about phytophagy. Sugar feeding is an essential aspect of mosquito biology. Both male and female mosquitoes must consume sugar as a primary fuel source. Mosquitoes use olfactory and visual cues among other cues to find suitable food sources. Abiotic factors, such as temperature and humidity, have been shown to impact mosquito behaviors, including sugar feeding. Recently, sugar feeding has been identified as a promising control target for multiple species of mosquitoes. Attractive toxic sugar baits (ATSBs) attract both male and females through the use of plant derived volatiles. In this work, we first examined the effects of temperature and humidity on the survival of sugar fed Aedes aegypti. We showed that sugar feeding greatly increases longevity in optimal conditions and that humidity impacted survival while temperature less so. Second, we aimed at developing an ATSB for controlling Aedes j. japonicus mosquitoes. Overall, this work sheds light on the importance of abiotic factors and sugar feeding on mosquito survival and lays the groundwork for controlling an invasive mosquito species. / Master of Science in Life Sciences / Mosquitoes are the deadliest organisms on the planet killing about a million people each year due to the multitude of pathogens they may transmit (e.g., malaria parasites, Zika virus, dengue virus). Female mosquitoes transmit pathogens by taking blood meals to obtain essential nutrients needed to develop eggs. If knowledge on host-seeking behavior and blood-feeding is extensive, comparatively less is known about sugar feeding. Sugar feeding is an important behavior displayed by both male and female mosquitoes to obtain energy for flying, reproduction, and survival. Mosquitoes feed on a variety of sugar sources including plant nectar and decaying fruits. They use multiple different cues in order to locate suitable meals including olfaction and vision. Environmental factors such as temperature and humidity affect mosquito activity, dehydration, and sugar feeding. In the present work, we first examined the effects of temperature and humidity on survival in the major disease vector species, Aedes aegypti. As the global temperatures are increasing, it is essential to better understand how mosquitoes adapt and deal with environmental stressors in a changing world. We then aimed at exploiting sugar feeding behavior by developing a novel method of control for another invasive mosquito species, Aedes j. japonicus. Together, these results help us have a better understanding of mosquito biology and ecology which is crucial for predicting future distribution of invasive species and designing new control strategies.