• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 37
  • 14
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 58
  • 58
  • 38
  • 38
  • 17
  • 16
  • 14
  • 12
  • 10
  • 10
  • 10
  • 8
  • 8
  • 7
  • 6
  • 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.
1

Transposable genetic elements in the mosquito Aedes aegypti

Warren, Ann January 1989 (has links)
No description available.
2

Aspectos morfológicos de ovos do gênero Rhodnius stal, 1859 (Heteroptera, Reduviidae) e sua importância na identificação específica / Morphological aspects of genre Rhodnius stal, 1859 (Heteroptera, Reduviidae) eggs and their importance in identification

Barata, Jose Maria Soares 11 May 1979 (has links)
O presente trabalho consta do estudo da escultura exocorial de ovos de dez espécies do gênero Rhodnius (Heteroptera-Reduviidae) através de microscopia eletrônica de varredura e microscopia ótica, com vistas à classificação taxionômica. Concomitantemente são apresentados dados sobre os aspectos gerais das cascas e dos ovos, quanto à forma, mensuração e coloração, bem como as modificações que poderão ocorrer quanto à forma e coloração desses ovos durante o desenvolvimento embrionário pós-oviposição. Utilizando as características citadas são elaboradas chaves dicotômicas para a classificação destas espécies, baseadas na utilização de caracteres visíveis pela microscopia ótica e microscopia eletrônica de varredura. / Morphological studies about exochorial patterns of Rhodnius (Heteroptera - Reduviidae) genus were made. Ten species were studied by scanning and common microscopy, and data were described mainly for systematic purposes. General aspects of eggs and shells such as shape, color patterns, and size measurements are also presented. Data about changes of shape and coloration ocurred during egg maturation were recorded and associated to the embryonic development. The characters described were utilized to work out identification keys for these Triatominae eggs, both by optical and scanning electron microscopy.
3

Aspectos morfológicos de ovos do gênero Rhodnius stal, 1859 (Heteroptera, Reduviidae) e sua importância na identificação específica / Morphological aspects of genre Rhodnius stal, 1859 (Heteroptera, Reduviidae) eggs and their importance in identification

Jose Maria Soares Barata 11 May 1979 (has links)
O presente trabalho consta do estudo da escultura exocorial de ovos de dez espécies do gênero Rhodnius (Heteroptera-Reduviidae) através de microscopia eletrônica de varredura e microscopia ótica, com vistas à classificação taxionômica. Concomitantemente são apresentados dados sobre os aspectos gerais das cascas e dos ovos, quanto à forma, mensuração e coloração, bem como as modificações que poderão ocorrer quanto à forma e coloração desses ovos durante o desenvolvimento embrionário pós-oviposição. Utilizando as características citadas são elaboradas chaves dicotômicas para a classificação destas espécies, baseadas na utilização de caracteres visíveis pela microscopia ótica e microscopia eletrônica de varredura. / Morphological studies about exochorial patterns of Rhodnius (Heteroptera - Reduviidae) genus were made. Ten species were studied by scanning and common microscopy, and data were described mainly for systematic purposes. General aspects of eggs and shells such as shape, color patterns, and size measurements are also presented. Data about changes of shape and coloration ocurred during egg maturation were recorded and associated to the embryonic development. The characters described were utilized to work out identification keys for these Triatominae eggs, both by optical and scanning electron microscopy.
4

Identification of bacteria associated with malaria mosquitoes : their characterisation and potential use /

Lindh, Jenny, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Stockholm universitet, 2007. / Härtill 4 uppsatser.
5

Airplane spray as a measure of sanitary vigilance a thesis submitted in partial fulfillment ... Master of Public Health ... /

Soares, Ruy. January 1944 (has links)
Thesis (M.P.H.)--University of Michigan, 1944.
6

Airplane spray as a measure of sanitary vigilance a thesis submitted in partial fulfillment ... Master of Public Health ... /

Soares, Ruy. January 1944 (has links)
Thesis (M.P.H.)--University of Michigan, 1944.
7

Behaviour, ecology, and vibrational manipulation of insect vectors: the case of the meadow spittlebug Philaenus spumarius, with notes on a psyllid pest

Avosani, Sabina 13 October 2021 (has links)
Insects can cause economic and environmental damages by transmitting bacterial pathogens to plants, making the use of control and prevention measures imperative. On the other hand, methods aimed at preventing crop pests’ outbreaks, such as tilling and insecticide applications, pose a threat to human and ecosystems health. Innovative and more sustainable control methods are therefore urgently needed to address farmers’ needs and preserve ecosystem services provided by biodiversity. Biotremology is an emerging science that studies the substrate-borne vibrational signals emitted by insects to communicate and interact with their others in the environment. As many insect pests rely on these signals to communicate, their behaviour can be manipulated by transmitting vibrations to the substrate where they thrive. Vibrational signals can, for instance, interfere with target’s behaviours such as mating, feeding, and residence time on the plant, and can therefore support integrated pest management strategies alternative to insecticides. In this work, I investigated the mating behaviour and vibrational communication of two insect vectors having an important economic impact: Philaenus spumarius (Hemiptera: Aphrophoridae) and Bactericera cockerelli (Hemiptera: Triozidae). I also provided novel insights regarding the vibrational manipulation of their behaviour. I characterised the sexual behaviour and associated vibrational signals of the meadow spittlebug P. spumarius, and I described other intraspecific interactions. I evaluated the correlation between the female signalling activity and development of the reproductive organs, suggesting that a vibrational mating disruption could be effective only if applied from the onset of egg maturation, which triggers the female proceptivity (from August onwards). Besides gathering behavioural data, I used occupancy models to estimate P. spumarius presence and detection probability in Trentino (Northern Italy), a rarely deployed approach to study insect distribution. Site covariates impacted P. spumarius detectability, suggesting that spittlebug presence can be overlooked if detection is not considered. As plant composition influences the presence and abundance of the spittlebug, I studied the association between P. spumarius and its host plants. Such information can support monitoring programs and control strategies aimed at reducing P. spumarius population in crops of interest by shaping the plant composition of the ground cover. After investigating the behaviours and the ecology of the spittlebug, I attempted to disrupt its feeding activity using vibrations, opening the gates for future research. In this regard, I combined for the first time biotremology with the Electrical Penetration Graph (EPG) technique. The tomato potato psyllid B. cockerelli is an important threat to New Zealand crops. Besides the characterisation of the pair formation process and associated vibrational signals, I used vibrations to disrupt mate finding by transmitting vibrations to the host plant. Given that the stimulus attracted male psyllids at small scale, this strategy is a feasible approach that could be implemented for use in fields and greenhouses. In this way, an innovative trapping and mating disruption device could join the farmers’ toolbox for monitoring and controlling B. cockerelli. In conclusion, I provided new information regarding the ethology of two insect vectors and suggested that there is room for applied biotremology to support sustainable management strategies.
8

Identificação de isolados do Sida mottle virus e Sida micrantha mosaic virus não transmissíveis por Bemisia tabaci biótipo B que infectam maracujazeiros (Passiflora edulis f. flavicarpa) / Identification of Sida mottle virus and Sida micrantha mosaic virus isolates non transmissible by Bemisia tabaci biotype B infecting passionflower (Passiflora edulis f. flavicarpa)

Alves, Ana Carolina Christino de Negreiros 14 September 2012 (has links)
Doenças causadas por virus do gênero Begomovirus (família Geminiviridae) são incomuns em espécies de passifloras. Nos últimos dez anos, entretanto, foram encontrados no Brasil begomovirus infectando passifloras em pomares nos municipios de São Fidelis (RJ), Paragominas (PA), Patos de Minas (MG) e Araguari (MG). Estes isolados foram transmitidos mecanicamente para plantas de Nicotiana benthamiana, que apresentaram sintomas de mosaico e deformação foliar. Também foi possível a transmissão para plantas de Sida rhombifolia através de inoculação por biobalística com o DNA amplificado do isolado de São Fidelis. Estas plantas demonstraram sintomas de mosaico amarelo e deformação foliar. O DNA total extraído de plantas infectadas foi amplificado por RCA, sendo que o componente A (DNA-A) dos isolados de Paragominas e Patos de Minas foram sequenciados diretamente por \"primer walking\". O DNA-A dos isolados de São Fidelis e Araguari foram clonados e sequenciados. As sequências de nucleotideos dos isolados de Paragominas e de São Fidelis apresentaram 90% de similaridade ao Sida mottle virus (SiMoV), enquanto a sequência de nucleotídeos do isolado de Araguari apresentou 96% de similaridade ao Sida micrantha mosaic virus (SimMV). Assim esses isolados encontrados em maracujazeiro podem ser considerados estirpes do SiMoV e SimMV, respectivamente. Não foi possivel a transmissão desses isolados através de Bemisia tabaci biótipo B, no entanto, os insetos foram capazes de adquirir o vírus. O isolado de São Fidelis foi detectado separadamente na região onde se encontra a glandula salivar (cabeça e protórax) e na região posterior do inseto, indicando que o vírus transpos a barreira do mesenteron e circulou pela hemolinfa do inseto. Alves (2008) obteve uma forma atenuada do isolado de São Fidelis através de inoculações mecanicas em plantas de N. benthamiana. O DNA-A desta forma atenuada foi sequênciado e apresentou 90% de identidade ao isolado do qual se originou. A forma atenuada do begomovirus foi capaz de proteger plantas de maracujazeiro contra a estirpe severa do vírus. / Diseases caused by begomoviruses (family Geminiviridae) are hardly found in Passiflora species. In the last years, however, begomovirus infected passionflowers were found in orchards in the counties of São Fidelis (state of Rio de Janeiro), Paragominas (Pará), Araguari and Patos de Minas (Minas Gerais). These isolates were mechanically transmitted to Nicotiana benthamiana plants, which showed variable symptoms of mosaic and leaf distortion. Another susceptible host is Sida rhombifolia, which was biolistic inoculated with amplified DNA of São Fidelis isolate, and showed symptoms of yellow mosaic and leaf distortion. Total DNA extracted from field infected passiflora was amplified by RCA, and the DNA-A of Paragominas and Patos de Minas isolates were directly sequenced by primer walking. The A component of São Fidelis and Araguari isolates were cloned and also completely sequenced. The complete nucleotide sequence of DNA-A of Araguari isolate shared 96% identity with that of Sida micrantha mosaic virus (SimMV), whereas the DNA-A of Paragominas and São Fidelis isolates shared 90% identity with that of Sida mottle virus (SiMoV). These viruses may be consider as strains of SiMoV and SimMV, respectively. It was not possible to transmit these isolates by Bemisia tabaci biótipo B, although the insects were able to acquire the virus. São Fidelis isolate could be detected separately at salivary gland region and posterior region of the insect, indicating that the virus could cross the digestive tract and circulate in the hemolymph. Alves (2008) obtained a mild strain of São Fidelis isolate by mechanical inoculation in N. benthamiana plants. The mild isolate was able to protect passionflower against the severe isoalte of this begomovirus.
9

Enfezamento do brócolis: identificação molecular de fitoplasmas, potenciais insetos vetores e hospedeiros alternativos, e análise epidemiológica da doença / Broccolo stunt: identification of phytoplasmas, potential insect vectors and alternative hosts and epidemiology of the disease

Eckstein, Barbara 23 August 2010 (has links)
O brócolis (Brassica oleraceae var. italica) é uma das hortaliças mais importantes do país, cujo volume de comercialização na CEAGESP é de aproximadamente 13 mil toneladas por ano. Recentemente, uma nova doença tem causado perdas relevantes para as culturas instaladas na maior região produtora do Estado de São Paulo. Os sintomas característicos da doença são expressos pelo enfezamento da planta e necrose dos vasos de floema. Devido ao fato destes sintomas indicarem a presença de fitoplasmas nas culturas de repolho e couve-flor, localizadas na mesma região geográfica onde foi observada esta nova doença, levantou-se a suspeita de que estes mesmos agentes patogênicos pudessem estar associados com as plantas doentes de brócolis. Assim, o DNA total de plantas de brócolis sintomáticas foi analisado por PCR com primers específicos para a região 16S rDNA de fitoplasmas. Os resultados revelaram que estes patógenos estavam associados com as plantas doentes. Através das técnicas de RFLP do sequenciamento de nucleotídeos desta mesma região genômica, os fitoplasmas foram identificados como pertencentes aos grupos 16SrI, 16SrIII e 16SrXIII. Através de análise de RFLP, fitoplasmas também foram identificados em diversas espécies de plantas daninhas e em cigarrinhas da família Cicadellidae coletadas em áreas adjacentes a campos de produção de brócolis. Fitoplasmas do grupo 16SrIII foram identificados em plantas daninhas das espécies Agetarum conyzoides (mentrasto), Crotalaria lanceolata (crotalária), Lepidium virginicum (mentruz), Nicandra physalodes (juá-de-capote), Paulicourea marcgravii (erva-de-rato), Ricinus communis (mamona), Sida rhombifolia (guanxuma), Sonchus oleraceae (serralha amarela), Bidens pilosa (picão preto), Erigeron bonariensis (buva), Emilia sonchifolia (falsa serralha), Leonorus sibiricus (rubim), enquanto que fitoplasmas do grupo 16SrVII foram encontrados as últimas quatro espécies citadas. Com relação aos insetos, fitoplasmas foram detectados em indivíduos das subfamílias Deltocephalinae, Agalliinae e Typhlocybinae. Dentro da subfamília Deltocephalinae, a cigarrinha Balclutha hebe portava fitoplasma do grupo 16SrI, enquanto que cigarrinhas das espécies Atanus nitidus, Planicephalus flavicosta e Schapytopius fuliginosus abrigavam fitoplasmas do grupo 16SrIII. Nos tecidos de duas cigarrinhas da subfamília Agalliinae e uma da Typhlocybinae, as quais não foram identificadas quanto a espécie, foram encontrados fitoplasmas do grupo 16SrIII. As análises epidemiológicas revelaram um padrão espacial agregado de plantas doentes e a ocorrência de um maior progresso da doença nos bordos dos campos de cultivo de brócolis, que estão localizados nas proximidades de áreas com a presença de plantas daninhas. / Broccoli (Brassica oleraceae var. italica) is one of the most important vegetables in Brazil, whose trading volume in CEAGESP is approximately 13 000 tons per year. Recently, a new disease has caused significant losses in this crop cultivated in the largest producing region of the São Paulo State. The characteristic symptoms of the disease are expressed by plant stunting and necrosis of phloem vessels. Because these symptoms indicate the presence of phytoplasmas in cabbage and cauliflower crops, grown in the same geographical region, it was suspected that the same pathogens could be associated with the affected broccoli plants. Therefore, the total DNA from symptomatic plants of broccoli was analyzed by PCR with specific primers for the 16S rDNA of phytoplasmas. Through the techniques of RFLP and nucleotide sequencing of the same genomic region, the phytoplasmas were identified as belonging to the groups 16SrI, 16SrIII and 16SrXIII. Through RFLP analysis, phytoplasmas were also identified in several species of weeds and leafhoppers in the family Cicadellidae collected in adjacent areas of broccoli fields. Phytoplasmas belonging of the 16SrIII group were identified in the weeds belonging to the species Agetarum conyzoides, Crotalaria lanceolata, Lepidium virginicum, Nicandra physalodes, Paulicourea marcgravii, Ricinus communis, Sida rhombifolia, Sonchus oleraceae, Bidens pilosa, Erigeron bonariensis, Emilia sonchifolia, Leonorus sibiricus, while phytoplasmas of the 16SrVII group were found in the last four mentioned species. In respect to insects, phytoplasmas were detected in individuals from subfamilies Deltocephalinae, Agalliinae and Typhlocybinae. Within the subfamily Deltocephalinae, the leafhopper Balclutha hebe carried phytoplasmas of the 16SrI group, while that of the species Atanus nitidus, Planicephalus flavicosta e Schapytopius fuliginosus harbored phytoplasmas of the 16SrIII group. In the tissues of two leafhoppers of the subfamily Agalliinae and one of the Typhlocybinae, which were not identified as specie, were found phytoplasmas of the 16SrIII group. The epidemiological analysis revelead an aggregated pattern of the diseased plants and a higher progress of the diseased in the border of the broccoli fields, whitch were located nearby areas where the presence of weeds was abundant.
10

Bioecologia, competição e hematofagia de Aedes (Stegomyia) aegypti (Linnaeus, 1762) e Aedes (Stegomyia) albopictus (Skuse, 1894) (DIPTERA: CULICIDAE)

Noia, Noiana de Paula 16 December 2013 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-05-11T14:27:17Z No. of bitstreams: 1 PDF - Noiana de Paula Noia.pdf: 1156392 bytes, checksum: a6a9764178b9ec1cd59f8dadd9cb363e (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-07-22T13:24:22Z (GMT) No. of bitstreams: 1 PDF - Noiana de Paula Noia.pdf: 1156392 bytes, checksum: a6a9764178b9ec1cd59f8dadd9cb363e (MD5) / Made available in DSpace on 2016-07-22T13:24:22Z (GMT). No. of bitstreams: 1 PDF - Noiana de Paula Noia.pdf: 1156392 bytes, checksum: a6a9764178b9ec1cd59f8dadd9cb363e (MD5) Previous issue date: 2013-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Aedes genus is of great epidemiological importance, highlighting the Aedes aegypti Linnaeus, 1762 and Aedes albopictus Skuse, 1894, the main vectors of dengue, yellow fever and other arboviruses. How are spread across the planet, have become a public health risk factors. Aimed to evaluate the effects of temperature on competition and in the life cycle, and the source of blood meal in fecundity and longevity of females of A. aegypti and A. albopictus. The collections of eggs were performed using traps ovitraps type. The experiments were performed at the Laboratory of Entomology, University of Paraíba State - UEPB in Campina Grande, PB. Competition between A. aegypti and A. albopictus was examined at temperatures of 20, 24, 28, 32 and 36 ° C in the proportion of 10:0, 7:3, 5:5, 3:7 and 10:0 (A. aegypti : A. albopictus). The cycle life was examined at the same temperatures. Feeding two treatments with each meal in quail and the other in swiss mice were used. For all experiments we used 12h light and 70% humidity. In interspecific relationship, there was overlap of A. aegypti on A. albopictus from the first generation (F1), independent of temperature and the proportion of species. The long life cycle did not differ significantly among species independent of temperature, but decreased with increasing temperature. The base temperature (Tb) and thermal constant (K) and hence the number of generations was greater for A. albopictus than for A. aegypti. The repast in mice resulted in greater number of eggs and female longevity for both A. aegypti as for A. albopictus. The substrate used for biting that was more appropriate for the two species, the mouse was, since we obtained the highest female fertility and longevity. The temperature and the substrate used for blood feeding interfere with competition, development, longevity and fecundity of the species studied. The number of generations of insects in the laboratory is higher for A. albopictus than for A. aegypti. / O grande importância epidemiológica, destacando o Aedes aegypti Linnaeus, 1762 e Aedes albopictus Skuse, 1894, principais vetores da dengue, febre amarela e outras arboviroses. Como estão distribuídos por todo o planeta, se tornaram fatores de risco à saúde pública. Objetivou-se avaliar os efeitos da temperatura na competição e no ciclo de vida, e da fonte de repasto sanguíneo na fecundidade e longevidade de fêmeas de A. aegypti e A. albopictus. As coletas dos ovos foram realizadas utilizando armadilhas do tipo ovitraps. Os experimentos foram realizados no Laboratório de Entomologia da Universidade Estadual da Paraíba – UEPB, em Campina Grande, PB. A competição entre A. aegypti e A. albopictus foi analisada nas temperaturas de 20, 24, 28, 32 e 36ºC nas proporções de 10:0, 7:3, 5:5, 3:7 e 10:0 (A. aegypti: A. albopictus). O ciclo de vida foi analisado nas mesmas temperaturas. Para nutrição foram utilizados dois tratamentos um com o repasto em codorna e o outro em camundongo swiss. Para todos os experimento utilizou-se fotofase de 12h e umidade de 70%. Na relação interespecífica, constatou-se a sobreposição de A. aegypti sobre A. albopictus a partir da primeira geração (F1), independente da temperatura e da proporção das espécies. O tempo do ciclo de vida não diferiu significativamente entre as espécies, independente da temperatura, porem diminuiu em função do aumento da temperatura. A temperatura base (Tb) e a constante térmica (K) e consequentemente o número de gerações anuais foi maior para A. albopictus do que para A. aegypti. O repasto em camundongos resultou em maior número de ovos e longevidade das fêmeas tanto para A. aegypti como para A. albopictus. O substrato utilizado para hematofagia que se mostrou mais adequado para as duas espécies, foi o camundongo, visto que obteve-se a maior fertilidade e longevidade da fêmea. A temperatura e o substrato utilizado para o repasto sanguíneo interferem na competição, desenvolvimento, longevidade e fecundidade das espécies estudadas. O número de gerações anuais dos insetos em laboratório é maior para A. albopictus do que para A. aegypti.

Page generated in 0.0553 seconds