• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 76
  • 47
  • 14
  • 11
  • 11
  • 11
  • 11
  • 5
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 160
  • 44
  • 32
  • 20
  • 19
  • 16
  • 16
  • 16
  • 12
  • 12
  • 12
  • 11
  • 10
  • 10
  • 10
  • 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.
21

Data analysis and preliminary model development for an odour detection system based on the behaviour of trained wasps : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Applied Science at Lincoln University /

Zhou, Zhongkun. January 2008 (has links)
Thesis (M. Appl. Sc.) -- Lincoln University, 2008. / Also available via the World Wide Web.
22

Ecology and management of Lygus and the distribution and species composition of Peristenus spp. in Washington

Waters, Timothy D. January 2009 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, May 2009. / Title from PDF title page (viewed on June 3, 2009). "Department of Entomology." Includes bibliographical references.
23

The Effects of Clearcutting and Glyphosate Herbicide Use on Parasitic Wasps in Maine Forests

Abell, Kristopher J. January 2007 (has links) (PDF)
No description available.
24

The effects of clearcutting and glyphosate herbicide use on parasitic wasps in Maine forests /

Abell, Kristopher J., January 2007 (has links) (PDF)
Thesis (M.S.) in Ecology and Environmental Science--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 55-59).
25

Interactions between fig wasps and their host figs

Nefdt, Rory John Charlton January 1990 (has links)
Fig trees (Ficus spp.) and fig wasps (Hymenoptera: Agaonidae) are partners in an intimate mutualism. The trees provide ovules in which wasp larvae develop while the wasps pollinate the flowers and are therefore indispensible for fig seed production. Agaonid fig wasps oviposit down the styles of fig flowers and it has generally been accepted that they were unable to reach the ovules of "long" styled flowers , which would produce seeds, thus maintaining an evolutionary stable mutualism. African fig species were found to have unimodal style length frequencies, with no separation into long and short styled flowers. In several species the ovipositors of their associated agaonids were long enough to reach the majority of ovules. The number of foundress agaonids entering a fig influenced fig seed set and therefore was an important factor regulating the proportion of flowers producing seeds or pollinators. In the two Ficus species that were studied, entry of more than three agaonid foundresses into one fig resulted in competition for limited oviposition sites and less female - biased offspring sex ratios. It is hypothesised that sequential laying of male eggs followed by female eggs, under variable oviposition site limitation, results in sex ratio adjustment, as predicted by local mate competition theory. Evidence in support of this hypothesis is presented. A number of non - pollinating torymid and pteromalid fig wasps also oviposit into each fig species. The sycophagines and sycoecines oviposit down the styles from inside the fig inflorescences like their agaonid counterparts, while other species insert their ovipositors through the wall of the fig from the outside. Like the agaonids, sycophagines were characterised by being pro - ovigenic, with numerous fully developed eggs at emergence. Sycoecines were able to re - emerge from figs they had oviposited in and lay their eggs in more than one fig. They had short ovipositors, allowing access to a smaller proportion of flowers than agaonids or sycophagines. Externally ovipositing fig wasps were syn-ovigenic, able to develop eggs as adults and invested more energy and time during each oviposition event. Differences in the ovipositor lengths of these species did not segregate their oviposition sites spatially, and therefore does not reduce competition between species. Attack by parasitoids and inquiline fig wasps from the exterior did not constitute a selection pressure against agaonids ovipositing in ovules closer to the periphery of the fig's surface, as predicted by Michaloud's enemy-free-space hypothes is. It cannot therefore explain the preference shown by ovipositing agaonids for shorter styled flowers.
26

Diferenciação etológica e morfofisiológica das castas de Mischocyttarus (Monogynoecus) montei, Zikán, 1949 (Hymenoptera, vespidae, mischocyttarini), com especial referência à regulação social das colônias /

Oliveira, Vanessa Cristina de. January 2007 (has links)
Orientador: Sulene Noriko Shima / Banca: Edilberto Giannotti / Banca: Fabio Prezoto / Resumo: As vespas, devido à característica difilética do grupo, são um excelente modelo para se tentar compreender a evolução do comportamento social nos Hymenoptera. A biologia e a organização social das vespas eussociais primitivas, em especial o gênero Mischocyttarus, são pouco conhecidas, apesar da grande diversidade de espécies desse gênero nos trópicos. Com o objetivo de identificar os mecanismos envolvidos na regulação social de Mischocyttarus (M.) montei, foram coletadas 9 colônias para a análise da morfofisiologia dos indivíduos, sendo que destas, 6 foram previamente observadas em condições naturais no Campus da Unesp de Rio Claro, SP. Foi verificado que a dinâmica hierárquica desta espécie é regulada através de três estratégias principais: a) interações agonísticas moderadas entre os indivíduos de maneira a permitir que fundadoras se associem, estabelecendo uma hierarquia de dominância mas ao mesmo tempo garantindo a viabilidade da colônia no início do ciclo; b) alimentação e gasto energético diferencial dos adultos, onde os mais dominantes ingerem maiores quantidades de alimento, em especial fontes de proteína, ao mesmo tempo em que realizam tarefas de baixo custo energético e comportamentos relacionados à dominância; e c) utilização da oofagia diferencial como forma indireta de competição e monopolização da postura de ovos. Através desses mecanismos, a hierarquia é regulada de forma dinâmica, de maneira a permitir que 2 qualquer indivíduo possa ocupar diferentes papéis dentro da colônia, uma vez que, como verificado, os adultos emergem com capacidades reprodutivas similares e não apresentam diferenças morfológicas significativas entre as castas. A determinação de suas funções na colônia dependerá, portanto, das estratégias acima descritas. / Abstract: The wasps, due to their monophyletic characteristics, are an excellent model to explain the evolutionary scenario of the social behavior in the Hymenoptera. The biology and social organization of primitively eusocial wasps, especially of Mischocyttarus genera, are relatively poor studied, despite of its marked diversity in Neotropical regions. With the aim of identify the traits involved in social regulation of M. (Monogynoecus) montei nine colonies were collected and used in morphological and physiological analysis, from these six were monitored in natural conditions at UNESP, in Rio Claro, SP. The results showed that the hierarchical dynamics of this specie is regulated based on three main strategies: a) moderated agonistics interactions among nestmates, which leads to foundress associations’ foundations and assure the establishment of a dominance hierarchy and the success of the colony in initial phases of development; b) different feeding and energetic cost tasking of adults, whereas the dominant females feed on higher quantities of food, especially protein, and perform tasks with low energetic cost, mainly those related to dominance; and c) differential oophagy as an indirect strategy of competition, avoiding the subordinate oviposition. Through these mechanisms the hierarchy is regulated in a dynamical way, in which any female can assume different tasks in the colony, once the adults emerge with similar reproductive potential and a marked morphological caste differentiation is absent. The role of each nestmate, therefore, will depend on the strategies previously described. / Mestre
27

Horários de atividade forrageadora e itens coletados por Protopolybia exigua (de Saussure) (Hymenoptera, Vespidae) na região do médio São Francisco, Bahia /

Rocha, Agda Alves da. January 2007 (has links)
Orientador: Edilberto Giannotti / Banca: Fabio Prezoto / Banca: Sulene Noriko Shima / Resumo: Neste trabalho foi estudada a atividade diária de busca por recursos de Protopolybia exigua em duas áreas no município de Bom Jesus da Lapa (13º15’S; 43º25’W), Bahia, Brasil, localizado na região do Médio São Francisco, com o objetivo de responder as seguintes questões: Qual a amplitude de horário da atividade forrageadora? Qual a relação entre os fatores físicos do tempo (temperatura, umidade relativa do ar, luminosidade e velocidade do vento) e a freqüência de saídas do ninho? Qual a influência das fases de desenvolvimento da colônia no número de saídas? Quais recursos as campeiras conduzem ao ninho? Qual a relação entre os fatores físicos do tempo e a coleta dos diferentes recursos? A coleta dos recursos é diferenciada de acordo com as fases do ciclo colonial e com o número de indivíduos (adultos e imaturos) presentes na colônia? Esta espécie, na região estudada, conduz presa macerada no papo? Durante o período de janeiro a junho de 2006 foram realizadas observações em 12 colônias de P. exigua, em diferentes fases do ciclo colonial. Os resultados revelaram que a espécie possui uma amplitude de quase 13 horas de atividade forrageadora e o Índice de Retorno com Recursos para a espécie foi de 93,5%. A atividade tornou-se mais intensa das 13:01 às 16:00h, quando foram registradas as maiores temperaturas (ºC) e menores valores de umidade relativa do ar (%). As colônias que possuíam maior número de larvas apresentaram um maior número médio de viagens ao campo por hora e o aumento do número de fêmeas na colônia tende a induzir a atividade forrageadora. Há diferença no número de saídas das campeiras do ninho, considerando as três fases de desenvolvimento colonial. A atividade de coleta de diferentes recursos (néctar, polpa de madeira, água, presa e resina) por P. exigua está relacionada ... ( Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this study the daily activity of search for resources by Protopolybia exigua was studied in two areas of the city of Bom Jesus da Lapa (13º15'S; 43º25'W), Bahia, Brazil, located in the region of Médio São Francisco River, aiming to answer the following questions: what is the amplitude of the foraging activity time? What is the relation between the physical factors of weather (temperature, relative air humidity, luminosity and wind speed) and the frequency of nest leaving? What is the influence of the stages of colony development on the number of exits by the bees? What resources do workers take to the nest? What is the relation between the physical factors of weather and the gathering of different resources? Is the resource collecting distinct according to the phases of the colony cycle and the number of individuals (adults and immatures) present in the colony? Does this species, in the region studied, carry its prey macerated in the crop? During the period from January to June 2006 twelve colonies of P. exigua in different phases of the colony cycle were observed. The results revealed this species presented an activity amplitude of almost 13 hours of foraging activity and the Rate of Returns with Resources for the species was 93.5%. The activity became more intense from 1:01 p.m. to 4:00 p.m., when the highest temperatures (ºC) and the least values of relative air humidity (%) were observed. The colonies that had a larger number of larvae presented a larger average number of trips to the camp per hour, and the increase in the number of females in the colony tended to induce to foraging activity. There was difference in the number of exits by the nest workers, considering the three phases of colony development. The activity of collecting different resources (nectar, wood pulp, water, prey and resin) by P. exigua is related both to physical factors of weather and to colony intrinsic ... (Complete abstract click eletronic access below) / Mestre
28

Análise proteômica dos alérgenos imunodominantes do veneno da vespa social Polybia paulista /

Santos, Lucilene Delazari dos. January 2007 (has links)
Orientador: Mario Sergio Palma / Banca: Fabio Fernandes Morato Castro / Banca: Gilberto Barbosa Domont / Banca: Luisa Karla de Paula Arruda / Banca: João Martins Pizauro Junior / Resumo: A prevalência de sensibilização de humanos aos venenos de himenópteros sociais foi estimada entre 9,3% e 28,5% na população mundial; muitas das alergias causadas por insetos desta ordem são provocadas por ferroadas de abelhas (família Apidae), vespas (família Vespidae) e formigas (família Formicidae). Há um interesse crescente no conhecimento da estrutura e função dos componentes do veneno desses insetos, principalmente no campo da imunologia clínica. Entre os Hymenoptera sociais, os venenos de abelhas e vespas endêmicas do hemisfério norte têm sido extensivamente estudados e, principalmente, seus componentes foram isolados e identificados. Por outro lado, os venenos de espécies de vespas das regiões neotropicais como aquelas típicas da biodiversidade brasileira têm sido pouco caracterizados. Apesar da ausência de dados epidemiológicos sobre esse assunto, a prática clínica diária mostra que as reações alérgicas ao veneno de Himenópteros são bastante freqüentes no Brasil. Cerca de 500 espécies diferentes de vespas sociais são conhecidas em todo Brasil; a maioria dessas espécies apresenta diferentes tipos de comportamentos biológicos em relação àquelas espécies endêmicas do hemisfério norte. Os extratos comercialmente disponíveis de extratos de venenos de vespas usados para diagnósticos e terapias de pacientes alérgicos a venenos de vespas são oriundos dos Estados Unidos e/ou da Europa. Apesar da história de reações sistêmicas após a ferroada destes insetos, a maioria dos pacientes brasileiros (sensíveis aos venenos de vespas) apresentam testes cutâneos negativos quando extratos de venenos importados são utilizados nesses testes. Com o objetivo de aperfeiçoar e alcançar uma melhor compreensão da bioquímica e imunologia dos venenos das principais espécies de vespas do Sudeste do Brasil... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The prevalence of human sensitivity to social Hymenoptera venom was estimated from 9.3 to 28.5% of word population; many allergies are caused by stingings of the insects representatives of Hymenoptera order such as bees (Apidae), ants (Formicidae) and wasps (Vespidae). There is a keen interest in the knowledge about the structure and function of the venom components of these insects, mainly in the field of clinical immunology. Among the social Hymenoptera the venoms of honeybees and wasps endemic from the North Hemisphere have been extensively studied and many of their components were isolated and identified. Meanwhile, the venoms of wasps species from the Neotropical regions of the planet like those typical of Brazilian biodiversity have been poorly characterized. Despite the absence of epidemiological data about this subject in the most of Brazilian regions, it well known by the doctors that this type of accident of very frequent in Southeast Brazil. About five hundreds different species of social wasps are reported all over Brazil; the large most of these species present different biology and aggressive behaviour in relation to those species endemic from the cold regions of the planet. The commercially available wasp venom extracts used for diagnosis and therapy of allergic patients to wasp venoms are produced by foreign pharmaceutical companies with the venom of wasp species obtained in United States and/or Europe. Despite of the history of systemic reactions when stung by local wasp species, the most of Brazilian patients (sensitive of wasps venoms) present negative skin tests when imported venom extracts are used in these tests. With the aim to improve the knowledge and to get a better understanding about the biochemistry and immunology of venoms of the most abundant wasp species from Southeast Brazil, the venom of the social wasp Polybia paulista ... (Complete abstract click eletronic access below) / Doutor
29

Análise proteômica dos alérgenos imunodominantes do veneno da vespa social Polybia paulista

Santos, Lucilene Delazari dos [UNESP] 13 March 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-13Bitstream added on 2014-06-13T20:40:55Z : No. of bitstreams: 1 santos_ld_dr_rcla.pdf: 2886206 bytes, checksum: c9a53b4683009217d7580a3bff769ea7 (MD5) / A prevalência de sensibilização de humanos aos venenos de himenópteros sociais foi estimada entre 9,3% e 28,5% na população mundial; muitas das alergias causadas por insetos desta ordem são provocadas por ferroadas de abelhas (família Apidae), vespas (família Vespidae) e formigas (família Formicidae). Há um interesse crescente no conhecimento da estrutura e função dos componentes do veneno desses insetos, principalmente no campo da imunologia clínica. Entre os Hymenoptera sociais, os venenos de abelhas e vespas endêmicas do hemisfério norte têm sido extensivamente estudados e, principalmente, seus componentes foram isolados e identificados. Por outro lado, os venenos de espécies de vespas das regiões neotropicais como aquelas típicas da biodiversidade brasileira têm sido pouco caracterizados. Apesar da ausência de dados epidemiológicos sobre esse assunto, a prática clínica diária mostra que as reações alérgicas ao veneno de Himenópteros são bastante freqüentes no Brasil. Cerca de 500 espécies diferentes de vespas sociais são conhecidas em todo Brasil; a maioria dessas espécies apresenta diferentes tipos de comportamentos biológicos em relação àquelas espécies endêmicas do hemisfério norte. Os extratos comercialmente disponíveis de extratos de venenos de vespas usados para diagnósticos e terapias de pacientes alérgicos a venenos de vespas são oriundos dos Estados Unidos e/ou da Europa. Apesar da história de reações sistêmicas após a ferroada destes insetos, a maioria dos pacientes brasileiros (sensíveis aos venenos de vespas) apresentam testes cutâneos negativos quando extratos de venenos importados são utilizados nesses testes. Com o objetivo de aperfeiçoar e alcançar uma melhor compreensão da bioquímica e imunologia dos venenos das principais espécies de vespas do Sudeste do Brasil... / The prevalence of human sensitivity to social Hymenoptera venom was estimated from 9.3 to 28.5% of word population; many allergies are caused by stingings of the insects representatives of Hymenoptera order such as bees (Apidae), ants (Formicidae) and wasps (Vespidae). There is a keen interest in the knowledge about the structure and function of the venom components of these insects, mainly in the field of clinical immunology. Among the social Hymenoptera the venoms of honeybees and wasps endemic from the North Hemisphere have been extensively studied and many of their components were isolated and identified. Meanwhile, the venoms of wasps species from the Neotropical regions of the planet like those typical of Brazilian biodiversity have been poorly characterized. Despite the absence of epidemiological data about this subject in the most of Brazilian regions, it well known by the doctors that this type of accident of very frequent in Southeast Brazil. About five hundreds different species of social wasps are reported all over Brazil; the large most of these species present different biology and aggressive behaviour in relation to those species endemic from the cold regions of the planet. The commercially available wasp venom extracts used for diagnosis and therapy of allergic patients to wasp venoms are produced by foreign pharmaceutical companies with the venom of wasp species obtained in United States and/or Europe. Despite of the history of systemic reactions when stung by local wasp species, the most of Brazilian patients (sensitive of wasps venoms) present negative skin tests when imported venom extracts are used in these tests. With the aim to improve the knowledge and to get a better understanding about the biochemistry and immunology of venoms of the most abundant wasp species from Southeast Brazil, the venom of the social wasp Polybia paulista ... (Complete abstract click eletronic access below)
30

Interaction Between the Seed-Chalcid Wasp, Megastigmus spermotrophus and its Host, Douglas-fir (Pseudotsuga menziesii)

Donaleshen, Kathleen Louise 28 September 2015 (has links)
Megastigmus spermotrophus is a parasitic chalcid wasp that spends most of its life in the seed of its host, Douglas-fir (Pseudotsuga menziesii). The adult female wasp lays its eggs into the megagametophyte deep within the ovule; the larva prevents an unpollinated ovule from aborting, redirecting resources to feed itself. Host-site selection pressures that influence female oviposition depend on a number of factors. Morphological characteristics of Douglas-fir cones including seed size, seed location, and scale thickness were measured for every ovuliferous scale. Seeds infested by M. spermotrophus as well as seeds fused to galls intiated by a competing conophyte, Contarinia oregonensis were noted. Using a generalized linear mixed effects model, I found that seed position, and the presence of C. oregonensis, were strong predictors of Megastigmus infestation. The percent of M. spermotrophus infested seed was higher in the apical and basal regions of the cone where seeds were smaller, scales were thinner and C. oregonensis were less frequently found. M. spermotrophus was also found to exploit seeds in regions of the cone, where seeds rarely complete development. These data suggest that competitors may not be the only factor influencing infestation; factors of cone morphology are also important. Douglas-fir seed does not show any anatomically detectable defense response to Megastigmus attack. To study mechanisms of host manipulation and defense response of the seed I took a genomics approach. Four types of ovules/seeds were studied: 1. pollinated & uninfested, 2. pollinated & infested, 3. unpollinated & uninfested, and 4. unpollinated and infested. A de novo reference transcriptome was assembled. Transcripts were annotated based on sequence similarity to genes of Pinus taeda, Arabidopsis thaliana, Nasonia vitripennis, and the UniProt database. Expression values were estimated based on the alignment of the original reads back onto the reference transcriptome. Differentially expressed transcripts were identified. Oviposition of M. spermotrophus caused changes in expression of Douglas-fir transcripts. Functional classification of differentially expressed transcripts between infested and uninfested seed revealed genes with possible roles in wounding, but none specific to herbivory. Infested treatments had more transcripts similarly expressed to pollinated than unpollinated seeds suggesting that M. spermotrophus is capable of manipulating gene expression. These transcripts had functional roles related to seed storage, cell division and growth, solute transport, hormone signalling, and programmed cell death among others. Overall, this study reveals a select set of genes that may be involved in stress response to wounding and also genes important for seed development and maturation. / Graduate

Page generated in 0.0335 seconds