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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.
1

Evolution of aposematic warning coloration in parasitic wasps (Hymenoptera:Braconidae)

Leathers, Jason Wayne 14 November 2005 (has links)
Many Hymenoptera, with their painful stings and noxious chemical defenses, exhibit bright aposematic warning color patterns and are the most frequently mimicked group of organisms. Such aposematic color patterns are found in parasitic wasps of the Neotropical Compsobracon group (Braconidae). Many members of this group exhibit color patterns similar to several thousand other species of Braconidae, Ichneumonidae, sawflies, assassin bugs, flies, moths, and beetles. One hypothesis to explain this observation is that the members of the complex and their colors are generated by multiple cospeciation events resulting in the constituent genera having isomorphic phylogenetic trees. An alternative hypothesis is that the organisms have colonized existing color pattern niches independently and do not have topologically similar phylogenetic histories. In order to test the hypothesis that these patterns are the result of cospeciation events they will be described and mapped onto a phylogenetic tree. If clades are found to have isomorphic topologies; evidence will suggest cospeciation. However, if clades are not found to have similar topologies, evidence will suggest independent colonization of color pattern niches. / Graduation date: 2006
2

The DM gene family in the parasitoid wasp Nasonia vitripennis : identification of a sex-specific homolog of the doublesex gene /

Riddle, Megan Christine. January 2008 (has links)
Thesis (M.S.)--Western Washington University, 2008. / Includes bibliographical references (leaves 160-166). Also available in electronic format.
3

Studies on the biology and host location behavior of Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae), a parasitoid of callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae)

Onagbola, Ebenezer Oloyede, Fadamiro, Henry Y., January 2008 (has links) (PDF)
Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references.
4

Hidden Creatures – systematics of the Euphorinae (Hymenoptera)

Stigenberg, Julia January 2013 (has links)
Parasitic wasps constitute one of the last remaining frontiers in the charting of animal diversity. The Braconidae is the second most species-rich family of parasitic wasps; the world fauna has been estimated at 40 000 species and the Swedish fauna is believed to include a little more than 2 000 species, 1 200 of which are currently documented. This thesis is a contribution to the rapidly increasing knowledge of braconid diversity. In paper I, a new gregarious parasitoid, Meteorus acerbiavorus sp. nov. (Braconidae: Eupohrinae), is described from specimens reared from the cocoons of the butterfly Acerbia alpina (Quensel) (Lepidoptera, Arctiidae) in northwestern Finnish Lapland. Based on a molecular phylogenetic analysis, the new species is shown to belong to the M. rubens species group. In the second paper, the Western Palearctic fauna of the tribe is revised, seven new species are described and a key to the Western Palearctic species is presented. Two molecular markers, 28S and COI, are used to study phylogenetic relationships in the tribe. The molecular results showed that the Meteorini fall into four well supported clades. The results also reveal a considerable cryptic species diversity. The third paper deals with distributional, phenological and in many cases rearing data from nearly 2 500 specimens (44 species) of the Meteorini in the collection of the National Museums of Scotland (NMS), Edinburgh. Patterns in the breadth of host ranges are discussed in relation to a reiterated speciation hypothesis. Paper IV examines the phylogenetic relationships of the entire subfamily Euphorinae based upon four gene regions (18S, CAD, 28S D2, and COI). A revised classification of the Euphorinae is proposed that recognizes 55 genera and 14 tribes. Our study shows that early members of the Euphorinae were parasitoids of coleopteran larvae, with a host shift to larval Lepidoptera, adult or immature hosts in the Hemiptera, Hymenoptera, Neuroptera, Orthoptera and Psocoptera. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.</p>
5

The role of biogenic amines and dopamine receptors in envenomation by the parasitoid wasp Ampulex compressa

Banks, Christopher Neil. January 2010 (has links)
Thesis (Ph. D.)--University of California, Riverside, 2010. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed May 18, 2010). Includes bibliographical references. Also issued in print.
6

Sexual selection and sex allocation in the gregarious parasitoid wasp Nasonia vitripennis

Moynihan, Anna Margaret January 2012 (has links)
Sex allocation and sexual selection have been heavily studied, but rarely linked. In this thesis I investigated the interface between them in the gregarious parasitoid wasp Nasonia vitripennis, both directly and through their interactions with the mating system and sexual conflict. Chapter 2 investigated sexual selection and mating at the natal site: earlier eclosing males mated more females independently of body size. Nasonia follows Local Mate Competition, which describes how a female laying eggs alone on a patch of resources (a so-called single-foundress) should lay an extremely female-biased brood to minimise competition between her sons, yet ensure all her daughters are fertilised. Based on this I predicted that males with with fewer brothers would be better inseminators. Despite finding significant among-strain variation in (1) single-foundress sex ratio, (2) mate competitiveness when alone and (3) when in competition, (4) sperm resources, but not (5) sperm-depletion (Chapters 3 &amp; 4), I did not find the predicted relationship. Conversely males from strains with more brothers had a higher mating success under competition (Chapter 3) leading to the question: does mating success select on sex ratio or vice versa? Either way it is a result of an interaction between sexual selection and sex allocation. Chapter 5 investigated the role of male post-copulatory courtship on female re-mating, and found that among- strain variation in female re-mating was not associated with variation in the duration of the post-copulatory courtship. Chapter 6 reviewed sexual conflict in the Hymenoptera: their haplodiploid genetics, newly sequenced genomes and varied life- histories provides a base for future research to build on. Finally I highlight the novel links between sexual selection, sex allocation, sexual conflict and the mating system found during my studies that will hopefully prompt future research on this topic.
7

BSF-colony management efficiency at a large scale fly larvae composting company in Kenya – A field study / Utvärdering av flugkolonieffektiviteten på ett storskaligt fluglarvskomposteringsföretag i Kenya – En fältstudie

Anderberg, Hilda January 2023 (has links)
The majority of organic waste globally is either dumped or placed on landfills, which can result in spreading of disease and pests, methane gas emissions, the deterioration of landscapes and odour pollution. One of the solutions to poor organic waste management is to create value from waste. A way to do this is with black soldier fly (Hermetia illucens) larvae (BSFL) composting. The interest for BSFL composting has increased the past 10 years mainly because it is a technology with relatively low investment costs. The part of the process where the seed larvae that are used in the treatment are produced is called BSF-colony. Producing seed larvae in an efficient way is an important part of the technology’s feasibility. However, there is limited research published on BSF-colony management, especially on a larger scale. The aim of the study was to investigate the factors that impact the efficiency of the BSF-colony on a large scale BSFL composting company in Kenya in a semi-open setting. The efficiency of the BSF-colony management was assessed in terms of emergence rate (percentage of pupa that emerge as flies), hatching rate (percentage of eggs that hatch and survive to 5 day old larva) and number of eggs laid per female BSF. The result of the study suggests that parasitic wasps (Dirhinus giffardii) can reduce the emergence rate significantly, and high temperatures and water shortage for the adult BSF can reduce the egg production. Observations made during the study indicate that personnel routines and how the BSF-colony is arranged also could affect the egg production significantly. The overall variation in the results suggests that other factors, beyond the ones investigated in the study, impact the efficiency of the BSF-colony, and further research regarding BSF-colony management is recommended / Merparten av det organiska avfallet i världen dumpas eller läggs på deponier, vilket kan leda till spridning av sjukdomar och skadedjur, utsläpp av metangas, förstörelse av landskap och luktföroreningar. En av lösningarna på bristfällig hantering av organiskt avfall är att skapa värde av avfallet. Ett sätt att göra det är med hjälp av fluglarvskompostering med amerikansk soldatfluga (Hermetia illucens). Intresset för fluglarvskompostering har ökat under de senaste tio åren, främst på grund av att det är en teknik som inte behöver innebära höga investeringskostnader. Flugkolonin är den del av processen där sättlarverna som användes i komposteringen produceras. Att sättlarver produceras på ett effektivt sätt är en viktig del av teknikens genomförbarhet. Det finns dock begränsad forskning publicerad om effektivisering av flugkolonier, speciellt sådan som berör storskaliga kolonier. Syftet med studien var att undersöka vilka faktorer som påverkar flugkolonins effektivitet på ett storskaligt fluglarvskomposteringsföretag i Kenya i en halvöppen miljö. Flugkolonins effektivitet bedömdes i termer av metamorfosfrekvens (den andel av pupporna som blir flugor), antalet lagda ägg per fluga och kläckningsfrekvens (den andel ägg som kläcks och överlever till 5-7 dagar gamla larver). Resultatet av studien tyder på att parasitsteklar kan minska metamorfosfrekvensen avsevärt, och att höga temperaturer samt vattenbrist kan minska äggproduktionen. De observationer som gjordes under studien tyder på att personalens rutiner och hur flugkolonin är anordnad också kan påverka äggproduktionen avsevärt. Den relativt stora variationen i alla resultat tyder på att andra faktorer än de som undersökts i studien påverkar flugkolonins effektivitet, fortsatta studier inom effektivisering av flugkolonier rekommenderas
8

Efeitos diretos e indiretos de características de plantas sobre a similaridade na composição de insetos herbívoros e parasitoides associados à Asteraceae / Direct and indirect effects of plant characteristics on the herbivores and parasitoids compositional similarities associated with Asteraceae

Alvarenga, Vinícius Silva de 15 March 2018 (has links)
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-04-12T12:45:11Z No. of bitstreams: 2 Dissertação - Vinícius Silva de Alvarenga - 2018.pdf: 1904835 bytes, checksum: bbe0e840d010a67f148c91a849dbbf10 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-13T11:08:09Z (GMT) No. of bitstreams: 2 Dissertação - Vinícius Silva de Alvarenga - 2018.pdf: 1904835 bytes, checksum: bbe0e840d010a67f148c91a849dbbf10 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-13T11:08:09Z (GMT). No. of bitstreams: 2 Dissertação - Vinícius Silva de Alvarenga - 2018.pdf: 1904835 bytes, checksum: bbe0e840d010a67f148c91a849dbbf10 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Understanding how interactions between trophic levels structure species composition is one of the main goals of ecological studies. Mechanisms that explain the compositional structure of parasitoid insects usually neglect the direct and indirect effects of plants’ characteristics, which can also determine the compositional structure of their host herbivore insects. In this context, our goal was to evaluate how plants’ characteristics (abundance, floral phenology, and phylogenetic distance) and herbivores’ compositional similarity determine parasitoids’ compositional similarity. As study system, we used Asteraceae species, flower-head feeding insects, and parasitoids. Using path analysis, we considered parasitoids and herbivores’ similarities, in qualitative (Sørensen similarity), quantitative (Bray-Curtis similarity), and phylogenetic proximity (taxonomic Sørensen similarity) terms. In general, we demonstrated that herbivores’ similarity is the major predictor of parasitoids’ similarity. Even though the effects of plants’ characteristics explained the smallest part of the variation in parasitoids’ similarity, these characteristics had inconsistent relative importance among the similarity indexes used here. Thus, our results indicate that although plant species constitute a potential additional barrier for the parasitoids of endophagous herbivores to find their insect hosts, herbivore parasitoids in flower heads of Asteraceae do not see the plant species in this way. The parasitoids respond mainly to the compositional variation of their insect hosts in the plant species that the latter consume. Therefore, we show how the composition of the upper trophic levels in this tri-trophic system is structured directly and indirectly by antagonistic interactions. / Entender quais fatores influenciam a variação na composição de espécies em sistemas multitróficos é um objetivo fundamental em ecologia. Entretanto, estudos sobre a composição local de insetos parasitoides geralmente negligenciam a importância relativa das características de plantas consumidas por seus insetos herbívoros hospedeiros. Neste contexto, nosso objetivo foi avaliar os efeitos diretos e indiretos, mediados pela similaridade de herbívoros, da distância filogenética, da sincronia do período de floração e da similaridade de abundância das plantas sobre a similaridade de parasitoides. Como sistema de estudo, usamos espécies de Asteraceae, herbívoros endófagos de capítulos e insetos parasitoides. Usando análises de rotas, consideramos as similaridades de herbívoros e parasitoides entre pares de espécies de plantas em termos qualitativos (similaridade de Sørensen), quantitativos (similaridade de Bray-Curtis) e filogenéticos (similaridade de Sørensen taxonômica). Em geral, demonstramos que a similaridade de herbívoros é o principal determinante da similaridade de parasitoides. Mesmo que as características das plantas tenham explicado a menor parte da variação na similaridade de parasitoides, essas características tiveram importâncias relativas inconsistentes entre os índices de similaridade usados. Dessa forma, nossos resultados indicam que, apesar das espécies de plantas constituírem uma barreira adicional potencial para os parasitoides de herbívoros endófagos encontrarem os seus hospedeiros, os parasitoides de herbívoros em capítulos de Asteraceae não as enxergam dessa forma. Estes parasitoides respondem principalmente à variação composicional dos seus hospedeiros nas plantas que estes últimos consumem. Logo, demonstramos como as composições dos níveis tróficos superiores nesse sistema tri-trófico é estruturado diretamente e indiretamente por interações antagônicas.

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