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Lewis, Graham Allan. "Development of a protocol for sampling arthropod diversity in areas of native vegetation /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09ACH/09achl674.pdf.
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Fagan, William Fredric. "Population dynamics, movement patterns, and community impacts of omnivorous arthropods /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/5270.
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Manning, Robert John. "Conidiobolus-arthropod interactions : spore germination on arthropod surfaces and its consequences." Thesis, Staffordshire University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272825.
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Terblanche, Jonathan Steed. "Variability among individuals and populations : implications for arthropod physiology." Thesis, Stellenbosch : Stellenbosch University, 2006. http://hdl.handle.net/10019.1/21763.
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Dissertation (PhD)--University of Stellenbosch, 2006.ENGLISH ABSTRACT: Within arthropods, inter-individual and inter-population variation is generally poorly explored for physiological parameters. Such physiological variability is important, as it can provide insight into the capacity for evolutionary adaptation and how animals may cope with anthropogenic climate change. Insect vectors of human and animal diseases, such as tsetse flies (Diptera, Glossinidae) which carry trypanosomes, are of particular interest. Predictions of tsetse fly (Glossina spp.) range expansion, possibly paralleled by increased disease occurrence, have been made under future climate scenarios. Moreover, since there are generally strong relationships between abiotic variables (e.g. temperature and moisture availability), population dynamics, distribution and abundance, determining the physiological mechanisms influencing such relationships has utility for predictive modelling of spatial and temporal changes in tsetse fly distributions. I investigated physiological variation among individuals and populations, focusing mainly on Glossina spp. but using other arthropods to address certain issues. Specifically, I show the following: i) metabolic rate is repeatable (intra-class correlation coefficient) within individuals, and may be influenced by several factors such as age, gender, body mass and pregnancy; ii) while metabolic rate is repeatable within individuals, it remains unaltered with acclimation to laboratory conditions from field collection; iii) within a population, metabolic rate-temperature relationships are surprisingly invariant among physiological states such as age, gender, feeding status, pregnancy and temperature acclimation; iv) the magnitude of the effect of temperature acclimation differs among traits, in that upper thermal tolerances respond less than lower thermal tolerances, while metabolic rate responds to heat but not to cold. Water loss rate is relatively unresponsive to either treatment; v) plasticity can account for most inter-population variation in physiological traits related to climatic stress resistance (e.g. thermotolerances and desiccation rates) in the natural environment; vi) adult physiological performance responds differently to developmental and adult acclimation, such that marked traitspecific variation occurs, and combinations of both developmental and adult plasticity can result in further alteration of adult performance. These results have implications for the evolution of stress resistance to abiotic factors in these and other arthropods. I conclude by discussing the potential physiological patterns linking population dynamics and abiotic factors, with particular reference to tsetse flies.
AFRIKAANSE OPSOMMING: Binne arthropoda, is tussen-individu en tussen-bevolking variasie in die algemeen sleg bestudeer vir fisiologiese parameters. Hierdie fisiologiese variasie is belangrik want dit kan insig gee in die mate van evolusionêre aanpassing en hoe diere antropogenies klimaatsverandering kan hanteer. Dit is veral belangrik in die geval van insekte wat mens- en diersiektes kan dra, soos tsetse vlieë (Diptera, Glossinidae) wat trypanosome oordra. In die geval van tsetse vlieë (Glossina spp.) is voorspellings vir verhoogde verspreiding, en gevolglik verhoogde siekte voorkoms, gemaak onder toekomstige voorkoms klimaat senario’s. Verder, aangesien daar in die algemeen sterk verwantskappe tussen abiotiese parameters (bv. temperatuur en water beskikbaarheid), bevolkingsdynamika, verspreiding en voorkoms is, is die bepaling van die fisiologiese meganisme, wat ‘n invloed het op hierdie verwantskappe, nuttig vir die voorspelling van tsetse oor spasie en tyd. Hier, met hoofsaaklik die gebruik van Glossina spp., maar ook ander arthropoda wanneer dit nodig is, word navorsing wat fisiologiese variasie tussen individue en bevolkings aanspreel voorgelê. Spesifiek, word dit gewys dat i) metaboliese tempo is herhaalbaar (intra-klas korrelasie koeffisient) binne individue, alhowel metaboliese tempo kan beinvloed word deur faktore soos ouderdom, geslag, liggaamsmassa en swangerskap, ii) terwyl metaboliese tempo binne individue herhaalbaar is, verander dit nie met akklimasie na laboratorium toestande vanaf versameling in die veld, iii) binne ‘n bevolking metaboliese tempo-temperatuur verwantskappe is verbasend eenders tussen fisiologiese toestande soos ouderdom, geslag, voeding staat, swangerskap en temperatuur akklimasie, iv) die grootte van die effek van temperatuur akklimasie verskil tussen eienskappe, en die boonste termiese limiete reageer minder as laer termiese limiete, terwyl metaboliese tempo reageer op hitte maar nie koue nie, en waterverlies tempo is relatief terughoudend tot enige temperatuur toestand, v) buigbaarheid kan die meeste van inter-bevolkingsvariasie in fisiologiese eienskappe van klimaatstres weerstandsvermoë (termiese toleransie en uitdrogingstempo) in die natuurlike omgewing verklaar, vi) volwasse fisiologiese prestasie reageer verskillend op ontwikkelende en volwasse akklimasie, soveel dat eienskap-spesifieke variasie kan voorkom, en ‘n kombinasie van beide ontwikkelende en volwasse buigbaarheid ‘n verskillende volwasse prestasie tot gevolg kan hê. Hierdie resultate het implikasies vir die evolusie van weerstandsvermoë tot abiotiese faktore in hierdie en ander arthropoda. Hierdie tesis word afgesluit met ‘n bespreeking van die moontlikke fisiologiese patrone wat bevolkingsdinamika en abiotiese faktore kan verbind, met ‘n fokus op tsetse vlieë.
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Azarbayjani, Fathollah Fathi, of Western Sydney Hawkesbury University, Faculty of Science and Technology, and School of Science. "Assessment of estimators and factors affecting arboreal arthropod biodiversity on Melaleuca Linariifolia." THESIS_FST_SS_Azarbayjani_F.xml, 1997. http://handle.uws.edu.au:8081/1959.7/246.
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This study was carried out in a woodland on the campus of University of Western Sydney at Richmond, Australia to investigate seasonal effects and recovery speed of arboreal arthropods after disturbance. Twenty one pairs of Melaleuca linariifolia Sm. trees were sampled using insecticide spraying in a log2 nine period sequence (1-32) of weeks supplemented by additional samples to incorporate seasonal (weeks 24 and 48) and annual (week 52) samples. Using species accumulation curves, it was found that four collectors provided a reasonable representation of a tree's fauna and that a single tree does not provide a representative sample of the arthropod fauna found on trees of this species in the study area. The application of richness and evenness indices in different seasons showed significant changes in diversity. It was clear from the findings of the study that careful attention needs to be paid to experimental design. Under replication is the normal situation in previous studies and the effects of location, season and disturbance are all critical factors affecting the estimation of diversity.Doctor of Philosophy (PhD)
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Longhorn, Stuart John. "Phylogenomic approaches to arthropod systematics." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429293.
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Pace, Ryan M. "Evolution Of Arthropod Morphological Diversity." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/578719.
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A fundamental problem in developmental and evolutionary biology is understanding the developmental genetic basis of morphological diversity. The current paradigm holds that a genetic and developmental program, or developmental genetic "toolkit", conserved across hundreds of millions of years patterns development in all metazoans. However, outside of a few well-characterized signal transduction pathways and developmental processes, overly broad strokes have been used to paint this "toolkit" metaphor as a hypothesis. Arthropoda, one of the largest groups of metazoans, represent the most morphologically diverse groups of metazoans, making them of particular interest for studies of morphological diversity and its evolution. Arthropoda is also home to one of the most well-understood model systems for developmental and genetic studies, the fruit fly Drosophila melanogaster. However, Drosophila is highly derived among arthropods with respect to the molecular genetic mechanisms that function during its development. As it is expected that all arthropods have access to the same development "toolkit", some changes are expected based on the observable differences in morphology, making arthropods extremely powerful tools for comparative genomic and molecular genetic studies. In this dissertation I characterize how modifications to the developmental "toolkit" contribute to the evolution of morphological diversity using emerging model arthropod systems. First, as part of a collaboration, I show that several genes expected to be conserved in all arthropods, belonging to the Hox family of transcription factors, have been lost from the genome of a phylogenetically basal arthropod, the two-spotted spider mite Tetranychus urticae. Second, I perform a genomic survey and find an overall reduction in the conservation of Drosophila orthologs from several major signal transduction pathways in the Tetranychus genome in comparison with findings from previous insect surveys. Third, I show that arthropod Hox genes, expected to be found in a tightly linked genomic cluster in most arthropod genomes, are not as tightly clustered as previously thought. Fourth, I show that changes in the genomic arrangement of Tetranychus Hox genes correspond with shifts in their expression and morphological change. Finally, I show the terminal Hox gene Abdominal-B is required for proper axial elongation and segment formation (both segment identity and number) during embryogenesis and metamorphosis in the red-flour beetle Tribolium castaneum. Taken together, these findings advance our knowledge of the evolution of morphological change, with a primary focus on Hox genes and their contribution to axial patterning during development.
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Horner, Kimberley Jane. "The diversity of arthropods in the surface soil layers of an old-growth redwood forest." Scholarly Commons, 1993. https://scholarlycommons.pacific.edu/uop_etds/2249.
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The abundance and diversity of arthropods present in the surface soil layers at various forest sites in northern California were investigated, primarily at two old-growth redwood forest sites in Prairie Creek Redwoods State Park and Jedediah Smith Redwoods State Park. A wide variety of arthropods were found, including representatives of Araneae, Pseudoscorpiones, Opiliones, Acarina, Isopoda, Diplopoda, Chilopoda, Symphyla, Pauropoda, Protura, Diplura, Collembola, Thysanoptera, Hemiptera, Coleoptera, Diptera, and Hymenoptera. Arthropod densities were significantly higher in the wet than in the dry period, indicating seasonal variation in surface densities of soil arthropods. The densities of arthropods in soils collected from beneath coast redwood (Sequoia sempervirens) and western hemlock (Tsuga heterophylla) trees were not significantly different.
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Ozanne, Claire Margaret Philippa. "The arthropod fauna of coniferous plantations." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303621.
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Palmer, William Jack Philip. "Immune system evolution in arthropod genomes." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709120.
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Sewell, William. "Genetic Basis for Arthropod Limb Diversification." Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/194706.
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Changes in the morphological character of appendages are essential to arthropod diversification and adaptation to a variety of living conditions. For instance, the fruit fly Drosophila melanogaster possesses cylindrical, uniramous (unbranched) walking legs that are well suited for terrestrial life, while Triops longicaudatus possesses paddle-like, multiramous (multibranched) limbs adapted to aquatic life. Comparative studies of limb patterning between different species of arthropods suggest that most animals utilize a conserved set of genes to construct a limb. How is this common set of genes used to produce morphological divergence? This question is addressed here by examining the spatiotemporal expression patterns of genes shown to establish distinct domains along the proximodistal (P/D) axis in arthropod species with legs morphologically distinct from Drosophila legs.In this dissertation, I investigate the role of the limb patterning genes, dachshund (dac) and homothorax (hth), in patterning the appendages of the crustacean Triops longicaudatus. I examine the spatiotemporal relationships of the expression of these two essential limb-patterning genes individually and simultaneously with two previously reported leg patterning genes, extradenticle (exd) and Distal-less (Dll). I discovered that Triops dac and hth, as expected, are expressed during leg development. I verified a cell-to-cell association between HTH and nuclear-EXD (n-EXD), a spatial relationship that had only been conjectured to exist outside of Drosophila. This spatial relationship represents an ancient unchangeable constraint on limb patterning. HTH expression reported here in addition to previously reported EXD and DLL expressions suggests a common, early subdivision of the leg into broad proximal and distal domains. However, the reiterated stripes of DAC expression found along the ventral axis do not support establishment of an intermediate leg domain but instead suggest that the ventral branches of the Triops limb are generated by a mechanism of segmentation not previously observed in other arthropod limbs. Additionally, I present a record of my attempts aimed at functional determination of genes believed to specify, pattern, or modify branchiopod appendages. Finally, I demonstrated that dac functions in the dung beetle leg to properly segment the tarsus as well as producing a structural modification, such as spiked protrusions.
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Titchener, Frederick Robert. "Plant-arthropod interactions in the late Tertiary." Thesis, Royal Holloway, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.482120.
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Bhandal, Narotam Singh. "Arthropod chloride channels as targets for pesticides." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335651.
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Van, Laere Gaëlle. "The Earliest Arthropod Trace Fossilsand Their Significance." Thesis, Uppsala universitet, Paleobiologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-452334.
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The trace fossil, or ichnofossil record provides a different perspective on animal evolution compared to that of body fossil, as it is typically preserved in different facies and lacks the bias towards mineralised body parts. As trace fossils record behaviours, they often cannot be assigned to particular producers, except in rare cases where they are found in association with them. However, they play an important role in the study of evolution and biostratigraphy and are particularly useful in stratigraphic studies of otherwise unfossiliferous rocks.Rusophycus is a rare exception as it is a trace fossil that is typically assigned to a trilobite tracemaker. However, this does not exclude other arthropods from being considered as potential producers of Rusophycus. Indeed, the trace appears before the first trilobite body fossils and is found after their disappearance. The earlier occurrences of Rusophycus are also the earliest undoubted signs of arthropods and are from the Terreneuvian. Pre-trilobitic forms seem to be different from their younger counterpart in morphological aspect, but this has not been formally quantified.This study investigates these early Rusophycus to obtain a clearer picture of what the pre-trilobitic Rusophycus record is like and to search for temporal trends in their morphology. Pre-trilobitic occurrences are also compared with younger ones to quantify their differences and try to interpret their significance. Pre-trilobitic Rusophycus appear to have lower length:width ratios than the younger ones. Moreover, they are also, on average wider than the younger Rusophycus. This is significant as it could result from a change in producer and probably in appendages used for digging. It could as well reflect a reduction in the number of appendages used. However, these low ratios could also be the result of taphonomic variation and the preservation of only the deeper parts of the traces. A reflection on the potential producers of the pre-trilobitic Rusophycus is also provided based on what is known of the morphology of early arthropods. While no definitive conclusion can be made, the probability that at least some of the earlier Rusophycus were not made by trilobites appears to be clear.
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Legg, David. "The impact of fossils on arthropod phylogeny." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24168.
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The arthropods are the most diverse, abundant and ubiquitous phylum on Earth. Five main extant groups (subphyla) can be recognized: Pycnogonida, Euchelicerata, Myriapoda, Hexapoda, and Crustacea. Each group displays a distinctive body plan and a suite of autapomorphies that makes determining their interrelationships difficult. Although a variety of hypotheses have been proposed regarding their interrelationships, just three have frequently been recovered in recent phylogenetic analyses. Rather than representing incongruent topologies these hypotheses represent variations of the position of the root on the same parent topology. The long histories of the major arthropod subclades, which had begun to diverge by, at least, the early Cambrian, means that long-branch artefacts are highly probable. To alleviate potential long-branch attraction and provide a more accurate placement of the root, 214 fossil taxa were coded into an extensive phylogenetic data set of 753 discrete characters, which also includes 95 extant panarthropods and two cycloneuralian outgroups. Preference was given to those fossil taxa thought to occur during the cladogenesis of the major arthropod clades, i.e. the lower and middle Cambrian. An extensive study of material from the middle Cambrian Burgess Shale Formation and the coeval Stephen Formation in British Columbia (Canada) was undertaken. This study focussed primarily on taxa thought to represent 'upper stem-group euarthropods', namely bivalved arthropods and megacheirans ('great-appendage' arthropods), as they will have the greatest utility in polarizing relationships within the arthropod crown-group [= Euarthropoda]. This study includes the description of three new genera and four new species: the bivalved arthropods Nereocaris exilis, N. briggsi, and Loricicaris spinocaudatus; and the megacheiran Kootenichela deppi; and a restudy selected material referred to the bivalved arthropod taxa Isoxys, Canadaspis perfecta, Odaraia alata and Perspicaris dictynna. Results of the phylogenetic analysis and additional perturbation tests confirm the utility of these taxa for polarizing relationships within Euarthropoda and reducing long-branch artefacts. For example, the hexapods were recovered within a paraphyletic Crustacea, a result anticipated by molecular phylogenetic analyses but until now elusive in morphological phylogenies. Perturbation tests indicate that close affinities of myriapods and hexapods, a result common in morphological analyses, is the result of a long-branch artefact caused by the convergent adaptation to a terrestrial habit, which is broken by the addition of fossil material. The phylogeny provides a detailed picture of character acquisition in the arthropod stem group.
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White, Katrina Marie. "Effects of fire on a prairie arthropod community." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq61048.pdf.
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White, Katrina Marie, and University of Lethbridge Faculty of Arts and Science. "Effects of fire on a prairie arthropod community." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2000, 2000. http://hdl.handle.net/10133/125.
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In this study, I addressed how a large-scale wildfire affected a prairie arthropod community in southern Alberta, Canada. First, I looked at the general effects of disturbance on the arthropod community. Second, I addressed how processes such as competition and secondary succession may have affected diversity in this arthropod community. Third, I determined how the arthropod community trophic structure was regulated.
Results showed that the effect of disturbance on arthropods varies greatly by taxa. Factors, such as site, year, distance from disturbance edge, as well as the disturbance itself, were important in determing the abudance, biomass, richness, and diversity of the arthropod community. There were strong year-to-year differences hat exceeded the disturbance effects. Results showed that the processess behind the intermediate
disturbance hypothesis, succession and competition are not detectable in this arthropod community. This arthropod community was likely regulated in a bottom-up manner, in which herbivores ultimately control the abundance of predators and parasitoids.x, 97 leaves : ill. ; 28 cm.
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Mousley, A. "Cross-phyla studies of helminth and arthropod neuropeptides." Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368480.
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Jumeau, Philippe J. A. M. "Arthropod predation in a simple Antarctic terrestrial community." Thesis, University of York, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277219.
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Pace, Ryan M., Miodrag Grbić, and Lisa M. Nagy. "Composition and genomic organization of arthropod Hox clusters." BioMed Central, 2016. http://hdl.handle.net/10150/615123.
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Camarinha, Inês Maria Ferreira. "Post-fire evaluation of shrub and arthropod communities." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10245.
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Mestrado em Biologia AplicadaDevido ao aumento da incidência de incêndios em Portugal, torna-se cada vez mais urgente uma avaliação dos efeitos deste fenómeno nas florestas, estando estas entre os ecossistemas mais afetados. As florestas de eucaliptos, de pinheiros e mistas, abundantes no centro do país, apresentam características distintas, sendo fundamental um estudo comparativo destas espécies. Este trabalho propôs-se a uma avaliação da regeneração da flora a médio prazo (5 anos após o evento), assim como da recuperação da comunidade de artrópodes, ambas componentes essenciais do meio florestal e severamente afetadas pelo fogo. Na regeneração da flora, registaram-se diferenças entre parcelas ardidas e não ardidas. Houve diferenças significativas entre as comunidades de artrópodes de pinhais e de eucaliptais. Os índices de diversidade obtidos indicam que a recuperação da comunidade foi mais elevada em florestas de pinheiro do que em florestas de eucalipto. A análise de redundância (RDA), demonstrou que as variáveis responsáveis pela distribuição de dados são as variáveis associadas com o horizonte orgânico do solo, nomeadamente a cobertura e profundidade da folhada, a percentagem de humidade e de matéria orgânica nesta camada. De forma global, os resultados indicaram diferenças significativas entre os povoamentos de eucaliptos e pinheiros, incluindo ao nível da regeneração pós-fogo das comunidades, que foi mais rápida em pinhais. Em geral, as diferenças encontradas foram sempre mais significativas entre parcelas ardidas e não ardidas, do que entre os diferentes tipos de povoamentos.
The incidence of fire in Portugal has been rising, and with it the urgency for a complete evaluation of the effects of these phenomena in forests, which are among the most affected ecosystems. Eucalypt, pine and mixed stands – the most abundant types of forest in the centre of the country – present distinct characteristics, being fundamental a comparative study of these different stands. This work is meant as a post-fire evaluation of the mid-term regeneration of the flora – 5 years after the event; as well as of the recovery of the arthropod community. Both these components are vital for the good functioning of a forest and are severely affected by fire. Regarding floristic regeneration, there were significant differences between burnt and unburnt plots. For the arthropod data, there were significant differences between pine and eucalypt stands. The results obtained from diversity indexes indicate that the recovery in pine stands was higher than in eucalypt stands. The redundancy analysis (RDA) revealed that the main variables responsible for the data variation were the ones associated with the organic horizon, namely litter depth and cover, humidity and organic matter percentage in this layer. Globally, results indicate that there are significant differences between pine and eucalypt stands, which include differences regarding the post-fire regeneration of communities, which was faster in pine stands. Nonetheless, differences were generally more profound between burnt and unburnt plots, than between types of stand.
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Li, Yunhe. "Ecological risks of insecticidal transgenic crops on arthropod predators /." [S.l.] : [s.n.], 2009. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Coluzzi, Karen. "Arthropod Scavengers of Colorado Potato Beetle (Leptinotarsa Decemlineata) Cadavers." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/ColuzziK2005.pdf.
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Taverner, Peter D. "Effects of postharvest oils on arthropod pests of citrus /." Title page, contents and summary only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09pht233.pdf.
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Khan, Tanwir Rahman. "Action of philanthotoxin on ion channels of arthropod muscle." Thesis, University of Nottingham, 1994. http://eprints.nottingham.ac.uk/11229/.
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Calcium ions play an important role in many signalling pathways involved in normal cell metabolism. Pertrebations of normal Ca++ signalling may also play a pivotal role in the initiation of cell death. In these studies I have examined the influx of 45Ca++ into the extensor tibiae muscle of the locust (Schistocerca gregaria ). 45Ca++ entry could be stimulated by the addition of glutamate receptor-agonists or by activation of voltage activated calcium channels. L-glutamate, L-quisqualate and NMDA stimulated the influx of 45Ca++ while L-aspartate had only a small effect. DL-ibotenate, kainate, AMPA and glycine had no effect on 45Ca++ uptake (all agonists were tested at concentrations up to (100μM). Glycine (1μM) enhanced the 45Ca++ entry induced by NMDA and L-glutamate. Only the glycine potentiation of L-glu-stimulated responses was abolished in the presence of Mg++ (2mM) or AP5 (10μM) whereas the NMDA-stimulated response was completely abolished by these agents. These finding suggests that in the presence of glycine, L-glutamate may activate NMDA receptors and that in the absence of glycine L-glu-stimulated 45Ca++ entry occurs via activation of the qGluR. Depolarisation of the extensor tibiae muscles (50mM KCl) stimulated 45Ca++ influx by activation of voltage-sensitive calcium channels. Philanthotoxin-343 (0.1μM) had no effect on depolarisation activated calcium entry, however, nifedipine (1μM) an L-type calcium channel antagonist inhibited this Ca++ influx. Nifedipine did not inhibit L-glu-stimulated Ca++ entry suggesting that in these muscles L-type Ca++ channels are not involved in the Ca++ influx pathway following G1uR activation. Philanthotoxin-433 (PhTX-433) and many of its synthetic analogues are potent inhibitors of locust GluR. In the future these analogues may prove as useful potential neuroprotective agents or as novel pesticides. Over 100 analogues of PhTX-433 have been synthesized with changes made in the four regions of the structure, the thermospermine moiety, the tyrosyl moiety, the butyryl moiety and the terminal amino moiety. The effects of different concentrations (10-4M to 10-14M) of synthetic analogues of PhTX-433 (PhTX-343, PhTX-343-Arg, PhTX-4) were investigated in the 45Ca++ influx assay using locust extensor tibiae muscle. PhTX-343-Arg was more potent (IC50= - 7x10-9) than PhTX- 343 (IC50= - 10-8M) or PhTX-4 in blocking 45Ca H uptake. These findings were further supported by electrophysiological studies. The interaction of these synthetic analogues of philanthotoxin with GluR of locust muscle were further investigated by examining the effect of these compounds on evoked excitatory post synaptic potentials. In recent years control of ticks have been very important issue because of the social and economical damage they cause. Neuromuscular transmission is a main target site for the chemical control of many pests. Philanthotoxin and its analogues block the glutamate receptors which are involved in arthropod neuromuscular transmission and thus may prove useful as novel pesticides. The action of synthetic analogues of philanthotoxin (C7PhTX-343, DNP12-, PhTX-343 and PhTX-343) were examined on evoked excitatory postsynaptic potential in tick coxal muscle. These compounds all antagonized the evoked EPSP. C7PhTX-343 and DNP12-PhTX-343 exhibited same potency (IC50 = 10-8M) and both were more potent than PhTX-343 (IC50 ='2X10-5M). In recent years Xenopus oocyte has taken over a new role as a test tube for the study of the biogenesis, functional architecture and modulation of plasma membrane protein. Attempts were made to express mRNA from embryonic tissue of tick and locust leg muscle in to Xenopus oocyte for pharmacological studies. Xenopus oocytes failed to translate RNA faithfully and efficiently from these sources. Rat brain RNA injected oocytes used as control, expressed routinely.
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Hochberg, Michael Edward. "The population dynamics of arthropod host-parasitoid-pathogen interactions." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47476.
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Rundle, S. D. "The micro-arthropod communities of some southern English streams." Thesis, Queen Mary, University of London, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396787.
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Coulcher, J. F. "Evolution of the arthropod mandible : a molecular developmental perspective." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1335716/.
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The mandible is thought to have evolved once in the ancestor to the mandibulate arthropods; the insects, crustaceans and myriapods. If the mandible is a homologous structure, it suggests that there will be shared developmental genes required to pattern the mandible in different species. As a representative of mandibulate arthropods, the red flour beetle Tribolium castanem was chosen to study genes required to pattern the mandible. This study show that the Tribolium orthologue of cap’n’collar (Tc cnc) patterns the mandible of Tribolium. Loss of Tc cnc function by RNA interference (RNAi) results in a transformation of the mandible to maxillary identity and deletion of the labrum. Analysis of gene expression by in situ hybridisation shows that Tc cnc represses the Tribolium orthologues of the Hox genes proboscipedia (pb) and Deformed (Dfd), which pattern the maxillary appendage. Similar expression patterns of cnc, Dfd and pb homologues in mandibulate arthropods suggests that the functions of these genes are conserved. As the mandible has evolved from a maxilla-like precursor in the ancestor to all mandibulate arthropods, the manner in which Tc cnc differentiates the mandible from a maxilla in Tribolium recapitulates the evolution of the mandible from a maxilla-like precursor. An orthologue of cnc was cloned from the spider Achaearanaea tepidariorum, chosen as an outgroup to the mandibulate arthropods, but no evidence of a developmental role was discovered. Study of the expression of genetic markers for appendage segments shows that the biting edge of the mandible is derived from one endite, and the mandible is divided into a subcoxa and coxa which are also present in the maxillary, labial and leg appendages. There are significant similarities in the expression of genetic markers that presumably indicate serial homology of the subcoxa and coxa of the mandible to the subcoxa and coxa of other appendages.
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Nelson, Jessica Lynn. "Arthropod communities in riparian grass buffers and adjacent crops." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8495.
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Thesis (M.S.) -- University of Maryland, College Park, 2008.Thesis research directed by: Marine, Estuarine, Environmental Sciences Graduate Program. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Barretta, Michelle. "Normal and taphonomic arthropod population survey in Holliston, Massachusetts." Thesis, Boston University, 2012. https://hdl.handle.net/2144/12279.
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Thesis (M.S.)--Boston University
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.In medicolegal death investigations, the collective endeavors of forensic anthropology and entomology are sometimes essential in determining the postmortem interval. Since organisms belonging to the class Insecta are the most abundant on Earth, their frequent appearance at death scenes have made entomological studies increasingly important for the field of forensic anthropology. In addition, arthropod diversity will vary depending upon the geographic location therefore entomological data collected from one scene may not be applicable at another. This study will attempt to document entomological specimens collected from both porcine remains and the area enclosed by the Boston University Forensic Anthropology Research Training Center in Holliston, Massachusetts. The intent is to reveal which species of arthropods populate the area, and which of those, particularly flies, are of forensic significance.
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Almond, J. E. "Studies on Palaeozoic Arthropoda." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384278.
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Hertzog, Lionel [Verfasser], Wolfgang W. [Akademischer Betreuer] [Gutachter] Weisser, Nico [Gutachter] Eisenhauer, and Eric [Gutachter] Chauvet. "Plant diversity impacts on arthropod communities and arthropod-mediated processes / Lionel Hertzog ; Gutachter: Wolfgang W. Weisser, Nico Eisenhauer, Eric Chauvet ; Betreuer: Wolfgang W. Weisser." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1130323226/34.
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Borges, Paulo Alexandre Vieira. "Pasture arthropod community in Azorean Islands of different geological ages." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285174.
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Szinicz, Gundula. "Biodiversity and arthropod abundance in the upland of Leyte, Philippines." [S.l. : s.n.], 2005. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB12103716.
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Nakamura, Akihiro. "Development of Soil and Litter Arthropod Assemblages in Rainforest Restoration." Thesis, Griffith University, 2008. http://hdl.handle.net/10072/367553.
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Broadscale forest clearance is a major human-induced disturbance with devastating consequences for biodiversity. With a rise in public awareness of biodiversity, the last few decades have seen an increasing number of reforestation activities aimed at recreating natural habitat. To date, research on the outcomes of reforestation for biodiversity have mostly focused upon the recovery of vegetation structure and composition, with relatively little attention being paid to the recovery of fauna, especially invertebrates.
Arthropods inhabiting soil and leaf litter constitute a considerable proportion of the biomass and diversity of a given faunal community, and exhibit strong associations with ecological functioning (i.e. soil formation, decomposition). The recovery of soil and litter arthropods in restored landscapes is therefore important, not only for the recovery of biodiversity but also for the re-development of a functioning ecosystem, a goal of most types of reforestation programs. However, we know little about the patterns of development of arthropod assemblages in reforested landscapes or the mechanisms underpinning any such patterns.
The broad objective of this study was to investigate the effects of selected factors on the colonisation patterns of restored rainforest patches by soil and leaf litter arthropods. Criteria for selecting factors for study included their potential influence on the development of arthropod assemblages and their potential for manipulation by restoration practitioners. The study was conducted on the Blackall Range near Maleny, a mid-elevation (250-530 m a.s.l.) basaltic plateau in subtropical eastern Australia (26°S, 152°E). The plateau supported subtropical rainforest until European settlement in the 19th century, when most of the rainforest was cleared for pasture.
The factors selected for study, in relation to the colonisation of restored habitat patches by soil and litter arthropods, were as follows:
1. the isolation of restored habitat patches from remnant forest;
2. the efficacy of inoculation (re-introduction of rainforest soil and litter arthropods) to restored habitat patches;
3. the quality and quantity of substrate (i.e. mulch) used during the initial stages of rainforest restoration;
4. the degree of shading and depth of substrate, and their interaction; and,
5. the short- and longer-term impacts of glyphosate herbicide on arthropod assemblages.
To test explicitly the effects of these factors on arthropod colonisation of restored habitat patches, an experimental approach was adopted in this study. The first four factors were addressed by means of a manipulative field experiment. Small-scale habitat patches were created by adding sterilised mulch to an area previously treated with glyphosate herbicide, and covered with shadecloth, to simulate various conditions of forest restoration which may be experienced by colonising arthropods. In order to test for the impacts of a glyphosate herbicide on rainforest arthropods, I carried out a separate field experiment in which experimental patches were established within remnant rainforests. The experimental approach adopted in this study allowed for the construction of replicated units, while controlling for extraneous factors (e.g. heterogeneity of litter composition, habitat area, age of restoration), to enable robust examination of the effects of selected factors.
To monitor assemblage composition, arthropods were collected using two methods: pitfall traps and extraction from litter. Responses of arthropods were analysed at two main levels of taxonomic resolution: ‘coarse’ arthropods (all arthropods sorted to Order/Class) and ants, identified to species.
Before the field experiments, a survey was carried out to collect reference information on the distribution of soil and litter arthropods in remnant rainforests (undisturbed reference sites) and cleared pasture (disturbed reference sites) in the study region. Regardless of the sampling method (pitfall or litter extraction) or taxonomic resolution employed (coarse arthropods or ant species), the composition of arthropod assemblages clearly differed between rainforest and pasture. The information obtained from this survey generated potential bio-indicators of forested and cleared habitats, assisting interpretation of the data obtained from the field experiments.
The effects of habitat isolation and inoculation were tested using ‘restored’ habitat patches which were established within cleared pasture at increasing distances (0, 15, 100 and ca. 400 m) from the edges of rainforest remnants. After nine months, rainforest-dependent taxa were found to have only colonised the habitat patches closely adjacent to rainforest remnants. Attempts to increase the extent of arthropod establishment by inoculation were unsuccessful: the majority of rainforest arthropods from the raw inoculum failed to persist within the isolated plots. The results indicated that many forest-dependent soil and litter arthropods may have a limited capacity to colonise isolated restoration sites, and/ or small experimental plots in the short term. Inference from the experiment was potentially limited by the relatively small temporal and spatial scales of restoration treatments. Avoiding these limitations in future research may require controlled and replicated efforts in experimental restoration over larger areas, based on collaborations between researchers and practitioners.
To test the effects of quality and quantity of substrate on arthropod colonisation, habitat patches were established by adding either sterilised hay (a conventionally used mulching material in restoration projects) or woodchip mulch (a structurally more complex alternative), each at two depths (3-5 cm, 10-15 cm). Habitat patches were positioned within pasture adjacent to the edges of rainforest remnants to minimise the effect of isolation, and were all unshaded to create conditions similar to those during the initial stages of rainforest restoration. Despite its simple composition, hay performed better than woodchips in facilitating colonisation by arthropods characteristic of rainforest. However, neither hay nor woodchip mulch inhibited arthropods invading from the surrounding pasture. Shallow hay was favoured by ants characteristic of rainforest, but other groups of arthropods (e.g. Coleoptera, Isopoda) were associated with deep hay (10-15 cm). The optimum amount of hay may therefore vary among different groups of arthropods.
The effects of shading and mulch depth, and potential interactions between them, were tested using habitat patches created with varying degrees of shading (none, 50% or 90% shading) and two depths of woodchip mulch (3-5 cm or 10-15 cm deep). The presence of shading, at both 50% and 90%, encouraged colonisation of habitat patches by arthropods characteristic of rainforest. However, only the more complete shading treatment (90%) inhibited re-invasion of restored patches by arthropods from the surrounding pasture habitat. Effects of mulch depth were significant only for rainforest-associated ant species which responded positively to shallow mulch within shaded plots. These results suggest that moderate levels of canopy closure, as produced by tree spacings typical of timber plantations, may be sufficient to facilitate colonisation of reforested land by rainforest arthropods. However, greater canopy shading (90%) is likely to be needed to inhibit re-invasion of arthropods from surrounding pasture habitat. Using deeper woodchip mulch does not necessarily create more suitable conditions for rainforest arthropods or offset the deleterious effects of the lower levels of shading.
Paired herbicide-treated and control plots were created within rainforest remnants to test the short- (approximately three days) and long-term (approximately three months) impacts of herbicide application on soil and litter arthropod assemblages on the floor of the remnant rainforests. The results found no deleterious effects of glyphosate herbicide formulated as Roundup® Biactive™ on rainforest soil and litter arthropods; hence, this herbicide appears suitable for the control of unwanted plants in rainforest restoration projects, from the perspective of arthropod biodiversity.
The outcomes of this study also have a number of important implications for the monitoring of the development of soil and litter arthropod assemblages in restored rainforests. First, pitfall traps (a commonly used sampling technique) can provide sufficient information on the state of arthropod assemblages in the context of subtropical rainforest restoration projects, although samples collected by this method alone do not necessarily represent the whole suite of soil and litter arthropods (e.g. cryptic arthropods that live in soil and litter). Second, a combination of higher-taxon sorting of all arthropods, together with species-level sorting of a significant major taxon (ants), provides a feasible compromise between comprehensiveness and detail in monitoring responses of arthropods. Third, ‘composite habitat indices’, such as those developed in this study to quantify the extent to which a site resembles rainforest or pasture in terms of its arthropod assemblage, can help alleviate problems associated with the patchy distribution of arthropod taxa in monitoring samples.
The experimental approach adopted in this study provided information that would otherwise have been limited by post-hoc empirical studies alone. This study’s results demonstrated that the selected aspects of different restoration techniques and management affect the colonisation of soil and litter arthropod assemblages in rainforest restoration of old fields.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Faculty of Science, Environment, Engineering and Technology
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Alharbi, B. "Arthropod-borne infections in the United Kingdom and Saudi Arabia." Thesis, University of Salford, 2018. http://usir.salford.ac.uk/46210/.
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Arthropod vectors can transmit different diseases that are both a significant and widespread cause of mortality and morbidity in both human and wildlife species. However, further studies are required to identify the role of wildlife species as reservoir hosts for such infections. In some countries, such as Saudi Arabia, few studies have taken place whist in other regions individual species may have been neglected, such as red foxes (Vulpes vulpes) in the United Kingdom (UK).To address this paucity of knowledge, samples from different host species from the UK and Ireland (small rodents, red foxes, shrew and ticks species) and from Saudi Arabia Libyan jirds (Meriones libycus) and desert hedgehogs (Paraechinus aethiopicus) were collected and screened for different haemoparasites including Trypanosoma spp., Babesia/Theileria spp., and Bartonella spp. The data within this study describe different haemoparasite prevalences from these different hosts using PCR- based molecular typing tools. Trypanosoma infections were found in mall rodents from the UK and Ireland, however the presence of the invading bank vole (Myodes glareolus) in Ireland appears to have disrupted the host-parasite relationship between wood mice (Apodemus sylvaticus) and trypansomes. Babesia vulpes was identified in 134/392 (34%) of red foxes in the UK, suggesting that this potentially important parasite may be common in the UK. From Saudi Arabia, the data within this study showed that 49/121 (40%) of jirds were infected with Theileria spp. whereas 74/112 (66%) of hedgehogs harboured this parasite. Furthermore, Bartonella spp. infections were found in both jirds and hedgehogs from Saudi Arabia, where 73(60% of jirds and 15(13%) of hedgehogs were found to be infected with Bartonella. To compare the methods of PCR, real- time PCR and the newest technique, Next Generation Sequencing (NGS), a number of Ixodes ricinus tick samples were screened by NGS by analysing 16S rRNA gene and the resultant data were confirmed by either PCR or real-time PCR. Different bacterial infections were found in the samples including Anaplasma phagocytophilum, Borrelia graini, Candidatus Midichloria, and Rickettsia Helvetica. The comparison between these techniques revealed that NGS offers the potential to be a useful tool in screening hosts and vectors for infections, particularly in identifying novel infections.
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Zangger, Adrian. "Wildlife overpasses over a motorway as connecting means for forest arthropod communities /." [S.l.] : [s.n.], 1995. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Azarbayjani, Fathollah Fathi. "Assessment of estimators and factors affecting arboreal arthropod biodiversity on Melaleuca Linariifolia." Thesis, Richmond, N.S.W. : Faculty of Science and Technology, University of Western Sydney, Hawkesbury, 1997. http://handle.uws.edu.au:8081/1959.7/246.
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This study was carried out in a woodland on the campus of University of Western Sydney at Richmond, Australia to investigate seasonal effects and recovery speed of arboreal arthropods after disturbance. Twenty one pairs of Melaleuca linariifolia Sm. trees were sampled using insecticide spraying in a log2 nine period sequence (1-32) of weeks supplemented by additional samples to incorporate seasonal (weeks 24 and 48) and annual (week 52) samples. Using species accumulation curves, it was found that four collectors provided a reasonable representation of a tree's fauna and that a single tree does not provide a representative sample of the arthropod fauna found on trees of this species in the study area. The application of richness and evenness indices in different seasons showed significant changes in diversity. It was clear from the findings of the study that careful attention needs to be paid to experimental design. Under replication is the normal situation in previous studies and the effects of location, season and disturbance are all critical factors affecting the estimation of diversity.
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O'Connell, Dean Michael, and n/a. "Plant-arthropod interactions : domatia and mites in the genus Coprosma (Rubiaceae)." University of Otago. Department of Botany, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090807.160026.
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Plant-based defence mutualisms involve aspects of plant morphology that influence the performance of plant parasites, their natural enemies and trophic interactions. Leaf domatia, small indentations on the underside of leaves, can be structurally complex, and are often inhabited by potentially beneficial mites and other arthropods. Plant morphological traits such as domatia that enhance mutualistic relationships may result in increased plant growth rates, and reproductive success. New Zealand supports ~60 plant species that have domatia, the most speciose genus being Coprosma. The aim of this thesis was to examine factors that affect the production of leaf domatia and their relationship with foliar mite assemblages. The three main objectives of this thesis are: First, to investigate the production of foliar domatia and their susceptibility to limited resources, particularly to carbon availability. Second, to test if domatia are inducible structures during leaf ontogeny in the presence of foliar mites and/or fungi. Finally, to explore the effect of domatia availability on foliar mite assemblages on leaves with and without resident mites. This thesis tested the stated objectives using C. lucida, C. ciliata, C. foetidissima and C. rotundifolia, with a combination of field investigations and controlled manipulative experiments. The cost of domatia production was investigated using two field surveys and two controlled experiments. Under natural conditions the relationship between leaf morphology and domatia were measured in situ and across an altitudinal gradient. The experimental manipulations used carbon and nutrient stress, induced by temperature, light and fertilizer application. The second objective was experimentally tested under field conditions by manipulating foliar mites and fungal densities on C. rotundifolia. The third objective was investigated by manipulating domatia availability on C. lucida shrubs across three different vegetation types. Under field conditions, the number of domatia per leaf was associated with leaf morphology in C. lucida and C. foetidissima, but not C. rotundifolia. Foliar carbon showed a positive, but weak association with domatia production in C. foetidissima and C. ciliata. Altitudinal induced-carbon stress on domatia production was ambiguous. Domatia production in C. foetidissima was positively associated to altitude in field survey (1), and negatively associated in the second survey, with no correlation found between carbon and altitude. Experimental C. rotundifolia shrubs held under elevated night-time temperatures showed a 2.5 fold increase in respiration, a 34% to 91% decrease in daily carbon gain, and 38% decrease in domatia per leaf mass. Domatia production showed no significant differences under nutrient stress. The results showed little evidence to support a role for induction of domatia. Domatia production in new leaves was similar across all experimental treatments. Diverse vegetation types supported 60% higher mite species. Leaves with domatia supported ~22 to 66% higher mite densities, greater colonisation success and more diverse mite assemblages, than those without domatia. In the pastoral vegetation, the absence of predatory mites on experimental shrubs resulted in no differences in fungivorous mite densities regardless of domatia availability. Plant investment in foliar domatia appears associated with the number of available sites on the leaf under field conditions. The role of carbon availability during leaf ontogeny suggests a complex and highly variable association with domatia production. Domatia are constitutive defence structures that influence mite assemblages, mediating both beneficial and antagonistic relationships. This thesis concludes that domatia are in part, carbon-based non-inducible structures that influence mite assemblages, plant-mite and mite-mite interactions, and increase the probability of successful colonisation.
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Coetzee, J. H. (Jacobus Hendrik). "Arthropod communities of Proteaceae with special emphasis on plant-insect interactions." Thesis, Stellenbosch : Stellenbosch University, 1989. http://hdl.handle.net/10019.1/66615.
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Thesis (PhD) -- Stellenbosch University, 1989.ENGLISH ABSTRACT: Arthropod communities of five proteaceous species viz. Protea repens. P. neriifolia. P.cynaroides, Leucospermum cordifolium and Leucadendron /aureolum were studied. A faunal list of the insects was compiled according to the feeding guilds of insects. Six phytophagous guilds were recognized: flower visitors, thrips, endophages, ectophages, sap-suckers, and ants. The guild composition, species packing and seasonal distribution for the free-IMng insects, spiders and other arthropods were investigated on the different plant species. The ants, flower visitors and sap-sucking species found on the plant species, were very similar, but the number of leaf chewing species common to all the plant species was low, suggesting that some species were monophagous. Insect abundance increased during the wet winter months when the plants were in flower. Of the total number of herbivores collected, flower visitors represented 69,5%, leaf feeders 14,5% and sap-suckers 16,1 %. The chewers constituted 60,1% of the total herbivore. biomass. Leaf damage increased with age ; young leaves were practically free of herbivore damage, while older leaves were stm acceptable as food. The degree of insect damage differed amongst the plant species varying from 2% to 15%. The following leaf characteristics were investigated to determine the factors involved in defence against insect herbivory : total phenolic content, protein precipitating ability, cyanogenesis, nitrogen content, leaf toughness, woodiness and fibre content lt appears that the plant species use different mechanisms to protect their leaves. The infructescences of Protea repens were exploited by the larvae of four Coleoptera and four Lepidoptera species. The community structure of these phytophagous insects was determined largely by negative interactions. Various strategies are followed (e.g. niche segregation in time and space) to lessen interspecific competition.
AFRIKAANSE OPSOMMING: 'n Studie van die arthropoocl gemeenskap op vyf proteasoorte, naamlik Protea repens. P. neriffolia. P. cynaroides. Leucospennum cordffolium en Leucadendron laureolum is gedoen. 'n Faunalys van insekte volgens hul voedingsgDdes is saamgestel. Die insekte is in ses fitofage gDdes verdeel naamlik blombesoekers, blaaspootjies, endovoeders, ektovoeders, sapsuiers en miere. Die samestelling van die gDdes, spesie-rangskikking en seisoenale verspreiding is bepaal vir die vrylewende insekte, spinnekoppe en ander arthropode. Die miere, blombesoekers en sapsuierspesies wat op die plantsoorte gevind is, is byna dieselfde, maar verslalle in die blaarvoederspesies is gevind wat 'n aanduiding is dat sommige spesies monofaag mag wees. Gedurende die nat wintermaande toon die insekgetalle 'n toename. Blombesoekers verteenwoordig 69,5%, blaarvoeders 14,5% en sapsuiers 16,1% van die aantal insekherbivore wat versamel is. Die kouers vorm 60,1% van die totale herbivoor biomassa Soos die blare verouder, neem die skade op die blare toe; jong blare toon byna geen skade nie, terwyl ouer blare steeds geskik is vir insekvoedsel. Die insekskade op die blare wissel by die verslallende plante tussen 2% en 15%. Om te bepaal watter blaareienskappe moontlik 'n rol kan speel in blaarverdediging teen insekte is die volgende ondersoek: totale fenoliese inhoud, die vermoe om proteiene te presipiteer, sianogenese. stikstofinhoud, blaartaaiheid, houtagtigheid en veselinhoud. Dit wil voorkom asof die plante verskillende meganismes gebruik om die blare te beskerm. Saadkoppe van Protea repens word deur vier Coleoptera en vier Lepidoptera spesies benut Die gemeenskapstruktuur van die boarders word tot 'n groat mate bepaal deur negatiewe interaksies. Verskeie strategiee word gevolg (bv. nissegregasie in ~ en ruimte) om kompetisie tussen spesies te verminder.
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Burkhalter, John Curtis. "Arthropod Biodiversity in Response to the Restoration of Former Pine Plantations." UNF Digital Commons, 2010. http://digitalcommons.unf.edu/etd/368.
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The goal of ecological restoration is to return degraded or altered ecosystems to their pre-disturbed state with respect to ecosystem structure, function, and composition. In the current study the research objective was to reestablish high levels of biodiversity on two restored pine plantations as well as restore a native pine flatwoods ecosystem. Managed, even-aged pine flatwoods are now the most extensive ecosystem in North Florida, comprising approximately 70% of the forested landscape. Slash pine trees were thinned in the experimental plots to restore the natural slash pine density of native ecosystems. In addition to the thinning treatments, experimental plots have been clear-cut and all vegetation removed from the plots. Arthropods were sampled by employing pitfall traps, sticky traps and sweep netting. This study assesseed the success of the restoration techniques employed by looking at biodiversity with a fine-resolution, taxonomically narrow approach by identifying the arthropods down to the taxonomic level of family and determining the number of morphospecies. Species were also subdivided into functional groups based upon the ecosystem services that they provide and their trophic level. Analyses revealed that arthropod species and guild diversity was not significantly affected by treatments in both 2008 and 2009. The experimental treatments were able to recover to pre-disturbance levels after two years following restoration. This indicates that these arthropod communities are fairly resilient and are able to recover fairly quickly following perturbation. Interestingly, community similarity measures revealed that although the experimental treatments were no more diverse than control plots the community species composition was fairly dissimilar between treatments, with plots becoming more dissimilar from 2008 to 2009. More long term data should reveal if these plots are proceeding along different successional trajectories in terms of community species composition and also will allow us to gain more insight into the long term effect of the treatments on biodiversity.
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Omena, Paula Munhoz 1982. "Effects of predators on bromeliad-aquatic arthropod communities and ecosystem functioning." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315725.
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Orientador: Gustavo Quevedo RomeroTexto em português e inglês
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Com a intensificação das transformações dos sistemas naturais pela atividade humana, o entendimento dos processos que afetam as comunidades e o funcionamento dos ecossistemas tornou-se um tema central para a ecologia contemporânea. As interações entre as espécies, bem como as interações entre as espécies e os componentes abióticos do meio ambiente, afetam tanto os padões de diversidade biológica como funções ecossistêmicas. Neste trabalho, buscou-se compreender o papel relativo das interações predador-presa e dos componentes abióticos sobre as propriedades das comunidades e funcionamento dos ecossistemas. No primeiro capítulo, investiguei o papel do tamanho do habitat sobre os efeitos de predadores terrestres na estrutura de comunidades e funcionamento de ecossistemas adjacentes. O tamanho do habitat modera cascatas tróficas dentro de ecossistemas, deste modo, esperei que efeitos similares do tamanho do habitat poderiam afetar cascatas tróficas que ocorrem através dos limites dos ecossistemas. No segundo capítulo, explorei predições relacionadas a variação no formato de pirâmides tróficas de biomassa ao longo de gradientes ambientais (tamanho do habitat, concentração de detritos e produtividade). Além disso, investiguei a contribuição relativa dos efeitos de consumo direto e do risco de predação nas interações predador-presa como mecanismos estruturadores de pirâmides tróficas de biomassa. No terceiro capítulo, tive como objetivo investigar os efeitos de dois extremos de um gradiente ambiental e os efeitos de predadores sobre os componentes da diversidade de presas detritívoras (i.e., diversidade funcional, filogenética e taxonômica). Além disso, explorei o papel relativo do ambiente, dos predadores e dos componentes da diversidade sobre o funcionamento ecossistêmico (i.e., decomposição e fluxo de nitrogênio). Os resultados encontrados nos três capítulos demonstram que fatores abióticos são cruciais na determinação das propriedades das comunidades, interações predador-presa e, consequentemente, no funcionamento ecossistêmico. O papel relativo dos efeitos cascatas de predadores é altamente dependente das condições ambientais que medeiam as interações entre predadores e presas
Abstract: In the face of the increasing transformation of environmental conditions by human activity, understanding the processes that affect communities and ecosystem functioning has become fundamental goals in ecology. The interactions between coexisting species and, their interactions with the abiotic components of environment, affect the patterns of biological diversity and functions of ecosystems. In this study, I sought to understand the relative role of predator-prey interactions and of abiotic factors on the communities¿ properties and ecosystem functioning. In the first chapter, I investigated the role of habitat size in mediating the effects of terrestrial predators on the structure of communities and the functioning of adjacent ecosystems. Habitat size mediated trophic cascades within ecosystems; therefore, I expected that similar effects of habitat size affect cross-ecosystem trophic cascades. In the second chapter, I explored predictions related to the variation of trophic pyramids of biomass across environmental gradients (i.e., habitat size, detritus concentration and productivity). Furthermore, I investigated the relative contribution of consumptive and non-consumptive effects of predators on the shape of trophic pyramids of biomass. In the third chapter, I sought to investigate the effects of two extremes of an environmental gradient and the effects of predators on the components of detritivores diversity (i.e., functional, phylogenetic and taxonomic). Moreover, I explored the relative role of environment, predators and detritivore diversity components on the functioning of ecosystems (i.e., detritus processing and nitrogen flux). The results from this study demonstrated that abiotic factors are crucial determinants of community properties, predator-prey interactions and ecosystem functioning. The relative role of the predators cascading effects are strongly dependent on the environmental conditions which mediate the interactions between predators and prey
Doutorado
Ecologia
Doutora em Ecologia
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Wikingson, Molly. "The effect of restoration of semi-natural grassland on arthropod populations." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-176392.
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Semi-natural grasslands are valuable ecosystems that have a high biodiversity. Unfortunately, a lot of this biodiversity is being lost as semi-natural grasslands are declining in both size and number. Restoration to reestablish semi-natural grasslands is often done by removing shrubs and trees and planting seeds. After this reinstalment of management such as mowing, and grazing is done to keep woody plants away. Grassland management and restoration have a proven positive effect on species richness and abundance regarding vascular plants. Yet little is known about the effects on insects and spiders. By reviewing scientific publications, I explored how insects and spiders are affected by management, as well as how local and landscape factors affect restoration. Grassland history and timing of restoration, as well as insect and spider’s dispersal ability, affects the possibility of a successful restoration. Larger habitats with good connectivity and surrounding supporting habitats are positive factors for viable insect and spider communities. By comparing different publications, some species benefit from intensive grazing and mowing, and some show a negative response. Long-term low to medium intensive management will favor a higher biodiversity compared to short-term intensive management. In conclusion, balancing conflicts and trade-offs is the real challenge when it comes to semi-natural grassland restoration. In general, to benefit as many insect and spider species as possible management should focus on variation in grass height and flower abundance. However, more research on how insect and spiders are affected by grassland restoration is something I believe would benefit future conservation projects.
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Wiwatwitaya, Decha. "Effects of forest disturbances on the soil arthropod communities in Thailand." Kyoto University, 2005. http://hdl.handle.net/2433/144996.
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Kyoto University (京都大学)0048
新制・論文博士
博士(農学)
乙第11677号
論農博第2560号
新制||農||913(附属図書館)
学位論文||H17||N4060(農学部図書室)
23490
UT51-2005-D595
(主査)教授 武田 博清, 教授 高藤 晃雄, 教授 東 順一
学位規則第4条第2項該当
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Wilson, Erin Elizabeth. "Ecological Effects of an Invasive Social Wasp on Hawaiian Arthropod Communities." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3369144.
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Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed September 15, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Ekwudu, O'mezie. "Diversity of arthropod-borne viruses and implications for Wolbachia-based biocontrol." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/127159/1/O%27mezie_Ekwudu_Thesis.pdf.
Full textAbstract:
This research examines the impact of genetic diversity in dengue virus (DENV) on incubation period in vector mosquitoes, and on Wolbachia, a novel vector biocontrol agent. It also extends the DENV study to other flaviviruses (Zika and West Nile - Kunjin) and alphaviruses (Barmah Forest, Ross River and Sindbis) to provide evidence as to whether a heat-resistant strain of Wolbachia, wAlbB, can be used to suppress the transmission of these mosquito-borne viruses. The research outcomes show that viral genetic variation is reflected in transmission kinetics of DENV. Data from the Wolbachia experiments provide the groundwork for future in vivo mosquito trials.
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Godber, J. F. "Spatial distribution of calcium release sites in muscle." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371540.
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Owens, Madeline. "Emmetropization in Arthropods: A New Vision Test in Several Arthropods Suggests Visual Input may not be Necessary to Establish Correct Focusing." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1563527198165493.
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Azarbayjani, Fathollah Fathi. "Assessment of estimators and factors affecting arboreal arthropod biodiversity on melaleuca linariifolia /." Richmond, N.S.W. : Faculty of Science and Technology, University of Western Sydney, Hawkesbury, 1997. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030527.110422/index.html.
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Sohlström, Esra Helena [Verfasser], Ulrich [Gutachter] Brose, Nico [Gutachter] Eisenhauer, and Eric [Gutachter] Allan. "Arthropod communities in a changing world : combined impacts of climate change and land-use intensification on arthropod communities / Esra Helena Sohlström ; Gutachter: Ulrich Brose, Nico Eisenhauer, Eric Allan." Jena : Friedrich-Schiller-Universität Jena, 2020. http://d-nb.info/1226217702/34.
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