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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.
51

Revision and phylogenetic analysis of the spider genus Glenognatha Simon, 1887 (Araneae, Tetragnathidae) / Revisão e análise filogenética do gênero Glenognatha Simon, 1887 (Araneae, Tetragnathidae)

Cabra García, Jimmy Jair 23 September 2013 (has links)
A taxonomic revision and phylogenetic analysis of the spider genus Glenognatha Simon, 1887 is presented. The analysis is based on a data set including 24 Glenognatha species plus eight outgroup representatives of three additional tetragnathine genera and one metaine, scored for 82 morphological characters. Eight unambiguous synapomorphies support the monophyly of Glenognatha, all free of homoplasy. Some internal clades within the genus are well-supported and its relationships are discussed. The genus Glenognatha has a broad distribution occupying the Neartic, Neotropic, Afrotropic, Indo-Malaya and Oceania ecozones. As revised here, Glenognatha comprises 27 species, four of them only know from males. New morphological data are provided for the description of thirteen previously described species. Eleven species are newly described: G. sp. nov. 1, G. sp. nov. 3, G. sp. nov. 4 and G. sp. nov. 7 from southeast Brazil, G. sp. nov. 6, G. sp. nov. 9 and G. sp. nov. 10 from the Amazonian region, G. sp. nov. 2, G. sp. nov. 5 and G. sp. nov. 8 from northern Andes and G. sp. nov. 11 from central Mexico and Southern United States. Females of G. minuta Banks, 1898, G. gaujoni Simon, 1895 and G. gloriae (Petrunkevitch, 1930) and males of G. globosa (Petrunkevitch, 1925) and G. hirsutissima (Berland, 1935) are described for the first time. Three new combinations are proposed in congruence with the phylogenetic results: G. argyrostilba (O. P.-Cambridge, 1876), G. dentata (Zhu & Wen, 1978) and G. tangi (Zhu, Song & Zhang, 2003), all previously included in Dyschiriognatha. The following taxa are newly synonymized: Dyschiriognatha montana Simon, 1897, Glenognatha mira Bryant, 1945 and Glenognatha maelfaiti Baert, 1987 with Glenognatha argyrostilba (O. P.-Cambridge, 1876) and Glenognatha centralis Chamberlin, 1925 with Glenognatha minuta Banks, 1898. A key to species of Glenognatha and distribution maps are provided. / A revisão taxonômica e análise cladística do gênero Glenognatha Simon, 1887 é apresentada. A análise é baseada em uma matriz que inclui 24 espécies de Glenognatha, oito representantes do grupo externo, incluindo três gêneros da subfamília Tetragnathinae e um de Metainae, e 82 caracteres morfológicos. Oito sinapomorfias não ambíguas sustentam a monofilia de Glenognatha, todas não homoplásticas. Alguns clados internos dentro do gênero são bem suportados e suas relações são discutidas. O gênero Glenognatha apresenta uma ampla distribuição ocupando as regiões Neártica, Neotropical, Afrotropical, Indo-Malaya, Australasia e Oceania. Vinte e sete espécies de Glenognatha são reconhecidas, quatro delas somente conhecidas por machos. Novos dados morfológicos são fornecidos para a descrição de treze espécies previamente conhecidas. Onze espécies novas são descritas: G. sp. nov. 1, G. sp. nov. 3, G. sp. nov. 4 e G. sp. nov. 7 do sudeste do Brasil, G. sp. nov. 6, G. sp. nov. 9 e G. sp. nov. 10 da região Amazônica, G. sp. nov. 2, G. sp. nov. 5 e G. sp. nov. 8 do norte da cordilheira dos Andes e G. sp. nov. 11 da região central do México e sul dos Estados Unidos. As fêmeas de G. minuta Banks, 1898, G. gaujoni Simon, 1895 e G. gloriae (Petrunkevitch, 1930) e os machos de G. globosa (Petrunkevitch, 1925) e G. hirsutissima (Berland, 1935) são descritos por primeira vez. São propostas três novas combinações em congruência com os resultados da análise cladística: Glenognatha argyrostilba (O. P.-Cambridge, 1876), Glenognatha dentata (Zhu & Wen, 1978) e Glenognatha tangi (Zhu, Song & Zhang, 2003), todas previamente incluídas no gênero Dyschiriognatha. Quatro sinonímias são propostas: Dyschiriognatha montana Simon, 1897, Glenognatha mira Bryant, 1945 e Glenognatha maelfaiti Baert, 1987 com Glenognatha argyrostilba (O. P.-Cambridge, 1876) e Glenognatha centralis Chamberlin, 1925 com Glenognatha minuta Banks, 1898. É apresentada uma chave para a identificação e mapas de distribuição para as espécies
52

The ecology, distribution and dispersion of Agelenopsis utahana Chamberlin and Ivie, 1933, and A. potteri (Blackwell, 1846), in the Morgan Arboretum of Macdonald College,P.Q.

Earnshaw, Alice P. R. January 1973 (has links)
No description available.
53

The effect of twice-over rotational cattle grazing on the ground beetles (Coleoptera: Carabidae) and spiders (Araneae) on the Yellow Quill Mixed Grass Prairie Preserve

Stjernberg, Anita 11 April 2011 (has links)
The Yellow Quill Mixed Grass Prairie Preserve is a remnant of an endangered community that is located in southwestern Manitoba and owned by The Nature Conservancy of Canada. In 2005 and 2006, this study was conducted to investigate the effect that the currently-practiced twice-over rotational cattle grazing regime is having on the carabid beetles and spiders. This study primarily compared grazed and ungrazed treatments on three paddocks. A secondary experiment investigated whether the spring graze, fall graze, or the combination of the two had the greatest impact on the carabids and spiders. Three periods were examined in three periods each season: before grazing had begun, after the spring graze, and after the fall graze. A total of 81 species of carabids and 156 species of spiders were recorded, including potentially new provincial records (two carabid species and 20 spider species). Seventy two species of plants were recorded in the study.
54

Navigation by male crab spiders Misumenoides formosipes (Araneae: Thomisidae) : use of floral cues to locate foraging females

Stellwag, Leonard M. January 2007 (has links)
The North American crab spider Misumenoides formosipes is a sit-and-wait predator of insect pollinators. Females are relatively sedentary and adult males must search for females within a heterogeneous habitat. Females are receptive to mating immediately after their adult molt and a first sperm priority pattern places a premium on male ability to locate females quickly. It is unknown what cues males use to navigate during searches for females. We report here on the male-biased operational sex ratio, the distances traveled and the possible cues utilized by moving males. Males in field trials moved towards inflorescences when both visual and chemical cues were available, but were less likely to do so when chemical cues were eliminated. Males in lab trials chose an inflorescence over leaf substrates even in the absence of visual cues. These findings support the hypothesis that these spiders utilize floral chemistry as an environmental cue to optimize mate searches. / Department of Biology
55

Assessment of epigeal arthropods along an urbanization gradient in the municipal area of Potchefstroom, North-West Province, South Africa / Ryan Emslie Jonas

Jonas, Ryan Emslie January 2007 (has links)
Human activities have dramatically altered the functioning of ecosystems through the ages. Urbanization illustrates the effect of anthropogenic activity by the transformation of natural areas to ecologically disturbed regions (development of towns, cities and settlements). The growing need for urban employment in South Africa has led to an increase in the number of informal settlements on the periphery of urban areas. These settlements result in fragmentation and sprawling of cities, which intensifies strain on the natural environment. Fragmentation in urban regions then leads to the formation of 'patches' of land which exhibit different disturbance levels and are generally typified as either urban, suburban or rural areas. These land use types may be ecologically studied along an urbanization gradient, with the intention of obtaining meaningful comparisons. An urbanization gradient contains an urban landscape which consists of a densely built and developed core surrounded by an area of decreasing development and increasing 'naturalness'. The use of urbanization gradients has been proven world-wide as a useful tool for the study of changes in ecological patterns and processes across landscapes. This approach has been used to examine many different impacts of urbanization, namely on invertebrate communities, bird community composition and plant community composition. Using biological indicators to determine the degree of anthropogenic impact on the environment has proven effective in past studies. These indicators can be used to monitor ecological change following habitat disturbance, identify changing trends over time, provide early warning systems of degradation and diagnose the cause of existing problems. Several authors have supported the use of arthropods as suitable indicators of disturbance. The aim of this study was to determine what impact disturbance, due to urbanization, may have had on the diversity and abundances of epigeal (surface roaming) arthropods (focussing on ants, beetles and spiders) following an urbanization gradient approach. In addition, plant and soil data were combined with the arthropod analysis for each site studied, in order to obtain a better picture of how arthropod community composition would change in relation to these factors. The ant group were the numerically dominant group of the arthropods studied, although the beetles did have the highest number of species captured. Spiders were caught in low abundances, but were also represented by a high number of species. Dramatic decreasing trends were observed with respect to the ant abundances and diversity from rural to the more urbanized sites. Quite the opposite, seemed to occur with the beetles and spiders, who were dominant in species and numbers in the urbanized areas. This trend may be explained on account of the occurrence of generalists and opportunistic beetle and spider species, which seem to thrive in these heterogenous urban habitats. When considering environmental components, percentage bare-ground and sand concentration seemed to be the determining factors in the rural sites, around which the ant group aggregated. Sandy habitats with patches of bare-ground provide more favourable micro-habitats for the ant species to roam and scavenge in, and are advantageous for nest building. Clay concentration and abundance of fruit seemed to assist in providing favourable habitats for the opportunistic and generalist beetle species, in the urbanized areas. High clay concentrations in the urban areas provided ideal conditions for abundant organic covering which would favour saprophagous (feed on decaying organic matter) beetle species and support diverse prey for the predatory beetle and spider species to feed on. Abundance of fruit may have attracted numerous herbivorous beetles (frugivorous beetles). Urbanization seemed to have a more pronounced effect on ant diversity and abundances in comparison to the beetles and spiders, and therefore recommended for future utilization as a suitable "Bio-indicator" group for further local disturbance studies. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.
56

The effect of twice-over rotational cattle grazing on the ground beetles (Coleoptera: Carabidae) and spiders (Araneae) on the Yellow Quill Mixed Grass Prairie Preserve

Stjernberg, Anita 11 April 2011 (has links)
The Yellow Quill Mixed Grass Prairie Preserve is a remnant of an endangered community that is located in southwestern Manitoba and owned by The Nature Conservancy of Canada. In 2005 and 2006, this study was conducted to investigate the effect that the currently-practiced twice-over rotational cattle grazing regime is having on the carabid beetles and spiders. This study primarily compared grazed and ungrazed treatments on three paddocks. A secondary experiment investigated whether the spring graze, fall graze, or the combination of the two had the greatest impact on the carabids and spiders. Three periods were examined in three periods each season: before grazing had begun, after the spring graze, and after the fall graze. A total of 81 species of carabids and 156 species of spiders were recorded, including potentially new provincial records (two carabid species and 20 spider species). Seventy two species of plants were recorded in the study.
57

Spider tracheation : its behavioural and physiological consequences

Bromhall, Clive January 1987 (has links)
No description available.
58

Studies in clinical toxinology in South Australia /

White, Julian. January 1988 (has links) (PDF)
Thesis (M.D.)--University of Adelaide, Dept. of Pathology, 1988. / Previous publications comprise main text of thesis. Includes bibliographical references.
59

Effects of wildfire and clear-cutting on ground level spider assemblages in a Boreal forest /

Larivée, Maxim, January 1900 (has links)
Thesis (M. Sc.)--Carleton University, 2003. / Includes bibliographical references (p. 67-75). Also available in electronic format on the Internet.
60

Extraction of potential chemical attractants from Rudbeckia hirta inflorescences

Judkins, Rojenia N. January 2009 (has links)
Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on June 07, 2010). Includes bibliographical references (p. [53]-56).

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