Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: p. 169-180.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 4 uppsatser.

I obtained densities of nocturnal rodents in the saguaro (Carnegiea gigantea) forest of Saguaro National Monument, Arizona with live trapping techniques, in 1984 and 1985. I sampled vegetation density, percent cover, and foliage height diversity. My objective was to determine if humans influenced nocturnal rodents and their habitat. Rodent populations and vegetation were analyzed through 2-way analysis of variance. Few significant differences were determined for rodent numbers between experimental and control plots. My findings show that minimal impact has occurred on rodent populations and on vegetation by humans in Saguaro National Monument.

Plants come under attack by a variety of organisms, including insects and pathogenic microorganisms such as viruses. Plant viruses can interact indirectly with their vectors by inducing changes to plant chemistry which may alter its attractiveness as a host for herbivore vectors. Using red raspberry as a study system, this study aimed to investigate the host plant mediated interactions occurring between the large raspberry aphid, Amphorophora idaei, and two of the viruses that it transmits, Black raspberry necrosis virus (BRNV) and Raspberry leaf mottle virus (RLMV). In whole plant bioassays, BRNV and RLMV-infected plants were shown to be initially more attractive to A. idaei and aphids remained on the initially selected host plant for a period of approximately 30 minutes. In addition, A. idaei took three days longer to reach reproductive maturity compared with those feeding on non-infected plants, suggesting a virally-induced manipulation of aphid behaviour whereby a deceptive attraction of the vector to a host plant found to be nutritionally poor, presumably acts to promote virus transmission. Investigations of the underlying plant chemistry revealed that raspberry viruses may be capable of facilitating aphid feeding by reducing leaf phenolic concentration when aphids are feeding and that infection with BRNV and RLMV resulted in significantly elevated levels of carbon and free amino acids in the leaves. While increased concentrations of amino acids might be expected to promote aphid performance, the amino acid composition was dominated by glutamate (77% of total content of infected plants), a previously suggested indicator of reduced host-plant suitability for aphids. Volatile entrainments from virus-infected plants showed elevated levels of the green leaf volatile (Z)-3-hexenyl acetate. Bioassays subsequently revealed that this compound acted as an aphid attractant at a concentration of 50 ng ml-1 but that aphid behaviour was unaffected by lower concentrations. The combined utilisation of PCR diagnostics developed from newly sequenced viral genomes and the implementation of a non-invasive, targeted method of sampling plant headspace volatiles enabled this study to provide novel insights into the nature of host plant mediated interactions between aphids and the viral pathogens that they transmit.

Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 7, 2007) Includes bibliographical references.

Thesis (Ph. D.)--University of Nevada, Reno, 2007. / "December, 2007." Includes bibliographical references . Online version available on the World Wide Web.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains x, 196 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 1995. / Typescript (photocopy). Includes bibliographical references (leaves 211-237). Also available online.

Thesis (M.S.)--Rhodes University, 2004. / Title from PDF t.p. (viewed on Apr. 23, 2006). Includes bibliographical references (leaves 122-136).