Thesis (D.Sc.1974) from the Dept. of Entomology, University of Adelaide.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1930. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 49-51).

Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 137-153).

Thesis (Ph. D.)--University of Wisconsin, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed on Nov. 10, 2006). PDF text: xiii, 198 p. : ill. ; 9.99Mb. UMI publication number: AAT 3214778. Includes bibliographical references. Also available in microfilm, microfiche and paper format.

This study has investigated the nature of host derived cues used by parous female <I>C. impunctatus </I>in the location of blood meal hosts. Olfaction has been shown to be a vital part of the process. The responses of antennal receptors of females to a variety of host-derived volatile compounds were assessed using the EAG technique. High antennal sensitivity to olfactory cues was indicated by low thresholds for response and, taking into account the volatility of the compounds, a clear hierarchy of response was obtained in which octenol was the most stimulatory, followed by phenolics, lactic acid and finally ketones. Of particular note with regard to phenolic compounds was the finding that 3-derivatives (3-n-propylphenol & 3-methylphenol) were more stimulatory than their 4-derivatives (eg 4-methylphenol). Behavioural assays conducted within a Y-tube olfactometer showed that attraction to olfactory cues was dose dependent. Supra optimal doses which caused receptor saturation (as demonstrated in the EAG assay), also induced marked changes in behaviour with responses being either no different to random expectation, or the compound appearing to be repellent. Wind tunnel assays corroborated these findings for octenol and acetone when used in conjunction with 0.01% CO<SUB>2</SUB>. Upwind flight was found to be maximal, and significantly different from responses to the CO<SUB>2</SUB> standard, at concentrations within the tunnel of 1.33x10<SUP>-8</SUP> g 1<SUP>-1</SUP> and 1.5x10<SUP>-6</SUP> g 1<SUP>-1</SUP>, respectively. These concentrations are approximately those released by a bovid host for octenol and 1/1000x for acetone. Females exhibited a linear dose dependent response to increases in the concentration of CO<SUB>2</SUB> in the wind tunnel up to 0.09% whether gas was released as a plume or as a lightly turbulent cloud. However, at cloud concentrations above this, CNS mediated habituation is suggested to have arrested upwind flight.

Apanteles rubecula is a solitary insect parasite of Pier is rapae (small cabbage white butterfly, imported cabbageworm). The parasite has been successfully introduced to Australia and Vancouver, Canada but has failed to become established at other North American release sites. This practical problem illustrates a fundamental aspect of insect ecology. The seasonal biology of insects is interpreted here as an interaction of responses to ambient conditions. Emphasis centers on the rates at which life history phenomena occur and the importance of the insect's biological chronometers on the outcome of its ecological relationships with its host and its local climate. Comparisons are made between Canberra, Australia and Vancouver, Canada. The parasite's developmental response to temperature is similar in Canberra and Vancouver but the host response differs. Canberra A. rubecula have a longer generation time relative to the host at low temperatures, but shorter generation times at higher, midseason temperatures. Vancouver parasites always have faster generation times than their hosts but the season is truncated in August by a diapause response to daylengths shorter than I5h. The beginning of the season is delayed until late May by the high thermal requirement to terminate diapause. These local responses to temperature and photoperiod result in different phenologies which, while appropriate locally, are disastrous elsewhere. The failure of North American attempts to establish Vancouver A. rubecula is attributed to the diapause characteristics of the released insects. They entered diapause while ambient temperatures remained warm enough for morphogenesis and were unable to survive the obligatory period to diapause termination. Manipulation of the diapause response is one technique in ecological pest management. A methodology for a breeding program and its analysis is presented. Practical suggestion for biological control efforts are made and the role of individual physiological responses in insect seasonal ecology are discussed. / Land and Food Systems, Faculty of / Graduate

No description available.

Host-parasite interactions are extremely important drivers of evolutionary change, characterised by co-evolutionary dynamics with strong reciprocal selective pressure on both host and parasite genomes. However, little is known about the genomic basis of host-parasite interactions, particularly which genes may affect parasite susceptibility, parasite burden and the ability to resolve energetic life-history trade-offs under chronic parasite insult. This thesis examines the genomic, epigenomic and transcriptomic basis of an avian host's physiological response to chronic parasite infection. The model system throughout is the red grouse (Lagopus lagopus scotica) and its main parasite, the gastrointestinal nematode Trichostrongylus tenuis. T. tenuis is highly prevalent and imposes substantial fitness costs that affect demography and population dynamics through an impact on territorial behaviour, energy balance, fecundity and mortality. Here, the genomic architecture of variation in individual T. tenuis burden is examined via de novo identified candidate genes, genome-wide SNPs and genome-wide cytosine methylation polymorphisms. Further, molecular signatures of natural selection in identified genomic regions are examined across a landscape in northeast Scotland with heterogeneous parasite pressure. Finally, the transcriptomic response of red grouse to experimental T. tenuis infection and manipulation of testosterone titre is harnessed to identify a transcriptomic component in testosterone-driven physiological trade-offs in a sexual selection context.