Bibliography: leaves 133-148. Examines sugar foraging in the field by adult female parasitoid wasp, Cotesia rubecula (Hymenoptera, Braconidae), to determine its effect on fecundity and lifespan. In the field, the area in which wasps search for sugar is likely to depend on the degree of association of hosts with nectar or honeydew, supporting the hypothesis that sugar encounters in the field happen opportunistically during host foraging activities. The survival gained by sugar feeding my often be severely limited by quality and quantity of sugary food and extrinsic mortality factors such as adverse weather conditions and predation, so the need for food must be studied in relation to a species' adaptation to its environment. Concentrations of sugar sources may distract wasps from host-foraging when the density of hosts is low. This has implications for flower propagation in agro-ecosystems with a view to supporting natural enemies of insect pests.

Bibliography: leaves 133-148. / xii, 148 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines sugar foraging in the field by adult female parasitoid wasp, Cotesia rubecula (Hymenoptera, Braconidae), to determine its effect on fecundity and lifespan. In the field, the area in which wasps search for sugar is likely to depend on the degree of association of hosts with nectar or honeydew, supporting the hypothesis that sugar encounters in the field happen opportunistically during host foraging activities. The survival gained by sugar feeding my often be severely limited by quality and quantity of sugary food and extrinsic mortality factors such as adverse weather conditions and predation, so the need for food must be studied in relation to a species' adaptation to its environment. Concentrations of sugar sources may distract wasps from host-foraging when the density of hosts is low. This has implications for flower propagation in agro-ecosystems with a view to supporting natural enemies of insect pests. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied & Molecular Ecology, 2002

Addendum in pocket. Biblography: leaves 162-173. Phytophagous sucking insects, aphids in particular, are common pests of plants. These insects secrete salivary enzymes into their food material. One plant defence mechanism is the induction and/or accumulation of deterrent phytochemicals. In the present study, a model enzyme system was chosen to mimic the oxidative activity of insect saliva. Isolation and sructural identification of the products of plant allelochemicals was achieved for several substrates. Insects were also exposed to individual plant chemicals in feeding "choice" tests. Preliminary examinations suggest that plants containing increased levels of phenolic allelochemicals show correlated increases in resistance to attack by aphids.

The biology and behavior of the codling moth, Cydia pomonella (L.), was studied to determine factors responsible for differences in susceptibility to moth damage among apple and pear cultivars. In release experiments, codling moth adults were intercepted in significantly greater numbers in host (apple, pear) than in non-host (maple) trees, suggesting a directed response rather than random movement to host trees. There was no correlation between adult preference for certain hosts and the susceptibility of the hosts to codling moth attack. Adults were guided by cues from the tree canopy, foliage and fruit. Cues from host fruit were less important at the beginning of the season. Similar adult behavior patterns were observed in different coding moth strains. However, moths reared on apples were guided more by olfactory cues from fruit than sterilized moths reared on artificial diet. The percentage of moths mating under caged conditions was higher in apple and pear than in maple trees. In host plants, stimuli from fruit were not essential for mating. The egg distribution in the field varied through the season depending on the host cultivar. However, mean distance of eggs to fruit, as well as larval travel speed, was not different among host cultivars. Selection of an oviposition site by the adult female was affected by several factors, including visual, chemical, and tactile stimuli of host fruit, as well as anatomical (pubescence) and chemical (oviposition stimulants) properties of leaves. There were no differences in natural mortality and developmental rates of the egg stage on host cultivars. However, there were significant differences in first instar larval mortality among hosts over most of the season. Mortality was much higher on 'Anjou' than on 'Bartlett' and 'Red Delicious', except at the end of the season. Differential first instar mortality was due to the different rate of success in entering the fruit. The ability to penetrate fruit was correlated with infestation levels observed in the field and related both to neonate behavior and anatomical characteristics of host fruits. Larval food source did not affect larval and pupal development rates, adult fecundity, or egg viability. / Graduation date: 2001

The probing behavior and feeding activity of green peach aphid, Myzus persicae Sulzer, on Bacillus thuringiensis ssp. tenebrionis- transgenic potatoes, insecticide treated potatoes, and host plants with different preference were electronically monitored. I found that first, transgenic potatoes had no effect on green peach aphid probing suggesting that transmission of green peach aphid-borne viruses would not be affected. Second, the probing behavior of green peach aphid was not modified by the insecticides, aldicarb, Admire, and Di-syston. However, the postfeeding behavior of aphids was different over time and with insecticides, which might have an influence on virus transmission in the field. Third, the probing behavior of green peach aphid on host plants with different preference varied. Aphids probed more when they moved from a higher-preference host plant (radish) to a lower preference host plant (potato). In addition, the settling rate was low when aphids were moved from higher to lower preference host plants. This difference might affect virus transmission in the field. Vector efficiency, relationship of virus transmission between vector and host plants, and vector control strategies are discussed. In addition, the probing behavior of two mosquito species, Aedes aegypti and Anopheles stephensi, on mice was recorded electronically to examine waveform patterns and to quantify sporozoite output. My studies indicated that sporozoite output of malaria-infected mosquitoes was not detected by using the electronic monitoring system. The relationship between waveform patterns and penetration activities of mosquitoes needs clarification before further studies can be conducted. / Graduation date: 1994

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 134-151).

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