Components of host plant affiliation for two, small, blue butterflies were examined and compared. The two butterflies, Glaucopsyche lygdamus and Plebijus icariodes (Lycaenidae), are superficially quite similar but differ in host range. Oviposition preferences were determined for each butterfly species by following individual butterflies in the field and recording butterfly behavior, host plant availability and host plant characteristics. Where preferences for one host species or one plant part over another were found, potential explanations were pursued by assessing and comparing larval performance on those plant species and parts in question. Larval performances were measured in terms of survival, growth, and ant attendance in the field, and survival, growth, and pupal mass in the laboratory. All foods were also analyzed for alkaloid content, and larvae were raised on plants known to differ in alkaloid content. Individuals of both butterfly species preferred to oviposit on those host species with which they had had recent experience; nevertheless, individual butterflies of both species frequently oviposited on multiple host species during the course of a single follow bout. For G. lygdamus the availability of flower buds was critical for ovipositing adults and feeding larvae. Flower buds of any one host species were unpredictable, however, and G. lygdamus consequently utilized different host species at different times. This observation predicted a positive relationship between butterfly population density and host species diversity. This prediction was tested and supported by two large-scale surveys of hostplant patches. P. icariodes differed from G. lygdamus in that both ovipositing adults and feeding larvae preferred old leaves to flower buds. The two species also differed in diapause stage, growth rates and reaction to alkaloids. Results predicted a relationship between diapause stage, oviposition site on the plant, and host range. The prediction was tested and upheld by a general survey of temperate lycaenid butterflies. The relationship was significant even when phylogenetic relationships were included in the analysis, and diapause stage was suggested as the characteristic evolutionarily most constrained.

Thesis (M.S.)--University of Tennessee, Knoxville, 2002. / Title from title page screen (viewed Feb. 26, 2003). Thesis advisor: Paris L. Lambdin. Document formatted into pages (vii, 78 p. : ill.). Vita. Includes bibliographical references (p. 53-62).

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed Aug. 1, 2007). PDF text: 230 p. : ill. (some col.) UMI publication number: AAT 3255893. Includes bibliographical references. Also available in microfilm and microfiche formats.

Rapeseed is grown from two closely related species of Brassica in many varieties. The behaviour of seven insects was studied to determine their responses to low erucic acid rapeseed, represented by a typical and a Canola variety of each species. The Canola varieties have a lower gluco-sinolate concentration in the seed coat than typical varieties. The insects were chosen because they were oligophagous or polyphagous. The actions of adults of two species of moths, Mamestra configurata Walker and Plutella maculipennis (Curtis), were studied by using an olfactometer; four species of aphids, Myzus persicae Sulzer, Macrosiphum euphorbiae (Ashmead), Brevicoryne brassicae (Linnaeus), and Acrythosiphon pisum (Harris), were studied when the adults were placed at the base of each type of plant. The insects responded in accordance with their normal associations with cruciferous plants as hosts. Their responses were not materially affected by genetic differences among the four varieties, even though these included distinct morphological and biochemical differences. Behavioural differences towards plant species were observed in the polyphagous aphids, which affected their distribution on the plants. These differences were not associated with varieties or glucosinolate contents. These results indicated that the differences between the two rapeseed species and typical and Canola varieties would neither materially affect the responses of attacking insects nor the resistance of the plants to insect attack in the field. / Land and Food Systems, Faculty of / Graduate

Call number: LD2668 .T4 1950 S775 / Master of Science

Thesis (Ph. D.)--Washington State University, May 2009. / Title from PDF title page (viewed on Feb. 12, 2010). "Department of Entomology." Includes bibliographical references.

Typescript / 261 leaves : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1966

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

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