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Showing 1 to 18 of 18 for “"Insect herbivore"”.
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Predicting Insect Herbivore Distribution Using Climatic and Biotic Variables
… species distribution in nature. The abundance of insect herbivores can vary greatly spatially and temporally. These variations can be explained by abiotic variables such as precipitation, they can also be explained by biotic variables such as nutrient availability. Here I present two field …
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Diet Breadth Evolution and Diversification of a Generalist Insect Herbivore
<p>Insect herbivores are one of the most diverse groups of multicellular organisms, and the vast majority are specialists, which feed on only a few plant species. The factors that cause some herbivores to be specialists and others to be generalists are still unclear. It is known that the selective …
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Patterns of association in a co-introduced insect herbivore and parasitoid wasp
… in the re-association of many exotic plant-herbivore species, but ecological fitting also readily occurs as evidenced by the prevalence of native species host switching to exotics, and vice-versa. For the remainder of my dissertation, I used molecular methods to determine the invasion routes …
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Aboveground effects of variation in the legume-rhizobium mutualism on insect herbivore Spodoptera exigua
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-09-01 without embargo terms
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Host Plant and Spatial Influences on the Natural Enemy Community Structure of a Host Specific Insect Herbivore
… ecology. Here I investigate the structure of the insect natural enemy community centered on galls produced by Belonocnema treatae (Hymenoptera: Cynipidae) on the leaves of its host plants across the gall former's geographic range while controlling for spatial autocorrelation among sample sites. …
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Insect herbivore communities colonising the flower-heads of Berkheya in South Africa and Carduoideae in Europe and California
… conclusions can be made about the association of insect herbivores with Berkheya and thistles and whether there are any 'rules' that have influenced the evolution of these associations. It is shown repeatedly that there are significant and interesting correlations between characteristics of the …
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Effects of Local Plant Neighborhood on Plant Herbivory in Perennial Polyculture Cropping Systems
… and row spacings) that could confer specialist insect pest resistance via reduced host plant apparency, changes in herbivore attraction, and host plant tissue quality. The three chapters in this dissertation examine these themes of perennial polyculture and effects of spatial heterogeneity on …
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The role of insect leaf herbivory on the mangroves Avicennia marina and Rhizophora stylosa
This thesis examines insect leaf herbivory and the insect herbivore community on two common mangrove species – Avicennia marina and Rhizophora stylosa, at two sites near Townsville, northern Queensland. Despite its widely recognised importance in other forested ecosystems, the role of insect …
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Parallel and Nonparallel Patterns of Genetic Co-Differentiation: Evidence for Host Associated Differentiation Among Trophic Levels of the Oak Gall Wasp System
Populations of phytophagous insects whose life cycles are intimately related to their host plants can express host-associated differentiation (HAD) in the form of genetic divergence and/or RI isolation across alternative host plants. In this work, we ask if HAD cascades to higher trophic levels in …
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Entomological considerations for domestication of pennycress, Thlaspi arvense, as a cash cover crop
… of the interactions between pennycress and insect herbivore communities and agroecosystems remains limited. This research aimed to fill these knowledge gaps and support the development of integrated pest management (IPM) programs for this emerging crop.First, a comprehensive review was …
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Hypersensitive Response in Live Oak: Characterization and Efficacy Against a Host of Specific Gall-Forming Wasp
… and spread of host-plant-specific pathogens and insect herbivores are fundamentally affected by plant defenses. Hypersensitive response (HR) is a plant defense classically recognized as resulting from a gene-for-gene interaction between pathogens and plants. More recently HR arising from …
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An experimental demographic approach to exotic plant success: <b>Cynoglossum officinale</b> in its native and introduced ranges
… and to determine the role of specialist herbivores and altered responses to disturbance in affecting plant population growth in both ranges.</p> <p>From reciprocal common gardens in each range, I found substantial population-level plasticity in size and fecundity between native and …
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An experimental demographic approach to exotic plant success: <b>Cynoglossum officinale</b> in its native and introduced ranges
… and to determine the role of specialist herbivores and altered responses to disturbance in affecting plant population growth in both ranges.</p> <p>From reciprocal common gardens in each range, I found substantial population-level plasticity in size and fecundity between native and …
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The red imported fire ant, Solenopsis invicta, in early-successional coastal plain forests: tests of distribution and interaction strength
… system, I tested whether the top-down effect of insect herbivore consumption by fire ants was strong enough to cascade through two trophic levels and improve plant growth and fitness. I compared this potential effect to that of other arthropod predators in the community. I found that fire ants …
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THE ROLE OF MICROBIAL ENDOSYMBIONTS IN SORGHUM HALEPENSE INVASIONS: EVIDENCE OF A NEW INVASION STRATEGY, MICROBIALLY ENHANCED COMPETITIVE ABILITY (MECA)
… also had increased production of the herbivore-defense compound, dhurrin, contained in leaves. When leaves from plants with bacterial endosymbionts were fed to a generalist insect herbivore (<i>Tricoplusia ni</i>), the insect could not grow and experienced significant mortality. …
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THE ROLE OF MICROBIAL ENDOSYMBIONTS IN SORGHUM HALEPENSE INVASIONS: EVIDENCE OF A NEW INVASION STRATEGY, MICROBIALLY ENHANCED COMPETITIVE ABILITY (MECA)
… also had increased production of the herbivore-defense compound, dhurrin, contained in leaves. When leaves from plants with bacterial endosymbionts were fed to a generalist insect herbivore (<i>Tricoplusia ni</i>), the insect could not grow and experienced significant mortality. …
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Understanding How Whole Genome Duplication in Plants Impacts Herbivore-plant Interactions
<p>Herbivory by insect herbivores is a strong selective force in many communities. Although herbivore-plant interactions have been a focus of interest for decades, we are still exploring how large-scale genetic changes in the host plant alters their interactions with insect herbivores. One such …
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Diel patterns of insect herbivory and plant secondary metabolites in understory shrubs on Barro Colorado Island
… against herbivory. In response, herbivorous insects have evolved a diversity of behavioral and biochemical counter-adaptations to these defenses. Despite that a significant portion of leaf area removal by insects in the tropics occurs at night, virtually all studies of chemically mediated …