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Investigating Ichneumonidae: Insights Into Species Identification And Venom Composition, Victoria G. Pook

Theses and Dissertations--Entomology

Parasitoid wasps are hyperdiverse, with current estimates suggesting that they may account for up to 20% of all insect species. Though their ecological significance and their importance in integrated pest management cannot be denied, these taxa remain understudied and, due to their small size, are often overlooked. However, recent advances in molecular techniques are helping to reverse this trend by providing tools which scientists can use to better understand species limits and host interactions.

Parasitoid wasps are often morphologically cryptic and their accurate delimitation requires the analysis of DNA sequence data from fast-evolving genes in addition to morphological characters. The …

Variable Consequences Of Toxic Prey On Generalist Insect Predators, Kelly Jackson

Theses and Dissertations--Entomology

Introduced species, like the lady beetle Harmonia axyridis, have been linked to declines of native species through mechanisms including intraguild predation and competitive superiority. However, competitive differentials between species may be mitigated if subdominant species can utilize resources that dominant species cannot. Previous research has shown that some strains of the aphid Aphis craccivora are toxic to H. axyridis. My goal was to investigate use of this resource by both H. axyridis and other lady beetles, to determine whether these aphids might be an exploitable resource for subdominant lady beetle species. I first examined the behavioral responses of …

The Chemical Ecology Of Bed Bugs (Cimex Lectularius, L.) And The Impact Of A Neurotoxic Insecticide On Physiology And Behavior, Sydney E. Crawley

Theses and Dissertations--Entomology

Following a decades-long hiatus in many nations, populations of bed bugs (Cimex lectularius) have rebounded and are thriving on a global scale posing substantial challenges for pest management professionals. Insecticide resistance to both pyrethroid and neonicotinoid compounds has been identified in many populations, leading to renewed interest in alternative control methods for management of this pest. The objectives of my dissertation research were to study various, typically cryptic, bed bug behaviors in order to improve both conventional and alternative management strategies. Novel behavioral interactions among mother and offspring were characterized. Additionally, changes in behavior and physiology after treatment …

Hormonal And Nutritional Regulation Of Molting, Metamorphosis, And Reproduction In Bed Bugs, Cimex Lectularius, Hemant Gujar

Theses and Dissertations--Entomology

The bed bug, Cimex lectularius is an obligate hematophagous ectoparasite that feeds on humans. The increase in travel and development of insecticide resistance to commercially available insecticides have enabled the bed bug population to resurge, causing economical and psychological trauma to the human population. Lack of knowledge about the basic molecular biology of bed bugs has motivated us to study the key aspects of molting, metamorphosis, and reproduction. A blood meal triggers expression of various genes that enable bed bugs to molt or undergo metamorphosis. Molting and metamorphosis in bed bugs are regulated by two key hormones: 20-hydroxyecdysone (20E) and …

Subacute Effects Of Prallethrin On Behavior Of Mosquitoes (Diptera: Culicidae) And Other Human Disease Vectors, Kyndall C. Dye

Theses and Dissertations--Entomology

The synthetic pyrethroid, prallethrin, is an active ingredient in a widely marketed ultralow volume (ULV) mosquito adulticide. Volatilized prallethrin is intended to stimulate mosquito flight, increasing overall effectiveness of the adulticide. However, field tests using volatilized prallethrin did not produce significant differences in various vector trap catches, suggesting prallethrin’s behavioral effects are not viable. Laboratory tests were conducted to evaluate prallethrin’s effect on flight behavior of adult female Asian tiger mosquitoes (Aedes albopictus). Mosquitoes were divided into three groups; a control, those exposed to volatilized prallethrin, and those exposed to a simulated ULV application at label rates. After …

Effects Of Landscape, Intraguild Interactions, And A Neonicotinoid On Natural Enemy And Pest Interactions In Soybeans, Hannah J. Penn

Theses and Dissertations--Entomology

Demand for food, fuel, and fiber has been increasing, escalating the intensification of agriculture during the past fifty years. A more comprehensive understanding of the impact of landscapes on sustainable agriculture production is required to meet the continual increase in human demand. This not only includes how chemical inputs are used but also how cultivated and surrounding landscapes are managed for ecosystem services. This research explains how land cover on landscape and farm scales impact ant and spider-mediated pest suppression. I successfully developed and optimized molecular methods to test ant gut contents from both laboratory and field-caught specimens. A multi-year …