Life Sciences Commons^™

Functional Diversity Enhances Detection Of Ecosystem Stability And Resolution Of Predator-Prey Interactions Within A Multitrophic Community, Ashley Lorraine Kissick

Open Access Dissertations

Habitat fragmentation and loss are principal factors that contribute to the decline of biodiversity which in turn has a negative impact on ecosystem function. There has been growing interest in understanding diversity’s role in the mechanisms behind ecosystem resilience with much attention focusing on how functional diversity, or the range of species’ ecological roles in a community, impacts ecosystem function. Under the functional insurance hypothesis, stability in ecosystems is maintained by species that perform similar functions but have asynchronous responses to disturbance. There are three proposed stability mechanisms that operate through species’ asynchronous responses: cross-scale resilience, response diversity, and density …

Advances In Solid Phase Microextraction For The Analysis Of Volatile Compounds In Explosives, Tire Treatments, And Entomological Specimens, William D. Kranz

Open Access Dissertations

Solid phase microextraction is a powerful and versatile technique, well-suited to the analysis of numerous samples of forensic interest. The exceptional sensitivity of the SPME platform, combined with its adaptability to traditional GC-MS systems and its ability to extract samples with minimal work-up, make it appropriate to applications in forensic laboratories.

In a series of research projects, solid phase microextraction was employed for the analysis of explosives, commercial tire treatments, and entomological specimens. In the first project, the volatile organic compounds emanating from two brands of pseudo-explosive training aids for use in detector dog imprinting were determined by SPME-GC-MS, and …

Investigating Physiological Collaborations Between A Lower Termite And Its Symbionts, Brittany F. Peterson

Open Access Dissertations

This project was completed in an effort to better understand the contributions of symbiotic microbes to the biology of Reticulitermes flavipes, the eastern subterranean termite. Lower-termites, like R. flavipes, house symbionts from all three domains of life within their hindgut paunch. This intimate association is reflected in nearly every aspect of termite biology. Here, I investigate these physiological collaborations as they relate to digestion and immunity. My efforts focused on 1) quantifying the role of bacteria in wood digestion within the termite gut, 2) evaluating the role of symbionts in protection against pathogens, and 3) identifying gene products that bacterial …

The Role Of Entomology In Environmental And Science Education: Comparing Outreach Methods For Their Impact On Student And Teacher Content Knowledge And Motivation, Faith J. Weeks

Open Access Dissertations

Outreach programming can be an important way for local students and teachers to be exposed to new fields while enhancing classroom learning. University-based outreach programs are offered throughout the country, including most entomology departments as few individuals learn about insects in school and these programs can be excellent sources of entomological education, as well as models to teach environmental and science education. Each department utilizes different instructional delivery methods for teaching about insects, which may impact the way in which students and teachers understand the insect concepts presented. To determine the impact of using entomology to enhance science and environmental …

Undercover Predators: Vegetation Mediates Foraging, Trophic Cascades, And Biological Control By Omnivorous Weed Seed Predators, Carmen K Blubaugh

Open Access Dissertations

Weed pressure is the most costly challenge that vegetable growers face, requiring more labor investment than other production inputs. Vertebrate and invertebrate seed predators destroy a large percentage of weed propagules on the soil surface, and their ecosystem services may ease labor requirements for farmers in herbicide-free systems. Cover provided by living vegetation is an important predictor of seed predator activity, and my dissertation takes a comprehensive approach to understanding the behavior, predator, and environment-mediated mechanisms by which cover impacts weed seed predation in crop environments. ^ First, I performed a meta-analysis of 27 studies to quantitatively evaluate what is …

Carrion-Associated Arthropods In Rural And Urban Environments, Serena Daye Gross

Open Access Dissertations

Preferences of arthropods are important in forensic entomology, as the species collected can help determine the postmortem interval or if remains have been moved. This study looked at arthropods that are attracted to pig carcasses in rural and urban habitats in Northwest Indiana. The species and number of carrion-associated arthropods that are found at a carcass vary with habitat type, month, and stage of decomposition. Lucilia sericata (Diptera: Calliphoridae) is a synanthropic species that was found in higher numbers in urban locations for both adults and larvae. Though L. sericata had higher numbers in urban habitats, caution must be exercised …

Characterization Of Hessian Fly From Israel, Alisha J Johnson

Open Access Dissertations

Mayetiola destructor Say, the Hessian fly, is a gall midge and a member of the Dipteran family Cecidomyiidae. It is a common pest of wheat found throughout all of the major wheat growing areas of the world and poses a serious economic threat to the United States (US), particularly in the Southeast winter wheat region. Damage to wheat is done solely by feeding first and second in-star larvae. Hessian fly (Hf) infestations result in a loss in grain yield by the stunting and/or killing of seedling wheat plants in the winter and by causing breakage at the nodes of the …

Investigation Of Dried Distillers Grains With Solubles (Ddgs) Susceptibility To Red Flour Beetle (Tribolium Castaneum (Herbst)) Infestation, Mahsa Fardisi

Open Access Dissertations

Protecting livestock feed from insect infestation is a common challenge that feed facility managers and farmers have to deal with. It becomes an issue of importance because insect infestation degrades feed quality and quantity. Dried Distillers Grains with Solubles (DDGS) is added to livestock feed because of its high protein content. As DDGS usage in animal feed increases, understanding the susceptibility of DDGS, when mixed with livestock feed, to insect infestation is necessary for safe feed storage. This research addressed four questions. The first looked at the susceptibility of DDGS, when stored as a raw ingredient, to Tribolium castaneum (Herbst) …

Changes In Gene Expression And Viral Titer In Varroa Jacobsoni Mites After A Host Shift Asian To European Honey Bees, Gladys K. Andino Bautista

Open Access Dissertations

Honey bees (Apis mellifera L.) are the most important insects for the pollination of crops and wildflowers. However, they have experienced increasing colony die-offs during the past two decades. Multiple species of parasitic mites have been described that affect honey bees. The most important species in beekeeping belong to the genus Varroa ( Varroa jacobsoniand Varroa destructor). Varroa mite parasitism of honey bees is thought to be the most significant cause of colony mortality worldwide, and mite resistance to active ingredients of acaricides has become common. V. destructor causes direct impacts on bee production as well as …

The Termite Digestome: Understanding The Digestive Physiology Involved In Lignocellulosic Biomass Degradation, Zachary John Karl

Open Access Dissertations

The purpose of this research was to advance the understanding of lower termite digestive physiology and discover potential biocatalysts that can aid in the degradation of lignocellulosic biomass. Various protein characterization and gene expression methods were used throughout this research in order to accomplish these objectives. The results of this dissertation indicate that: 1) termites and their symbionts act in a synergistic manner to degrade biomass in vitro, 2) the host fraction of the gut (i.e., foregut and midgut) is the likely site of glucose absorption, 3) the termite and its symbionts contribute specific enzymes to the digestive process, 4) …

The Role Of Resource Predictability In The Metapopulation Dynamics Of Insects, Byju Nambidiyattil Govindan

Open Access Dissertations

The metapopulation paradigm has emerged as an important tool to understand the dynamics of species living in fragmented landscapes. In this dissertation, I investigate the unpredictable nature of resource availability for species living in human-dominated heterogeneous and dynamic landscapes in the context of its consequences for long-term regional persistence of species. In particular, I test theoretical advancements in metapopulation ecology following a two-pronged approach - via experiments in the lab and observations in the field - using insects. In chapter 1, I introduce the concept of metapopulation ecology in the context of its relevance for dynamics of species living in …

Management Of Potato Leafhopper And Maple Spider Mite On Nursery Grown Maples, Julia Prado Beltran

Open Access Dissertations

Potato leafhopper Empoasca fabae (Harris) (Homoptera: Cicadellidae) and maple spider mite Oligonychus aceris (Shimer) (Acarina: Tetranychidae) are important pests of maple trees. Investigations determined how insecticide use and fertilization impacted the abundance of E. fabae and O. aceris on `Red Sunset' red maple and `Autumn Blaze' Freeman maples. Bifenthrin applications directed against leafhoppers reduced damage to both cultivars, but increased O. aceris on Autumn Blaze. Using a threshold of one leafhopper per branch to trigger pesticide applications protected Red Sunset maples from leafhopper injury. It also prevented outbreaks of O. aceris on Autumn Blaze because few trees reached this density. …

Genetic Engineering Of Black Cherry (Prunus Serotina) For Reproductive Sterility And Insect Pest Resistance, Ying Wang

Open Access Dissertations

Black cherry (Prunus serotina Ehrh.) is one of the most valuable hardwoods for high- end cabinetry, furniture, architectural millwork, paneling, and veneer. However, the damage caused by cambial-mining insect pests triggers gummosis in black cherry, a non-specific defense response in which resinous gum is deposited at the site of injury. The gum defects dramatically decrease the yield of high-quality black cherry lumber, and the value can be reduced by as much as 90%. The goal of this project was to optimize the transformation and in vitro rooting system, and to develop transgenic black cherry for reproductive sterility and insect pest …

Ozonation Systems As A Non-Chemical Alternative For Stored Grain Protection, Carlos A. Campabadal

Open Access Dissertations

The use of ozone as a non-chemical alternative in stored grain protection was studied by conducting scale-up demonstrations using a fixed bed ozonation system and developing a semi-continuous counterflow and a continuous flow ozonation treatment system. The objectives of this research were to determine the efficacy of ozonation to control insect pests without affecting end-use quality; to prove the concept of the semi-continuous counterflow ozonation system to ozonate grain at a faster rate and quantify its effect on mold growth reduction; to evaluate the efficacy of a modified screw conveyor for pest control by treating grain in a continuous-flow ozonation …