Life Sciences Commons^™

Microbiome Assembly And Function In The Solitary Mason Bee, Osmia Lignaria (Megachilidae), Bailey Crowley

All Graduate Theses and Dissertations, Fall 2023 to Present

Animal-microbe interactions can influence host biology, ecology, and evolution. The assembly and function of microbes found within animal hosts oftentimes depends on which species are involved. Advances in sequencing technologies have permitted the exploration of host-microbe interactions in a variety of animals, including bees. Early research aimed at understanding the microbiomes of social bees, such as honey bees and bumble bees, found that microbes prevent the spoilage of stored pollen, breakdown indigestible nutrients into smaller molecules available for uptake by the host, and also protect the host from pathogens. When environmental stressors, such as increased temperatures, disrupt the microbiome, the …

The Interactions Between Drought Tolerant Corn Hybrids And Plant Water-Stress On Weeds And Their Host Capability For Spider Mites, Mercy Adhiambo Odemba

All Graduate Theses and Dissertations, Fall 2023 to Present

With climate change, it is predicted that more frequent high temperatures and drought severity will lead to an increase in damage caused by pests that thrive under these conditions. Spider mite outbreaks, for example, are associated with plant waterstress and there is evidence that some weeds are more resilient and adapted to drought than some crops, leading to major concerns for the management of these two pest types. Weeds directly compete with crops for limited resources, but what is unclear is which weeds harbor spider mites and whether they exacerbate the impact of spider mites on corn crops under water-stressed …

Spatial Ecology Of Mule Deer Migrations From Grand Teton National Park And The Teton Range, Justin K. Schwabedissen

All Graduate Theses and Dissertations, Fall 2023 to Present

The Greater Yellowstone Ecosystem hosts several of the longest, fully intact ungulate migrations remaining in the continental United States. However, expanding development and an increasing human footprint continue to truncate migratory routes. While the endpoints are often a seasonal range on protected lands, these migration corridors frequently cross other jurisdictional boundaries, including large tracts of private or multiple-use lands, with varying levels of protection. Thus, it is critical resource managers understand the dynamics of migratory movements to define population-level corridors and prioritize appropriate conservation strategies. Mule deer in Wyoming have been documented traveling long distances between summer and winter ranges; …

The Impacts Of Maturation And Experience On Volumetric Neuroplasticity In Solitary And Social Bees, Mallory A. Hagadorn

All Graduate Theses and Dissertations, Fall 2023 to Present

Some animals are incredibly social, living and working together as one cohesive group. Alternatively, many animals are solitary, never living with and rarely interacting with others. A large body of biological research has focused on understanding the role that brains play in promoting these behavioral differences across species. Even so, it remains unclear why some brains facilitate social behavior while others do not. My dissertation aims to advance our understanding of this concept by characterizing bees’ brains and how they change over a lifetime. Bees are beneficial for investigating relationships between the brain and social behavior because some species are …

Phenology Of The Invasive Balsam Woolly Adelgid, Adelges Piceae (Ratz.) (Hemiptera: Adelgidae), On Subalpine Fir In Northern Utah, Elizabeth L. Rideout

All Graduate Theses and Dissertations, Fall 2023 to Present

Balsam woolly adelgid (BWA) is an invasive true fir pest in North America. Native to Europe, BWA was first discovered in Utah attacking subalpine fir in 2017. Recent BWA-caused subalpine fir mortality in northern Utah has prompted the need for baseline biological research to support pest management. Small-bodied and blending easily with its environment, BWA is a challenging pest to detect and study. Phenology, or the timing and characteristics of life stages through the year, of BWA varies depending on elevation and climate and is unstudied in Utah. This research focuses on defining aspects of BWA’s phenology, including the number …

Linking Microbial Community Assembly In Flowers With Function Under Diverse Environmental Conditions: A Case Study Involving Erwinia Amylovora, Christopher Skylar Mcdaniel

All Graduate Theses and Dissertations, Fall 2023 to Present

Fire blight, a devastating disease of pome fruit trees caused by the bacterium Erwinia amylovora, can cause millions of dollars in losses for producers each year around the globe. Management approaches that involve use of antibiotics, such as streptomycin, can be effective; although concerns exist over pollinator and crop health when using them regularly. Recently, there have been developments that allow for biological agents such as microbes to curtail fire blight infection. These agents work by competing with Erwinia for resources or space, producing antibacterial compounds, or even killing Erwinia cells on contact. Unfortunately, these agents do not yet …

Geographic Variation In Blue Orchard Bee (Osmia Lignaria) Development And Performance As A Managed Pollinator In The Western United States, Morgan B. Scalici

All Graduate Theses and Dissertations, Fall 2023 to Present

Most flowering plants, including many cultivated food crops, will only produce well-developed fruits and seeds if pollen is transferred from one flower to another with the help of an animal pollinator. Honey bees are the most well-known and ubiquitous but are poor pollinators of some commercially important crops, or are in poor supply during crop bloom. In such cases, farmers will employ other managed pollinators such as bumble bees or solitary bees like mason and leafcutting bees. The blue orchard bee is North America's most agriculturally important native mason bee as effective pollinators of spring-blooming fruit crops. Differences in developmental …

The Mojave Poppy Bee (Perdita Meconis) And A Primary Plant Host, The Las Vegas Bear Poppy (Arctomecon Californica): Status And Interactions, Sarit Chanprame

All Graduate Theses and Dissertations, Fall 2023 to Present

The Mojave Desert is one of the most biodiverse places in North America. A harsh environment with many species results in complex relationships between animals and plants. This study focuses on one bee-plant relationship, the Mojave poppy bee, and the Las Vegas Bear Poppy.

The Mojave poppy bee is rare and has only been collected from Las Vegas Bear Poppy, Dwarf Bear Poppy, and a few species of prickly poppies. A 1995 report suggested the bee was a major contributor of pollination for the Las Vegas Bear Poppy in Clark County, Nevada. More recently (2019), their local extinction in southwestern …

Population Physiology, Demography, And Genetics Of Side-Blotched Lizards (Uta Stansburiana) Residing In Urban And Natural Environments, Spencer B. Hudson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife populations across the globe are poised to lose their natural habitat to urbanization, yet there is limited information on how different species handle living in cities. Animals in urban environments are often susceptible to novel stressors, which can threaten their individual health and population viability. The physiological characteristics of animals, such as those related to metabolic hormones, oxidative stress, and immunity, are expected to be important for survival in this context. If so, animals persisting in urban areas may demonstrate physiological differences from their natural counterparts, perhaps due to evolutionary change. These potential outcomes have been documented in birds …

Antimicrobial Peptides In Transgenic Silkworm Silk, David Jaden Turner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Overview: People in India and China have produced silk textiles for thousands of years. Silk is a biodegradable, biocompatible compound used in the production of clothing, bedding, furniture, industrial materials, and medical applications. Over the last 30 years, research has increasingly investigated silk’s antimicrobial effects and how to augment its natural abilities. Antimicrobial peptides, or AMPs, are also an area of increasing interest as the rise of antibiotic resistance reduces the efficacy of current treatments. This project plans to systematically synthesize a fusion protein that incorporates the beneficial properties of each constituent into commercial silkworms.

Innovation: This project seeks to …

Physiological Consequences Of Adrenal Enlargement And Implications For Toxin Resistance In North American Snakes, Megen E. Kepas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The long observed relationship between enlarged adrenal glands and toad-eating in snakes has remained a mystery in physiological ecology and herpetology. It has been predicted that large adrenal glands may be capable of producing higher amounts of key hormones, and that higher plasma hormone levels may lend some behavioral or physiological benefits after a toxic toad has been eaten. I address questions surrounding adrenal enlargement and its potential benefits to toad eaters in four research chapters. In my second chapter, I quantify adrenal hormone output at different embryonic stages in the toad-generalist snake Thamnophis elegans and examine the ability of …

Assessing Stream Ecosystem Structure And Function In An Urban Canal And Logan River In Logan, Utah, Ellie Smith-Eskridge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans have constructed canals to support agriculture, to mitigate flooding, and to discharge stormwater, especially in the Intermountain West. These canals are common in Cache Valley, where they receive flows from the Logan River during summer months. However, the ecological structure (e.g., water quality, freshwater invertebrates) and function (e.g., leaf decomposition) of these canals remains largely unknown. Studying ecosystem structure and function of these urban waterways is important because it can inform us of the health of these waterways.

My research had three objectives. First, I compared water chemistry, invertebrate assemblages, and leaf decomposition in an urban canal and the …

We Travel Together: Examining The Drivers And Functions Of Animal Movement In Biotic Seed Dispersal, Binod Borah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants and frugivorous animals exist in mutually beneficial relations, as these animals feed on fruits, ingest the seeds, and carry them away from the parent trees. Such dispersion of seeds over space helps them colonize new habitats, escape high mortality rates near their parent trees, and avoid competition with conspecifics. Therefore, seed dispersing animal movement can be critical for the persistence of plant populations. Yet what drives such seed disperser movement is often less understood and how it affects seed dispersal is little explored. In my dissertation, I investigate multiple drivers of seed disperser movement, link movement to potential seed …

The Effects Of Recent Climate Change On Spring Phenology, With A Special Focus On Patterns Of Bee Foraging, Michael Stemkovski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The date on which plants flower and on which bees begin to pollinate varies year-to-year depending on differences in weather. This seasonal timing is known as phenology, and it is already clear that climate change has pushed the spring phenology of many species earlier by increasing temperatures. This is particularly clear in flowering plants, but studying how and why the phenology of pollinators is shifting is more difficult. Most flowering plants rely on pollinators such as bees for their reproduction, and most bees rely on flowers for their sustenance, so bee and flower phenology has to overlap for the crucial …

Thermal Tolerance, Physiology, And Microhabitat Use Of Eleutherodactylus Coqui Across An Elevational Gradient In Hawai‘I, Jack Marchetti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The coqui frog (Eleutherodactylus coqui) is an invasive species in Hawai‘i, and has spread across much of the island. While elevational temperature differences are thought to restrict the coqui’s spread, it is unclear if they have resulted in changes to the coqui’s physiology and microhabitat use as it has expanded into higher elevations.

We first sought to determine if the coqui’s substrate use and baseline physiology differs between elevations. We found that frogs at high elevation were found closer to the forest floor and used different substrates than frogs from low and mid-elevations. This change in microhabitat use …

Consequences Of Host Life Cycles For Symbiont Genome Evolution, Ashley Elizabeth Dederich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aphids are small insects that feed exclusively on plant sap, a notoriously low source of nutrients due to the high sugar content and low amino acid content. To make up for these deficiencies in nutrition, aphids harbor Buchnera aphidicola, a bacterial endosymbiont that resides in a specialized organ called the bacteriome. B. aphidicola provides essential amino acids and vitamins for the aphid in exchange for a safe place to live. Over the course of the symbiosis (established 160 million years ago), B. aphidicola has lost much of its genome, including essential genes for cell envelope synthesis, DNA replication and …

Fractally Sampling Diversity-Environment Relationships To Understand Plant Assemblage Health Across Spatial Scales, Elizabeth G. Simpson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans influence the health of ecosystems and rely on healthy ecosystems to support their livelihoods and well-being. By looking at how the parts of ecosystems interact we can understand and improve ecosystem health. Ecosystem interactions change across spatial scales or different size patches of area. For example, individual organisms interact with each other at small spatial scales, while at large spatial scales, communities of organisms interact with weather conditions. However, many research studies do not look at how ecosystem interactions change across spatial scales. To address this gap in ecological research, I use a fractal sampling design which samples at …

Status And Enhancement Of Trissolcus Japonicus (Ashmead) (Hymenoptera: Scelionidae) For Biological Control Of Halyomorpha Halys (Stål) (Hemiptera: Pentatomidae) In Northern Utah, Kate V. Richardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The invasive brown marmorated stink bug (BMSB) is a major insect pest that invades human structures causing nuisance issues and attacks numerous fruit and vegetable crops in Northern America. As this pest threatens $23 billion worth of specialty and agricultural crops in the U.S. and is difficult to manage due to insecticide resistance, control practices such as the use of biological control through egg parasitoid wasps are critical. In its native range of Asia, BMSB populations are controlled primarily by members of the Trissolcus genus such as the samurai wasp, but U.S. native wasps have demonstrated low success of BMSB …

Characterization Of Neutrophil Extracellular Traps In Naked Mole-Rats: A Step Towards Cancer Resistance, Thomas Abraham Smith

Undergraduate Honors Capstone Projects

Cancer is the second leading cause of death in the United States, exceeded only by heart disease. One of every five deaths in the United States is due to cancer. A growing area of research involves the analysis of cancer resistant traits in other species to understand their biological mechanisms and eventually make translations to human cancer research and clinical treatment. Because of their remarkable cancer resistance, the naked mole-rat (NMR) is a prime subject for this research, and various studies have already suggested that the immune mechanisms of the NMR might be harnessed for human cancer therapies^1-4,7. …

Protein Nutrition And Immunity In Male Bumblebees (Bombus Impatiens), Carson Stoker

Undergraduate Honors Capstone Projects

Male bumble bees play a vital but understudied role in their colonies. They are essential to colony reproduction and success, despite not emerging until the end of the colony's life cycle. Even so, the biology of male bumble bees is not well understood, which leaves our understanding of colony health incomplete. This knowledge gap is important because bumblebee populations are declining, which threatens the ecosystems and industries which rely on them for pollination. This study aimed to understand how two understudied factors of bumble bee health—diet and immunity—are related in males. Pollen, a bee’s main source of protein, has been …

Immunological Tradeoffs And The Impacts Of Urbanization On The Reproductive Ecology And Physiology Of The Side-Blotched Lizard (Uta Stansburiana), Emily E. Virgin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investing resources into reproduction can limit energy available to other competing demands, such as fighting off an infection; yet, both processes are necessary for organisms to survive and pass on their genes to the next generation. These strategies often follow patterns associated with lifespan, such that shorter-lived animals are more likely to invest more resources into reproduction over survival, and vice versa in long-lived animals. However, environmental change caused by urbanization can disrupt these relationships, and the within- and transgenerational costs of urbanization on females and offspring are unknown. I address these uncertainties in three research chapters to better understand …

Avian Species Distribution Models: Using Location Data To Inform Management Decisions, Marilyn E. Wright

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Both state and federal wildlife agencies strive to conserve and protect wildlife and their habitats as an important public resource. Applied management decisions often rely on being able to obtain data that can efficiently and effectively enhance the understanding of these systems for informing management actions. Wildlife managers often focus efforts on a small subset of species from an ecosystem, typically called focal species, who can serve as surrogates for understanding the health and function of the system. Models that consider how these focal species interact with the ecosystem are often used to better understand important aspects of their life …

Bugs, Bullets And Birds: Factors Affecting The Health And Survival Of Ferruginous Hawk Nestlings In The Intermountain West, Ellis A. Juhlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ferruginous Hawks are a bird of prey species that nest in sagebrush steppe and grassland habitat. These birds are threatened by habitat loss and fragmentation from urbanization, rural development, oil and natural gas extraction, habitat treatment projects, and wildfires, and experiencing widespread population declines across their breeding range. Because of this, Ferruginous Hawks (FEHAs) have been deemed a Species of Greatest Conservation Need by state management agencies in Utah, Idaho, Wyoming and Nevada. The health and survival of Ferruginous Hawk (FEHA) nestlings is crucial to long-term population viability. Understanding the threats these birds are facing as nestlings can provide valuable …

Insecticide Susceptibility And Resistance Detection In Phlebotomus Argentipes Sandflies (Diptera: Psychodidae: Phlebotominae), Shawna M. Hennings

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leishmaniasis is an understudied disease found predominantly in high heat and humidity areas. The disease is transmitted by sandflies which are blood-feeding, biting insects. There is currently no known vaccine for any form of leishmaniasis and treatment imposes a significant economic impact on already poor and marginalized populations, as well as severe, lingering side effects for afflicted individuals. Annually, there are millions of people around the world afflicted with a form of Leishmaniasis that is transmitted by species of sandflies. The primary sandfly population control method for over half a century has been indoor residual spraying using insecticides. The selective …

Biodiversity And Foraging Preferences Of Bee Communities At Pinnacles National Park Over Time, Abigail M. E. Lehner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bees are considered to be the most important animal pollinator, providing billions of dollars in pollination services each year. Despite their importance in both natural and agricultural settings, the status of most native bees is unknown. Native bees are subject to a variety of threats including habitat loss, pesticide use, and climate change. Yet, monitoring programs have been implemented in few natural areas. Pinnacles National Park, PNP, in California is one of the only natural areas to have a large historical dataset on bees across decades with surveys conducted in 1996, 1997, 1998, 1999, 2002, 2011, and 2012. These surveys …

An Evaluation Of Landscape, Climate, And Management Impacts On Bumble Bees (Hymenoptera: Apidae: Bombus) In Agroecosystems, Morgan Elizabeth Christman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bumble bees play pivotal roles in pollinating wild and cultivated plant communities. Unfortunately, bumble bee populations are declining due to disturbances such as landscape conversion and climate change. Additionally, traps used to monitor pest insect populations often capture bumble bees, leading to a concern that trap captures increase bumble bee mortality. First, I studied bumble bee communities based on land cover and weather variables in agricultural fields in Utah. Bumble bee communities were more diverse in agricultural fields with more agricultural land in the surrounding area, low temperatures, and high humidity during the growing season, and less diverse in fields …

Natural History And Development Of Melittobia Acasta On Megachile Rotunda , Alan R. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alfalfa is one of the most economically important crops in North America. To produce alfalfa seed, a pollinator must release plant reproductive organs by applying pressure to keel petals. The alfalfa leafcutting bee, Megachile rotundata, is the primary commercial pollinator of alfalfa. U.S. bee managers struggle to maintain populations due to many mortality factors. One cause is attack from parasitoid wasps such as Melittobia acasta. Females can lay hundreds of eggs and have multiple generations, which can decimate bee stocks. Chapter Two investigates the life cycle and base temperature that allows development of M. acasta on bee hosts. …

Maternal Effects And Management Of Alfalfa Leafcutting Bees, Makenna May Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most bees are solitary and important contributors to pollination of a variety of crops. Solitary bees do not live in colonies. Instead, females work individually to construct nests and provision nutrients for each offspring. However, solitary bees can be difficult to manage, especially on a large scale like honey bees, because of differences in how species provision for their offspring and construct nests. Variations in the timing of offspring development to adulthood even within species makes commercial management difficult. Variations in reproductive strategy, like how many offspring to make, how much provision to give each, and when to make them …

Global Change Effects On Carbon Cycling In Terrestrial Ecosystems, Guopeng Liang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since terrestrial ecosystems store approximately 3 times more carbon (C) than the atmosphere, they have a significant effect on the atmospheric CO₂ concentration. Although many studies have been conducted to determine global change effects on C cycling in terrestrial ecosystems, the underlying mechanisms remain uncertain. To address this knowledge gap, I utilized meta-analysis, laboratory experiments, and soil microbial community analysis.

In chapter 2, I conducted a meta-analysis to examine whether effects of long-term N addition on plant productivity can shift over time. I found that 44% of studies showed a marked trend (increase or decrease) in the strength of …

Greater Sage-Grouse Brood Responses To Livestock Grazing In Sagebrush Rangelands, Hailey Peatross Wayment

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The distribution and abundance of the greater sage-grouse (Centrocercus urophasianus; sage-grouse) have declined in the last 60 years. Range contractions and population declines have been attributed to loss and fragmentation of their sagebrush (Artemisia spp.) habitats. Grazing by livestock remains the predominant anthropogenic land-use across sagebrush ecosystems in North America, occurring on 87% of remaining sage-grouse habitat. Most of the peer-reviewed literature reports the potential for negative impacts of sagebrush reduction treatments, to increase livestock forage, on sage-grouse habitat. However, few studies have linked livestock grazing at the landscape level to vital rates (e.g., nest initiation rates, …