Entomology Commons^™

Landscape Genetics Of The Gulf Coast Tick, Amblyomma Maculatum, Sara Simmons Benham

Biological Sciences Theses & Dissertations

Connectivity among populations helps to maintain genetic diversity, population stability, and resilience. The Gulf Coast tick, Amblyomma maculatum, is a vector of the pathogen Rickettsia parkeri. Persistence of tick populations with high rates of R. parkeri infection poses health risks to humans and animals. Mitochondrial haplotypes were characterized by sequencing a fragment of the mitochondrial 16S rRNA gene. A comparative study of A. maculatum and Amblyomma americanum was conducted to identify similar and unique patterns between the species within the same region. Next, I compared A. maculatum sites across three different regions of the United States. This work …

Potential Fitness Trade-Offs Of Elevated Esterase Activity Associated With Insecticide Resistance In The Mosquito Culex Quinquefasciatus, Timothy Schulte

Electronic Theses, Projects, and Dissertations

One of the current major issues in the control of vector-borne disease is resistance to insecticides. Resistance to one or more insecticides has appeared in over 580 different arthropod species. Widespread resistance has led to the field of Insecticide Resistance Management (IRM). The goal of IRM is to develop insecticide-use strategies that prevent or slow down the evolution of resistance. Computer models have shown that more effective IRM strategies rely on the assumption that resistance carries a fitness cost in the absence of insecticide use.

In the mosquito Culex quinquefasciatus resistance to certain organophosphate insecticides is caused by an increased …

Mitochondrial Dna Diversity, Parasite And Pathogen Occurrence, And A Potential Disease Vector In Managed And Unmanaged Honey Bee, Apis Mellifera L. Populations, Dylan Cleary

Graduate Theses and Dissertations

The western honey bee, Apis mellifera L., is a globally important pollinator plagued by several harmful stressors impacting colony health and survival. At least eight A. mellifera subspecies were imported and continue to be the genetic ancestors of U.S. honey bee populations today. Successive genetic bottle-neck events have led to reduced genetic diversity in U.S. honey bees. First, the subset of subspecies imported into the U.S. represents only a third of A. mellifera subspecies. Next, the parasitic varroa mite reduced managed and feral populations. Third, ongoing breeding practices have selected for traits from a single genetic lineage and bred from …

Investigation Of Dna Variability And Phylogenetic Relationships Of Perlesta (Plecoptera: Perlidae) In Mississippi, James C. Valentine, Mac H. Alford

Master's Theses

The genus Perlesta Banks, 1906 (Plecoptera: Perlidae) consists of 35 species, 33 native to the United States and Canada and two native to China. For over a century these small, brown stonefly adults and freckled yellow nymphs have gone by the name of the type species of the genus, Perlesta placida, but taxonomic work in the genus since 1989 has resulted in the recognition of additional species. These species were mostly recognized and described using morphological characteristics, but two areas that are lacking include (1) linking nymphs to adults and (2) phylogenetic analysis of all species occurring in Mississippi …

Characterization Of Hemocytes In Amblyomma Americanum And Investigation Of Traf6’S Role In Proliferation Of Hemocytes In Response To Infection, Jacquelyn T. May

Electronic Theses and Dissertations

Amblyomma americanum is a medically important vector in the southeast United States. Cellular and molecular aspects of the immune system of this species were examined. To investigate cellular processes, hemocytes produced in response to gram-negative infection were characterized according to their ultrastructure. Four hemocyte types were identified: prohemocytes, plasmatocytes, type-I granulocytes, and type-II granulocytes. To elucidate molecular processes, we investigated AamTRAF as an immune-related gene by silencing the gene using RNAi then quantifying the hemocytes after inoculation with gram-negative and positive bacteria. It was found that silencing AamTRAF caused a decrease in hemocyte proliferation in response to gram-positive but not …

High Rates Of Polygyny In Tropical Mexico Within The Native Range Of Vespula Squamosa., Alex K. Snyder, Kevin J. Loope

Honors College Theses

Polygyny, or the formation of colonies with multiple cooperating queens, has been observed in a variety of social Hymenoptera and likely exists as a convergent evolutionary strategy. Polygyne cooperation has been observed in several Vespula sp. and is correlated with a perennial social strategy. This perennial-polygyne behavior has been observed most commonly within the tropical and subtropical regions of the invasive Vespula pensylvanica and V. germanica, and rarely within their native temperate ranges. This phenomenon has been relatively undocumented within the tropical portions the V. squamosa native range, despite it being observed in their temperate ranges several times. We observed …

Determination Of The Presence Of Rickettsia Spp. And Borrelia Spp. Carried By Tortoise Ticks From Madagascar, Anna Phan

Biological Sciences Theses & Dissertations

Ticks were removed from three species of Malagasy tortoises, Astrochelys yniphora, A. radiata, and Pyxis arachnoides (comprising two subspecies P. a. arachnoides and P. a. oblonga), between 2012 and 2015. The ticks were presumed to be from the genus Amblyomma. Ticks were morphologically identified and then checked molecularly to confirm their classification or identify any ticks that could not be morphologically identified. Molecular identification was done via end-point PCR that amplified tick cytochrome oxidase (CO1) and tick 12S rRNA genes. Ticks were screened via a real-time polymerase chain reaction assay for the presence of Rickettsia spp. …

Weak Olfactory Preferences Of The Gall Midge Asphondylia Borrichiae, Associated Fungal Endophytes And Implications On Gene Flow And Host Range Expansion, Frances S. Nagle

UNF Graduate Theses and Dissertations

Asphondylia borrichaie is a small fly (Diptera: Cecidomyiidae) that is currently undergoing host-associated sympatric divergence. Asphondylia borrichaie is an ambrosia galler, these insects utilize a host plant for oviposition, but its offspring also rely on a symbiotic fungus (or fungal community) to promote the formation of the gall as well as serve as a food source for the developing larvae. Previous studies indicate that A. borrichaie consists of two host- associated populations based on its original host plant Borrichia frutescens (Asterales: Asteraceae), and another one from the two Iva species (I. frutescens (Asterales: Asteraceae) and I. imbricata …

The Effects Of Internal Physiology On Polyphenic Horn Development In The Dung Beetle Onthophagus Taurus, Naomi Garrett Williamson

Graduate Theses, Dissertations, and Problem Reports

An organism’s phenotype can be affected in development by alterations to gene expression based on environmental inputs. Nutrition is one such environmental input and the central regulator of development of large horn or small horn phenotypes in the dung beetle species, Onthophagus taurus. However, little is known about the nature of chemical compounds that are critical to this plastic horn development. To better understand these compounds, we are utilizing an untargeted metabolomic approach as well as a targeted gene approach. Through the metabolomic approach, it was uncovered that environmental conditions tend to have a greater impact on metabolomic composition …

Genetic Variation Within A Broadly Distributed Chewing Louse Genus (Thomomydoecus), Clarissa Elizabeth Bruns

Honors Program Theses

No broad study has been conducted to examine the genetics of Thomomydoecus species and their patterns of geographic variation. Chewing lice and their parasite-host relationships with pocket gophers have been studied as a key example of cophylogeny (Demastes et al., 2012). Despite this, genetic data on interspecific and intraspecific variation in Thomomydoecus is unexplored, and prior studies consisted within the narrow frame of one complex or species and its relative host gopher. This project collected, and analyzed genetic data, then generated phylogenetic trees. Many of the existing relationships between Thomomydoecus species was confirmed, and there were a number of unexpected …

The Host Gatekeeper: Using The Flagellar Pathway To Understand Symbiont Host Adaptation, Adam R. Pollio

Graduate Theses, Dissertations, and Problem Reports

The acquisition of microbial partners is a strategy used by a diverse group of arthropods to overcome ecological barriers that might normally make certain niches uninhabitable. The unique phylogenetic opportunities attainable from the natural experiment of the Sodalis-allied clade allow for better understanding of how molecular structures evolve through time. Here, we focus on the evolution of the flagellar synthesis pathway, due to its complexity and ability to diverge in response to ecological pressures. We used this molecular pathway and natural experiment to show that normal evolutionary outcomes associated with symbiosis (i.e., genome reduction) do not explain the predicted conservation …

Trees, Fungi, Insects: How Host Plant Genetics Builds A Community, Sandra Jeanne Simon

Graduate Theses, Dissertations, and Problem Reports

Organisms, such as fungi and insects, can cause millions of acres of agricultural and forest damage, while others provide billions of dollars in ecological services such as education, aesthetic enjoyment, pollination, and gardening. Plant breeding and biotechnology can potentially help establish a balance between the proliferation of detrimental pests and attraction of beneficial insects. Variation in plant physiological and morphological characteristics are extremely important in the ability of host tissues to support many different types of organisms. When that variation is genetically heritable in a plant population, shifts in the underlying genes can have predictable consequences in structuring entire ecosystems. …

Phenotypic And Genetic Variation Of The Brazilian Malaria Vector Nyssorhynchus Darlingi At Regional And Local Scales, Virginia Mildred Chu

Legacy Theses & Dissertations (2009 - 2024)

There have been major successes in the fight to eliminate malaria in the Americas, with 11

Spatial And Temporal Patterns Of Neutral And Adaptive Genetic Variation In The Alpine Butterfly, Parnassius Smintheus, Maryam Jangjoo

Electronic Thesis and Dissertation Repository

Understanding how much genetic diversity exists in populations, and the processes that maintain that diversity, has been a central focus of population genetics. The evolutionary processes that determine patterns of genetic diversity depend on underlying ecological processes such as dispersal and changes in population size. In this thesis, I examine the influence of dispersal and population dynamics on neutral and adaptive genetic variation in a naturally occurring network of populations of the alpine butterfly, Parnassius smintheus.

My first objective was to determine the combined consequences of demographic bottlenecks and dispersal on neutral genetic variation within and among populations. Using …

Population Structure, Demographic History, And Environmental Niche Of The Sand Fly Disease Vector Lutzomyia Shannoni (Dyar) (Diptera: Psychodidae) In The U.S., Mexico, And Colombia, Matthew E. Wolkoff

Biology Theses

Lutzomyia shannoni (Dyar, 1929) (Diptera: Psychodidae) is the only known sand fly vector of vesicular stomatitis virus, a putative leishmaniasis vector, and also boasts the widest distribution of any sand fly in the New World. Research on Lu. shannoni in Central and South America has revealed genetically divergent subpopulations; however, tentative analysis of Lu. shannoni in the U.S. has failed to detect any significant population structure, even between specimens collected from highly disparate localities.

The present study used four molecular markers to more closely investigate the population structure of Lu. shannoni in the U.S., and assess the species’ relationships with …

Characterizing Mekk1: Candidate Behavioural Isolation Gene, Caryn Dooner

Electronic Thesis and Dissertation Repository

Behavioural isolation can occur due to divergence in aspects of courtship and mating, and can contribute to reproductive isolation. The purpose of this study is to determine how a gene, Mekk1, contributes to female rejection behaviour between D. melanogaster and D. simulans. Unique polymorphisms were identified within D. simulans Mekk1 that could contribute to behaviour, most of which are non-coding. Both transcripts of Mekk1 appear to be expressed at similar levels in D. simulans and D. melanogaster. These data also indicate that Mekk1 may be expressed in a specific region of the brain called the mushroom body, …

Characterization Of Plant-Spider Mite Interactions And Establishment Of Tools For Spider Mite Functional Genetic Studies, Nicolas Bensoussan

Electronic Thesis and Dissertation Repository

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most polyphagous herbivores feeding on cell contents of over 1100 plant species including more than 150 crops. However, despite its important pest status and a growing understanding of the molecular basis of its interactions with plant hosts, knowledge of the way mites interface with the plant while feeding and the plant damage directly inflicted by mites is lacking. Likewise, while the use of the reverse genetic tools in plants facilitated our understanding of the establishment of defense mechanisms against spider mite herbivory, such tools are lacking for …

Evolutionary Genetic Aspects Of Host Association In Generalist Ectoparasites, Benoit Talbot

Electronic Thesis and Dissertation Repository

Despite the use of the host for dispersal by most parasite species, the extremely loose relationship typical between highly mobile hosts and generalist ectoparasites may lead to very different gene flow patterns between the two, leading in turn to different spatial genetic structure, and potentially different demographic history. I examined how similar gene flow patterns are between Cimex adjunctus, a generalist ectoparasite of bats present throughout North America, and two of its key bat hosts. I first analyzed the continent-scale genetic structure and demographic history of C. adjunctus and compared it to that of two of its hosts, the …

Tropical Trees As Islands: Diversity Accumulation Of Armored Scale Insects (Hemiptera: Diaspididae) On Trees As A Function Of Forest Age, Hannah Shapiro

Undergraduate Honors Theses

Armored scale insects (Hemiptera: Diaspididae) are some of the most invasive insects in the world. These cryptic plant parasites are most often encountered in managed agricultural ecosystems, but very little is known about their distribution, abundance, and diversity in tropical rainforest canopies, where they are likely to have their highest diversity. Because these ubiquitous insects are extreme generalists with undirected dispersal, their diversity (alpha and beta) accumulation can conceivably be modeled according to tenets derived from island biogeography theory. For example, one expectation is that older established trees should boast a higher species diversity and abundance than younger ones. Other …

Differential Gene Expression Of Minnesota (Mn) Hygienic Honeybees (Apis Mellifera) Performing Hygienic Behavior, Eric Northrup

All Graduate Theses, Dissertations, and Other Capstone Projects

Hygienic behavior is the ability to remove dead and diseased brood from the comb early as to limit the detrimental impact of the parasite or pathogen. Minnesota (MN) Hygienic bees are generalists of hygienic behavior with the ability to remove several brood infected with several pathogens including the Varroa mite. This study explored the mechanisms of MN Hygienic behavior by comparing the transcriptome of MN Hygienic bee brains to non-hygienic bee brains via cDNA microarray. The results suggest that the brains of MN Hygienic bees may have a greater number of dendritic connections or are more sensitive to neurotransmitters. Quantitative …

Effects Of Melatonin On Heartbeat And Possible Identification Of A Melatonin Receptor In Drosophila Melanogaster, Tricia L. Vankirk

Electronic Theses and Dissertations

Chapter 1 of this manuscript is a literature review that serves as an introduction to the entire dissertation. Chapter 2 examines the effects of the melatonin injection on heart rate and rhythmicity in Drosophila melanogaster Canton-S (wild-type) pupae and pupae bearing a variety of heart mutations. Chapter 3 investigates further the possible mechanisms of melatonin’s ability to increase heart rhythmicity without significantly affecting heart rate. A melatonin antagonist, luzindole; a high-affinity melatonin agonist, 2-iodomelatonin and RNAi techniques are used to identify a possible melatonin receptor in Drosophila melanogaster.

An appendix contains a previously published manuscript detailing experiments performed at the …

Evolution And Phylogeny Of The Parasitoid Subfamily Phasiinae (Diptera: Tachinidae), Jeremy Daniel Blaschke

Doctoral Dissertations

The first molecular phylogenetic analysis of the agriculturally important parasitoid subfamily Phasiinae (Diptera: Tachinidae) is presented, estimated from 128 worldwide taxa (80 genera) and approximately 7.6 kilobases of nuclear data. Special emphasis is placed on taxa with controversial taxonomic placement. The resultant phylogenetic tree is used to reconstruct ancestral character states, trace the evolution of significant adaptive traits within the Tachinidae, and test hypotheses about the classification of Phasiinae. Subfamily placements of the taxa Eutherini, Epigrimyiini, Litophasia, Strongygastrini, and Parerigonini are confidently resolved, the former three within Dexiinae and the latter two within Phasiinae. Due to sparse molecular evidence, …

Genetic Variation And Species Distribution Of Subterranean Termites In The Southeastern U.S. Focusing On Family Structure And The Invasive Formosan Subterranean Termite, Mark Allan Janowiecki

Graduate Theses and Dissertations

This work applies molecular genetic tools to distinguish the identity and understand the biology of termites, particularly Reticulitermes Holmgren and Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) in the southeastern U.S. Termites are important economic pests costing billions of dollars annually to Americans but also are important wood decomposers in natural settings. Molecular tools are essential for species identification because of the morphological ambiguities among species. The cryptic nest structure of subterranean termites which prevents adequate sampling makes molecular genetic tools essential to examine an entire colony.

A molecular diagnostic technique was created to differentiate Coptotermes formosanus, an invasive species in the …

Primer Efficacy In The Dna Barcoding Of Spiders, Rhennetta Jo Bork

Honors Program Theses

DNA barcoding is the process of amplifying a 650 base pair segment of the sequence of the mitochondrial gene cytochrome c oxidase (COI), and amplifying this gene with a polymerase chain reaction (PCR). It is used to help identify and distinguish animal species and also to help determine genetic differences in species. DNA barcoding can be especially useful when working with spiders since they tend to be very small and hard to distinguish. However, achieving a DNA barcode can be difficult and thus techniques to improve the method of DNA barcoding can be helpful. This research looked into the different …

The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington

Electronic Theses and Dissertations

Wolbachia was recently identified in the Brown Widow Spider (Latrodectus geometricus). This symbiont has not previously been found in this genus, therefore the consequences on the host’s population dynamics are unknown. The frequency of endosymbiont infection can provide insight into the population dynamics of the host as this bacteria is known to alter host life history. In my 1^st chapter I determine the prevalence of Wolbachia pipentis infection in in the Brown Widow Spider (Latrodectus geometricus) from five locations in the Southeastern United States. Infection frequency differed significantly among sampling locations, ranging from 20% to …

Population Genetics And Ecology Of Regional Malaria Vectors In Amazonian Brazil, Sascha Naomi Mckeon

Legacy Theses & Dissertations (2009 - 2024)

Species complexes are common among anopheline mosquitoes, but only some members of complexes are disease vectors. Research involving overall patterns of divergence, phylogenetic relationships and population structure is partly driven by the operational need to be able to reliably distinguish component taxa that may be involved in malaria transmission. Anopheles triannulatus, An. nuneztovari and An. albitarsis are broadly distributed species complexes that contain local and regionally important malaria vectors, whose genetic diversity has been largely overshadowed by studies involving An. darlingi, the principal vector of Central and South America. I have analyzed the ecological suitability of habitats and geographical ranges …

Gene Expression And Phenotype Response Of Drosophila Melanogaster To Selection., Kenneth W. Mcdonald

Electronic Theses and Dissertations

The evolution of phenotypic plasticity is currently a topic of paramount interest in a diverse field of sub-disciplines. Salience is placed by all fields in describing the interaction of selection and phenotypic plasticity and the consequence of this interaction more broadly on evolution. Lacking in the discussion is substantial empirical description of genotype/phenotype interactions that by definition constitute the plastic response to novel and stressful environments. Here, I present empirical observations that bring the interaction of genotype and phenotype into focus. Drosophila melanogaster populations subjected to selection for tolerance to low food or high alcohol conditions each exhibited an enhancement …

Aphytophagy In The Miletinae (Lycaenidae): Phylogeny, Ecology, And Conservation, John Mathew

Biological Sciences Theses & Dissertations

Less than 1% of all Lepidoptera are aphytophagous; of these, a considerable proportion is found in the family Lycaenidae. The aphytophagous Lycaenidae are believed to have arisen from a mutualistic template involving ant attendance. With this association firmly in place, it is a relatively simple shift to exploitation, either of the ants themselves, through active carnivory on the brood/trophallactic feeding from adults, or by carnivory on ant-tended homopterans, with little to no interference by the ants. Among lycaenids, aphytophagy has arisen several times; most spectacularly in the subfamily Miletinae, where all of the approximately 150 species are presumed or known …

Inbreeding, Male Diploidy, And Complementary Sex Determination In The Solitary Wasp Euodynerus Foraminatus, Julie Kozaczka Stahlhut

Dissertations

In the insect order Hymenoptera, which includes wasps, bees, and ants, females normally develop from fertilized eggs and are diploid, while males develop from unfertilized eggs and are haploid. Underlying mechanisms of sex determination are more complex and vary among different hymenopteran taxa. One such method is single-locus complementary sex determination, or sl-CSD, in which sex is determined by a single gene locus with many alleles. In species with sl-CSD, diploid individuals that are heterozygous at the sex locus develop as normal females and hemizygous (haploid) individuals as normal males, but diploids homozygous at the sex locus will also develop …

The Cytogenetics Of The Salivary Gland Chromosomes Of Three Wild Type Strains Of Drosophila Melanogaster, Rosemary Ann Harris

Masters Theses

This investigation involves the cytogenetics of three strains of field-collected, wild-type Illinois Drosophila melanogaster. These three strains were collected from Charleston, Channahon, and Olney, Illinois, in 1967.

The purpose of this study was to compare cytogenetically these three strains and to determine if there exists differences among them. First, the chromosomes themselves were studied for the purpose of identifying the four chromosomes of D. melanogaster by their characteristic banding patterns. Then, the chromosomes of the three strains were examined for chromosomal aberrations, principally inversions. The cytogenetics of the chromosomes of the three strains were then compared and contrasted.

Photographs …