Entomology Commons^™

The Influence Of At-Planting Insecticide Treatments On Tobacco Thrips, (Thysanoptera:Thripidae), And Reniform Nematode, (Tylenchida:Hoplolaimidae), In Conventional And Thryvon Cotton Systems, Walker Brett Farmer

Theses and Dissertations

One of the objectives of this research was to evaluate the need for an additional imidacloprid seed treatment on ThryvOn^® (Bayer Crop Science^®, St. Louis, MO) cotton to effectively manage tobacco thrips, Frankliniella fusca (Hinds). While evaluating thrips densities and damage ratings, ThryvOn cotton continued to display reduced damage and thrips populations than non-ThryvOn. Thrips populations and damage ratings were consistently reduced when incorporating a higher rate of imidacloprid, but they were not reduced enough to justify the higher rates of imidacloprid. Another objective of this research was to evaluate the impact of aldicarb (AgLogic Chemical^{® …}

Aedes Aegypti Host Preference On Canines Versus Human Volatile Skin Compounds, Melissa Bernadette Rosalez

Theses and Dissertations

It is critical to understand how Aedes aegypti mosquitoes detect hosts through cues such as volatile skin compounds. In South Texas, evidence suggests that this mosquito is showing a feeding preference for canines over humans. This shift may impact the transmission of Dirofilaria immitis, canine heart worms, in local dog populations. Our study is set to explore Ae. Aegypti attraction to hosts using canine and human volatile compounds. Volatile skin compounds will be collected using a volatile collection system. Compounds will be analyzed using gas chromatography/mass spectrometry. It is anticipated that the main volatile skin compounds amongst humans are nonanal, …

The Interaction Between Predation And Sound Pollution On The Internal And External Microbiome Of The Grasshoppers Melanopus Sanguinipes, Alanna Bond

Theses and Dissertations

Anthropogenic activities such as construction and agriculture directly affect its surrounding environments. Many studies have focused on how megafauna and flora are impacted by human activities, however, relatively little is known how new occupation of land affects smaller organisms such as insects and microbes. Additionally, other stressors such as predation can impact host physiology. The grasshopper species Melanopussanguinipes was chosen to be used in a study to measure how stress caused by artificial sound and predation can alter exoskeleton and gut microbiomes once exposed to these stressors.

The Community Ecology Of Ants On The Cumberland Plateau And A Taxonomic Redescription Of The Genus Stenamma Westwood, 1839 (Hymenoptera: Formicidae: Myrmicinae) In A Southeastern Treatment, Zachary Brown

Theses and Dissertations

Grassland communities represent major biodiversity hotspots across the United States. Among these grassland types is the short-leaf pine savanna, a major historical habitat along the Cumberland Plateau. The Cumberland Plateau’s grasslands are under threat due to land use changes such as urbanization and land conversion to pasture and hardwood forests. This study seeks to better understand the community ecology of ants on the Cumberland Plateau using powerlines as a comparison to degraded and historic habitats. Ants have a preference between open sites and forested sites, a separation of 44.5% on a DCA. The Simpson diversity places the short-leaf pine savanna …

Biochar Reduces The Pupation And Eclosion Of A Specialist (Manduca Sexta) And A Generalist Pest (Spodoptera Frugiperda), Nischal Wagle

Theses and Dissertations

Chapter 1: This chapter incorporates detailed information about the biochar concept, its production, composition, and properties, harmful arthropods and their damage, the effect of soil on the arthropod community, and the application of biochar on arthropod control.

Chapter 2: The comprehensive lab experiment was conducted with modified pupation media enriched with walnut shell biochar (Chapter II) to evaluate the effects of biochar on the pupation and eclosion success rates of a specialist (Manduca sexta) and a generalist pest (Spodoptera frugiperda). We found that the biochar treatment led to a significant reduction in pupal mass, adult mass, adult wingspan, body length, …

Cover Crops Influence Arthropod Community Dynamics Through Seasonal Variation And Cascading Effects, Adegboyega Fajemisin

Theses and Dissertations

Chapter 1: This chapter gives an overview of how cover crops influence soil’s physical, chemical, and biological properties, and their role on mediating arthropod community dynamics with implications for pest management in the subsequent cash crop.

Chapter 2: This chapter examines the effects of cover-cash crop rotation on arthropod community dynamics on four growers fields in the Lower Rio Grande Valley, Texas. We assessed the impact of cover crops planted in the summer months on the subsequent cash crops planted in the winter. Our results showed that cover crops had a differential effect on the population of beneficials and herbivores …

Interactive Effects Of Bark Beetles, Ophiostomatoid Fungi, And Subterranean Termites On Wood Decomposition And The Biogeochemical Cycling Of Pine Forests, Kimberlyn Pace

Theses and Dissertations

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the …

Determining The Impact Of Post-Harvest Water Management On Chironomid Abundance, Agrochemical Biomass And Potential Trophic Biomagnification, Mason Thomas

Theses and Dissertations

Agriculture has diminished shorebirds’ natural habitat in the Mississippi Alluvial Valley. Remaining natural stopover sites are supplemented with agricultural fields during the fall and winter. This study evaluates the impact of 4 different post-harvest water management strategies on shorebird food abundance and potential agrochemical biomagnification. Chironomid samples estimated abundance, biomass, and chironomid agrochemical concentration in each field. A risk assessment of agrochemical biomagnification to shorebirds was made across all treatments. Of treatments represented on all study sites, winter treatment had greatest chironomid abundance and biomass. Models indicated that days since flood initiation, start date, and temperature are significant predictors of …

Determining The Importance Of Propagule Pressure And Dispersal Mechanisms For The Establishment And Spread Of Crapemyrtle Bark Scale, Acanthococcus Lagerstroemiae Kuwana (Hemiptera: Eriococcidae), Erika Renee Wright

Theses and Dissertations

Non-native scale insects can be economically and ecologically important pests of urban forests. Crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae Kuwana (Hemiptera: Eriococcidae), is a scale that causes declines in plant vigor for a popular ornamental tree in the southeastern United States, crapemyrtle (Lagerstroemia spp.). CMBS has spread rapidly throughout the Southeast and, more recently, into the Middle Atlantic. Despite problems associated with CMBS, important aspects of its ecology, such as the role of propagule pressure in establishment and the relative importance of mechanisms for between-tree dispersal, are not well-understood. We used field and laboratory studies to investigate these aspects of …

Activity Level Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) And Feeding Habits Of Helicoverpa Zea Larvae After Ingestion Of Hearnpv In Mississippi Soybean, Judge Tyler Fortenberry

Theses and Dissertations

HearNPV was applied to a soybean field and evaluated for residual efficacy at different time intervals (0, 12, 24, 36, 48, and 72 hours) after application in laboratory bioassays with treated leaves. Larval mortality was rated at five, seven and twelve days after larval infestation. Larval mortality increased as the number of days after infestation increased. To evaluate the feeding habits of Helicoverpa zea at the 2^nd and 3^rd instar, HearNPV exposed larvae and untreated larvae were weighed at zero (before diet exposure), four, and seven days. At four days after exposure, larval weight gain of …

Population Genetics Among Rhipicephalus Sanguineus Ticks In The Lower Rio Grande Valley, Bianca Liana Guerra

Theses and Dissertations

Rhipicephalus sanguineus is a common tick species in the lower Rio Grande Valley of both human and veterinary concern. Two lineages of R. sanguineus have been described across the United States known as the tropical and temperate lineage. Both lineages can be differentiated morphologically, genetically, biologically, and by vector competence. The species name for both lineages has not been well established therefore this thesis will utilize their widely used identification. Both lineages have been identified in Texas. While the distribution of these lineages has been well-defined in some regions across the world, recent studies have observed sympatric populations in certain …

Study Of Population Dynamics Of Sugarcane Aphid (Melanaphis Sacchari) In Rio Grande Valley, Texas, Neetu Khanal

Theses and Dissertations

Chapter 1: This chapter incorporates detailed information about the biotype concept, aphids, their types and their biotypes, importance of studying insect biotypes and their role in mediating host plant defenses.

Chapter 2: This chapter explains in detail about the biology, biotypes, feeding behavior, damage, and economic loss caused due to sugarcane aphid infestation. This chapter further elaborates on the need for studying population level differences and justifies the objectives and significance of this research study.

Chapter 3: This chapter provides information about the comprehensive work done on three different populations of sugarcane aphid collected from three different locations in Rio …

The Molecular Evolution Of Insect Opsin Genes, Maria Jose Cardenas Muedano

Theses and Dissertations

Opsins are part of the superfamily of G-coupled receptor proteins and together with chromophores, are responsible for initiating the signal transduction cascade responsible for animal vision. Since opsins have a critical role on visual perception these genes are crucial for a myriad of adaptive traits and behaviors and should show diverse signs of natural selection at the molecular level. Understanding the evolution of opsins across the wide diversity of insect groups will allow us to better understand the evolutionary pressure on insect opsins and serve as a model for both other gene systems and other taxonomic groups of animals that …

Incorporating Native Plants In Insectary Strips To Promote Insect Diversity And Below-Ground Beneficial Microbes In South Texas, Lindsey N. Richards

Theses and Dissertations

Farm edges are generally the most undisturbed areas in a farm with diverse vegetation and can enhance agrobiodiversity and provide crucial food and shelter for wildlife, insects, and soil biota. Planting native wildflowers with the ability to reseed and withstand local climatic conditions for semi-permanent vegetation around farm edges or in between crops has potential to biologically control pests. To test this, we ran a two-year study and installed three different flowering insectary strips on a certified organic vegetable farm in South Texas during the winter season. The treatments were: 1) a commercially sourced 17-species native wildflower seed mix; 2) …

Effectiveness Of Food-Grade Coating Treated Nets After Various Drying Methods At Controlling Mite Growth On Dry-Cured Hams, Sadie White

Theses and Dissertations

Tyrophagus putrescentiae, known as the ham mite, is the most difficult pest to control in the dry-cured ham industry. Food-grade propylene glycol coated nets have been studied as an alternative to conventional mite infestation treatments but were heavy and costly to ship. This study aimed to increase the ease of use of the coated nets via drying. Three drying treatments: oven dried for 7 min (OD7m), oven dried for 20 min (OD20m), and counter dried for 24 h (CD24h), were tested to determine the efficacy at controlling mites as well as the mechanical properties of the nets and sensory characteristics …

Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones

Theses and Dissertations

Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect …

Utilizing Unmanned Aerial Systems To Sample Insects In Soybean, Marvin Merkl

Theses and Dissertations

To overcome some limitations of manual insect sampling in soybeans, an unmanned aerial vehicle (UAV) sampling platform was developed that could collect insects in a sweep net attached to the bottom of a UAV. Before this UAV sampling platform can be used to make management decisions, correlations with manual sweep net and/or drop cloth sampling methods are needed. This will allow action thresholds for the various pests to be calculated for the UAV sampling platform. To make the correlations, 87 soybean fields were sampled during 2020 and 2021 with each of 4 sampling methods, a UAV travelling 50-m, the same …

Examination Of The Realized Host Range Of North American Lacebug (Gargaphia Arizonica Drake & Carvalho) And Texas False Potato Beetle (Leptinotarsa Texana Schaeffer) As A Potential Biocontrol Agents For Silverleaf Nightshade (Solanum Elaeagnifoli Cav.), Samikshya Subedi

Theses and Dissertations

Silverleaf nightshade (Solanum elaeagnifolium Cav.) is a perennial forb native to South Texas and Central and South America, but it has become a serious agricultural weed across the world. Because silverleaf nightshade (SLN) is difficult and expensive to manage using chemical and mechanical controls, there is growing attention and research focused on biological control options. In this project, we used both field and laboratory studies to examine the suitability of two North American insects, namely North American lacebug (Gargaphia arizonica Drake & Carvalho) and Texas false potato beetle (Leptinotarsa texana Schaeffer) as prospective biological control agents for …

Ultrastructure Of Cimex Lectularius L. (Hemiptera: Cimicidae) Salivary Glands After A Blood Meal Infected With Bartonella Henselae (Hyphomicrobiales: Bartonellaceae), Afsoon Sabet

Theses and Dissertations

Bed bugs (Hemiptera:Cimicidae) are a common, hematophagous ectoparasite of humans and other animals, and are experiencing an international resurgence. Cimicids have been implicated in the transmission many disease agents, including various Bartonella species, however disease transmission has not yet been confirmed. Bartonella spp. are transmitted by a variety of arthropods, including fleas, lice and sand flies, and it is speculated that bed bugs may also serve as a potential vector. In this study, we used an artificial membrane to feed two groups of adult Cimex lectularius rabbit blood, either infected or uninfected with Bartonella henselae. After two weeks, the …

Studies On The Impact Of An Insect Growth Regulator And Host Plant On Reproductive Physiology Of Lygus Lineolaris, James Houston Chance Anderson

Theses and Dissertations

The tarnished plant bug, Lygus lineolaris, is an economically important polyphagous pest with a broad host range. With occurrence of insecticide resistance, strategies to limit its ability to reproduce, which would curb population growth, are becoming increasingly more valuable. Strategies toward this goal include the application of insect growth regulators (IGRs) and utilization of resistant cotton lines. This thesis summarizes experiments that elucidate the physiological underpinnings of the mode of action of novaluron, an IGR, and a cotton chromosome substitution (CS) line on the reproductive physiology of L. lineolaris. Investigations reported herein indicate that novaluron inhibits oviposition by …

Determining Residual Control And Systemic Activity Of Commonly Used Insecticides In Soybean And Cotton, Jacob H. Smith

Theses and Dissertations

Chemical control is a critical component of integrated pest management in cotton and soybean production. Residual efficacy of foliar insecticides can be highly variable and difficult to quantify due to several factors. The purpose of this research was to determine residual control and concentrations in flowering structures of commonly used insecticides. This research focused on the concentrations of active ingredient within the plant as well as efficacy over time. Previous research suggested chlorantraniliprole had a long residual and was highly lethal on corn earworm up to 28 days after treatment (DAT) in soybean; however, the results found in cotton were …

The Application Of Food-Grade Chitosan And Another Food-Grade Compound In Coatings To Control Tyrophagus Putrescentiae (Schrank, Family: Acaridae) Growth On Dry-Cured Hams And Their Impact On Dry-Cured Ham Quality, Wenjie Shao

Theses and Dissertations

The objective of this research was to evaluate if chitosan and another food-grade compound can be incorporated into food-grade coatings in conjunction with propylene glycol and polysaccharides to control Tyrophagus putrescentiae growth without affecting sensory attributes, water activity, and moisture content of dry-cured hams. Each coating solution was coated on ham cubes (2.5 × 2.5 × 2.5 cm³, n = 5/treatment) or infused in ham nets, and dry-cured ham cubes were wrapped in the ham nets prior to inoculation with 20 mixed-sex adult mites. Randomized complete block designs with two replications were utilized to evaluate the efficacy of …

Systematics And Population Structure Of Amblyomma Maculatum Group Ticks And Rickettsia Parkeri, An Emerging Human Pathogen In Southern Arizona, Usa, Michelle E.J. E Allerdice

Theses and Dissertations

The recent discovery of Amblyomma maculatum sensu lato (s. l.) ticks in southern Arizona has renewed discussions around species designations for members of the Amblyomma maculatum tick group. Amblyomma maculatum s. l. from Arizona appear to be morphologically intermediate between A. maculatum sensu stricto (s. s.) and A. triste s. s. At present there is no conclusive species designation for the ticks from Arizona. My research focused on analyzing the systematics of both A. maculatum s. l. and Rickettsia parkeri, a common bacterial pathogen transmitted by these ticks.

In the laboratory, A. maculatum s. l. from Arizona and A. maculatum …

Seasonal Management Strategies For Tarnished Plant Bug, Lygus Lineolaris (Palisot De Beauvois), In Midsouth Cotton Production Systems, Ryan Taylor Mann

Theses and Dissertations

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is considered the most economically important pest of midsouth cotton. This study was designed to understand the impact of tarnished plant bug populations in the later weeks of flowering cotton and residual effects of novaluron with subsequent applications. Experiments evaluated dynamic threshold approaches in the later flowering period of midsouth cotton, the impacts of novaluron plus subsequent applications at the 3^rd week of square, as well as residual properties in a laboratory experiment. Results suggest that a dynamic late season approach can reduce the amount of insecticide applications targeting tarnished …

Morphological Characterization And Functional Assessment Of Trichomes In Solanaceae, Sakshi Watts

Theses and Dissertations

Chapter 1: This chapter provides an overview of various trichome types in plants, and also empirically examines their variation on abaxial and adaxial leaf surface of 14 Solanum species. Detailed nomenclature, density, and dimension measurements of each trichome type has been provided using scanning electron-microscopy.

Chapter 2: Scanning electron microscopy was major component of methodology used in my thesis for scanning leaf samples to estimate trichome traits. In this chapter, a more efficient and cost-effective methodology for scanning electron microscopy has been explored.

Chapter 3: This chapter examines the relationship of trichome density and herbivore feeding behavior using abaxial and …

Bee Diversity Of Three Appalachian Shale Barren Sites, Olivia C. Latham

Theses and Dissertations

Insect pollination is vital to ecosystem function. However, climate change, habitat loss, pesticides, and a variety of other anthropogenic sources are contributing to a decline in pollinator diversity. Fragile small ecosystems with a high composition of specialized plant species that rely on specific pollinators such as Appalachian shale barrens, are especially at risk of losing biodiversity. This study combines the use of active sweep net sampling of endemic shale barren forbs and passive trap methods over the course of a bloom season (April-August) in three barren sites to identify bee community populations and visitation relationships between pollinator species and endemic …

Plant-Pollinator Associations In An Eastern Serpentine Savannah And The Effects Of Overbrowsing, Allyson Richins

Theses and Dissertations

Chapter 1: Native plant response to deer overbrowsing in a serpentine savannah

Plants are particularly vulnerable to physical disturbance in low productivity areas, due to a high cost of replacing lost plant tissue. In the eastern United States, serpentine grasslands are fragmented ecosystems with high concentrations of rare endemic plant species, low concentrations of soil nutrients, and uncontrolled deer overpopulation. This study assessed functional responses of native angiosperms in a rare eastern serpentine savannah to selective deer browsing. Plant count, flower count, floral area, vegetative area, and plant height of 10 serpentine plant species were compared inside and outside of …

Temperature Influence On Insecticide Resistance In Aedes Aegypti And Aedes Albopictus Mosquitoes From South Texas, Wendy Soledad Salinas

Theses and Dissertations

Aedes aegypti and Aedes albopictus are vectors for several emerging arboviruses including Zika, chikungunya and dengue. Both mosquitoes are found along the Rio Grande River in South Texas, along the border between Mexico and the United States of America. These mosquito species typically reside near human settlements. A preventative measure public health official use to help halt the spread of diseases is by controlling vector population with the use of insecticides, but as temperature vary, and with the constant exposure to commonly used insecticides, mosquitoes from South Texas may be developing a resistance to the insecticides. Resistance to insecticides may …

Upper Thermal Limits Vary Among And Within Native Bee Species In Relation To Season, Voltinism, And Nest Type, Kálmán K. Csigi Xiv

Theses and Dissertations

Native bees are only recently gaining attention for the extent to which they aid in pollination and ecosystem services. These services are threatened by predictions of warming temperatures if bees are not able to respond. Voltinism - the number of generations produced annually- can strongly influence thermal conditions experienced by both developing and adult bees based on emergence strategies for each voltinism type. Differences in experienced thermal conditions brought on by climate change could therefore affect upper thermal limits (UTL) in bees. This study observes UTLs across a foraging season within and among native bee species vi to elucidate the …

"Fanciful But Not Forgotten: A Historical Examination Of The Study Of The Flea, 1840-1930", Andrea Jean Buhler

Theses and Dissertations

Although the Victorian and Progressive periods saw a rise in entomological research, fleas were not a priority for scientific investigation. The discovery of fleas as disease vectors in the late nineteenth century marked a turning-point in interest in fleas. Expanding this standard history of fleas, the thesis probes flea research conducted outside the confines of disease during 1840-1930. It documents and analyzes the contributions of Louis Bertolotto, William Heckler, Charles Rothschild, Karl Jordan, and L. O. Howard. Whereas those working in the new profession of entomology saw fleas as disease vectors, these men had different relationships with fleas: Bertolotto and …