Entomology Commons^™

Revision And Biogeography Of The Tribulus Group (Orthoptera, Acrididae, Melanoplinae, Melanoplus) And Establishment Of The Rusticus Group With A Description Of Four New Species Of West Of Mississippi River, Usa, Jireh Mwamukonda

Theses and Dissertations

The genus Melanoplus represents one of the most diverse groups of acridid grasshoppers in North America, comprising over 430 described species within the subfamily Melanoplinae. Among its various species groups, the Tribulus group consists of flightless grasshoppers typically found in open woodlands and forest margins, primarily in the eastern United States. The Melanoplus tribulus group was first established by Blatchley (1920) as Obovatipennis Group. However, since species groups are informal taxonomic units not governed by nomenclatural rules, the group later became known as the Tribulus group. It currently includes 11 taxa. These brachypterous species occur from New Jersey south Florida …

Arthropod Communities Associated With Endangered Physaria Thamnophila (Zapata Bladderpod) And Its Nurse Plants, Cesar Adrian Hinojosa

Theses and Dissertations

Physaria thamnophila is a federally endangered plant whose associated arthropods are understudied and poorly understood. This study surveyed environmental conditions and the arthropod community within the Arroyo Ramirez Tract of the Lower Rio Grande Valley National Wildlife Refuge, assessed which environmental factors influenced the arthropod community, and sought arthropod taxa statistically associated with Physaria thamnophila. Sticky cards and pitfall traps were deployed for a 7 day period, and vacuum samplings occurred quarterly over the span of a year to collect arthropods that were identified to order and family level for Coleoptera, Hymenoptera, and Lepidoptera. Biotic and abiotic surveys were performed …

Determination Of An Effective Natural Boxelder Bug (Boisea Trivittata) Repellent, Reyna Chavez

Theses and Dissertations

This study investigates the use of ecofriendly repellant alternatives to pest management to control boxelder bugs (Boisea trivittata). This bug gathers by the thousands on warm surfaces of exterior suburban homes during early fall and late spring. I determined bug repellency to turmeric oil (Curcuma longa), catnip (Nepeta cataria), citronella (Cymbopogon nardus), and lavender (Lavandula angustifolia). The treatments consisted of essential oils containing 20% methanol. All treatments demonstrated repellency of Boxelder bugs. Citronella was the most effective and had the highest level of repellency range of 90-99%. Catnip was the least effective with a repellency range of 63-82%.

Influence Of Diverse Forage Environments On Honey Bee Colony Health, Angus Catchot Iii

Theses and Dissertations

Honey bees are important pollinators that face a multitude of stressors in their environment such as pathogens, parasite pressure, forage availability and pesticide exposure. This study examined how the makeup of different environments and the stressors related to those environments are affecting honey bee health in Mississippi. A field experiment was conducted during the first year of the study across four distinct landscapes ranging from intensively cultivated cropland to predominantly natural forage habitats to assess the impact of landscape availability on varying honey bee colony health parameters. Locations that had cultivated crops within foraging range produced more honey and brood …

Understanding Pollinator-Forb Interactions And Evaluating Trapping Methods For Pollinator Monitoring In Lawns Of The Southeastern United States, Sara Rose Kirby

Theses and Dissertations

Urban turfgrass landscapes are widespread across the southeastern United States but offer limited ecological value under conventional management. This thesis evaluates the pollinator support potential of ten forb species commonly found in low-maintenance lawns and assesses the effectiveness of two insect sampling methods, sweep netting and pan trapping. Over two years of field surveys, native forbs such as Symphyotrichum divaricatum and Claytonia virginica supported significantly greater insect abundance and diversity than introduced species. Network and modularity analyses revealed that native plants facilitated more specialized pollinator interactions, including those involving oligolectic bee species. In a complementary study, pan traps effectively sampled …

Sweetpotato Insect Pests: Virus Vector Management And Rearing, Rachel Emily Morrison

Theses and Dissertations

Sweetpotatoes (Ipomoea batatas) are vegetatively propagated through slips, making them prone to viral buildup. Aphids are insect pests known for transmitting viruses to crops, which reduces yield. This study examined different options for aphid management to reduce the spread of potyviruses: crop borders, crop oils, and insecticides. However, the results of this research showed that treatments were not successful at reducing the spread of the four potyviruses tested. An additional objective was to establish a colony of banded cucumber beetles (Diabrotica balteata) in the laboratory. These beetles are a leaf-feeding and root-feeding pest of sweet potatoes. Two colonies of banded …

Evaluating Simulated Threecornered Alfalfa Hopper (Hemiptera: Membracidae) Damage In Cotton (Malvales: Malvaceae) And Identifying Conducive Environments, Reece Starnes Butler

Theses and Dissertations

This research evaluated the effects of simulated threecornered alfalfa hopper (TCAH), Spissistilus festinus (Say), damage in cotton and aimed to identify environments that may contribute to an increase in TCAH injury. During the 2023 and 2024 growing season, simulated TCAH damage was imposed at 0%, 10%, 20%, 30%, 40%, and 50% at the three and six leaf growth stage. Agronomic data included plant heights, node counts, and plant mapping, which was collected throughout the growing season, while lint yield was recorded at harvest. Damaged plants exhibited reduced plant heights and node counts, with an increase in nodes above cracked boll …

Taking Flight: Utilizing Unmanned Aerial Systems To Sample Insects In Soybean, William "Covey" Lockhart

Theses and Dissertations

Insect scouting in soybean is a labor-intensive task but is needed throughout the season to minimize losses. When soybeans are tall, soils are wet, or soybeans are planted in narrow rows, walking through these fields can be difficult. To overcome these limitations of manual sampling, an unmanned aerial vehicle (UAV) sampling platform was developed that can collect insects in a sweep net attached to the bottom of a UAV. This system has been named the “Drone Insect Net Sampling System” (DINSS). Previous research with this system has shown positive correlations to traditional manual sampling methods. To improve this system, modifications …

Larval Environments Affect The Implementation Of The Sterile Insect Technique On Aedes Mosquitoes, Katherine G. Evans

Theses and Dissertations

Sterile Insect Technique (SIT) is an effective method for controlling pests and has been increasing in popularity to control Aedes mosquitoes. SIT involves inundating an area with sterilized male mosquitoes to reduce egg hatch and ultimately the number of wild adults. Previous research indicates that enacting mortality early in the larval life of Aedes mosquitoes can result in counter-productive effects, due to reduced competition among developing larvae. I hypothesize that the effectiveness of SIT at reducing adult populations is modified by densitydependent mortality and density-dependent growth among larvae. I performed two field-to-lab studies and developed an individual-based model to test …

Bugs In The Flux: Links Between Arthropod Diversity And Spatial Variation Of Soil Respiration In A Temperate Forest, Erin-Darby H. Mcclain

Theses and Dissertations

Soil respiration (Rs) is the largest terrestrial flux of carbon (C) to the atmosphere, with heterotrophic contributions to Rs varying spatially and temporally. While microbes are the primary and most thoroughly studied source of soil heterotrophic respiration (Rh), contributions from higher trophic organisms, including arthropods, are rarely quantified and poorly understood. Arthropod abundance and diversity correspond with variation in soil microclimate, which is influenced by site factors including canopy structure, site productivity, and disturbance. However, the extent to which these site factors influence arthropod abundance and diversity, and consequently, spatial variation in Rs is not known. The objective of our …

Evaluation Of Current Management Strategies For The Tarnished Plant Bug And Tobacco Thrips In Midsouthern Cotton, Hunter Lane Lipsey

Theses and Dissertations

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important economic pest of cotton, Gossypium hirsutum (L.), in the Midsouth region of the United States. An experiment was conducted to determine the impact of insecticide class loss on yield and Lygus populations in the recently commercialized ThryvOn cotton technology. Data indicated no significant yield loss when excluding any currently utilized insecticide class for tarnished plant bug management. An additional objective was to reevaluate the sampling interval necessary to scout ThryvOn cotton for Lygus. No significant differences were observed between a 3 or 7-day sample interval compared to plots …

Survey And Comparative Analysis Of Pollinator Diversity, Abundance, And Foraging Activity Of Diptera And Hymenoptera In Selected Habitats Of South Texas, Melissa Villarreal

Theses and Dissertations

With the declining bee population, non-bee pollinators can serve as an alternative source for pollination. Diptera is a potential source of untapped pollinator resources based on their abundance and visitation rate, but they are understudied in the field of pollination ecology. This study aimed to characterize the pollinator community in selected areas of South Texas. It focused on the Diptera and Hymenoptera families to compare their diversity, relative abundance, foraging behaviors, environmental influences, and vegetation associations. Active sampling and line transect were used in the survey to sample the Hymenoptera and Diptera communities to their family taxonomic rank. Statistical analyses …

The Effects Of Livestock On Mosquito Diversity And Abundance In Hidalgo County, Taylor Nicole Moya

Theses and Dissertations

Mosquitoes are detrimental to animals and threaten humans. More information is needed on how farm animal presence may impact mosquito abundance and diversity at farms. My goal in this study is to determine if there is any correlation between animal abundance or diversity on a farm and the abundance and diversity of mosquitoes collected. Hidalgo County, Texas, has a subtropical desert climate, ideal for mosquitoes. I hypothesized that the mosquito abundance and diversity indices would increase as the livestock abundance or diversity increases. Adult mosquitoes were collected using two CO2-baited light traps per farm from Spring 2022 to Fall 2022. …

Assessing The Influence Of Native And Invasive Grasses On The Behavior Of Aedes Aegypti In South Texas, Emily Medelez

Theses and Dissertations

Invasive grasses in South Texas can have widespread negative effects, displacing native species, reducing biodiversity, and posing risks to public health. These grasses may flourish in moist, shaded environments, which not only support their growth but also creates habitats favorable for mosquito activity. This can increase the population and alter the behavior of mosquitoes, potentially raising the risk of disease transmission. In this thesis, I look at the behavior of mosquito species Aedes aegypti, primary vector of the yellow fever virus. I analyzed the influence of oviposition, flight and resting behaviors. I tested the relative attraction of Aedes mosquitoes …

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, …

Identification And Characterization Of Silk Gland Specific Ugt34 Gene In Helicoverpa Zea, Courtney Nicole Wynn

Theses and Dissertations

Uridine diphosphate glycosyltransferase (UGT) is a multigene family of enzymes responsible for catalyzing glycosylation of small hydrophobic molecules. Recently, a genomic analysis of the corn earworm (Helicoverpa zea) identified 45 different UGT genes. We discovered a UGT gene (UGT34) showing high levels of expression exclusively in the silk gland tissue. The expression levels of UGT34 were analyzed in different developmental stages and silk gland sub-segments, revealing that UGT34 is generally expressed at all larval instar stages and largely expressed in the middle and posterior subsegments of the silk glands. The soybean looper (Chrysodeixis includens), another noctuid …

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.

Assessing Drivers Of Overwintering Survival And Annual Range Shifts By The Redbanded Stink Bug, Piezodorus Guildinii (Westwood), Thomas Gustavus Paul

Theses and Dissertations

The redbanded stink bug, Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae), is a non-native pest of soybeans in the Americas outside of the Carribean. Mortality of overwintering adults due to cold exposure has been implicated as a major driver of interannual fluctuations in the occurrence of P. guildinii in the southeastern United States, but formal investigations of drivers, including factors other than cold temperatures, are rare. We conducted overwintering assays with field-collected P. guildinii to quantify survival and coupled historical occurrence with climatic data to develop a species distribution model. We found that leaf litter provides substantial insulation from lethal temperatures and …

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 …

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 …

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 …

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 …

Plastivore: Identification And Functional Characterization Of Plastic Degrading Lipase And Carboxylesterase Enzyme Families From Galleria Mellonella, Joseph Boctor

Theses and Dissertations

[provided as attachment while patent is pending]

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 …