Entomology Commons^™

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) …

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 …

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 …

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 …

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 …

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

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 …

The Heat Is On: Comparison Of Thermoregulatory Behavior In Parasitised Versus Unparasitized Caterpillars Of The Tobacco Hornworm, Manduca Sexta (L.) [Lepidoptera: Sphingidae], Jessica M. Johnston

Theses and Dissertations

Insect thermoregulatory research has demonstrated evidence of variation occurring within and among species with respect to infection, pathogens, and parasitism, but few studies have examined differences in thermoregulatory behavior in a host-parasite system with a coevolved symbiotic virus. I investigated the role of parasitism by Cotesia congregata (Say) (Hymenoptera: Braconidae) on the thermoregulatory behavior of Manduca sexta (L.) (Lepidoptera: Sphingidae) using an experimental design in a thermal gradient chamber and a complementary observational field study on wild M. sexta collected from tobacco farms. Parasitism and larval age were not found to have a significant effect on the preferred body temperature …

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 …

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 …

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 …

Effects Of Olfactory Cues On The Movement Behavior Of The Predatory Beetle Calosoma Wilcoxi, Kennesha Myrick-Bragg

Theses and Dissertations

Arthropod predators often use prey and conspecific cues to make foraging decisions. Calosoma wilcoxi (Leconte) is a voracious predatory beetle that specializes on lepidopteran larvae often found in the forest canopy, including the fall cankerworm. This study tested the hypothesis that C. wilcoxi uses olfactory cues to detect prey and conspecifics. A Y-tube olfactometer was used to test attractiveness to larvae, larval frass, conspecific cues, and volatiles from herbivore-damaged white oak leaves. C. wilcoxi did not preferentially choose the treatment in any of the experiments. There was no difference in mean time spent in the treatment or control arm for …

Upper Thermal Limits Differ Among Component Species In A Host-Parasitoid-Hyperparasitoid System, Kanchan A. Joshi

Theses and Dissertations

Among the predicted impacts associated with global climate change, warming is of special interest because the rates of physiological processes are temperature-dependent. Insects and other ectotherms are likely to be affected due to their limited ability to control body temperature. In this study, I measured the tolerance to extreme high temperatures, i.e., critical thermal maximum (CT_max), of component species in a tri-trophic system, including an herbivore (Manduca sexta), a primary larval parasitoid (Cotesia congregata) and a hyperparasitoid (genus Silochalcis). For wild insects, the parasitoid had the lowest CT_max, the hyperparasitoid had …

Bacterially-Based Immune Challenges And Trauma Elicit Terminal Investment In Male Aedes Aegypti, Molly K. Schumacher

Theses and Dissertations

Investment in life history traits such as immune function and reproduction is constrained by finite available resources. A cost-of-immunity trade-off may occur in response to infection when resources are diverted away from reproductive effort and into an immune response. Alternatively, an infected individual may enhance reproductive effort to maximize terminal reproductive success in response to the survival threat inherent to infection (terminal investment). We measured male Aedes aegypti reproductive behavior following inoculations with: living bacteria; killed bacteria as an immune elicitor; and a sham control. Mating competitiveness relative to naïve males was also determined through a binary mate choice experiment …

Environmental Impacts On Life History In Container Breeding Mosquitoes, Kathleen May Westby

Theses and Dissertations

In this dissertation I explore different ways that the environment impacts life history in mosquitoes in ways that may alter vectorial capacity. In chapter I, I tested if short-term sugar deprivation experienced after exposure to La Crosse virus altered infection rates in Aedes albopictus and if sugar treatment and virus infection status altered blood feeding behavior and fecundity. I found no evidence that sugar deprivation impacted infection rates or fecundity. Sugar deprivation did increase blood feeding. There was no effect of infection status on blood feeding or fecundity. In chapter II, I tested for effects of seasonal cues (temperature and …

Speed And Resolution In The Age Of Technological Reproducibility, Shawn Taylor

Theses and Dissertations

The rate of acceleration of the biologic and synthetic world has for a while now, been in the process of exponentially speeding up, maxing out servers and landfills, merging with each other, destroying each other. The last prehistoric relics on Earth are absorbing the same oxygen, carbon dioxide and electronic waves in our biosphere as us. A degraded .jpeg enlarged to full screen on a Samsung 4K UHD HU8550 Series Smart TV - 85” Class (84.5” diag.). Within this composite ecology, the ancient limestone of the grand canyon competes with the iMax movie of itself, the production of Mac pros, …

Behavioral Responses Of Male Parasitic Wasps To Plant Cues: A Comparison Of Two Host-Plant Complex Sources Of Cotesia Congregata (Say), Megan Ayers

Theses and Dissertations

Prior exposure to plants cues can enhance assortative mating in insects. We hypothesized that, as previously reported for females, males of Cotesia congregata would display inherent responses to plant cues that could be modified by postemergence experience and further, that males originating from two different host-plant complexes (HPCs) would display different behavioral responses to these HPCs. In no-choice contact assays with a non-host plant, searching responses of males and females increased sharply at Day 2 and remained stable through Day 4. In no-choice assays with potential host plants, males searched longer on catalpa than tobacco; responses were not modified by …

Responses Of The Catalpa Sphinx, Ceratomia Catalpae, And Its Primary Parasitoid, Cotesia Congregata, To Varying Levels Of Iridoid Glycosides In Catalpa, Jessica L. Bray

Theses and Dissertations

The catalpa sphinx, Ceratomia catalpae, is a specialist on Catalpa trees, which produce iridoid glycosides (IGs). Whereas some trees are defoliated every year, others escape herbivory. Caterpillar populations are either heavily parasitized by the braconid wasp, Cotesia congregata, or remain unparasitized. We hypothesized that these patterns could be explained by variable IG concentrations among trees and insect responses to these chemicals. IG concentrations varied among trees. Percent defoliation was positively related to IG concentration. In comparisons of insect responses to relatively high or low IG concentrations, moths preferred to oviposit on trees with high IG concentrations. Caterpillars did …

Ecology Of Insect Pests Of Cotton And Their Natural Enemies, Soolaf Abud Kathiar

Theses and Dissertations

This thesis represents a combination of three projects, all related to cotton agriculture, their pests, and natural enemies of those pests. In the first project, I compared the abundance of soil-surface arthropods in cotton fields with three different tillage methods (conventional and two conservation tillage methods). Cotton plants produce extrafloral nectar, an adaptation of many plants that attracts natural enemies of plant pests and reduces feeding injury from herbivores. Therefore, in the second project, I analyzed the sugar and amino acid concentrations of the extrafloral nectar of five lines of cotton. Green lacewings are natural enemies that are often used …

Diversity And Abundance Of Insects From The Reduviidae And Pentatomidae Families In Three Ecological Niches Of Six Communities In The Coroico And Coripata Municipalities, Department Of La Paz, Fernando Miguel Manrique Mamani

Theses and Dissertations

The Hemiptera order has 23,000 species that are distributed among many families. Two of these are the Pentatomidae and Reduviidae families. The aim of this study was to identify the different species of insects from the Reduviidae and Pentatomidae families as well as each species’ abundance in three ecological niches (forest, forest edge, and farm land). The study was conducted in six communities of Los Yungas, La Paz (Carmen Pampa, San Pablo, San Juan de la Miel, Altuspata, Choro Alto, and Choro). In each community, three Malaise traps were installed in the three ecological niches (forest, forest edge, and farm …

Biodiversity Of Insects From The Syrphidae And Carabidae Families In Three Ecological Niches (Forest, Forest Boarder, And Farming Area) In Three Communities Of The Coroico Municipality, Nor Yungas, La Paz, Eddy Alarcón

Theses and Dissertations

Today, biodiversity is one of the most studied disciplines because it encompasses all species of plants, animals, and microorganisms that exist and act within an ecosystem. In recent decades, biodiversity has been degrading rapidly due to the simplification of agricultural systems, and the irrational use of pesticides that alter the normal function of ecosystems. Within nature, each insect population is attacked by one or more natural enemies. In this investigation, during a six month period from June to December 2006, the biodiversity of predatory insects from the syrphidae and carabidae families was determined in three ecological niches of three communities …

Quantification Of Pollinating Insects Of The Superfamily Apoidea In Three Ecological Niches Of Three Communities In The Municipality Of Coroico-Nor Yungas, Department Of La Paz, Óscar Jaime Claros Sossa

Theses and Dissertations

The superfamily Apoidea (commonly referred to as bees), are insects whose diet consists of the nectar and pollen from flowering plants. Therefore, they are essential pollinators of many species, both wild and cultivated.
Bees are similar to other Hymenoptera in appearance, size, and color variety. The superfamily Apoidea contains 17,000 known species and could possibly contain up to 30,000. Bees perform many tasks that benefit humanity such as pollinating the flowers of both wild and cultivated plants. Without this work, fruits and seeds necessary for the survival of different species, for our own food supply, and for industry would not …

Study Of Two Species Of Bees (Apis Mellifica) And Three Types Of Beehives In And Around Chulumani (Prov. Chapare), Jose Cruz Pardo

Theses and Dissertations

In order to improve the diet of the comunarios of Chulumani, and to expect a better production of honeybee; it has been introduced the Apis mellífica cárnica queen in Apis mellífica scutellata colonies. It was also carried out comparative tests among beehives Langstroth, Schirmer and Dadant. The nucleus “S” was only used as an introduction of queens, and the nucleus “M” and “K” were utilized for the development of the colony (submúltiplos of the beehive Schirmer). The study was carried out totally at random with the experimental design with factorial arrangement, and the meaning of the comparative analysis it was …

Artificial Alimentation Of Bees Using Natural Juices During The Dry Season, Ramiro Bernal Acosta

Theses and Dissertations

In the community of Tunshi San Nicols of the Licto parish in the Province of Chimborazo, an evaluation was done on the effect of an energetic supplementary feeding of bees (Italian-mestizas) during the dry season (September 23 to February 20). These supplements consisted of carrot juice (T1), orange juice (T2) and sugar cane juice (T3). These supplements were also compared to a control group (T0). The experimental units consisted of 16 standard beehives distributed randomly with the 4 treatments and 4 repetitions of each treatment. The results showed that sugar cane juice (T3) obtained the best results in the consumption …