Entomology Commons^™

Do Cover Crops Influence Beneficial And Herbivorous Arthropod Communities Across Growing Seasons?, Adegboyega Fajemisin, Satinderpal Kaur, Alejandro Vasquez, Alexis Racelis, Rupesh R. Kariyat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Cover crops provide multiple ecosystem services in agriculture, yet their influence on arthropod communities remains poorly understood, especially in commercial farming. Despite their potential benefits, it remains unexplored how cover crops affect arthropod community dynamics across multiple growing seasons. We conducted a two-year study across three commercial farms in the Lower Rio Grande Valley, Texas, to examine how cover crops influence arthropod community composition and abundance, whether beneficial arthropods (natural enemies and pollinators) persist into cash-crop phases, and how cover crops affect natural enemy–herbivore relationships. We compared arthropod communities between cover-crop treatments and control plots and tracked responses through subsequent …

Drought × Herbivory Induce Leaf Trichomes In Soybean With Differential Impact On Its Major Herbivore Soybean Looper Chrysodeixis Includens, Manish Gautam, Karen Alanis, Rupesh R. Kariyat

School of Integrative Biological & Chemical Sciences Faculty Publications

Trichomes have been well studied as a physical defense against stress. With climate change, stressors like drought and/or herbivory can have exacerbated effects on crop morpho-physiology. However, the interactive effects of such stressors on physical defenses like trichomes and their effects on herbivores is poorly understood. To examine this, soybean plants were exposed to a major herbivore, soybean looper (SBL) (Chrysodeixis includens Walker), under simulated drought conditions to examine the interactive effects of drought and herbivory (D × H) on leaf trichomes. Additionally, SBL growth traits were monitored under different leaf diet concentrations (10% and 20%) and trichome enriched diets …

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%.

Comparing Machine Learning, Deep Learning, And Reinforcement Learning Performance In Culex Pipiens Predictive Modeling, Wei Yin, Sanad H. Ragab, Michael G. Tyshenko, Teresa Patricia Feria-Arroyo, Tamer Oraby

School of Mathematical & Statistical Sciences Faculty Publications

Several machine learning (ML) and deep learning (DL) methods have been used to predict the presence of species in classification problems. Another set of methods, called reinforcement learning (RL), has been used in training agents to perform various tasks, but not in predicting species distribution. Culex pipiens (Diptera: Culicidae), commonly known as the common house mosquito, is a globally distributed species prevalent in temperate and subtropical regions. They serve as a primary vector for West Nile Virus (WNV), a mosquito-borne pathogen that affects humans and other animals. The study objective is to compare the performance of logistic regression, random forest …

Native Ticks As A Model For The Effectiveness Of Fire As A Tool For The Management Of Cattle Fever Ticks In South Texas, Lauren P. Maestas, Sarah E. Mays Maestas, Kathleen M. Yeater, Manuel Zavala, Reyes Garcia, John A. Goolsby

School of Integrative Biological & Chemical Sciences Faculty Publications

The species of cattle fever ticks (CFT) present in North America, Rhipicephalus (=Boophilus) annulatus, and R. microplus, remain an important agricultural and economic burden. The use of acaricides to control CFT has been a common practice over the past half century. However, alternative strategies for control are needed to improve the options for sustainable pest control. Fire is a tool to manage vegetation, and some evidence supports its potential for use to control ticks. We evaluated the effectiveness of fire as a management tool for ticks in South Texas. Our site was a 28.2-ha property in Cameron …

Meta-Transcriptomes Of The Microbial Communities Of The Different Developmental Life Stages Of Anastrepha Ludens (Diptera: Tephritidae), Erin L. Schuenzel

School of Integrative Biological & Chemical Sciences Faculty Publications

The Mexican fruit fly, Anastrepha ludens, is a polyphagous pest that is a constant threat to US agriculture because of its proximity to citrus production in border region of the United States and Mexico. Sterile Insect Technique has been used to manage and eradicate of the Mexican Fruit Fly. SIT, however, requires millions of sterile male flies to be released each week from mass-rearing facilities. The mass-reared colonies must deal with microbial infections that reduce survivorship, fecundity and male-male competition. Meta-transcriptomics joins culturing and next generation DNA sequencing techniques to understand these changing microbial communities. This study uses advances …

Editorial Overview: From Neurons To Ecology: How Sensory Information Guides Insect Behaviour, Natalie Hempel De Ibarra, Julie A. Mustard

School of Integrative Biological & Chemical Sciences Faculty Publications

No abstract provided.

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. …

Variation In Sorghum Aphid (Melanaphis Sorghi) 1 Populations Translates Into Life History Traits On Sorghum-Sudangrass (Sorghum´ Drummondii), Neetu Khanal, Christopher J. Vitek, Rupesh R. Kariyat

School of Integrative Biological & Chemical Sciences Faculty Publications

Sorghum aphid (Melanaphis sorghi; SA) (Theobald) is a new invasive pest of sorghum first reported in the USA in 2013. Since then, the use of synthetic pesticides and resistant cultivars have increased, which has caused levels of differences in the populations of SAs and led to the potential emergence of new biotype(s) of SA. However, most research has concentrated on comparing SA fed on sorghum, sugarcane, and other hosts, which may have obscured any population differences that may exist within sorghum. To understand this, we collected three populations of SA that fed on sorghum from three different locations around …

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 …

Red Harvester Ants Pogonomyrmex Barbatus (Smith, 1858) (Hymenoptera: Formicidae) Do Not Distinguish Between Sorghum Head Mold Symptomatic And Asymptomatic Seeds, Lilly Victoria Elliott-Vidaurri, Hannah J. Penn, Robin A. Choudhury

School of Earth, Environmental, & Marine Sciences Faculty Publications

Red harvester ants, Pogonomyrmex barbatus (Smith, 1858) (Hymenoptera: Formicidae), common in the Lower Rio Grande Valley of Texas, are known to gather seeds from areas around their nests and store the seeds inside their nests for later consumption. As these ants often nest in and near agricultural fields, some of these seeds may be from crops and may also be infected with fungal plant pathogens. These pathogens can degrade seed coats and may cause the seeds to rot within the ant nests, decreasing storage time and potentially spreading the pathogen to other stored seeds. We studied how head mold, a …

A New Record Of Fleas From Nilgai Antelope In Southern Texas And Fleas From Other Wildlife, Sarah E. Mays Maestas, Jason Tidwell, John A. Goolsby, Lauren P. Maestas

School of Integrative Biological & Chemical Sciences Faculty Publications

Wildlife are hosts of ectoparasites, such as fleas and ticks that may transmit human and animal pathogens. Little is known about the ecology of many ectoparasite species native to southern Texas, or their role in pathogen maintenance and transmission. Much attention has been given to the role of nonnative nilgai antelope as cattle fever tick hosts and agents of dispersal, but little attention has been given to other ectoparasites that may utilize nilgai antelope as hosts. As southern Texas is a hot-spot for flea-borne (murine) typhus, it is important to examine flea species presence, abundance, and host use in this …

Anti-Apostatic Feeding Behavior In Two Species Of Assassin Bug, The White-Spotted Assassin Bug Platymeris Biguttatus And Red-Spotted Assassin Bug Platymeris Rhadamanthus (Hemiptera: Reduviidae), Julia H. Potocnjak, Christopher Vitek

School of Integrative Biological & Chemical Sciences Faculty Publications

Predator-prey relationships are a driving force when examining community ecology. One question in predator-prey interactions is how a predator may respond to novel prey phenotypes, a form of frequency dependent prey selection. A predator may selectively target or avoid the novel prey, a behavior referred to as anti-apostatic or apostatic selection respectively. We examined apostatic prey selection by observing feeding behavior in two species of assassin bugs (Hemiptera: Reduviidae), the white-spotted assassin bug (Platymeris biguttatus) and the red-spotted assassin bug (Platymeris rhadamanthus) which were fed unmodified and modified (novel) phenotypes of Turkistan cockroaches, Blatta lateralis (Blattodea: …

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, …

Phylogenomics Reveals The History Of Host Use In Mosquitoes, John Soghigian, Charles Sither, Silvia Andrade Justi, Gen Morinaga, Brian K. Cassel, Christopher J. Vitek, Todd Livdahl, Siyang Xia, Andrea Gloria-Soria, Jeffrey R. Powell

School of Integrative Biological & Chemical Sciences Faculty Publications

Mosquitoes have profoundly affected human history and continue to threaten human health through the transmission of a diverse array of pathogens. The phylogeny of mosquitoes has remained poorly characterized due to difficulty in taxonomic sampling and limited availability of genomic data beyond the most important vector species. Here, we used phylogenomic analysis of 709 single copy ortholog groups from 256 mosquito species to produce a strongly supported phylogeny that resolves the position of the major disease vector species and the major mosquito lineages. Our analyses support an origin of mosquitoes in the early Triassic (217 MYA [highest posterior density region: …

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 …

Pathogenicity Of Multiple Providencia Species (Enterobacteriales: Morganellaceae) To The Mass-Reared Mexican Fruit Fly (Diptera: Tephritidae), Bacilio Salas, Hugh E. Conway, Don C. Vacek, Christopher Vitek, Erin Schuenzel

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is used to suppress and eradicate wild populations. Success of this control method necessitates weekly production of hundreds of millions of flies, their sterilization by irradiation, and their aerial release. Diet needed to produce large fly numbers are conducive to the spread of bacteria. Pathogenic bacteria were isolated from 3 rearing facilities and from multiple sources: eggs, larvae, pupae and spent diet, and were found to include some isolates identified to the genus Providencia (Enterobacteriales: Morganellaceae). We …

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 …

Greenbug Feeding-Induced Resistance To Sugarcane Aphids In Sorghum, Heena Puri, Edith Ikuze, Jessica Ayala, Isabella Rodriguez, Rupesh R. Kariyat, Joe Louis, Sajjan Grover

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Plants are attacked by multiple insect pest species and insect herbivory can alter plant defense mechanisms. The plant defense responses to a specific herbivore may also contribute to the herbivore growth/survival on plants. Feeding by one insect species can modulate the plant defenses, which can either facilitate or hamper the colonization of subsequent incoming insects. However, little is known about the effect of sequential herbivory on sorghum plants. In this study, we demonstrate that a specialist aphid, sugarcane aphid (SCA; Melanaphis sacchari) grows faster on sorghum than a generalist aphid species, greenbug (GB; Schizaphis graminum). We also determined …

The Known And Unknowns Of Aphid Biotypes, And Their Role In Mediating Host Plant Defenses, Neetu Khanal, Christopher Vitek, Rupesh R. Kariyat

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Insect species are subjected to disparate selection pressure due to various biotic and abiotic stresses. Management practices including the heavy use of chemical insecticides and introduction of insect-resistant plant cultivars have been found to accelerate these processes. Clearly, natural selection coupled with human intervention have led to insect adaptations that alter phenotypes and genetic structure over time, producing distinct individuals with specialized traits, within the populations, commonly defined as biotypes. Biotypes are commonly found to have better fitness in the new environment and, in the case of aphids, the most commonly studied system for biotypes, have the ability to successfully …

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) …

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 …

Diel Activity Patterns Of Two Distinct Populations Of Aedes Aegypti In Miami, Fl And Brownsville, Tx, John-Paul Mutebi, André Barretto Bruno Wilke, Erik Ostrum, Chalmers Vasquez, Gabriel Cardenas, Augusto Carvajal, Maday Moreno, William D. Petrie, Arturo Rodriguez, Henry Presas, Jesus Rodriguez, Fred Barnes, Christopher Vitek, Xochitl Estrada, Thalia Rios, Jeremy Marshall

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The diel biting activity of Aedes (Stegomyia) aegypti (L) populations was extensively investigated in the early 1900s to gain more information on the biology of Ae. aegypti, and this information was used to devise effective approaches to controlling populations of this species and protect the human population from widespread arbovirus outbreaks. However, few contemporary studies are available regarding the diel activity patterns of Ae. aegypti. To assess the diel activity patterns of Ae. aegypti in southern Florida and Texas, we conducted 96-h uninterrupted mosquito collections once each month from May through November 2019 in Miami, Florida, and Brownsville, Texas, using …

Insecticide Resistance In Aedes Aegypti Varies Seasonally And Geographically In Texas/Mexico Border Cities, Heather Hernandez, Flor A. Martinez, Christopher Vitek

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Insecticide use is the primary method of attempting to reduce or control the spread of mosquito-borne diseases. Insecticide resistance is a major concern as resistance will limit the efficacy of vector-control efforts. The lower Rio Grande Valley region of South Texas has had autochthonous transmission of multiple mosquito-borne diseases including those caused by dengue virus, chikungunya virus, and Zika virus. However, the current status of mosquito resistance to commonly used pesticides in this region is unknown. In this study, we collected field samples from multiple municipalities in South Texas and assessed resistance using the Centers for Disease Control and Prevention …

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 …

Effects Of Patch Size, Fragmentation, And Invasive Species On Plant And Lepidoptera Communities In Southern Texas, James A. Stilley, Christopher A. Gabler

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Simple Summary

Human land use has removed habitats, separated habitats into small and disconnected fragments, and introduced foreign species, which all harm wildlife. South Texas is highly diverse and home to many endangered species, but human disturbance threatens its wildlife. In south Texas, we poorly understand how different aspects of human land use influence wildlife diversity and abundance. We studied this by surveying plants and butterflies in 24 habitat fragments in south Texas that differed in size, shape, type, and land use history. Human disturbance was extensive, and foreign and weedy species were dominant in most habitats. Habitat types had …