Entomology Commons^™

Deciphering The Role Of Ion Channels In Early Defense Signaling Against Herbivorous Insects, Akanksha Gandhi, Rupesh R. Kariyat, Amaravadhi Harikishore, Marzieh Ayati, Anirban Bhunia, Nirakar Sahoo

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

Plants and insect herbivores are in a relentless battle to outwit each other. Plants have evolved various strategies to detect herbivores and mount an effective defense system against them. These defenses include physical and structural barriers such as spines, trichomes, cuticle, or chemical compounds, including secondary metabolites such as phenolics and terpenes. Plants perceive herbivory by both mechanical and chemical means. Mechanical sensing can occur through the perception of insect biting, piercing, or chewing, while chemical signaling occurs through the perception of various herbivore-derived compounds such as oral secretions (OS) or regurgitant, insect excreta (frass), or oviposition fluids. Interestingly, ion …

Temperatures Influence Susceptibility To Insecticides In Aedes Aegypti And Aedes Albopictus (Diptera: Culicidae) Mosquitoes, Wendy S. Salinas, Teresa Patricia Feria-Arroyo, Christopher Vitek

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

Aedes aegypti and Aedes albopictus (Diptera: Culicidae) are vectors for several arboviruses, including dengue, Zika virus and chikungunya virus. The primary method of controlling these diseases is controlling the vector population, often with insecticides. Insecticide resistance may impact the success of these efforts. We tested the effect of variable temperature exposures on susceptibility to insecticides by exposing adult A. aegypti and A. albopictus to different temperatures and tested their susceptibility to insecticides. We hypothesized that adults maintained at high temperatures would show increased susceptibility to insecticides relative to lower temperatures. Colony mosquitoes were hatched, reared to adulthood and then maintained …

A Method For Repeated, Longitudinal Sampling Of Individual Aedes Aegypti For Transmission Potential Of Arboviruses, E. Handly Mayton, Heather Hernandez, Christopher Vitek, Rebecca C. Christofferson

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

Mosquito-borne viruses are the cause of significant morbidity and mortality worldwide, especially in low- and middle-income countries. Assessing risk for viral transmission often involves characterization of the vector competence of vector–virus pairings. The most common determination of vector competence uses discreet, terminal time points, which cannot be used to investigate variation in transmission aspects, such as biting behavior, over time. Here, we present a novel method to longitudinally measure individual biting behavior and Zika virus (ZIKV) transmission. Individual mosquitoes were exposed to ZIKV, and from 9 to 24 days post-exposure, individuals were each offered a 180 μL bloodmeal every other …

Honeybees Fail To Discriminate Floral Scents In A Complex Learning Task After Consuming A Neonicotinoid Pesticide, Julie A. Mustard, Annie Gott, Jennifer Scott, Nancy L. Chavarria, Geraldine A. Wright

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

Neonicotinoids are pesticides used to protect crops but with known secondary influences at sublethal doses on bees. Honeybees use their sense of smell to identify the queen and nestmates, to signal danger and to distinguish flowers during foraging. Few behavioural studies to date have examined how neonicotinoid pesticides affect the ability of bees to distinguish odours. Here, we use a differential learning task to test how neonicotinoid exposure affects learning, memory, and olfactory perception in foraging-age honeybees. Bees fed with thiamethoxam could not perform differential learning and could not distinguish odours during short and long-term memory tests. Our data indicate …

Gaba Signaling Affects Motor Function In The Honey Bee, Julie A. Mustard, Lisa Jones, Geraldine A. Wright

School of Integrative Biological & Chemical Sciences Faculty Publications

GABA is the most common inhibitory neurotransmitter in both vertebrate and invertebrate nervous systems. In insects, inhibition plays important roles at the neuromuscular junction, in the regulation of central pattern generators, and in the modulation of information in higher brain processing centers. Additionally, increasing our understanding of the functions of GABA is important since GABAA receptors are the targets of several classes of pesticides. To investigate the role of GABA in motor function, honey bee foragers were injected with GABA or with agonists or antagonists specific for either GABAA or GABAB receptors. Compounds that activated either type of GABA receptor …

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 …

Development Of A Remotely Activated Field Sprayer And Evaluation Of Temperature And Aeration On The Longevity Of Steinernema Riobrave Entomopathogenic Nematodes For Treatment Of Cattle Fever Tick-Infested Nilgai, John A. Goolsby, Diana Cantu, Alejandro Vasquez, Alexis Racelis

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

A remotely activated field sprayer was developed for application of the entomopathogenic nematode, Steinernema riobrave (Cabanillas, Poinar, and Raulston) for eradication of the southern cattle fever tick, Rhipicephalus microplus (Canestrini) infesting free-ranging nilgai (Boselaphus tragocamelus) in South Texas. The battery powered sprayer is activated by sonic sensors that detect movement of nilgai through fence crossings. An onboard computer operates the sprayer pump and aerator that oxygenates the solution of nematodes. Several types of aeriation, agitation, and cooling were tested to prolong the viability of the nematodes in water. Continuous aeration extended the longevity of S. riobrave to more than two …

Bait Stations For Control Of Mexican Fruit Flies (Anastrepha Ludens), First Year, Hugh E. Conway, Guadalupe Garcia, Pedro Rendón, Christopher J. Vitek

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

The Mexican fruit fly, Anastrepha ludens (Loew) (Mexfly), is a pest of economic importance with the potential to cause millions of dollars in damage to citrus and other fruits. This chapter presents the first-year results from a three-year field study (2014–2017) conducted to evaluate the effectiveness of bait stations with Spinosad embedded in a wax matrix to control Mexfly. Spinosad is produced by a naturally occurring bacteria, Saccharopolyspora spinosa, and is considered an organic insecticide acceptable for use by organic growers. The flies feed on the wax matrix, and the Spinosad acts as a stomach poison killing the flies. Each …

Efficacy Evaluation Of Six Entomopathogenic Nematode Species Against Engorged Females Of Southern Cattle Fever Tick, Rhipicephalus (=Boophilus) Microplus, N. K. Singh, John A. Goolsby, David I. Shapiro-Ilan, R. J. Miller, D. B. Thomas, Guilherme M. Klafke, Jason Tidwell, Alexis Racelis, Parwinder Grewal, Adalberto A. Perez De Leon

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

The southern cattle fever tick, Rhipicephalus microplus Canestrini, is widely distributed in tropical and subtropical regions, causing huge economic losses to milk and meat production. Application of acaricides is the most widely used control strategy, but because of increasing evidence of resistance to acaricide and environmental concerns, novel strategies are needed. Use of entomopathogenic nematodes is a promising alternative for tick control. Six species of nematodes, Steinernema riobrave Cabanillas, Poinar, and Raulston (355 strain), S. carpocapsae (Weiser) (All strain), S. feltiae Filipjev (SN strain), Heterorhabditis bacteriophora Poinar (VS strain), H. indica Poinar, Karunakar, and David (HOM1 strain), and H. floridensis …

Morganella Morganii (Enterobacteriales: Enterobacteriaceae) Is A Lethal Pathogen Of Mexican Fruit Fly (Diptera: Tephritidae) Larvae, Bacilio Salas, Hugh E. Conway, Erin Schuenzel, Kristen Hopperstad, Christopher Vitek, Don C. Vacek

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

Tephritid pests, such as the Mexican fruit fly, Anastrepha ludens (Loew), represent a major threat to fruit production worldwide. In order to control these pests, sterile insect technique is used to suppress and eradicate wild populations. For this control method to be successful, hundreds of millions of flies must be produced weekly in mass rearing facilities. The large quantity of artificial diet and close proximity of flies at various life stages allows bacteria from family Enterobacteriaceae, Bacillaceae, Pseudomonadaceae, and others to multiply and spread more easily. In this study, bacteria with a possible pathogenic effect were isolated from Mexican fruit …

Fungi Isolated From House Flies (Diptera: Muscidae) On Penned Cattle In South Texas, Cherity A. Ysquierdo, Pia U. Olafson, Donald B. Thomas

Health & Biomedical Sciences Faculty Publications

Musca domestica L. were collected from cattle diagnosed with bovine ringworm to evaluate the potential of the house fly to disseminate Trichophyton verrucosum E. Bodin, a fungal dermatophyte that is the causative agent for ringworm in cattle. Fungal isolates were cultured from 45 individual flies on supplemented Sabouraud dextrose agar, and isolates were identified using morphological and microscopic approaches. Each isolate was identified further by PCR amplification of the ribosomal DNA locus with fungal-specific primers and subsequent amplicon sequencing. Trichophyton verrucosum was not identified using these approaches. However, 35 different fungal species representing 17 genera were cultured from collected flies, …

Molecular Comparison Of Cattle Fever Ticks From Native And Introduced Ranges, With Insights Into Optimal Search Areas For Classical Biological Control Agents, John A. Goolsby, F. D. Guerrero, John F. Gaskin, K. G. Bendele, P. Azhahianambi, D. Amalin, M. Flores-Cruz, J. Kashefi, Alexis Racelis

School of Earth, Environmental, & Marine Sciences Faculty Publications

Cattle fever ticks, the southern cattle tick, Rhipicephalus microplus (Canestrini), and cattle tick, Rhipicephalus annulatus (Say), are livestock pests endemic to Mexico and invasive along the Texas-Mexico border. Resistance to acaricide, alternate wildlife hosts, and pathogenic landscape-forming weeds present challenges for sustainable eradication of this pest in the U.S. Classical biological control is being explored as a strategy to control cattle fever ticks, especially on alternate hosts such as nilgai antelope, Boselaphus tragocamelus (Pallas), and white-tailed deer, Odocoileus virginianus (Zimmermann). Molecular genetic tools were used to compare populations of cattle fever ticks from native and introduced ranges to provide insights …

Early Embryology Of The Insect Oligotoma Saundersii (Embiidina) Using Targeted Genes As Developmental Landmarks, Omar Doria

Theses and Dissertations - UTB/UTPA

Embiidina, or "webspinners", is a small, sexually dimorphic, polyneopterous insect order and is the only order to spin silk throughout their life cycle. Unique morphological features and the phylogenetic position of Embiidina make it an attractive subject for study of the evolution and development of the insect body plan and the origin of novel morphological features. Oligotoma saundersii is easily cultured and a viable laboratory organism. It has a fairly standard short-germ embryogenesis process requiring 453 hours at 28°C with progressive development beginning in the anterior region. Preliminary work on targeted developmental genes has yielded small portions of seven genes. …

Searching Response Of A Wandering Spider To Potential Cues Associated With Lepidopteran Eggs, Rosa Isela Ruiz

Theses and Dissertations - UTB/UTPA

Cheiracanthium inclusum (Hentz), a wandering spider, has been frequently observed feeding on the eggs of Helicoverpa zea (Boddie), an important cotton pest. Wandering spiders are known to feed mainly on mobile prey, thus mechanisms used by these spiders to locate sessile prey remain understudied. Vibratory and visual are among the main cues used by spiders to identify prey. However, other sensory modalities such as chemoreception may be used but are poorly understood. This study investigated the types of cues utilized by C. inclusum to locate and identify H. zea eggs as prey. Results show that C. inclusum responds positively to …

Comparative Pollen Foraging Of Africanized And European Honeybees In A Non-Agricultural Environment, Ruben Ruiz

Theses and Dissertations - UTB/UTPA

With the advent of the Africanized honeybee, ways to differentiate it from the European honeybee have been greatly sought in attempts to better understand the role of Africanized bees in pollination. Pollen collecting strategies for both honeybee subspecies have been explored in attempts to exploit their pollinating capabilities. This project examined pollen collected by honeybees from feral and managed European and Africanized colonies in a relatively isolated site. Paired European and Africanized honeybee colonies were used to obtain pollen foragers. Through acetolysis (series acidified Acetic Anhydride washings); the collected pollen from the individual foragers was treated and observed with light …

Chorionic Morphology Of Mayfly (Ephemeroptera) Eggs Of The Lower Rio Grande Valley, Maria D. De Leon

Theses and Dissertations - UTB/UTPA

External egg morphology of ten species of Lower Rio Grande Valley (LRGV) mayflies are compared using scanning electron microscopy (SEM) and a taxonomic key to the eggs is provided. The eggs of five species are described here for the first time. Preserved female adults or subadults were critical-point dried using liquid CO2 . The eggs were removed and placed on metal stubs for sputter coating with gold/palladium. The coated eggs were then observed and photographed by SEM. The morphological features described were the chorionic sculpturing, polar caps, accessory attachment structures, and micropyles. This is the first mayfly egg comparison and …

Detection Of The Phototoxic Dye Phloxine B In Anastrepha Ludens (Loew) (Diptera: Tephritidae), Apis Mellifera Linnaeus (Hymenoptera: Apidae) And Honey, Aleena M. Tarshis Moreno

Theses and Dissertations - UTB/UTPA

A spectrophotometric method for detection of phloxine B, a phototoxic dye proposed as a replacement for malathion bait sprays, in extracted tissues of Anastrepha ludens, Apis mellifera and in honey was developed. Dye detection was increased with a pH change from 6 to 13.7 in tissues or from 3.7 to 8 in honey with 2% sodium hydroxide. An LC 50 of 29.62 ppm phloxine B in 30% sucrose was obtained by feeding honey bees. A predictive model for dye in insect tissues and honey was developed and shown to be 89–92% effective. This study provides a forensic approach to determine …

Homology Among The Autosomal Chromosomes Of Boophilus Annulatus (Say) And B. Microplus (Canestrini), Bonnie S. Gunn

Theses and Dissertations - UTB/UTPA

Autosomes of Boophilus annulatus and B. microplus were compared using C- and G-bands to establish the degree of homology. Karyotypes of both species consisted of 20 autosomes and an XX:XO sex determination system with the X being the largest chromosome. All chromosomes of B. annulatus were acrocentric with heterochromatin limited to centromeric regions. The B. microplus karyotype was acrocentric with one band of noncentromeric heterochromatin occurring in three chromosome pairs. Interspecific comparisons indicated seven pairs of G-band homologous autosomes and three G-band homologous pairs when added interstitial heterochromatin was considered. The number three chromosome of both species showed variation in …

Flowering Vegetation Of South Texas As An Aggregation Site For Screwworm Flies, Cochliomyia Hominivorax (Coquerel), Geral Lenford Long

Theses and Dissertations - UTB/UTPA

Flowering vegetation was investigated to determine its potential as an aggregation site for the mating of screwworm flies, Cochliomyia hominivorax (Coquerel). Fly activity was observed at vegetation on a typical south Texas shrub community. Noted were the species of vegetation present and the phenology of their flowering. Screwworm flies were found to be attracted to specific species of brush; however, in the absence of the most attractive species, the flies responded to secondary species. Both feeding and mating behavior were observed on vegetation.

Olfaction and visual mechanisms of aggregation were investigated. Results from an olfactometer showed the attractancy of some …