Entomology Commons^™

Assessing Integrated Pest Management Protocols For The Invasive Aquatic Weed Giant Salvinia (Salvinia Molesta), Samantha Lee Prinsloo

LSU Doctoral Dissertations

Giant salvinia (Salvinia molesta) is free-floating aquatic fern that originates from South America. Through human introduction, giant salvinia has escaped its native range and is listed as an invasive species across multiple continents causing negative socio-economic and environmental impacts. This research aimed to expand our understanding of integrated pest management for controlling giant salvinia by combining chemical and biological control. The objectives were to assess the effects of rainfastness, carrier volume, and growth stage on herbicide efficacy, assess augmented biological control and optimal weevil release densities, assess weevil populations in the field, determine herbicide and surfactant toxicity to …

Population Dynamics, Host Range, And Impact Of The Naturalized Weevil Ochyromera Ligustri: A Potential Biological Control Agent Of Invasive Ligustrum Sinense, Brandi H. Misiaszek

LSU Master's Theses

Invasive woody plants have become dominant components of many forest understories in the southeastern United States. These species can displace native species, disrupt ecosystem processes, and reduce biodiversity. Chinese privet (Oleaceae: Ligustrum sinense Lour.) is an invasive shrub distributed through the Southeastern United States. The ligustrum weevil (Coleoptera: Curculionidae: Ochyromera ligustri Warner) is a non-native insect that was first found in the U.S. on Ligustrum in 1959. This weevil is considered a potential fortuitous biological control agent of invasive Ligustrum spp. in the U.S. The objectives of this study were to evaluate O. ligustri as a potential biological control agent …

Environmental, Social, And Molecular Regulation Of Foraging Behavior In The Formosan Subterranean Termite, Arjun Khadka

LSU Doctoral Dissertations

Foraging is a critical activity in social insects, essential for resource acquisition and colony sustenance. In termites, this behavior is shaped by environmental, social, and genetic factors, yet the underlying regulatory mechanisms remain poorly understood. In this study, we examined how environmental food and moisture availability, and the age of termites affected foraging activities, along with the molecular regulation of foraging in the Formosan subterranean termite, Coptotermes formosanus, using a combination of behavioral assays, transcriptomics, and molecular biology approaches. First, we demonstrate that food and moisture deprivation (FMD) significantly affects foraging, with termites under deprivation conditions exhibiting increased foraging …

Evaluation Of Diy Pest Management Strategies For The German Cockroach (Blattella Germanica) In The Presence Of Vitamin K Precursors And Synthetic Amorphous Silica, Mohamed S. Shaik

LSU Master's Theses

The German cockroach, Blattella germanica (Linnaeus) is a globally distributed indoor dwelling pest of medical concern. Insecticides are the preferred method of cockroach management due to their low cost, quick action, and availability. However, after continuous use, the development of insecticide resistance has emerged as a challenge for the pest management industry to effectively eliminate German cockroaches. Integrated pest management (IPM) is a sustainable framework which includes the use of glue board traps, vacuuming, in combination with different insecticide formulations such as sprays, gel or dust baits, and insecticide rotation has been successful for the management of German cockroaches. This …

Biological Control Of Roseau Cane Scale With Parasitoid Wasps In Louisiana, Tanner C. Sparks

LSU Doctoral Dissertations

Roseau cane scale, Nipponaclerda biwakoensis (Hemiptera: Aclerdidae) is an invasive species of scale insect negatively impacting Phragmites australis (Cyperales: Poaceae) stands within the Mississippi River Delta. The scales were first detected in 2017 from reports of Phragmites die-back within the MRD by landowners. Initial range surveys located RCS infested Phragmites stands were primarily limited to southeastern Louisiana with a single population near Port Arthur, Texas. Follow-up field surveys conducted annually from 2021 to 2023 monitoring further range expansion by the scale show the current range extends nearly 600 km between High Island, Texas and Bayou la Batre, Alabama. Climate matching …

Determining The Impact Of Lethal Temperature And Relative Humidity When Combined With Various Insecticide Classes Against A Bed Bug (Cimex Lectularius) Population., Bandana Shrestha

LSU Master's Theses

Common bed bugs (Cimex lectularius) are obligatory blood-feeding pests that have adapted well to survive in challenging environmental conditions. Known for their high tolerance to dehydration, low water loss, and high critical thermal maximum, they have become difficult to manage. Environmental factors, particularly temperature and humidity, play a significant role in their survival. However, with growing resistance to insecticides, integrated pest management (IPM) strategies are now essential for effective bed bug control. A key strategy in IPM involves combining insecticides with heat treatments. This method aims to overcome the limitations of heat treatment alone, as bed bugs may …

Susceptibility Of Spodoptera Frugiperda And Helicoverpa Zea Populations In The Southern Region Of The United States To Common Chemical Insecticides, Bhavana Patla

LSU Master's Theses

Abstract

The fall armyworm, Spodoptera frugiperda and corn earworm/bollworm, Helicoverpa zea, are two polyphagous pests prevalent in the U.S. In recent years, there were increased infestations of the two pests in the U.S., especially in its southern region. Information on the susceptibility/resistance status of the two pests in the region to chemical insecticides, especially to some new chemistries, is very limited or has not been updated for many years. In this study, susceptibility of 17 S. frugiperda and six H. zea field collected populations from the southern U.S. during 2021-23 to common insecticides was investigated in the laboratory. Dose-responses with …

Revisionary Taxonomy Within The Acmaeoderini, Joel Dubois

LSU Master's Theses

The jewel beetles (Coleoptera: Buprestidae) are the 8th largest family of beetles and fill various important ecological roles including decomposers, pollinators, and leaf miners. The cosmopolitan buprestid tribe Acmaeoderini is extremely diverse, with more than 700 species across 14 genera. Historically, the acmaederines from Afro-Eurasia have received thorough morphological treatment and nearly all species from these areas have been separated into various genus and subgenus groupings. Contrastingly, past studies in the Americas have been mostly restricted to alpha-level taxonomic descriptions, and only a very small percentage of species are placed into any formal group. The aim of this study was …

Settling Preference Of Nipponaclerda Biwakoensis (Hemiptera: Aclerdidae) On Phragmites Australis Stems, Alexia Catherine Desoto

LSU Master's Theses

Phragmites australis, a wetland grass that stabilizes the Louisiana coastline, has been undergoing a major die-off near the Mississippi River Delta (MRD) since the autumn of 2016. One suspected cause for this plant decline is the attack of an invasive scale insect, Nipponaclerda biwakoensis. We lack information on the host preference of the crawlers, the life stage that decides where to settle and when to start feeding on the plant. The objectives of this study were to identify what positions along the vertical stem N. biwakoensis prefers to settle and what host-plant traits may be influencing this choice. We recorded …

Optimizing Virulence And Understanding The Endophytic Colonization Of Metarhizium Spp. In Sweetpotato For The Control Of Cylas Formicarius Elegantulus (Summers), Santosh Bhandari

LSU Master's Theses

In the United States, control of the sweetpotato weevil [SPW, Cylas formicarius elegantulus (Summers)] occurs through quarantine and regular use of chemical insecticides. However, an overreliance on chemical control may lead to resistance. Entomopathogenic fungi have potential to act as an alternative to chemical control. In this study, we assessed four different strains of Metarhizium isolated from soil collected in Louisiana (Mp-K048, Ma-K056, Mr-K082, and Mr-K101) and compared them to a well-known licensed strain (Mb-ARSEF 1095) for virulence against C. formicarius elegantulus. Results suggested that Mp-K048, Ma-K056, and Mr-K082 …

Integrated Pest Management And Behavior Of Stored Grain Beetles, Ethan Doherty

LSU Doctoral Dissertations

The lesser grain borer, Rhyzopertha dominica, and the rice weevil, Sitophilus oryzae, are two of the most destructive pests of stored rice. Their management has relied heavily upon fumigant insecticides. However, amid growing concerns that fumigant-resistant pests are becoming widespread, there is an urgent need for diversified management techniques and integrated pest management. Here, we explored management techniques and the behavior of these beetles. Host plant resistance toward both beetles was evaluated for 13 varieties of rice. We found large differences among varieties for both beetles in all resistance measures. We found that while nutritional components of a …

Morphological And Molecular Characterization Of The Olfactory System In The Formosan Subterranean Termite, Paula Castillo

LSU Doctoral Dissertations

The Formosan subterranean termite, Coptotermes formosanus, is a eusocial insect species. Its members live in colonies consisting of reproductive (queen and king) and non-reproductive individuals (workers and soldiers). Olfaction is an essential sense for the social life of many insects. However, in termites, little is known about how olfactory cues are perceived in the peripheral sensory system (antennae) and processed in the central nervous system (brain) to elicit different behavioral responses across castes. In this study, we investigated the olfactory system in all castes (soldiers, workers, and reproductive alates), from the antennal and brain morphology to the antennal gene …

Evaluation Of Salvinia Weevil Establishment, Dispersal, And Environmental Pressures Impacting The Giant Salvinia Biological Control Program, Korey Danielle Pham

LSU Master's Theses

Giant salvinia (Salvinia molesta Mitchell), an invasive free-floating aquatic fern, invaded the Toledo-Bend reservoir along the Texas-Louisiana border in the 1990s. The rapid spread threatens critical ecosystems, economies, and cultural services by altering water quality, and impacting fishing, hunting, and navigation. To combat this issue, the LSU AgCenter has been rearing and distributing the salvinia weevil (Cyrtobagous salviniae Calder and Sands), which has demonstrated effectiveness in reducing giant salvinia populations within a matter of months to a few years. The first study assessed the impact of propagule pressure on salvinia weevil effectiveness in outdoor mesocosms and revealed that …

Susceptibility Of Spodoptera Frugiperda Populations In The Southern Region Of The U.S. To Common Bt Proteins And Performance Of A Dual-Gene Resistant Helicoverpa Zea Strain On Common Pyramided Bt Corn Traits, Tiago H. Da Silva

LSU Master's Theses

The fall armyworm (Spodoptera frugiperda) and corn earworm (Helicoverpa zea) are two polyphagous pests that, in the Americas, are targeted by transgenic corn and cotton expressing Bacillus thuringiensis (Bt) proteins. A previous study during 2011-2013 demonstrated practical resistance to Cry1F corn in S. frugiperda in the southeastern seaboard of the U.S., while resistance of H. zea to Bt corn and cotton containing cry1A and cry2A genes has widely occurred in the U.S. The first objective of this study was to investigate the current susceptibility status to four Bt proteins commonly expressed in Bt corn plants, including …

Integrating Cultivar Resistance And Entomopathogens For Pest Management Of Sweetpotato Weevil, Cylas Formicarius Elegantulus (Summers), Schyler M. Lee

LSU Master's Theses

Sweetpotato, Ipomoea batatas (L.) Lam, is the number one vegetable crop in Louisiana, producing 21,178 kg/ha in the year 2021. The sweetpotato weevil, Cylas formicarius elegantulus (Summers), is an economically important pest of sweetpotato. C. formicarius elegantulus females lay eggs into feeding holes on the storage root surface. Larvae then hatch and tunnel through the sweetpotato flesh where they complete their development. This cryptic-natured brentid can cause up to 100% yield loss when left unmanaged. The Louisiana Department of Agriculture and Forestry mandates protocols to limit C. formicarius elegantulus spread (e.g., clean seed, pheromone trapping, and quarantines); however, scheduled chemical …

Evaluating The Pesticide-Induced Outbreak Of Soybean Looper, Chrysodeixis Includens (Walker) (Lepidoptera: Noctuidae), In Louisiana Soybean, Scott Lee

LSU Doctoral Dissertations

Soybean looper, Chrysodeixis includens (Walker), has established itself as the primary lepidopteran defoliator in Midsouth soybean agroecosystems. Pesticide-induced outbreak events associated with this pest have been observed by soybean producers. The insecticides believed to prompt these incidents are routinely used for the control of other co-occuring pests, such as stink bugs. Outbreak conditions present soybean producers with conflicting management decisions for pests. Laboratory, greenhouse, and field experiments were conducted to provide a better understanding of insecticide usage impact on populations of C. includens and the arthropod community. To discern the potential mechanisms behind C. includens outbreak, a baseline for the …

Investigating The Potential Role Of Termites As Pathogen Vectors In The Decline Of Ironwood Trees (Casuarina Equisetifolia) In Guam, Garima Setia

LSU Master's Theses

Termites have been found associated with the decline of Casuarina equisetifolia (ironwood), an important agro-forestry species in Guam. While the ironwood tree decline (IWTD) was first reported in 2002, its association with termites as well as with bacteria Ralstonia solanacearum and Klebsiella species (K. oxytoca and K. variicola) was determined in 2010 and 2012 respectively. In 2019, the termite species attacking the ironwood trees were identified as Nasutitermes takasagoensis, Coptotermes gestroi, and Microcerotermes crassus. However, the role of termites in IWTD is not known. Since termites are repositories of bacteria and consume wood, termite foragers might …

Characterization Of Antiviral Immunity, Host Virus Interactions, And Toxicity Of Agrochemical Residues In The Western Honey Bee, Christopher Fellows

LSU Doctoral Dissertations

Honey bee colonies have perished at an alarming rate for over 15 years. Among the multitude of threats to bee health, virus infections and agrochemical exposure appear to be major drivers of colony loss. As virus infection is among the most damaging influences on bee health, we first investigated a putative target for antiviral immunity, termed K_ATP channels. We previously demonstrated that pharmacologically activating K_ATP channels induces the production of reactive oxygen species and increases survival during infection with Israeli Acute Paralysis Virus. Here, we demonstrate that K_ATP modulation and ROS induction reduce virus replication and enhance …

Defining Understudied Mechanisms Of Potassium Ion Flux In The Insect Nervous System, Rui Chen

LSU Doctoral Dissertations

To identify novel insecticide target sites that can address the evolution of insecticide resistance, our group has tested the insecticidal potential of two potassium flux pathways: potassium-chloride (K+/Cl−) cotransporter (KCC) and inward rectifier potassium (Kir) channels. GABAergic signaling is the cornerstone of fast synaptic inhibition for neural signaling in arthropods; thus, the γ-aminobutyric acid (GABA)-receptor-chloride-channel (GRCC) complex has been a longstanding target for insecticides. Despite the importance to neuronal homeostasis, the upstream mechanisms enabling GRCC function are poorly defined. The data presented in this dissertation provide strong support that KCC is an essential ion transport system for proper neural function …

The Applied Use Of Zein Nanoparticles In Agriculture, Colin Bonser

LSU Doctoral Dissertations

Nanotechnology is a multifaceted and a promising strategy in agricultural pest management for the development of insecticides or insecticide carriers. Research has shown that nanoparticles increase stability and efficacy of entrapped chemical pesticides to prevent active ingredient degradation while improving chemical stability and solubility. The following work evaluated nanoparticles synthesized from biopolymers, materials that originate from renewable sources also have an increased biodegradability.
Work was conducted under laboratory, greenhouse, and field conditions to test the biopoloymers as possible insecticide and insecticide carriers. The primary biopolymer evaluated in the following studies was zein, although lignin and chitosan were also evaluated. Overall, …

Esterase Mediated Insecticide Resistance In The Southern House Mosquito, Culex Quinquefasciatus, Vivek Pokhrel

LSU Doctoral Dissertations

Much is known about the development of insecticide resistance associated with targeted application against insect populations. However, off-target selection by applications of insecticides in agricultural and residential sites also impacts development of insecticide resistance and is understudied. Similarly, the impact of selecting one life stage of mosquitoes on the insecticide susceptibility of different life stages is largely unknown. The first part of this study shows that susceptibility to chlorantraniliprole, which is applied in rice and sugarcane fields in LA, decreased (5.7 to12-fold) in populations of Culex quinquefasciatus collected from near these fields compared to a reference field strain. In addition, …

Review Of Structural Color In The Genus Chrysochroa Dejean, 1833 (Coleoptera: Buprestidae), Able Chow

LSU Master's Theses

The jewel beetles, (Coleoptera: Buprestidae Leach, 1815), is the eighth most speciose coleopteran family, with the majority of its members possessing diverse bright, saturated structural coloration of multilayer origin. This study focuses on the genus Chrysochroa Dejean, 1833, which includes some of the most brilliantly and charismatically colored buprestid species. While members of Chrysochroa are prised by entomologists amateurs and professional and are well-represented in museum collections, the evolution and ecology of their structural color remain underexplored. Twenty-eight select taxa including exemplars from all 13 subgenera of Chrysochroa were investigated to provide an overview of the objective optical properties and …

The Risks Posed By Mosquito Ultra-Low Volume Applications To Procambarus Clarkii Production, Timothy Mcnamara

LSU Doctoral Dissertations

Mosquito abatement has received much scrutiny due to concerns about the impacts of control applications on non-target organisms. In Louisiana, a great deal of this concern has come from crawfish farmers claiming mosquito abatement applications have damaged crawfish production. To determine which mosquito abatement practices and products pose a risk to crawfish production, we conducted a series of studies examining mosquito abatement practices in the vicinity of crawfish production fields and the impacts of common mosquito abatement product exposure on crawfish health and production. We found that mosquito ULV applications are the most likely to result in exposure to crawfish …

Defining Toxicological Endpoints Of Aphis Gossypii Feeding, Flinn O'Hara

LSU Master's Theses

The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a destructive agricultural pest, due to photosynthate removal and plant virus transmission. This project consisted of two main goals. First, we employed toxicity bioassays and electrical penetration graph (EPG) methodology to quantify changes to feeding behavior and toxicity of A. gossypii after exposure to commercialized aphicides. Commercialized aphicides containing flupyradifurone, sulfoxaflor, thiamethoxam, thiamethoxam + lambda cyhalothrin, and bifenthrin induced > 90% aphid mortality within 4 hours of exposure. This was supported by our EPG results that showed a significant reduction in the proportion of aphids that continued to probe on cotton 4 …

Identifying The Components Of A Hemp (Cannabis Sativa L.) (Rosales: Cannabaceae) Integrated Pest Management Program In Louisiana, Nathan C. Arey

LSU Master's Theses

Hemp, Cannabis sativa (L.) (Rosales: Cannabaceae), is defined as a plant in the genus Cannabis with a delta-9 3 tetrahydrocannabinol (THC) concentration of not more than 0.3% on a dry weight basis. Domestic acreage of this crop has increased in response to the ratification of the Agricultural Act of 2014 and the Agricultural Improvement Act of 2018. In 2021, 21,915 hectares of hemp were planted in the United States with a production value of $712 million. There is a current lack of literature on insect related research in this reemerging crop system in the state of Louisiana. Therefore, this present …

Understanding The Horse Fly Species And Species Relations Of The Tabanus Nigrovittatus Complex Along Coastal Louisiana, Darrius M. Davis

LSU Master's Theses

The Dipteran family Tabanidae is among the most diverse families of insects that is comprised of approximately 144 genera with 4455 described species (Pape et al. 2011). Members of the family Tabanidae have been studied for well over 100 years in Louisiana. Hine (1906, 1907) conducted the first surveys of the members of the tabanid family and noted the presence of 14 species. Jones and Bradley (1923) supplemented Hine’s observations with their own inventory of horse flies across four parishes and found an additional 14 species that were not recorded by Hine. Subsequently, Tidwell (1970, 1973) conducted a survey of …

Soil Moisture Mediated Behavioral And Physiological Alterations Of Coptotermes Formosanus And Reticulitermes Flavipes (Blattodea: Rhinotermitidae), Steven J. Richardson

LSU Master's Theses

Substrate moisture is a critical environmental factor for the survival and behavior of subterranean termites (Blattodea: Rhinotermitidae). The invasive Formosan subterranean termite (Coptotermes formosanus) and the native eastern subterranean termite (Reticulitermes flavipes) co-occur in the southeastern United States, but C. formosanus is predominant in subtropical and R. flavipes is more common in temperate regions. The difference in their geographic distributions is largely attributed to their different behavioral and physiological ecology. While ample research has been done on foraging behavior of the two species, there was no empirical evidence for the effects of constant soil moisture on …

Aphid Herbivory On Industrial Hemp, Cannabis Sativa L., And The Impact Of Plant-Soil Feedbacks On Hemp Performance In Louisiana, Alex Leede

LSU Master's Theses

Industrial hemp, Cannabis sativa L., is defined as having less than 0.3% delta-9-tetrahydrocannabinol by dry weight. It can be grown for fiber, food, oil, and cannabinoids. As a newly legalized crop, little research exists regarding the cultivation or pest management practices in Louisiana. The versatility of industrial hemp may allow for substantial future production in Louisiana. This project set out to understand the impact of previous crops on hemp performance and soil microbial communities. Soybean, Glycine max L. (Merr), grain sorghum, Sorghum bicolor (L.) Moench, and sweetpotato, Ipomeae batatas (L.) Lam, were selected as soil conditioning crops because they are …

Geographical Distribution, Allele Frequency, And Inheritance Of Cry1a.105 And Cry2ab2 Resistance In Helicoverpa Zea In The Southeastern Region Of The United States, Wenbo Yu

LSU Doctoral Dissertations

The corn earworm, Helicoverpa zea (Boddie), is a target pest of Bacillus thuringiensis (Bt) maize and cotton in the U.S. Previous studies have reported that this pest has developed field resistance to pyramided Cry1A/Cry2A maize and cotton in certain areas of the southern United States. The objectives of this study were to 1) determine the current status and distribution of the resistance to Cry1A.105 and Cry2Ab2 in H. zea in the southeastern United States; 2) estimate the resistance allele frequencies to the two Bt proteins in H. zea field populations in the region, and 3) assess the inheritance of the …

Sodium Mediates Developmentally Plastic Responses In Plants And Herbivores, Luis Santiago-Rosario

LSU Doctoral Dissertations

Sodium plays a crucial role in organismal performance, trophic-level interactions, and eco-evolutionary dynamics. For plants, sodium impacts osmoregulation, growth, and water uptake. For animals, sodium is essential influencing osmoregulatory processes, muscle and neural development, and blood regulation. My dissertation aims to disentangle why sodium mismatch affects resource-consumer interactions and its influence on morphological and behavioral plasticity. First, I identified how sodium impacts plant performance and sodium accumulation strategies. I initially focused my research on understanding how increasing substrate sodium affects plant growth and tissue sodium accumulation strategies in controlled settings using a systematic review approach. I found that saltier plants …