Entomology Commons^™

The Xenobiotic Transcription Factor Cap N Collar C Regulates Expression Of Multiple Insecticide Resistant Genes, Megha Kalsi

Theses and Dissertations--Entomology

Insecticide resistance is a global problem. Insecticide resistance management is very important, considering the time, effort, and cost of discovering and developing a new insecticide. There are diverse resistance mechanisms, but enhanced detoxification through overexpression of cytochrome P450s and target site insensitivity through mutation in insecticide binding site are the two most common mechanisms. The xenobiotic detoxification is divided into three successive phases (I, II and III), which ensures the metabolism and excretion of the detrimental toxins. Each phase comprises of a specific group of metabolizing enzymes such as P450s (phase I), GSTs (phase II) and ABC transporters (phase III). …

Exploring Predator-Prey Interactions In Agroecosystems Through Molecular Gut-Content Analysis, Kacie J. Athey

Theses and Dissertations--Entomology

Generalist predators can contribute to vital ecosystem services by potentially inducing trophic cascades as natural enemies of pests in agroecosystems. As the human population of the world gets larger, we need to produce more food on ever-smaller swaths of available land relying on ecosystem services, in the form of pest control, that may contribute to agricultural sustainability. Teasing apart the exact trophic linkages between predators and prey is a vital first step and essential to uncovering which predators are inducing trophic cascades and should be enhanced through conservation biological control.

Combined with ecological experimentation, the main tool used throughout my …

Evaluation Of Pyriproxyfen Applied In Barrier Sprays For Mosquito Suppression, Andrea Glenn Skiles

Theses and Dissertations--Entomology

Despite advances in mosquito management, mosquito-borne disease in the United States is still of relevant public health concern and vector control is a top priority in preventing transmission of pathogens. Insecticide barrier sprays have become a common tool for suppression of mosquitoes in single-homeowner backyards. The application of the synthetic pyrethroid, lambda-cyhalothrin to perimeter vegetation with a backpack sprayer has been shown to significantly suppress mosquito levels for around 6 weeks. In an attempt to lengthen the effective duration of treatment, the IGR, pyriproxyfen, was added to a backpack mist blower with lambda-cyhalothrin, as adult mosquitoes exposed to pyriproxyfen have …

Binding, Protection, And Rna Delivery Properties Of Porous Silica Nanoparticles In Spodoptera Frugiperda Cells, Emily Nadeau

Theses and Dissertations--Entomology

Traditional methods of pest control are threatened by the development of insecticide resistance, both to traditional insecticides and Bt toxins. Discovery of RNA interference (RNAi) has created opportunities to develop new insect control mechanisms. However, RNAi responses appear to be robust in coleopteran pests, but other orders, e.g. Lepidoptera and Hemiptera, present varied or ineffective RNAi responses. Current delivery strategies for double-stranded RNA (dsRNA) include microinjection, ingestion, and soaking. These approaches have benefits and problems. This study investigates the potential for porous silica nanoparticles (pSNPs) to improve the delivery of dsRNA and induce an RNAi response in Spodoptera frugiperda cells. …

A Non-Native Forest Invader Alters Forest Structure And The Associated Arthropod Community, Matthew B. Savage

Theses and Dissertations--Entomology

The emerald ash borer (EAB, Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a non-native wood boring beetle that is causing extensive ash (Fraxinus spp.) mortality in eastern North America, affecting both urban and wildland forests and drastically altering forest structure and composition. As EAB-induced ash mortality progresses, native arthropod associates of ash forests are impacted by the effects of rapid and broad scale tree mortality. These include loss of food source, increased canopy gap formation, alterations in litter inputs causing shifting temperature and moisture regimes on the forest floor, and significant accumulation of coarse woody debris.

I assessed the sub-canopy …

Investigating Ichneumonidae: Insights Into Species Identification And Venom Composition, Victoria G. Pook

Theses and Dissertations--Entomology

Parasitoid wasps are hyperdiverse, with current estimates suggesting that they may account for up to 20% of all insect species. Though their ecological significance and their importance in integrated pest management cannot be denied, these taxa remain understudied and, due to their small size, are often overlooked. However, recent advances in molecular techniques are helping to reverse this trend by providing tools which scientists can use to better understand species limits and host interactions.

Parasitoid wasps are often morphologically cryptic and their accurate delimitation requires the analysis of DNA sequence data from fast-evolving genes in addition to morphological characters. The …

Influence Of Structural Disturbance On Stream Function And Macroinvertebrate Communities In Upper Coastal Plain Headwater Streams, Richard Andrew Biemiller

Theses and Dissertations--Entomology

Freshwater is a resource under threat due to anthropogenic actions. Stream restoration is a common method for mitigating disturbance. Inconsistent methodologies used for evaluating restorations have drawn criticism. Limited use of baseline data for guiding stream restoration activities is of particular concern. This study was developed to elucidate metrics that differentiate reference and disturbed sites in Upper Coastal Plain streams. This information could improve resource use and successes of restorations. Structural and functional variables were examined in 10 reference and 10 streams that meet the traditional definition of disturbance and would be restoration priorities. Disturbed streams were classified into two …

Subacute Effects Of Prallethrin On Behavior Of Mosquitoes (Diptera: Culicidae) And Other Human Disease Vectors, Kyndall C. Dye

Theses and Dissertations--Entomology

The synthetic pyrethroid, prallethrin, is an active ingredient in a widely marketed ultralow volume (ULV) mosquito adulticide. Volatilized prallethrin is intended to stimulate mosquito flight, increasing overall effectiveness of the adulticide. However, field tests using volatilized prallethrin did not produce significant differences in various vector trap catches, suggesting prallethrin’s behavioral effects are not viable. Laboratory tests were conducted to evaluate prallethrin’s effect on flight behavior of adult female Asian tiger mosquitoes (Aedes albopictus). Mosquitoes were divided into three groups; a control, those exposed to volatilized prallethrin, and those exposed to a simulated ULV application at label rates. After …

Effects Of Landscape, Intraguild Interactions, And A Neonicotinoid On Natural Enemy And Pest Interactions In Soybeans, Hannah J. Penn

Theses and Dissertations--Entomology

Demand for food, fuel, and fiber has been increasing, escalating the intensification of agriculture during the past fifty years. A more comprehensive understanding of the impact of landscapes on sustainable agriculture production is required to meet the continual increase in human demand. This not only includes how chemical inputs are used but also how cultivated and surrounding landscapes are managed for ecosystem services. This research explains how land cover on landscape and farm scales impact ant and spider-mediated pest suppression. I successfully developed and optimized molecular methods to test ant gut contents from both laboratory and field-caught specimens. A multi-year …

Hormonal And Nutritional Regulation Of Molting, Metamorphosis, And Reproduction In Bed Bugs, Cimex Lectularius, Hemant Gujar

Theses and Dissertations--Entomology

The bed bug, Cimex lectularius is an obligate hematophagous ectoparasite that feeds on humans. The increase in travel and development of insecticide resistance to commercially available insecticides have enabled the bed bug population to resurge, causing economical and psychological trauma to the human population. Lack of knowledge about the basic molecular biology of bed bugs has motivated us to study the key aspects of molting, metamorphosis, and reproduction. A blood meal triggers expression of various genes that enable bed bugs to molt or undergo metamorphosis. Molting and metamorphosis in bed bugs are regulated by two key hormones: 20-hydroxyecdysone (20E) and …

Variable Consequences Of Toxic Prey On Generalist Insect Predators, Kelly Jackson

Theses and Dissertations--Entomology

Introduced species, like the lady beetle Harmonia axyridis, have been linked to declines of native species through mechanisms including intraguild predation and competitive superiority. However, competitive differentials between species may be mitigated if subdominant species can utilize resources that dominant species cannot. Previous research has shown that some strains of the aphid Aphis craccivora are toxic to H. axyridis. My goal was to investigate use of this resource by both H. axyridis and other lady beetles, to determine whether these aphids might be an exploitable resource for subdominant lady beetle species. I first examined the behavioral responses of …

The Manipulation And Examination Of Wolbachia In Medically Important Mosquitoes, Timothy D. Mcnamara

Theses and Dissertations--Entomology

Mosquitoes are a major vector of human disease and result in massive costs to public health in affected regions. It has been suggested that Wolbachia pipientis could be used for mosquito population reduction. Wolbachia is a maternally-transmitted endosymbiont of arthropods and nematodes that infects the cytoplasm of host cells. In mosquitoes, Wolbachia manipulates reproduction through Cytoplasmic Incompatibility (CI), which is characterized by a cessation of embryonic development in certain crossing-types. However, the relationship between Wolbachia and its host is complex and not fully understood. The crossing relationships between naturally-infected and aposymbiotic populations of Culex pipiens pipiens and Culex pipiens molestus …

The Chemical Ecology Of Bed Bugs (Cimex Lectularius, L.) And The Impact Of A Neurotoxic Insecticide On Physiology And Behavior, Sydney E. Crawley

Theses and Dissertations--Entomology

Following a decades-long hiatus in many nations, populations of bed bugs (Cimex lectularius) have rebounded and are thriving on a global scale posing substantial challenges for pest management professionals. Insecticide resistance to both pyrethroid and neonicotinoid compounds has been identified in many populations, leading to renewed interest in alternative control methods for management of this pest. The objectives of my dissertation research were to study various, typically cryptic, bed bug behaviors in order to improve both conventional and alternative management strategies. Novel behavioral interactions among mother and offspring were characterized. Additionally, changes in behavior and physiology after treatment …

Endosymbiotic Bacteria In The Bed Bug, Cimex Lectularius L. (Hemiptera: Cimicidae), Mark H. Goodman

Theses and Dissertations--Entomology

The return of bed bugs to prominence as an urban pest has precipitated an emphatic research response from the scientific community in an effort to better understand their biology and management. However, not all aspects of bed bug biology have received equal attention. The role of symbiotic bacteria in the normal function and biology of insects is often underappreciated, and this is true of bed bugs. Bed bugs have two main endosymbiotic bacteria, a Wolbachia species and a poorly-characterized gamma-proteobacterium referred to as BLS. However, their interactions with the host are poorly understood. I explored various aspects of these symbionts …

Spatial And Temporal Dynamics Of Predator-Prey Interactions In Winter Wheat, Katelyn A. Kowles

Theses and Dissertations--Entomology

Aphids (Hemiptera: Aphididae) are pests of multiple cropping systems, primarily due to the viruses they vector and direct crop damage that is exacerbated by their rapid population growth. In Kentucky, grain aphids (Rhopalosiphum padi and Sitobion avenae) cause significant yield loss to winter wheat as vectors of Barley Yellow Dwarf virus (BYDV), prompting the routine application of insecticides. Coupled with increasing human populations and decreasing arable land, it is increasingly evident that biological control services provided by natural enemies represent a viable long-term management option. Aphids are preyed upon by a diverse array of predators that can be …

A Revision Of The New World And Select Old World Species Of Cremnops Förster (Hymenoptera: Braconidae: Agathidinae), Erika M. Tucker

Theses and Dissertations--Entomology

Parasitoid wasps are an important group of organisms in need of systematic revision. This dissertation examines the cosmopolitan parasitoid wasp genus Cremnops. It is a compilation of three projects and significantly advances the taxonomic foundation of the genus.

The New World species of the genus Cremnops are revised. Thirty-three species of Cremnops are treated; five are described as new, i.e., C. bertae sp. nov., C. cluttsis sp. nov., C. nymphius sp. nov., C. wileycoyotius sp. nov. and C. witkopegasus sp. nov. Six species are synonymized, i.e., Cremnops caribensis Berta 1998, is synonymized under C. guanicanus Wolcott 1924; C. nigrosternum (Morrison …

A Comprehensive Understanding Of Corpse Management In Termites, Qian Sun

Theses and Dissertations--Entomology

Undertaking behavior is the disposal of dead individuals in social colonies to prevent potential pathogenic attack. This behavioral trait has convergently evolved in social insects (primarily termites, ants, and honeybee), and is considered an essential adaptation to social living. In honey bee and ants, workers recognize dead colony members through the postmortem change of chemical profile, and corpses are usually removed out of nest. However, in termites, little is known about the behavioral pattern, chemical cue or molecular basis. In the eastern subterranean termite, Reticulitermes flavipes, this study investigated undertaking behavior toward corpses of different origins and postmortem times. …

Invasiveness Of An Exotic Gall Wasp Is Influenced By Interactions With Exotic And Endemic Organisms, Ignazio Graziosi

Theses and Dissertations--Entomology

American chestnut was once a crucial component of North American forests, but it was functionally eliminated by the introduction of the chestnut blight fungus. Chestnut is recently experiencing resurgence, but the introduced Asian chestnut gall wasp, a specialist herbivore, threatens chestnut recovery. I characterized this invasion and the interactions developing with host associates as the gall wasp spread in North America. Gall wasp dispersal is attributable to host plant distribution, effects of prevailing winds during adult insect emergence, and to topography. This knowledge may be useful to more accurately predict locations of future gall wasp infestations. Gall wasp invasiveness is …

Evaluating A Novel Endophytic Grass For Its Potential To Reduce Invertebrate Populations And Associated Bird Strike Risk At Airports, Diana M. Miller

Theses and Dissertations--Entomology

Aircraft strikes are a significant safety hazard on airports worldwide. Wildlife management at airfields is the most effective tactic to reduce airstrike risk – to modify the habitat to be undesirable to animals. Tall fescue grasses containing a fungal symbiont may serve that purpose. They produce alkaloids that convey resistance to some grass-feeding invertebrates, which might in turn reduce incidence of insectivorous birds. A commercial endophytic grass (Avanex™) consisting of ‘Jackal’ tall fescue infected with a unique endophyte (AR 601) is purported to contain especially high levels of alkaloids and to reduce bird populations if planted at airports. I evaluated …

Mechanical Exclusion And Biological Control Strategies For The Invasive Brown Marmorated Stink Bug, Halyomorpha Halys (Hemiptera: Pentatomidae), Rachelyn Dobson

Theses and Dissertations--Entomology

The brown marmorated stink bug (Halyomorpha halys) is an invasive, agriculturally destructive pest present in most of the United States. Because organic farmers have few effective control options to combat this pest, three potential control options were investigated. Screens of different mesh sizes (0.42cm, 0.32cm, and 0.10cm) that covered vegetable crops were evaluated for their ability to exclude H. halys, allow the entry of beneficial insects, and protect the crop from various types of damage. H. halys and native stink bug egg masses were placed in an organic field and evidence of predation and parasitism from native …

Taxonomic And Molecular Studies In Cleridae And Hemiptera, John Moeller Leavengood Jr.

Theses and Dissertations--Entomology

Taxonomic changes are made based on checkered beetle (Coleoptera: Cleridae) types of the Natural History Museum, London (BMNH).Lectotypes are designated (and holotypes and paralectotypes recognized) for 44 species of Hydnocerinae, including the type species for Isolemidia, Parmius, Paupris, Allelidea, Blaesiopthalmus and Lemidia, four species of Enoclerus (Clerinae), and 14 species of Cymatodera (Tillinae). Annotations include comments on additional type material, new type locality, previous (type series) locality, and questionable or missing types. Phyllobaenus pallipes(Gorham) and P. rufithorax (Gorham) are synonymized with P. flavifemoratus(Gorham), P. chapini (Wolcott) is synonymized under P. lateralis (Gorham), and P. villosus (Schenkling) …

Developing A Sustainable Approach To Emerald Ash Borer Management, William C. Davidson

Theses and Dissertations--Entomology

Emerald ash borer, Agrilus planipennis Fairmaire, is an invasive wood boring beetle native to eastern Asia which was first detected in North America in 2002. All North American Fraxinus (ash) species are suitable hosts and susceptible to attack. Emerald ash borer larvae feed on phloem beneath the bark of infested trees resulting in girdling and mortality in as little as five years following initial infestation. Since its introduction near Detroit, Michigan, emerald ash borer has rapidly spread throughout much of the United States and portions of Canada, threatening the persistence of ash in invaded regions.

I tested a management strategy …

A Comparative Study Of Eastern And Western North American Populations Of Hippodamia Convergens (Coleoptera: Coccinellidae), Joshua S. Mccord

Theses and Dissertations--Entomology

Hippodamia convergens is a widely distributed insect predator in the United States and parts of Canada and Mexico. Several insectaries collect overwintering adults from aggregation sites in the Rocky Mountains during their winter dormancy. Collected beetles are then sold throughout the United States for augmentative biological control. This practice could have negative impacts on local populations of Hippodamia convergens in the Eastern United States. Intra-specific variation among H. convergens populations was examined for two characteristics of adults: photoperiodic induction of diapause and the presence of three known male-killing endosymbiont bacteria; Wolbachia, Spiroplasma, and Rickettsia. Four populations of H. …

New Insights Into The Function And Development Of The Soldier Caste In Termites, Li Tian

Theses and Dissertations--Entomology

The evolution of nonreproductive castes is a defining characteristic of eusociality. The function and developmental regulation of the altruistic worker and soldier caste is the central element contributing to major advantages of eusociality over solitary animals. The soldier caste is the first evolved sterile caste in termites. Their primary function is believed to be colony defense. However, the function and development of termite soldiers remains largely unknown. Because of their apparent morphological adaptation for fighting and their limited behavior repertoire, our understanding of colony defense by termite soldiers is limited to their physical defense. In addition, we know little about …

Characterizing The Maternally Inherited Endosymbionts Of Solitary Bees, Abiya Saeed

Theses and Dissertations--Entomology

Solitary bees are important pollinators of crops, with species in the family Megachilidae (mason bees) being used for orchard pollination. Commercial movement of these bees also moves their microbiota, including bacterial endosymbionts capable of reproductive manipulation. To test for presence of these bacteria, I screened commercially available species of US orchard pollinators and locally captured solitary bees from Kentucky. I also set up mason bee boxes in five apple orchards to examine recruitment of local pollinators. I conducted 454-pyrosequencing to determine bacterial diversity within four species followed by diagnostic PCR of 30 collected species (184 individuals) to determine infection frequency …

Computational Identification And Molecular Verification Of Mirna In Eastern Subterranean Termites (Reticulitermes Flavipes), Tian Yu

Theses and Dissertations--Entomology

Reticulitermes flavipes is one of the most common termite species in the world, and has been an intriguing research model due to its ecological and biological and economic significance. The fundamental biological question addressed by this study is to elucidate the role of miRNAs in termite development and how miRNA can influence labor division. miRNAs are short non-coding RNAs that have an important role in gene regulation at post-transcriptional level, and can potentially be involved in the regulation of caste polyphenism. Using a computational approach, I identified 167 conserved and 33 novel miRNAs in the dataset. miR-iab-4 and 19 other …

The Role Of The Bacterial Endosymbiont, Arsenophonus, In The Soybean Aphid, Aphis Glycines, Jason A. Wulff

Theses and Dissertations--Entomology

Bacterial endosymbionts can have profound impacts on their host’s ecology. Notably, endosymbionts can protect their hosts against natural enemies and influence host plant interactions. The endosymbiont Candidatus Arsenophonus infects a wide taxonomic range of arthropod hosts, and is suspected of an uncharacterized mutualistic role in hemipterous insects. In the soybean aphid, Aphis glycines, an introduced pest of soybeans in the United States, Arsenophonus is the sole facultative endosymbiont. The focus of this dissertation is to characterize the role of Arsenophonus in the aphid, with an overall emphasis on its impact on aphid management strategies.

I first used diagnostic PCR …

Changing Litter Resources Associated With Hemlock Woolly Adelgid Invasion Affect Benthic Communities In Headwater Streams, Christopher J. Strohm

Theses and Dissertations--Entomology

Hemlock woolly adelgid is an invasive herbivore causing extensive mortality of eastern hemlock, an important foundation species that provides stable conditions influencing biological communities. Hemlock is often found in riparian areas and following its decline, broadleaved species, including birch, beech, and rhododendron, will replace it. These plants differ from hemlock in patterns of canopy cover and leaf properties, which influence conditions and resources within streams.

My goal was to evaluate potential impacts of adelgid-induced alterations to riparian canopies and litter on benthic communities and litter breakdown in streams. I characterized benthic invertebrate communities, litter colonization and litter breakdown in streams …

Exploring The Links Between Seasonal Variation And Spider Foraging, Thomas Edward Dantas Whitney

Theses and Dissertations--Entomology

According to optimal foraging theory, generalist predators, such as spiders, are thought to feed indiscriminately on prey according to its availability, especially when food is scarce. In contrast, generalists can display selective feeding decisions under regimes of high prey abundance, but few studies have tracked changes in prey choice on a seasonal basis under open field conditions. Additionally, adaptations to surviving winter have been largely ignored in the research of foraging behavior. To elucidate this, I monitored prey availability and collected common forest-dwelling wolf spiders for molecular gut-content analysis, in parallel for 18 months, to assess the temporal changes occurring …

Assessing And Mitigating Lawn Insecticide Hazards To Bees And Other Beneficial Invertebrates, Jonathan Lane Larson

Theses and Dissertations--Entomology

Turfgrass settings, including lawns, golf courses, and sports fields, support many beneficial invertebrates that provide important ecosystem services. These non-target organisms and their associated predation, decomposition, and pollination services can be disrupted by the use of certain insecticides. I compared the ecotoxicity of representatives from three major turf insecticide groups, the neonicotinoids, premix formulations, and the anthranilic diamides, in lab and field realistic settings in order to inform industry initiatives towards environmental sustainability.

In lab and field bioassays clothianidin, a neonicotinoid, and a premix clothianidin/pyrethroid spray were acutely toxic to beneficial insects. Populations of predators, springtails, and earthworms, as well …