Life Sciences Commons^™

Integration Of Plant Defense Traits With Biological Control Of Arthropod Pests: Challenges And Opportunities, Julie A. Peterson, Paul J. Ode, Camila Oliveira-Hofman, James D. Harwood

Entomology Faculty Publications

Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be …

Genome Of The Asian Longhorned Beetle (Anoplophora Glabripennis), A Globally Significant Invasive Species, Reveals Key Functional And Evolutionary Innovations At The Beetle-Plant Interface, Duane D. Mckenna, Erin D. Scully, Yannick Pauchet, Kelli Hoover, Roy Kirsch, Scott M. Geib, Robert F. Mitchell, Robert M. Waterhouse, Seung-Joon Ahn, Deanna Arsala, Joshua B. Benoit, Heath Blackmon, Tiffany Bledsoe, Julia H. Bowsher, André Busch, Bernarda Calla, Hsu Chao, Anna K. Childers, Christopher Childers, Dave J. Clarke, Lorna Cohen, Jeffery P. Demuth, Huyen Dinh, Harshavardhan Doddapaneni, Amanda Dolan, Jian J. Duan, Shannon Dugan, Markus Friedrich, Karl M. Glastad, Michael A. D. Goodisman, Stephanie Haddad, Yi Han, Daniel S. T. Hughes, Panagiotis Ioannidis, J. Spencer Johnston, Jeffery W. Jones, Leslie A. Kuhn, David R. Lance, Chien-Yueh Lee, Sandra L. Lee, Han Lin, Jeremy A. Lynch, Armin P. Moczek, Shwetha C. Murali, Donna M. Muzny, David R. Nelson, Subba R. Palli, Kristen A. Panfilio, Dan Pers, Monica F. Poelchau, Honghu Quan, Jiaxin Qu, Ann M. Ray, Joseph P. Rinehart, Hugh M. Robertson, Richard Roehrdanz, Andrew J. Rosendale, Seunggwan Shin, Christian Silva, Alex S. Torson, Iris M. Vargas Jentzsch, John H. Werren, Kim C. Worley, George Yocum, Evgeny M. Zdobnov, Richard A. Gibbs, Stephen Richards

Entomology Faculty Publications

Background: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle.

Results: …

Selection Of Reference Genes For Rt-Qpcr Analysis In Coccinella Septempunctata To Assess Un-Intended Effects Of Rnai Transgenic Plants, Chunxiao Yang, Evan L. Preisser, Hongjun Zhang, Yong Liu, Liangying Dai, Huipeng Pan, Xuguo Zhou

Entomology Faculty Publications

The development of genetically engineered plants that employ RNA interference (RNAi) to suppress invertebrate pests opens up new avenues for insect control. While this biotechnology shows tremendous promise, the potential for both non-target and off-target impacts, which likely manifest via altered mRNA expression in the exposed organisms, remains a major concern. One powerful tool for the analysis of these un-intended effects is reverse transcriptase-quantitative polymerase chain reaction, a technique for quantifying gene expression using a suite of reference genes for normalization. The seven-spotted ladybeetle Coccinella septempunctata, a commonly used predator in both classical and augmentative biological controls, is a …

Citations Increase With Manuscript Length, Author Number, And References Cited In Ecology Journals, Charles W. Fox, C. E. Timothy Paine, Boris Sauterey

Entomology Faculty Publications

Most top impact factor ecology journals indicate a preference or requirement for short manuscripts; some state clearly defined word limits, whereas others indicate a preference for more concise papers. Yet evidence from a variety of academic fields indicates that within journals longer papers are both more positively reviewed by referees and more highly cited. We examine the relationship between citations received and manuscript length, number of authors, and number of references cited for papers published in 32 ecology journals between 2009 and 2012. We find that longer papers, those with more authors, and those that cite more references are cited …

Juvenile Hormone Regulation Of Female Reproduction In The Common Bed Bug, Cimex Lectularius, Hemant Gujar, Subba Reddy Palli

Entomology Faculty Publications

To begin studies on reproduction in common bed bug, Cimex lectularius, we identified three genes coding for vitellogenin (Vg, a protein required for the reproductive success of insects) and studied their hormonal regulation. RNA interference studied showed that expression of Vg3 gene in the adult females is a prerequisite for successful completion of embryogenesis in the eggs laid by them. Juvenile hormone (JH) receptor, Methoprene-tolerant (Met), steroid receptor coactivator (SRC) and GATAa but not ecdysone receptor (EcR) or its partner, ultraspiracle (USP) are required for expression of Vg genes. Feeding and mating working through Vg, Met, SRC, EcR, and …

Comparative Profiling Of Micrornas In The Winged And Wingless English Grain Aphid, Sitobion Avenae (F.) (Homoptera: Aphididae), Xiangrui Li, Fangmei Zhang, Brad Coates, Yunhui Zhang, Xuguo Zhou, Dengfa Cheng

Entomology Faculty Publications

MicroRNAs (miRNAs) are short single-stranded non-coding RNAs that regulate gene expression, particularly during development. In this study, 345 miRNAs were identified from the English green aphid, Sitobion avenae (F.), of which 168 were conserved and 177 were S. avenae-specific. Quantitative comparison of miRNA expression levels indicated that 16 and 12 miRNAs were significantly up-regulated in winged and wingless S. avenae small RNA libraries, respectively. Differential expression of these miRNAs was confirmed by real-time quantitative RT-PCR validation. The putative transcript targets for these candidate miRNAs were predicted based on sequences from a model species Drosophila melanogaster and four aphid species …

Microfabricated Sufaces For The Physical Capture Of Insects, Catherine Loudon, Robert Corn, Megan Szyndler, Kenneth F. Haynes, Michael F. Potter

Entomology Faculty Patents

Novel devices and methods of capturing, controlling and preventing infestation of insects using microfabricated surfaces are provided. In particular, a mechanism of insect capture inspired by the microstructures of the leaf surfaces of plants and the key features of those surfaces with respect to the capture and control of pests have been determined and engineered into a variety of microfabricated surfaces capable of reproducing the effectiveness of these physical capture methods.

Functional Value Of Elytra Under Various Stresses In The Red Flour Beetle, Tribolium Castaneum, David M. Linz, Alan W. Hu, Michael I. Sitvarin, Yoshinori Tomoyasu

Entomology Faculty Publications

Coleoptera (beetles) is a massively successful order of insects, distinguished by their evolutionarily modified forewings called elytra. These structures are often presumed to have been a major driving force for the successful radiation of this taxon, by providing beetles with protection against a variety of harsh environmental factors. However, few studies have directly demonstrated the functional significance of the elytra against diverse environmental challenges. Here, we sought to empirically test the function of the elytra using Tribolium castaneum (the red flour beetle) as a model. We tested four categories of stress on the beetles: physical damage to hindwings, predation, desiccation, …

Female Adult Aedes Albopictus Suppression By Wolbachia-Infected Male Mosquitoes, James W. Mains, Corey L. Brelsfoard, Robert I. Rose, Stephen L. Dobson

Entomology Faculty Publications

Dengue, chikungunya and zika viruses are pathogens with an increasing global impact. In the absence of an approved vaccine or therapy, their management relies on controlling the mosquito vectors. But traditional controls are inadequate, and the range of invasive species such as Aedes albopictus (Asian Tiger Mosquito) is expanding. Genetically modified mosquitoes are being tested, but their use has encountered regulatory barriers and public opposition in some countries. Wolbachia bacteria can cause a form of conditional sterility, which can provide an alternative to genetic modification or irradiation. It is unknown however, whether openly released, artificially infected male Ae. albopictus can …

Multiple Lines Of Evidence From Mitochondrial Genomes Resolve Phylogenetic Relationships Of Parasitic Wasps In Braconidae, Qian Li, Shu-Jun Wei, Pu Tang, Qiong Wu, Min Shi, Michael J. Sharkey, Xue-Xin Chen

Entomology Faculty Publications

The rapid increase in the number of mitochondrial genomes in public databases provides opportunities for insect phylogenetic studies; but it also provides challenges because of gene rearrangements and variable substitution rates among both lineages and sites. Typically, phylogenetic studies use mitochondrial sequence data but exclude other features of the mitochondrial genome from analyses. Here, we undertook large-scale sequencing of mitochondrial genomes from a worldwide collection of specimens belonging to Braconidae, one of the largest families of Metazoa. The strand-asymmetry of base composition in the mitochondrial genomes of braconids is reversed, providing evidence for monophyly of the Braconidae. We have reconstructed …

Assessment Of Potential Risks Of Dietary Rnai To A Soil Micro-Arthropod, Sinella Curviseta Brook (Collembola: Entomobryidae), Huipeng Pan, Linghua Xu, Jeffrey E. Noland, Hu Li, Blair D. Siegfried, Xuguo Zhou

Entomology Faculty Publications

RNAi-based genetically engineered (GE) crops for the management of insect pests are likely to be commercialized by the end of this decade. Without a workable framework for conducting the ecological risk assessment (ERA) and a standardized ERA protocol, however, the utility of RNAi transgenic crops in pest management remains uncertain. The overall goal of this study is to assess the risks of RNAi-based GE crops on a non-target soil micro-arthropod, Sinella curviseta, which could be exposed to plant-protected dsRNAs deposited in crop residues. Based on the preliminary research, we hypothesized that insecticidal dsRNAs targeting at the western corn rootworm, …

The Salicylic Acid-Mediated Release Of Plant Volatiles Affects The Host Choice Of Bemisia Tabaci, Xiaobin Shi, Gong Chen, Lixia Tian, Zhengke Peng, Wen Xie, Qingjun Wu, Shaoli Wang, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and …

20-Hydroxyecdysone (20e) Primary Response Gene E75 Isoforms Mediate Steroidogenesis Autoregulation And Regulate Developmental Timing In Bombyx, Kang Li, Ling Tian, Zhongjian Guo, Sanyou Guo, Jianzhen Zhang, Shi-Hong Gu, Subba Reddy Palli, Yang Cao, Sheng Li

Entomology Faculty Publications

The temporal control mechanisms that precisely control animal development remain largely elusive. The timing of major developmental transitions in insects, including molting and metamorphosis, is coordinated by the steroid hormone 20-hydroxyecdysone (20E). 20E involves feedback loops to maintain pulses of ecdysteroid biosynthesis leading to its upsurge, whereas the underpinning molecular mechanisms are not well understood. Using the silkworm Bombyx mori as a model, we demonstrated that E75, the 20E primary response gene, mediates a regulatory loop between ecdysteroid biosynthesis and 20E signaling. E75 isoforms A and C directly bind to retinoic acid receptor-related response elements in Halloween gene promoter …

Duplication And Remolding Of Trna Genes In The Mitochondrial Genome Of Reduvius Tenebrosus (Hemiptera: Reduviidae), Pei Jiang, Hu Li, Fan Song, Yao Cai, Jianyun Wang, Jinpeng Liu, Wanzhi Cai

Markey Cancer Center Faculty Publications

Most assassin bugs are predators that act as important natural enemies of insect pests. Mitochondrial (mt) genomes of these insects are double-strand circular DNAs that encode 37 genes. In the present study, we explore the duplication and rearrangement of tRNA genes in the mt genome of Reduvius tenebrosus, the first mt genome from the subfamily Reduviinae. The gene order rearranges from CR (control region)-trnI-trnQ-trnM-ND2 to CR-trnQ-trnI2-trnI1-trnM-ND2. We identified 23 tRNA genes, including 22 tRNAs commonly found in insects and an additional trnI (trnI2), which has high sequence similarity to trnM. We found several …

Identification Of Ecdysone Hormone Receptor Agonists As A Therapeutic Approach For Treating Filarial Infections, Amruta S. Mhashilkar, Sai L. Vankayala, Canhui Liu, Fiona Kearns, Priyanka Mehrotra, George Tzertzinis, Subba R. Palli, H. Lee Woodcock, Thomas R. Unnasch

Entomology Faculty Publications

Background A homologue of the ecdysone receptor has previously been identified in human filarial parasites. As the ecdysone receptor is not found in vertebrates, it and the regulatory pathways it controls represent attractive potential chemotherapeutic targets.

Methodology/ Principal Findings Administration of 20-hydroxyecdysone to gerbils infected with B. malayi infective larvae disrupted their development to adult stage parasites. A stable mammalian cell line was created incorporating the B. malayi ecdysone receptor ligand-binding domain, its heterodimer partner and a secreted luciferase reporter in HEK293 cells. This was employed to screen a series of ecdysone agonist, identifying seven agonists active at …

Identification Of G Protein-Coupled Receptors Required For Vitellogenin Uptake Into The Oocytes Of The Red Flour Beetle, Tribolium Castaneum, Hua Bai, Subba R. Palli

Entomology Faculty Publications

Previous studies suggested that a membrane receptor might be involved in mediating vitellogenin (Vg) uptake and juvenile hormone (JH)-regulated remodeling of follicular epithelium (also called ‘patency’). G protein-coupled receptor (GPCR) family is one of the largest membrane receptor protein families and controls many key physiological processes. To investigate the role of GPCRs in insect reproduction and juvenile hormone-regulated Vg uptake, we performed a comprehensive RNA interference (RNAi) screen targeting GPCRs in the red flour beetle, Tribolium castaneum. Out of 112 GPCRs tested, knockdown of 41 GPCRs resulted in a reduction in fecundity. Interestingly, RNAi against two GPCRs (a Rhodopsin-like …

A 2-Cys Peroxiredoxin In Response To Oxidative Stress In The Pine Wood Nematode, Bursaphelenchus Xylophilus, Zhen Li, Qingwen Zhang, Xuguo Zhou

Entomology Faculty Publications

The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease that has devastated pine forests in Asia. Parasitic nematodes are known to have evolved antioxidant stress responses that defend against host plant defenses. In this study, the infestation of whitebark pine, Pinus bungean, with B. xylophilus led to a significant increase in plant hydrogen peroxide (H₂O₂) and salicylic acid levels. Correspondingly, the expression of an antioxidative enzyme, 2-Cysteine peroxiredoxin (BxPrx), was elevated in B. xylophilus following the H₂O₂ treatments. Recombinant BxPrx, a thermal stabile and pH tolerant …

Krüppel Homolog 1 And E93 Mediate Juvenile Hormone Regulation Of Metamorphosis In The Common Bed Bug, Cimex Lectularius, Hemant Gujar, Subba Reddy Palli

Entomology Faculty Publications

The common bed bug is an obligate hematophagous parasite of humans. We studied the regulation of molting and metamorphosis in bed bugs with a goal to identify key players involved. qRT-PCR studies on the expression of genes known to be involved in molting and metamorphosis showed high levels of Krüppel homolog 1 [Kr-h1, a transcription factor that plays key roles in juvenile hormone (JH) action] mRNA in the penultimate nymphal stage (N4). However, low levels of Kr-h1 mRNA were detected in the fifth and last nymphal stage (N5). Knockdown of Kr-h1 in N4 resulted in a precocious development of adult …

Capturing The Phylogeny Of Holometabola With Mitochondrial Genome Data And Bayesian Site-Heterogeneous Mixture Models, Fan Song, Hu Li, Pei Jiang, Xuguo Zhou, Jinpeng Liu, Changhai Sun, Alfried P. Vogler, Wanzhi Cai

Entomology Faculty Publications

After decades of debate, a mostly satisfactory resolution of relationships among the 11 recognized holometabolan orders of insects has been reached based on nuclear genes, resolving one of the most substantial branches of the tree-of-life, but the relationships are still not well established with mitochondrial genome data. The main reasons have been the absence of sufficient data in several orders and lack of appropriate phylogenetic methods that avoid the systematic errors from compositional and mutational biases in insect mitochondrial genomes. In this study, we assembled the richest taxon sampling of Holometabola to date (199 species in 11 orders), and analyzed …

Aphid Performance Changes With Plant Defense Mediated By Cucumber Mosaic Virus Titer, Xiaobin Shi, Yang Gao, Shuo Yan, Xin Tang, Xuguo Zhou, Deyong Zhang, Yong Liu

Entomology Faculty Publications

Background: Cucumber mosaic virus (CMV) causes appreciable losses in vegetables, ornamentals and agricultural crops. The green peach aphid, Myzus persicae Sulzer (Aphididae) is one of the most efficient vectors for CMV. The transmission ecology of aphid-vectored CMV has been well investigated. However, the detailed description of the dynamic change in the plant-CMV-aphid interaction associated with plant defense and virus epidemics is not well known.

Results: In this report, we investigated the relationship of virus titer with plant defense of salicylic acid (SA) and jasmonic acid (JA) during the different infection time and their interaction with aphids in CMV-infected tobacco plants. …

Key To The Species Of Megarhyssa (Hymenoptera, Ichneumonidae, Rhyssinae) In America, North Of Mexico, Victoria G. Pook, Michael J. Sharkey, David B. Wahl

Entomology Faculty Publications

A dichotomous and an interactive key to the species of Megarhyssa (Hymenoptera: Ichneumonidae) in America, north of Mexico are presented. A diagnosis accompanied by images is provided for male and female wasps of each of the four species, Megarhyssa atrata, Megarhyssa greenei, Megarhyssa macrurus and Megarhyssa nortoni.

A Specialist Herbivore Pest Adaptation To Xenobiotics Through Up-Regulation Of Multiple Cytochrome P450s, Fang Zhu, Timothy W. Moural, David R. Nelson, Subba R. Palli

Entomology Faculty Publications

The adaptation of herbivorous insects to their host plants is hypothesized to be intimately associated with their ubiquitous development of resistance to synthetic pesticides. However, not much is known about the mechanisms underlying the relationship between detoxification of plant toxins and synthetic pesticides. To address this knowledge gap, we used specialist pest Colorado potato beetle (CPB) and its host plant, potato, as a model system. Next-generation sequencing (454 pyrosequencing) was performed to reveal the CPB transcriptome. Differential expression patterns of cytochrome P450 complement (CYPome) were analyzed between the susceptible (S) and imidacloprid resistant (R) beetles. We also evaluated the global …

Unique Features Of A Global Human Ectoparasite Identified Through Sequencing Of The Bed Bug Genome, Joshua B. Benoit, Zach N. Adelman, Klaus Reinhardt, Amanda Dolan, Monica Poelchau, Emily C. Jennings, Elise M. Szuter, Richard W. Hagan, Hemant Gujar, Jayendra Nath Shukla, Fang Zhu, M. Mohan, David R. Nelson, Andrew J. Rosendale, Christian Derst, Valentina Resnik, Sebastian Wernig, Pamela Menegazzi, Christian Wegener, Nicolai Peschel, Jacob M. Hendershot, Wolfgang Blenau, Reinhard Predel, Paul R. Johnston, Panagiotis Ioannidis, Robert M. Waterhouse, Ralf Nauen, Corinna Schorn, Mark-Christoph Ott, Frank Maiwald, Subba R. Palli

Entomology Faculty Publications

The bed bug, Cimex lectularius, has re-established itself as a ubiquitous human ectoparasite throughout much of the world during the past two decades. This global resurgence is likely linked to increased international travel and commerce in addition to widespread insecticide resistance. Analyses of the C. lectularius sequenced genome (650 Mb) and 14,220 predicted protein-coding genes provide a comprehensive representation of genes that are linked to traumatic insemination, a reduced chemosensory repertoire of genes related to obligate hematophagy, host-symbiont interactions, and several mechanisms of insecticide resistance. In addition, we document the presence of multiple putative lateral gene transfer events. Genome …

Genome-Wide Transcriptomic And Proteomic Analyses Of Bollworm-Infested Developing Cotton Bolls Revealed The Genes And Pathways Involved In The Insect Pest Defence Mechanism, Saravanan Kumar, Kanakachari Mogilicherla, Dhandapani Gurusamy, Krishan Kumar, Prabhakaran Narayanasamy, Padmalatha Kethireddy Venkata, Amolkumar Solanke, Savita Gamanagatti, Vamadevaiah Hiremath, Ishwarappa S. Katageri, Sadhu Leelavathi, Polumetla Ananda Kumar, Vanga Siva Reddy

Entomology Faculty Publications

Cotton bollworm, Helicoverpa armigera, is a major insect pest that feeds on cotton bolls causing extensive damage leading to crop and productivity loss. In spite of such a major impact, cotton plant response to bollworm infection is yet to be witnessed. In this context, we have studied the genome-wide response of cotton bolls infested with bollworm using transcriptomic and proteomic approaches. Further, we have validated this data using semi-quantitative real-time PCR. Comparative analyses have revealed that 39% of the transcriptome and 35% of the proteome were differentially regulated during bollworm infestation. Around 36% of significantly regulated transcripts and 45% …

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 …

The Role Of Rapgap1 In Sxl Activation In Drosophila Melanogaster, Katherine M. Barnes

Lewis Honors College Capstone Collection

The master switch of the sexual differentiation and dosage compensation pathway in Drosophila is the sex lethal gene, Sxl. The early promoter, SxlPe, is activated in females, resulting in female-specific splicing of later transcripts (notably the late Sxl transcript SxlPm), while inactive in males. Chromatin immunoprecipitation (ChIP) assays have previously shown association of two conventionally heterochromatin-localized proteins, HOAP and HP1, at SxlPe, and in situ hybridization as well as RT-PCR assays have confirmed a repressive role for HOAP and both repressive and activating roles for HP1. The mechanism for the activity shift of HP1 is currently unknown. Deletions in the …

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 …

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 …

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 …

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 …