Entomology Commons^™

Species-Specific Manipulation Of Microbially-Derived Volatiles By Burying Beetle Parents, Stephen T. Trumbo

EEB Articles

1. Hosts and microbes interact in dynamic relationships that can alter the volatile profile emitted by the microbial community. The extent to which closely related species diverge in these relationships is not well known.

2. Burying beetles associate with a rich microbial community that is present on their breeding resource, a small vertebrate carcass. Prior work demonstrated that Nicrophorus orbicollis manage the microbial community during parental care to alter the volatile profile emanating from the nest, reducing cues for competitors that would usurp the resource.

3. The present study extended this work to N. marginatus to first determine the distinctive …

The Ecological Consequences Of Horizontal Transmission Of Symbionts, Bibek Singh Parajuli

Biology Dissertations

Most multicellular organisms depend on their microbial symbionts for various functions, such as digestion, nutrient supplementation, pesticide degradation, and defense. While many insects acquire their symbionts vertically from their parents, thousands of species of true bugs (Hemiptera) across different families acquire their microbial symbiont, Caballeronia, from the environment each generation. Acquiring symbionts from the environment (horizontal transmission) has various ecological consequences for the host. In this study, I used the bug-Caballeronia model 1) to understand whether the free-living symbionts benefit from association with multicellular hosts, 2) to evaluate whether host specialization on symbiont strains varies across taxonomic levels, …

Effect Of Environmental Conditions On German Cockroach (Blattella Germanica) Behavior And Survival, Allison Lopina

Theses and Dissertations--Entomology

German cockroaches (Blattella germanica L.) remain one of the most challenging indoor pests to manage, due to resistance to many commonly used insecticides, and necessary contact/interaction with common management tactics. As such, it is critical to fully understand their aggregation, movement, and longevity, such that treatments can be optimally placed to result in maximal efficacy. The first part of this study explored the effects of multiple factors (harborage width, harborage materials, heat, resource-harborage distance) on initial site selection, and how environmental modifications and infestation density impact harborage site switching. The second half of the study aimed to explore the …

Short Term Trends In Benthic Macroinvertebrate Communities Downstream Of Iron Gate Dam Before And During Klamath Dam Removal, Rosa Cox

Cal Poly Humboldt theses and projects

Dam removals are increasingly being used to restore connectivity and ecological function to rivers degraded by impoundments, yet the short-term ecological impacts of large-scale dam removals remain poorly understood. In 2023-2024, four hydroelectric dams were removed from the Klamath River in Northern California and southern Oregon, mobilizing large volumes of fine sediments stored in reservoirs.  This study evaluated short-term trends in benthic macroinvertebrate (BMI) communities within the first ~90 km downstream of the Klamath dam removal project reach by comparing benthic kick net, invertebrate drift, and juvenile salmonid diet samples before (2022-2023) and during (2024) dam removal at paired mainstem …

Limitations Of Reproductive Manipulation By Bacterial Endosymbionts In A Spider Host, Jordyn D. Proctor

Theses and Dissertations--Entomology

Maternally inherited bacterial endosymbionts are common in arthropods. Many of these bacteria manipulate host reproduction to favor the production of infected females, thereby increasing bacterial prevalence in the host population, even if cost is incurred to the host. However, there are also many factors that may inhibit symbionts’ ability to spread in host populations, including environmental constraints, symbiont-imposed costs on the host, interactions with co-infecting bacteria, or host biology. I explored two aspects of symbiont biology within a spider host, Mermessus fradeorum (Linyphiidae), which has varying combinations of up to five different bacterial endosymbionts in local populations: Rickettsiella, Tisiphia …

Impacts Of Livestock Dewormers On Dung Beetle Foraging Choices Across Spatial Scales, Madison L. Kluge

Theses and Dissertations--Entomology

Dung beetles provide ecosystem services in pasture systems but are vulnerable to chemical residues in livestock dung. Parasiticides containing macrocyclic lactones (MLs) are used to control parasites in livestock and are excreted unmetabolized in dung, exposing non-target organisms to these compounds. We used a multi-scale approach to examine whether ML residues alter dung beetle foraging ecology. At the field scale, we assessed dung beetle abundance and community composition using traps baited with dung from untreated cattle and cattle treated with ivermectin, moxidectin, or eprinomectin across eight farms and natural areas. At a smaller scale, we conducted behavioral assays to quantify …

Effect Of Endophytic Fungi On Thrips Tabaci Development And Population Dynamics, Ngoc Anh Vu, Sevgan Subramanian, Rainer Meyhöfer

All Peer-Reviewed Publications

Endophytic fungi are promising biocontrol agents because they colonise healthy plant tissues asymptomatically while inducing systemic resistance that negatively affects herbivorous insects. We investigated whether treatments with the endophytes Trichoderma harzianum and Beauveria bassiana in two onion cultivars (Allium cepa L.; Sturon and Red Baron) induce plant responses that alter Thrips tabaci behaviour and population development. Under controlled conditions, seeds were treated with conidial suspensions and plants subsequently received foliar applications; plants were then exposed to T. tabaci for 72 h, 4 weeks, or 8 weeks in no-choice assays. Both endophytes reduced thrips host-plant preference: at 72 h post-exposure, inoculated …

Tick Lipocalin Triggers Mammalian Igfbp-3-Mediated Apoptosis In Macrophages And Keratinocytes, Krittika Nandy, P. P. Mahesh, Lichao Liu, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several molecules, including lipocalins, in their saliva during blood feeding on a vertebrate host. In this study, we provide novel evidence on the role of Ornithodoros turicata americanus tick lipocalin (Otlip) in modulating cytokine expression and in triggering apoptosis in mammalian macrophages and keratinocytes. The cytokine array analysis revealed significantly increased secretion of insulin-like growth factor-binding protein 3 (IGFBP3) from murine macrophage cell line upon treatment with recombinant Otlip protein (rGST-Otlip) when compared to the secretion noted from cells treated with a control protein (rGST). Similar observation with cytokine protein array analysis was noted when murine macrophages were …

Herbivore Identity And Species Richness Shape Fruit Chemical And Quality Responses To Foliar Herbivory, Xavier Ozowara, Taylor M. Sloey, Susan R. Whitehead

Biological Sciences Faculty Publications

The cascading consequences of foliar herbivory on fruit chemistry and quality remain relatively underexplored, with most existing studies focusing on the effects of only one or two attackers. In this study, we examine how increasing herbivore species richness during foliar herbivory alters strawberry (Fragaria × ananassa Duch) fruit quality and phenolic chemistry. We conducted a greenhouse experiment with single species feeding and different combinations of feeding by three generalist lepidopteran species: Spodoptera frugiperda, Heliothis virescens, Helicoverpa zea. Species fed on leaves for 72 h as fruits ripened, and fully ripe fruits were harvested 72 h after …

Effects Of Rnai Of Ribophorin 1, Eukaryotic Translation Initiation Factor 2 Beta, And Peptidylprolyl Isomerase A In Acyrthosiphon Pisum, Brandon L. Kennemer

Master's Theses or Doctor of Nursing Practice

Three genes found in the Unfolded protein response, Ribophorin 1, Eukaryotic translation initiation factor 2 beta, and Peptidylprolyl isomerase A are thought to be potential targets for RNA Interference (RNAi) in Acyrthosiphon pisum.  Ribophorin 1 (RPN1) is a transmembrane glycoprotein that assists in anchoring ribosomes to the rough endoplasmic reticulum membrane.  It acts as a substrate-specific chaperone.  It facilitates N-glycosylation by delivering newly synthesized proteins to the oligosaccharyltransferase (OST) complex.  Eukaryotic translation initiation factor 2 beta (eIF2B) is a key component of the eIF2 heterotrimer that facilitates protein synthesis initiation by binding GTP and recruiting a specific transfer RNA to …

Bayesian Multivariate Modelling Of Lone Star (Amblyomma Americanum) Tick Life Stage Abundance And Temporal Trends To Inform Public Health Risk In Virginia, Thabo Lephoto, Henry Mwambi, Oliver Bodhlyera, Holly Gaff

Biological Sciences Faculty Publications

The increasing abundance of ticks poses a growing public health concern due to heightened human exposure to tick bites. The lone star tick (Amblyomma americanum: Ixodida: Ixodidae), a common human-biting species in the United States, has expanded its range in recent years. However, how its different life stages vary across time, habitats, and locations remains insufficiently understood. We analyzed tick abundance data collected in southeastern Virginia between 2009 and 2018, focusing on larval, nymphal, and adult life stages. A Bayesian multivariate modelling framework was used to examine seasonal patterns, habitat effects, spatial variation, and biological links between life stages. Two …

Optimizing Insect Exclusion Systems For Organic Specialty Crop Production, Elaine Losekamp

Theses and Dissertations--Entomology

Feeding damage from insect pests is a leading challenge for specialty crop growers who follow organic practices. Past research has shown that fine-mesh row covers installed over mesotunnel structures, which form a physical barrier between plants and insects, often reduce insect pest abundance and increase yield compared to open field conditions. However, there are several challenges associated with this practice. Exclusion efficacy varies across a spectrum of insect body sizes and mesh sizes, and effects on yield vary across crops. Additionally, pollination management for pollinator-dependent crops introduces labor requirements and may result in reduced pest exclusion efficacy. Mechanical weed management …

Seasonal Population Dynamics And Interspecific Interactions Of Drosophila Suzukii, Eleanor Mccabe

Theses and Dissertations--Entomology

Invasive species are a growing problem, and it is important to investigate how invasives interact with novel ecosystems, which are characterized by distinct abiotic and biotic factors. In this dissertation, I investigate abiotic and biotic factors affecting two invasive pests in central Kentucky, Drosophila suzukii and Zaprionus indianus. In Kentucky, seasonality, and landscape features on population dynamics and fitness are unknown. I found that D. suzukii overwinters in Kentucky and that wild berry species improve winter survival. I used local weather data to identify meteorological variables that best predict D. suzukii populations. I tested the extent to which D. suzukii …

Applied Forest Restoration And Conservation In Michigan: Advancing American Beech Restoration And Documenting A Historical Insect Collection, Thomas E. Panella

Dissertations, Master's Theses and Master's Reports

Forest restoration and conservation require both practical management approaches and the preservation of biological resources that support future research. This dissertation presents applied research conducted in Michigan that advances American beech (Fagus grandifolia) restoration in response to beech bark disease (BBD) while documenting an important historical entomological resource. Chapters 1–3 focus on overcoming practical barriers to American beech restoration. Restoration protocols were developed and refined for identifying BBD-resistant trees, graft propagation, rootstock collection, container production, and the field establishment of grafted BBD-resistant trees. A greenhouse experiment evaluated the influence of growing media and fertilization on container stock quality, …

County-Level Surveillance For The American Dog Tick (Dermacentor Variabilis) And Rickettsia Species In Kentucky, Callista W. Vandegriff, Jun Seok Ryoo, Maria C. Carrasquilla, Anna Rosalee Pasternak, Wayne T. Sanderson, Subba R. Palli

Entomology Faculty Publications

Spotted fever group (SFG) rickettsiosis includes a group of illnesses with similar symptoms caused by Rickettsia species bacteria. While Rickettsia rickettsii, the agent of Rocky Mountain spotted fever (RMSF) is a well-known pathogen, other SFG Rickettsia spp. can infect ticks and occasionally contribute to human disease. We conducted county-level surveillance of Dermacentor variabilis ticks in Kentucky to characterize the distribution and diversity of SFG Rickettsia. Ticks were collected from the environment from 2019 to 2024 by dragging a white cloth and through our Kentucky Tick Submission Program. In total, 2,023 D. variabilis ticks were collected from 114 …

Clinical Manifestations Of Bed Bug Bites: A Systematic Review Of Case Reports, Julian Felipe Porras-Villamil, Zachary C. Devries

Entomology Faculty Publications

Importance: Clinical characterization of bed bug (Cimex spp.) bite manifestations remains limited.   Objective: This systematic review synthesizes case reports to describe dermatological, systemic, and psychological outcomes of bed bug bites.   Evidence review: Following PRISMA guidelines, multiple databases, including Pubmed and Scopus, were searched using terms such as “bed bug,” “Cimex lectularius,” “Cimex hemipterus,” “case report,” and “case series.” Extracted data included demographics, species, lesion type, anatomical distribution, and clinical manifestations. Quantitative and qualitative analyses were conducted.   Results: Eighty-four patients were included: 76 with C. lectularius (90.5%) and, 8 with C. hemipterus (9.5%). Sex distribution was …

Complex Interplay Between Facilitation And Competition In Two Invasive Fruit Pests, Eleanor Mccabe, Nicholas M. Teets

Entomology Faculty Publications

When one invasive species facilitates the invasion of another species, it can lead to invasional meltdown. However, when the two species depend on the same finite resource, facilitation and competition can occur simultaneously and impact population dynamics. Furthermore, factors like resource availability and population density could alter the balance between facilitation and competition. Drosophila suzukii and Zaprionus indianus are two invasive insect pests that infest small fruit crops. The co-localization of these species in the same fields, coupled with the fact that Z. indianus lacks a hardened ovipositor that can penetrate the skin of fruit, has led to the hypothesis …

Elevated Temperatures Disrupt Wolbachia-Induced Feminisation And Reshape Microbial Community Dynamics Across Generations In A Spider Host, Virginija Mackevicius-Dubickaja, Jennifer A. White, Ellen E. Williams, Eyal Klement, Yuval Gottlieb, Matthew R. Doremus

Entomology Faculty Publications

Longitudinal microbial interactions within a host are challenging to study, leading to a focus on constructed microbial communities in vitro settings. Here, we take advantage of a naturally defined microbial community within a spider host to study how elevated temperatures influence microbial dynamics and phenotypes across host generations. The spider Mermessus fradeorum hosts up to five endosymbionts, including a Wolbachia strain, W1, which induces feminisation, causing genetic males to develop as phenotypic females, skewing sex ratios and promoting symbiont spread. Despite this, Wolbachia 1 persists at intermediate frequencies in wild populations. We hypothesised that elevated temperatures might reduce penetration of …

Evolutionary Transitions In Social Behavior Are Associated With Convergent And Partially Reversible Expansions Of Transcription Factor Binding Sites, Savanna G. Ploessl, Beryl M. Jones

Entomology Faculty Publications

The evolution of sociality involves shifts in physiology and behavior, most notably the emergence of a reproductive division of labor. Within social colonies, these distinct behavioral phenotypes arise from differential regulation of a shared genome. Changes in transcription factor (TF) binding motifs are one potential mechanism underpinning this plasticity, with prior studies suggesting that social species exhibit expansions in TF binding sites. However, it remains unclear whether motif expansions are reversed when sociality is lost. Here we analyze predicted TF motif occurrences across gene promoters in 42 bee species spanning millions of years of evolutionary divergence and multiple independent gains …

Characterizing Gut Microbial Communities And Symbiont-Mediated Detoxification In Herbivorous Insects, Rachel C. Vargas

Biology Dissertations

Insect gut bacteria are vital contributors to host physiology, yet the broader prevalence and fitness implications of symbiont-mediated detoxification remain poorly understood. This thesis investigates these dynamics across three research chapters. Chapter 1 uses 16S rRNA sequencing to characterize how grasshopper gut microbial communities vary across species, dietary breadths, and gastrointestinal segments. Chapter 2 evaluates the detoxification capacity of over 150 bacterial isolates from diverse herbivores against the plant allelochemicals phenethyl isothiocyanate, rutin, and chlorogenic acid to determine if host dietary specialization predicts microbial metabolic ability. Finally, Chapter 3 employs fitness bioassays to test whether inoculating generalist herbivores with detoxifying …