Entomology Commons^™

Landscape Genetics Of The Gulf Coast Tick, Amblyomma Maculatum, Sara Simmons Benham

Biological Sciences Theses & Dissertations

Connectivity among populations helps to maintain genetic diversity, population stability, and resilience. The Gulf Coast tick, Amblyomma maculatum, is a vector of the pathogen Rickettsia parkeri. Persistence of tick populations with high rates of R. parkeri infection poses health risks to humans and animals. Mitochondrial haplotypes were characterized by sequencing a fragment of the mitochondrial 16S rRNA gene. A comparative study of A. maculatum and Amblyomma americanum was conducted to identify similar and unique patterns between the species within the same region. Next, I compared A. maculatum sites across three different regions of the United States. This work …

Determination Of The Presence Of Rickettsia Spp. And Borrelia Spp. Carried By Tortoise Ticks From Madagascar, Anna Phan

Biological Sciences Theses & Dissertations

Ticks were removed from three species of Malagasy tortoises, Astrochelys yniphora, A. radiata, and Pyxis arachnoides (comprising two subspecies P. a. arachnoides and P. a. oblonga), between 2012 and 2015. The ticks were presumed to be from the genus Amblyomma. Ticks were morphologically identified and then checked molecularly to confirm their classification or identify any ticks that could not be morphologically identified. Molecular identification was done via end-point PCR that amplified tick cytochrome oxidase (CO1) and tick 12S rRNA genes. Ticks were screened via a real-time polymerase chain reaction assay for the presence of Rickettsia spp. …

Double Anus In An Ixodes Scapularis Nymph, A Medically Important Tick Vector, Vikas Taank, Frank A. Lattanzio, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Ixodes scapularis ticks are medically important arthropod vectors that transmit several pathogens to humans. The observations of morphological abnormalities, including nanism, missing leg, extra leg, and gynandromorphism, have been reported in these ticks. In this study, we report the presence of two anuses in a laboratory-reared I. scapularis nymph.

Results: Larval ticks were allowed to feed on mice and to molt to nymphs. Two anuses were observed in one of the freshly molted nymphs. Stereo and scanning electron microscopy confirmed the presence of two anuses in one nymph within a single anal groove.

Conclusions: This report confirms the rare …

Trends And Opportunities In Tick-Borne Disease Geography, Catherine A. Lippi, Sadie J. Ryan, Alexis L. White, Holly D. Gaff, Colin J. Carlson

Biological Sciences Faculty Publications

Tick-borne diseases are a growing problem in many parts of the world, and their surveillance and control touch on challenging issues in medical entomology, agricultural health, veterinary medicine, and biosecurity. Spatial approaches can be used to synthesize the data generated by integrative One Health surveillance systems, and help stakeholders, managers, and medical geographers understand the current and future distribution of risk. Here, we performed a systematic review of over 8,000 studies and identified a total of 303 scientific publications that map tick-borne diseases using data on vectors, pathogens, and hosts (including wildlife, livestock, and human cases). We find that the …

Scoping Review Of Distribution Models For Selected Amblyomma Ticks And Rickettsial Group Pathogens, Catherine A. Lippi, Holly D. Gaff, Alexis L. White, Sadie J. Ryan

Biological Sciences Faculty Publications

The rising prevalence of tick-borne diseases in humans in recent decades has called attention to the need for more information on geographic risk for public health planning. Species distribution models (SDMs) are an increasingly utilized method of constructing potential geographic ranges. There are many knowledge gaps in our understanding of risk of exposure to tick-borne pathogens, particularly for those in the rickettsial group. Here, we conducted a systematic scoping review of the SDM literature for rickettsial pathogens and tick vectors in the genus Amblyomma. Of the 174 reviewed articles, only 24 studies used SDMs to estimate the potential extent …

Exploring The Niche Of Rickettsia Montanensis (Rickettsiales: Rickettsiaceae) Infection Of The American Dog Tick (Acari: Ixodidae), Using Multiple Species Distribution Model Approaches, Catherine A. Lippi, Holly Gaff, Alexis L. White, Heidi K. St. John, Allen L. Richards, Sadie J. Ryan

Biological Sciences Faculty Publications

The American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae), is a vector for several human diseasecausing pathogens such as tularemia, Rocky Mountain spotted fever, and the understudied spotted fever group rickettsiae (SFGR) infection caused by Rickettsia montanensis. It is important for public health planning and intervention to understand the distribution of this tick and pathogen encounter risk. Risk is often described in terms of vector distribution, but greatest risk may be concentrated where more vectors are positive for a given pathogen. When assessing species distributions, the choice of modeling framework and spatial layers used to make predictions are important. …

Varroa Destructor Mites Vector And Transmit Pathogenic Honey Bee Viruses Acquired From An Artificial Diet, Francisco Posada-Florez, Eugene V. Ryabov, Matthew C. Heerman, Yanping Chen, Jay D. Evans, Daniel E. Sonenshine, Steven C. Cook

Biological Sciences Faculty Publications

The ectoparasitic mite Varroa destructoris one of the most destructive pests of the honey bee (Apis mellifera) and the primary biotic cause of colony collapse in many regions of the world. These mites inflict physical injury on their honey bee hosts from feeding on host hemolymph and fat body cells/cellular components, and serve as the vector for deadly honey bee viruses, including Deformed wing virus (DWV) and the related Varroa destructor virus-1 (VDV-1) (i.e., DWV-like viruses). Studies focused on elucidating the dynamics of Varroa-mediated vectoring and transmission of DWV-like viruses may be confounded by viruses present in …

Identification Of Planktothrix (Cyanobacteria) Blooms And Effects On The Aquatic Macroinvertebrate Community In The Non-Tidal Potomac River, Usa, Joshua Henesy, Jennifer L. Wolny, John E. Mullican, Detbra S. Rosales, Joseph S. Pitula, Joseph W. Love

Virginia Journal of Science

Using transverse cross-sectional transects, a survey of 31 km of the non-tidal Potomac River was conducted from White’s Ferry, Virginia to Brunswick, Maryland, USA, between June and September in 2013 through 2015 to assess a recurring benthic cyanobacteria bloom. Abundant benthic cyanobacteria blooms were detected during the 2014 and 2015 sampling seasons and the primary taxon was identified morphologically and molecularly as Planktothrix cf. isothrix. When present, P. cf. isothrix blooms were concentrated from river center to the Maryland shoreline. This pattern was correlated with significantly greater benthic chlorophyll-a and phycocyanin concentrations. In an apparent response to …

Olfactory Behavioral Responses Of Mosquito Vectors To Select Attractants And Floral Scents As Related To Circadian Rhythms And Photoperiod Regimes, Bernadette A. Ferraro

Biomedical Sciences Theses & Dissertations

This dissertation discusses mosquito behavioral activities involving circadian rhythms defined as insect sensitivity to select of chemical volatiles that vary throughout the 24-hour day. Circannual rhythms occur over seasons varying in photoperiod, defined as the seasonal cycle of light and darkness. These cycles can be endogenously controlled by circadian clocks. The impetus for this research was initiated when reading about the neglected temporal dimension in the context of insect chemical ecology, including insect olfaction. It was proposed that sensitivity to odors does not change in general, but specific sensitivities could vary according to time of day. Chemical scents emitted by …

Lymesim 2.0: An Updated Simulation Of Blacklegged Tick (Acari: Ixodidae) Population Dynamics And Enzootic Transmission Of Borrelia Burgdorferi (Spirochaetales: Spirochaetaceae), Holly Gaff, Rebecca J. Eisen, Lars Eisen, Robyn Nadolny, Jenna Bjork, Andrew J. Monaghan

Biological Sciences Faculty Publications

Lyme disease is the most commonly reported vector-borne disease in the United States, and the number of cases reported each year continues to rise. The complex nature of the relationships between the pathogen (Borrelia burgdorferi sensu stricto), the tick vector (Ixodes scapularis Say), multiple vertebrate hosts, and numerous environmental factors creates challenges for understanding and predicting tick population and pathogen transmission dynamics. LYMESIM is a mechanistic model developed in the late 1990s to simulate the life-history of I. scapularis and transmission dynamics of B. burgdorferi s.s. Here we present LYMESIM 2.0, a modernized version of LYMESIM, that includes …

Insights Into The Feeding Behaviors And Biomechanics Of Varroa Destructor Mites On Honey Bee Pupae Using Electropenetrography And Histology, Andrew Y. Li, Steven C. Cook, Daniel E. Sonenshine, Francisco Pasada-Florez, Noble I.I. Noble, Joseph Mowery, Conner J. Gulbronson, Gary R. Bauchan

Biological Sciences Faculty Publications

Feeding behaviors and biomechanics of female Varroa destructor mites are revealed from AC-DC electropenetrography (EPG) recordings of mites feeding from Apis mellifera honey bee pupae and histology of mite internal ingestion apparatus. EPG signals characteristic of arthropod suction feeding (ingestion) were identified for mites that fed on pupae during overnight recordings. Ingestion by these mites was confirmed afterwards by observing internally fluorescent microbeads previously injected into their hosts. Micrographs of internal ingestion apparatus illustrate the connection between a gnathosomal tube and a pharyngeal lumen, which is surrounded by alternating dilator and constrictor muscles. Inspection of EPG signals showed the muscularized …

Pollinator Visitation Frequency Associated With Native And Non-Native Plants In A Mid-Atlantic Piedmont (Usa) Urban Garden, Nicholas J. Ruppel, Saunders M. Riley, Ellis D. Mumford, Barbara L. Swedo

Virginia Journal of Science

The recent focus on the importance of native plants and their pollinators has highlighted the critical role of local species in their natural environment. As urban encroachment, climate change, and invasive species continues to threaten native habitats, it is increasingly important to promote the use of local green spaces as refugia for native plants and their pollinators. The aim of this project, therefore, was to identify and assess the visitation frequency of insect pollinators associated with an urban setting within the Piedmont region of Virginia, and compare their association with native versus closely-related but non-native summer-flowering plants. Several modes of …

Vitellogenin Receptor As A Target For Tick Control: A Mini-Review, Robert D. Mitchell Iii, Daniel E. Sonenshine, Adalberto A. Pérez De León

Biological Sciences Faculty Publications

While much effort has been put into understanding vitellogenesis in insects and other organisms, much less is known of this process in ticks. There are several steps that facilitate yolk formation in developing oocytes of which the vitellogenin receptor (VgR) is a key component. The tick VgR binds vitellogenin (Vg) circulating in the hemolymph to initiate receptor-mediated endocytosis and its transformation into vitellin (Vn). The conversion of Vg into Vn, the final form of the yolk protein, occurs inside oocytes of the female tick ovary. Vn is critical to tick embryos since it serves as the nutritional source for their …

Review: Application Of Tick Control Technologies For Blacklegged, Lone Star, And American Dog Ticks, Alexis White, Holly Gaff

Biological Sciences Faculty Publications

Tick population control technologies have been studied for several decades but no method is successful in all situations. The success of each technology depends on tick species identity and abundance, host species identity and abundance, phenology of both ticks and hosts, geographic region, and a multitude of other factors. Here we review current technologies, presenting an overview of each and its effect on three common tick species in the eastern United States: blacklegged ticks (Ixodes scapularis (Say; Ixodida: Ixodidae)), lone star ticks (Amblyomma americanum (Linnaeus; Ixodida: Ixodidae)), and American dog ticks (Dermacentor variabilis (Say; Ixodida: Ixodidae)). Moreover, …

Using An In Vitro System For Maintaining Varroa Destructor Mites On Apis Mellifera Pupae As Hosts: Studies Of Mite Longevity And Feeding Behavior, Noble I. Egekwu, Francisco Posada, Daniel E. Sonenshine, Steven Cook

Biological Sciences Faculty Publications

Varroa destructor mites (varroa) are ectoparasites of Apis mellifera honey bees, and the damage they inflict on hosts is likely a causative factor of recent poor honey bee colony performance. Research has produced an arsenal of control agents against varroa mites, which have become resistant to many chemical means of their control, and other means have uncertain efficacy. Novel means of control will result from a thorough understanding of varroa physiology and behavior. However, robust knowledge of varroa biology is lacking; mites have very low survivability and reproduction away from their natural environment and host, and few tested protocols of …

Molecular Candidates For Blocking The Transmission Of Vector-Borne Diseases, Ashish Naresh Vora

Biological Sciences Theses & Dissertations

Vector-borne diseases (VBDs) require urgent attention as they have a high mortality rate, with 700,000 people dying in a year as of 2017. So far, extremely few reliable vaccination strategies and solutions have emerged. Transmission blocking vaccines are one among many solutions available to manage the control of VBDs. These require identification of both vector and pathogen molecules that play important roles in the transmission, dissemination and establishment of VBDs. Our strategy is to characterize these candidates that play important roles in vector-host-pathogen interactions. This manuscript presents two such studies identifying the participation of two arthropod molecules in vector-host-pathogen interactions. …

Strawberries (Frag X Anan) Are Bigger When Native Mason Bees (Osmia Lignaria) Are Experimentally Added To Small Farms, Laura A. Campbell

Biological Sciences Theses & Dissertations

Agriculture is the cornerstone of our economy, and pollination plays a vital role in nearly all non-wind pollinated crops. Declining honey bee populations have caused a more diligent investigation into using solitary bees for crop pollination. The native, solitary Orchard Mason Bee has shown to successfully pollinate almonds and apples, but there has been little work conducted on their effectiveness as a low fruit crop pollinator. This study assesses their effectiveness as a small strawberry farm pollinator, and preferences for nesting materials. Mason bee cocoons and nest homes made with different materials (bamboo, Phragmites, or wood) were supplemented on …

Foraging Behavior Of Spring Bees And Their Agricultural Implications, Michael D. Gregory

Biological Sciences Theses & Dissertations

Colony Collapse Disorder has greatly reduced honey bee populations in the last decade. Native bees have been largely neglected in research, and their floral preferences may have agricultural implications because native bees ameliorate the demand to rely solely on non-native bees. In this work, pollinator visitation to flowers with manipulated ultraviolet floral patterns was monitored. Populations of wild showy golden-eye in Colorado, plus cultivar populations of black-eyed Susan and lawn populations of buttercups in Virginia were monitored for pollinator landings to compare preference for unmanipulated ultraviolet-absorptive floral guide preferences. Another number, a proxy for pollen load, was manipulated on strawberry …

Tick Haller's Organ, A New Paradigm For Arthropod Olfaction: How Ticks Differ From Insects, Ann L. Carr, Robert D. Michell Iii, Anirudh Dhammi, Brooke W. Bissinger, Daniel E. Sonenshine, R. Michael Roe

Biological Sciences Faculty Publications

Ticks are the vector of many human and animal diseases; and host detection is critical to this process. Ticks have a unique sensory structure located exclusively on the 1st pairs of legs; the fore-tarsal Haller's organ, not found in any other animals, presumed to function like the insect antennae in chemosensation but morphologically very different. The mechanism of tick chemoreception is unknown. Utilizing next-generation sequencing and comparative transcriptomics between the 1st and 4th legs (the latter without the Haller's organ), we characterized 1st leg specific and putative Haller's organ specific transcripts from adult American dog ticks, Dermacentor variabilis. The …

Section Abstracts: Entomology

Virginia Journal of Science

Abstracts of the Entomology Section for the 94th Annual Virginia Academy of Science Meeting, May 18-20, 2016, at University of Mary Washington, Fredericksburg, VA.

A Hitchhiker’S Guide To Invasion Biology: Describing The Ecological Mechanisms Underlying The Range Expansions Of Two Ixodid Tick Species, Robyn M. Nadolny

Biological Sciences Theses & Dissertations

Increasing incidence of many tick-borne diseases have been linked to recent expansions of tick species distributions. Many tick species are expanding their ranges because of anthropogenic changes in the landscape, shifting climatic variables, and increasing populations of suitable host species and tick habitat. Few empirical studies have been performed, however, investigating the ecological mechanisms underlying these range expansions. Ticks are parasitic organisms that disperse across landscape by hitchhiking on hosts, but must then survive in the environment for long periods of time between bloodmeals. Two species of ixodid tick, Ixodes affinis and Amblyomma maculatum, are simultaneously expanding their ranges throughout …

Tick Genome Assembled: New Opportunities For Research On Tick-Host-Pathogen Interactions, Jose De La Fuente, Robert M. Waterhouse, Daniel E. Sonenshine, R. Michael Roe, Jose M. Ribeiro, David B. Sattelle, Catherine A. Hill

Biological Sciences Faculty Publications

As tick-borne diseases are on the rise, an international effort resulted in the sequence and assembly of the first genome of a tick vector. This result promotes research on comparative, functional and evolutionary genomics and the study of tick-host-pathogen interactions to improve human, animal and ecosystem health on a global scale.

Mevalonate-Farnesal Biosynthesis In Ticks: Comparative Synganglion Transcriptomics And A New Perspective, Jiwei Zhu, Sayed M. Khalil, Robert D. Mitchell, Brooke W. Bissinger, Noble Egekwu, Daniel E. Sonenshine, R. Michael Roe

Biological Sciences Faculty Publications

Juvenile hormone (JH) controls the growth, development, metamorphosis, and reproduction of insects. For many years, the general assumption has been that JH regulates tick and other acarine development and reproduction the same as in insects. Although researchers have not been able to find the common insect JHs in hard and soft tick species and JH applications appear to have no effect on tick development, it is difficult to prove the negative or to determine whether precursors to JH are made in ticks. The tick synganglion contains regions which are homologous to the corpora allata, the biosynthetic source for JH in …

Evidence Of Female Sex Pheromones And Characterization Of The Cuticular Lipids Of Unfed, Adult Male Versus Female Blacklegged Ticks, Ixodes Scapularis, Ann L. Carr, Daniel E. Sonenshine, John B. Strider Jr., R. Michael Roe

Biological Sciences Faculty Publications

Copulation in I. scapularis involves physical contact between the male and female (on or off the host), male mounting the female, insertion/maintenance of the male chelicerae in the female genital pore (initiates spermatophore production), and the transfer of the spermatophore by the male into the female genital pore. Bioassays determined that male mounting behavior/chelicerae insertion required direct contact with the female likely requiring non-volatile chemical cues with no evidence of a female volatile sex pheromone to attract males. Unfed virgin adult females and replete mated adult females elicited the highest rates of male chelicerae insertion with part fed virgin adult …

Determining The Prevalence And Distribution Of Tick-Borne Pathogens In Southeastern Virginia And Exploring The Transmission Dynamics Of Rickettsia Parkeri In Amblyomma Maculatum, Chelsea L. Wright Thompson

Biological Sciences Theses & Dissertations

Tick-borne pathogens are an increasing threat to human and animal health worldwide. In the United States, cases of Lyme disease, spotted fever rickettsioses, ehrlichiosis and anaplasmosis are on the rise. Factors related to emergence include appearance of a new pathogen, recognition of an existing pathogen and environmental changes that result in new exposure events. Despite the rise in tick-borne disease incidence within many states, including Virginia, there is a paucity of data related to the prevalence and distribution of ticks and tick-borne pathogens.

The first aim of this dissertation research was to determine the tick-borne pathogen composition within tick populations …

Perch Selection By Male Dragonflies (Odonata, Anisoptera) Related To Competitive Ability And Species Composition, Jessica L. Beard

Biological Sciences Theses & Dissertations

Males of many species of dragonflies (Odonata, Anisoptera) establish territories in aquatic habitats where they compete with other males for access to food and females. Territorial males typically perch on emergent vegetation and chase rival males who intrude into their territories. This dissertation research examined the role of male size in perch height selection, position on the perch, and competitive ability. Four hypotheses were tested: 1) Dragonfly species would vary by size and that territorial species would show sexual size dimorphism (SSD), 2) Perch height selection would be related to dragonfly size, 3) Position on the perch would be related …

Identification And Comparative Analysis Of Subolesin/Akirin Ortholog From Ornithodoros Turicata Ticks, Hameeda Sultana, Unnati Patel, Daniel E. Sonenshine, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Subolesin is an evolutionary conserved molecule in diverse arthropod species that play an important role in the regulation of genes involved in immune responses, blood digestion, reproduction and development. In this study, we have identified a subolesin ortholog from soft ticks Ornithodoros turicata, the vector of the relapsing fever spirochete in the United States.

Methods: Uninfected fed or unfed O. turicata ticks were used throughout this study. The subolesin mRNA was amplified by reverse transcription polymerase chain reaction (RT-PCR) and sequenced. Quantitative-real time PCR (QRT-PCR) was performed to evaluate subolesin mRNA levels at different O. turicata developmental stages …

The Role Of Chemical Attractants In The Use Of Tick Traps For Life Stages Of Tick Species Ixodes Scapularis, Dermacentor Variabilis And Amblyomma Maculatum, Pamela C. Kelman

Biological Sciences Theses & Dissertations

Amblyomma maculatum, Ixodes scapularis and Dermacentor variabilis are three of the hard-bodied ticks found in the United States. This study explored three aspects of the appetence process of these tick species: attraction, desiccation survival, and locomotive activity. The first portion of this work was to improve one of the standard methods used for collecting ticks from the environment, the tick trap. To determine the attractants needed to capture all life stages of the three chosen species of ticks in the field using tick traps, a series of experiments were conducted using laboratory-reared larval, nymphal and adult A. maculatum, I. scapularis …

Transcriptome Of The Female Synganglion Of The Black-Legged Tick Ixodes Scapularis (Acari: Ixodidae) With Comparison Between Illumina And 454 Systems, Noble Egekwu, Daniel E. Sonenshine, Brooke W. Bissinger, R. Michael Roe

Biological Sciences Faculty Publications

Illumina and 454 pyrosequencing were used to characterize genes from the synganglion of female Ixodes scapularis. GO term searching success for biological processes was similar for samples sequenced by both methods. However, for molecular processes, it was more successful for the Illumina samples than for 454 samples. Functional assignments of transcripts predicting neuropeptides, neuropeptide receptors, neurotransmitter receptors and other genes of interest was done, supported by strong e-values (<-6), and high consensus sequence alignments. Transcripts predicting 15 putative neuropeptide prepropeptides ((allatostatin, allatotropin, bursicon α, corticotropin releasing factor (CRF), CRF-binding protein, eclosion hormone, FMRFamide, glycoprotein A, insulin-like peptide, ion transport peptide, myoinhibitory peptide, inotocin ( = neurophysin-oxytocin), Neuropeptide F, sulfakinin and SIFamide)) and transcripts predicting receptors for 14 neuropeptides (allatostatin, calcitonin, cardioacceleratory peptide, corazonin, CRF, eclosion hormone, gonadotropin-releasing hormone/AKH-like, insulin-like peptide, neuropeptide F, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin) are reported. Similar to Dermacentor variabilis, we found transcripts matching pro-protein convertase, essential for converting neuropeptide hormones to their mature form. Additionally, transcripts predicting 6 neurotransmitter/neuromodulator receptors (acetylcholine, GABA, dopamine, glutamate, octopamine and …

Quantitative Factors Proposed To Influence The Prevalence Of Canine Tick-Bourne Disease Agents In The United States, Roger W. Stich, Byron L. Blagburn, Dwight D. Bowman, Christopher Carpenter, M. Roberto Cortinas, Sidney A. Ewing, Desmond Foley, Holly Gaff, Graham J. Hickling, R. Ryan Lash

Biological Sciences Faculty Publications

The Companion Animal Parasite Council hosted a meeting to identify quantifiable factors that can influence the prevalence of tick-borne disease agents among dogs in North America. This report summarizes the approach used and the factors identified for further analysis with mathematical models of canine exposure to tick-borne pathogens.