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Boarman, McKaila J. S.Trade-offs and Temporal Variation in Predator-Mediated Natural Selection and Sexual Selection on the Wings of the Damselfly Calopteryx splendens
Master of Science (MS), Ohio University, 2017, Biological Sciences (Arts and Sciences)
Evolutionary theory predicts a trade-off between sexual selection and natural selection on secondary sexual traits. Understanding the relationship between mating success and predation risk can give insight into the evolutionary dynamics that interact to promote or constrain phenotypic change, yet it has been little studied in the wild. I conducted a two-year cross-sectional field study on the Banded Demoiselle damselfly (Calopteryx splendens) to test for trade-offs between sexual selection and predation risk, and to assess variation in sexual and natural selection. At the study population, the White Wagtail (Motacilla alba) captures C. splendens in flight, then flies to feeding stations where it removes the wings and consumes the body. I used geometric morphometric techniques to quantify damselfly wing morphology, and compared wing shape and secondary sexual traits of wings from feeding stations to a random sample of wings from the population to quantify the strength, mode, and direction of natural selection on males. Simultaneously, I measured wing traits from individuals caught in the act of mating and compared them to a random sample of wings from the population to quantify the strength, mode, and direction of sexual selection on male wings. By comparing natural selection and sexual selection on wing traits simultaneously, I tested for trade-offs between types of selection. My results suggest that predator-mediated selection fluctuates through time, and is especially variable in how it operates on the size of secondary sexual traits displayed by males. Sexual selection operated almost exclusively on secondary sexual traits, and was consistent across years. Predator-mediated selection acted differently on fore- and hindwings, favoring males with long, narrow forewings and short, broad hindwings. A trade-off between natural and sexual selection was revealed on wing patch characteristics, with males possessing larger and darker wing patches experiencing higher predation rates, while achieving the highest mating success.

Committee:

Shawn Kuchta, PhD (Advisor); Willem Roosenburg, PhD (Committee Member); Kelly Johnson, PhD (Committee Member)

Subjects:

Animal Sciences; Biology; Ecology; Entomology; Evolution and Development

Keywords:

geometric morphometrics; selection trade-offs; predation; sexual selection; natural selection; Calopteryx splendens; selection gradient; selective agent; secondary sexual trait

Ndiaye, Susan GloriaBiological control of twospotted spider mite on hops in Ohio
Master of Science, The Ohio State University, 2018, Entomology

The twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae), is a key pest on hops. Hop production is a new industry in the Midwestern USA, and little is known about management of T. urticae in this region. During 2017, we conducted an exclusion trial at four hop yards in Ohio, to determine the services provided by predators already present in hop yards, as well as the ability of the combination of predatory mites, Neoseiulus fallacis and Neoseiulus californicus (Acari: Phytoseiidae), to effectively suppress T. urticae by augmentative releases. To determine the effectiveness of these predatory mites, three treatments were compared: a ratio of two predators per ten adult female T. urticae, a ratio of one predator per ten adult female T. urticae, and a ratio of zero predators per ten adult female T. urticae. Each treatment was established on paired leaves; one leaf was covered with a fine mesh bag and one leaf was left uncovered. After two weeks, the average number of spider mite motiles on the open leaves that received zero predators was significantly less than the initial ten released per leaf, suggesting that naturally occurring predators are capable of suppressing spider mite populations. The average number of spider mite motiles on the closed leaves that received two predators was also significantly less than ten per leaf showing that a ratio of one predator to five spider mites is effective at reducing spider mite populations.

During 2016, we conducted a trial to determine the efficacy of augmentative biological control to suppress T. urticae populations. Treatments compared were Neoseiulus fallacis and Galendromus occidentalis (Acari: Phytoseiidae), each released at a high and a low rate, with eight blocked replicates distributed over four hop yards. T. urticae populations were monitored on the cultivar `Cascade’. When populations reached a threshold of one T. urticae per ten leaves, predatory mites from a commercial insectary were released. Treatment had a significant effect on hop yield, but when we separated it by site, the yields only differed among treatments at two of the three sites. At both of these sites, the yields from the high release rate of both N. fallacis and G. occidentalis were greater than the yield of the control treatment. During 2017, a similar augmentation study was done using earlier and more intense sampling, to ensure early detection of spider mites in a system where mite density varied widely. Treatments compared N. fallacis released at a high rate and a low rate in 17 replicates. Yields did not differ significantly among treatments.

Our studies show that when spider mites are found at low to moderate densities, natural occurring predators are able to suppress their populations in Ohio hop yards. Although spider mite populations never reached economically damaging levels, augmentation using predatory mites did affect the yields at two of our eight sites. Naturally occurring predators were documented to be important in the suppression of spider mite populations and we propose that future studies should focus on biological control by conservation rather than augmentation.

Committee:

Celeste Welty (Advisor); Mary Gardiner (Committee Member); Hans Klompen (Committee Member); Elizabeth Long (Committee Member)

Subjects:

Agriculture; Entomology

Keywords:

spider mites; Tetranychus urticae; hops; biological control; augmentation; Neoseiulus fallacis; Galendromus occidentalis; predatory mites; midwest

Whitehead, Hannah RVarroa mite management among small-scale beekeepers: Characterizing factors that affect IPM adoption, and exploring drone brood removal as an IPM tool
Master of Science, The Ohio State University, 2017, Environmental Science
Varroa mites (Varroa destructor) are the most damaging pest in modern beekeeping, and have been linked with elevated levels of colony loss. Experts increasingly recommend an integrated pest management (IPM) strategy to manage Varroa, which incorporates both preventative and therapeutic controls. However, Varroa IPM is complicated and knowledge-intensive. Small-scale beekeepers in particular seem to have difficulty adopting effective Varroa control strategies, and suffer especially high rates of colony loss. This study took an interdisciplinary approach to understanding the adoption of Varroa IPM among small-scale beekeepers. First, I used surveys and interviews to characterize mite management strategies among Ohio small-scale beekeepers, and to explore the effect of experience and risk perception on behavior. Second, as a case study, I took a closer look at the efficacy and adoption of one complex IPM tool – drone brood removal (DBR) – through interviews, surveys, and an on-farm trial. Overall, I found no relationship between beekeeping experience and mite management strategies, but sampling (risk perception) was associated with the use of “soft” miticides (organic acids/essential oils) and DBR. I also found that most beekeepers who used DBR combined it with drone sampling (adjusting DBR based on sampled mite levels), and that labor was the biggest barrier to DBR use. In the on-farm trial, DBR significantly reduced mites in year one but not year two. These results suggest that mite management failures among small-scale beekeepers are not due to inexperience and may indicate a broader communication breakdown. They also suggest that risk perception – beekeepers’ understanding that they even have mites – may be a key factor driving adoption of mite management practices. Finally, they point to the fact that DBR is already being used in nuanced ways as a combined management and sampling strategy. They suggest that DBR is not a silver bullet, but can be an effective tool to reduce mites if used consistently, intensively, and in combination with other management tactics.

Committee:

Casey Hoy, Ph.D. (Advisor); Reed Johnson, Ph.D. (Committee Member); Anna Willow, Ph.D. (Committee Member)

Subjects:

Agriculture; Entomology; Environmental Science

Keywords:

varroa mite; mite management; mite sampling; drone brood removal; IPM; sustainable agriculture; beekeeping; farmer decision-making; risk perception; honey bee

Buzzelli, ChristopherCue processing and spatial navigation in the terrestrial isopod
Doctor of Philosophy, University of Akron, 2017, Psychology-Adult Development and Aging
Survival for the individual and for the continuation of the species requires processing spatially derived information and responding adaptively. Thus, the physiological, cognitive, and behavioral processes that serve spatial navigation are considered core abilities in living organisms. Prior to this work, the spatial abilities of the monophyletic terrestrial isopod were unknown. A series of spatially based experiments discovered the cues terrestrial isopods use to navigate and an ability to learn. The first experiment manipulated the availability of the visual nest cues to discover that terrestrial isopods use visual information to locate a target by manipulating the availability of the visual information that identified the nest. This experiment eliminated olfaction and substrate color as cue sources. The second experiment revealed the ability to locate a target is affected by the extra maze environment and nest color. These findings implicate the visual system of the terrestrial isopod is adept at using proximal and distal cues provided the contrast of the target to the background does not exceed their resolving ability. Additionally, this experiment revealed that under the proper conditions of contrast, the performance of the terrestrial isopod improved over time indicating the presence of learning. The third study found the terrestrial isopod capable of detecting visual information under a wide luminance range from 2.5 lux to modest light of 300 lux. The visual system of the species was not effective in near dark conditions of 0.5 lux. The fourth experiment by manipulating the ommatidia and tactile apparatuses of the terrestrial isopods verified that information via the ommatidia guide navigation and that antennae do not contribute to the ability to locate a target. The last experiment sought to explore the learning potential of Onsicidean isopods by reducing their proclivity for positively thigmokenetic behavior by creating a special arena that featured a water perimeter. Following 5 rewarded trials, isopods successfully discriminated between the nest encountered during training and a decoy nest on an unrewarded probe trial. This experiment is the first to discover discrimination-based learning in the suborder Oniscidea.

Committee:

Kevin Kaut, Ph.D (Advisor)

Subjects:

Entomology; Psychology

Keywords:

Isopod; terrestrial isopod; spatial navigation; learning; invertebrate learning; discrimination learning; vision; visual system; ommatidia; Oniscidea; maze; aversive maze;

Zhang, Mei-LingA maternal effect that influences pupal diapause in progeny of the flesh fly, Sarcophaga Bullata Parker (Diptera: Sarcophagidae) /
Doctor of Philosophy, The Ohio State University, 1994, Graduate School

Committee:

Not Provided (Other)

Subjects:

Entomology

Michaels, Simone ColetteDevelopment and Assessment of Artificial Manduca sexta Forewings: How Wing Structure Affects Performance
Master of Sciences (Engineering), Case Western Reserve University, 2016, EMC - Aerospace Engineering
This research presents novel fabrication and testing techniques for artificial insect wings. A series of static and dynamic assessments are designed which allow consistent comparison of small, flexible wings in terms of structure and performance. Locally harvested hawk moths are tested and compared to engineered wings. Data from these experiments shows that the implemented replication method results in artificial wings with comparable properties to that of M. sexta. Flexural stiffness (EI) data shows a considerable difference between the left and right M. sexta wings. Furthermore, EI values on the ventral wing side are found to be consistently higher than the dorsal side. Based on dynamic results, variations in venation structure have the largest impact on lift generation. Lift tests on individual wings and wing sets indicate detrimental effects as a result of wing-wake interaction.

Committee:

Roger Quinn (Advisor); Mark Willis (Committee Member); Richard Bachmann (Committee Member)

Subjects:

Aerospace Engineering; Aerospace Materials; Biology; Engineering; Entomology; Mechanical Engineering

Keywords:

Manduca sexta; artificial wings; wing fabrication; biomimicry

Zhou, YuchengCultivated and Wild Highbush Blueberry Composition and Influence of Brown Marmorated Stink Bug Infestation on Its Anthocyanin and Phenolics Accumulation
Master of Science, The Ohio State University, 2015, Food Science and Technology
Blueberry was firstly domesticated almost 100 years ago. In the past century, the cultivated blueberries have gradually owned some desirable characteristics by selection. Field observations on blueberry revealed differences in insect selection preference exhibited between cultivated and wild highbush blueberries. However, little is known about the link between insect selection and domestication. There are a number of pests that can infect blueberries, and the brown marmorated stink bug (BMSB) is a potential serious pest for them. Some studies have focused on the blueberries feeding injury caused by BMSB, few works have studied the response of the blueberry plant to this pest, so little is known about influence of BMSB infestation on blueberry secondary metabolites, especially anthocyanin and phenolics accumulation. In this research, cultivated and wild highbush blueberries in New Jersey were analyzed comparatively to determine their quality attributes including pH, total soluble solids and individual weight, as well as their content of anthocyanin and phenolics. Samples were collected from 8 different locations to determine the interaction between domestication and location. Result showed that cultivated highbush blueberry had bigger fruit weight and higher pH value than wild blueberries, while wild blueberries were with higher anthocyanin and phenolic content. The growing location also affected pH and phenolic content of blueberry. The influence of BMSB infestation on highbush blueberry sugar, anthocyanin and phenolic accumulation was also determined in this experiment. Blueberries provided by the Marucci Blueberry and Cranberry Research and Extension Center in New Jersey were either mechanically damaged or infected by 0, 2, 5 or 10 adult or nymph BMSB and were collected at select time points from 3 different plots. UV-Vis spectrophotometry was applied for anthocyanins and phenolics quantitative analysis. The HPLC chromatographs were recorded to determine compositional differences among samples. The results showed that when samples were compared at similar maturity degree, the 2 or 5 nymph BMSB infestation stimulated blueberries to produce more phenolic compounds, and modified the proportion of certain individual anthocyanins, with little effect on anthocyanin content and sugar profile.

Committee:

M.Monica Giusti (Advisor); Luis Rodriguez-saona (Committee Member); Jiyoung Lee (Committee Member)

Subjects:

Entomology; Food Science

Keywords:

BMSB; Vaccinium; domestication; phenolics

Rigsby, Chad MichaelMechanisms of Antixenosis and Antibiosis of Ash Against Emerald Ash Borer
Doctor of Philosophy (PhD), Wright State University, 2016, Environmental Sciences PhD
Emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae), is an invasive forest pest causing widespread mortality of ash (Fraxinus spp.) in North America. Host resistance research and the development of resistant hosts offers a promising strategy for the long-term conservation of ash and management of EAB. Manchurian ash (F. mandshurica) shares an evolutionary history with EAB in Asia, resulting in its greater resistance relative to naive North American ashes. In the following studies I investigate antixenosis and antibiosis mechanisms of resistant and susceptible ashes. Antixenosis in Manchurian ash was demonstrated by quantifying substantially lower oviposition on this species relative to North American ashes. The potential underlying mechanisms of antixenosis were addressed by profiling the bark and canopy volatile organic compounds (VOCs) emitted by susceptible black (F. nigra) and resistant Manchurian ashes and major species differences in VOC profiles were demonstrated. To address antibiosis, the physiological responses of EAB larvae that had fed on Manchurian, white (F. americana), and green (F. pennsylvanica) ash were quantified. It was found that antioxidant and quinone-protective enzyme activities of larvae feeding on Manchurian ash were substantially higher, suggesting that larvae feeding on Manchurian ash experience relatively high levels of reactive oxygen species and quinone stress. Manchurian ash demonstrated substantially higher activities of defense-associated enzymes and reactions than black ash, especially phenolic-oxidizing enzymes. These results support the conclusions of the larval physiology study that Manchurian ash appears to be able to generates greater amounts of quinone- and ROS-stress in vivo than North American ashes. Lastly, larval performance and bark phenolic chemistry and physiology were compared for Manchurian ash that were experimentally girdled or not. Girdling reduced larval performance by half but bark defenses did not differ by treatment indicating that decreases in larval performance are associated with factors other than a reduction in levels of host defenses. It was concluded that Manchurian ash expresses antixenosis, which may be driven by the emission of certain volatiles. Also, that antibiosis appears to be related to the ability of Manchurian ash to generate an oxidatively stressful diet for larvae and larval success in compromised trees does not stem from a reduction in defense levels.

Committee:

Don Cipollini, Ph.D. (Advisor); John Stireman, Ph.D. (Committee Member); Pierluigi Bonello, Ph.D. (Committee Member); Daniel Herms, Ph.D. (Committee Member); Thaddeus Tarpey, Ph.D. (Committee Member)

Subjects:

Biology; Ecology; Entomology; Plant Biology

Keywords:

biology;entomology;plant biology;ecology

Sigal, Marvin DavidThe water balance physiology of the lone star tick, Amblyomma americanum (Acari; ixodoidea), with ecophysiological comparisons to other ixodid species
Doctor of Philosophy, The Ohio State University, 1990, Entomology
none

Committee:

Glen R. Needham (Advisor)

Subjects:

Entomology

Chen, YutingMolecular interactions between Maize fine streak virus and insect vector, Graminella nigrifrons
Doctor of Philosophy, The Ohio State University, 2013, Entomology
Phytophagous hemipteran insects are suitable vectors for plant viruses, such as plant-infecting rhabdoviruses, which have caused severe yield loss. These single-stranded negative RNA viruses are specifically transmitted by hemipteran insects in a circulative propagative manner. My research investigated the vector-virus interactions using the black-faced leafhopper Graminella nigrifrons and an emerging plant-infecting rhabdovirus, Maize fine streak virus (MFSV) from molecular, genetic and ecological perspectives. G. nigrifrons is the only identified vector for MFSV, and vector competence varies within laboratory populations. G. nigrifrons can be experimentally separated into three types based on their ability to transmit MFSV: transmitters, which can transmit MFSV to new host plants; acquirers, which are positive MFSV, but do not transmit the virus; and non-acquirers, which are neither positive for nor able to transmit the virus. My research focused on how antiviral immunity responds to MFSV challenge among different types of G. nigrifrons, which was proposed to associate with vector competence. The transcriptome of G. nigrifrons was first characterized, and a significant similarity of immune response transcripts was discovered with other well-characterized insects. Expression of ten transcripts that putatively functioned in insect RNAi and humoral pathways was evaluated among three types of G. nigrifrons using RT-qPCR: Ars-2, Dcr-2, Ago-2, four PGRPs (SB1, SD, LB and LC), Toll, spaetzle and defensin. Overall down regulation was seen in MFSV challenged leafhoppers. In particular, Ars-2, Dcr-2 and Ago-2 were significantly suppressed in acquirers and non-acquirers compared to transmitters or control (MFSV unchallenged) leafhoppers. Expression of three PGRPs (SB1, SD, and LC) and Toll were similar in all MFSV challenged leafhoppers but was significantly suppressed compared to control. Genetic variation of RT-qPCR evaluated transcirpts was analyzed among three types of G. nigrifrons. A non-synonymous SNP in the MFSV-N gene was identified only in transmitters. However, there was no correlation between differentially expressed immune transcripts and the presence of putative synonymous/non-synonymous SNPs. RNAi was successfully developed to investigate the functions of PGRP-LC and Dcr-2 related to virus acquisition and transmission. Expression of PGRP-LC and Dcr-2 was reduced to 30% and 20% of levels in control leafhoppers respectively, after 14 and 22 dpi of dsRNAs. The reduction in expression was equally effective for both nymphs and adults. There was no effect on MFSV transmission or acquisition between non-injected or dsRNAs for GFP and PGRP-LC or Dcr-2 injected leafhoppers, however, acquisition was slightly higher in Dcr-2 silenced leafhoppers. Silencing PGRP-LC resulted in 90% mortality before MFSV could be transmitted. A significantly higher number of abnormally molted; leafhoppers were observed after silencing PGRP-LC. Higher temperature and light intensity tended to increase MFSV transmission during 1-week inoculation access period. There was no difference of transmission between insect genders under different environmental treatments. To conclude, my research revealed complex vector-virus-plant interactions at the molecular, genetic and environmental levels. Successful use of RNAi to decrease G. nigrifrons transcript levels may provide possible targets of RNAi-based pest management.

Committee:

Andrew Michel (Advisor); David Denlinger (Committee Member); Omprakash Mittapalli (Committee Member); Margaret Redinbaugh (Committee Member)

Subjects:

Entomology

Keywords:

Maize fine streak virus; Graminella nigrifrons; insect immune response; RNAi; environmental factors

Ravisankar, PadmapriyadarshiniContributions of abrupt in the evolution of beetle elytra
Master of Science, Miami University, 2012, Zoology
Morphological innovation is a fundamental process in evolution, yet its molecular basis is still elusive. Acquisition of elytra, highly modified beetle forewings, is an important innovation that has driven the successful radiation of beetles. Our RNAi screening for candidate genes has identified abrupt (ab) as a potential key player in elytron evolution. In this study, we performed a series of experiments in both Tribolium and Drosophila to understand the contributions of ab in the evolution of beetle elytra. We found that ab has gained a novel function in determining the unique elytron shape. We also found an essential function of ab in the Notch signal-associated wing formation process, which has been conserved between Tribolium and Drosophila. Hence, ab has gained a new function during elytron evolution without compromising the conserved wing-related functions. Gaining a new function without losing evolutionarily conserved functions appears to be a key theme in the evolution of morphologically novel structures.

Committee:

Yoshinori Tomoyasu, PhD (Advisor); David Pennock, PhD (Committee Member); Katia Del Rio-Tsonis, PhD (Committee Member)

Subjects:

Biology; Developmental Biology; Entomology; Molecular Biology; Zoology

Keywords:

abrupt; elytron; Tribolium castaneum; RNAi

Neal, Stacy RaeThe Evolution of Phenotypic Variation in Anabrus simplex (Orthoptera: Tettigoniidae): Shape Differences in Morphology and Patterns of Morphological Integration in Mormon crickets
MS, Kent State University, 2009, College of Arts and Sciences / Department of Biological Sciences
Mormon crickets (Anabrus simplex) are flightless North American shield-backed katydids that exist with a broad range of phenotypic variation including coloration, body size, movement behavior, and male calling behavior. Population types of Mormon crickets are classified as band-forming, non-band-forming, or intermediate based on estimated population density and movement behavior. Despite marked differences in morphology and behavior, these population types are still considered the same species although there is some evidence suggesting that they are genetically distinct (Bailey et al 2005). Mormon cricket morphology has been systematically described in terms of allometric, or size-correlated differences in shape between populations of Mormon crickets. The patterns of relationships between morphological characters have also been examined using morphological integration to see how they have changed over evolutionary time. Twenty-three morphological features of Mormon crickets collected from five populations in 2008 were measured and compared to the geometric mean for each individual. Shape differences by sex and by population type were tested for significance using two-way ANOVA. Principal component analysis of the covariance matrices was employed for data reduction and to explore the interactions between characters among BF and NBF Mormon crickets in terms of variance explained by size and shape versus shape alone. Correlation analysis was employed to test the relationships between morphological characters and movement patterns. Seven hypotheses of differences in covariation structure, or integration, were tested by constructing correlation matrices of the morphological variables and subjecting them to matrix correlations and Mantel tests. Integration patterns were discussed in terms of shape differences in morphology, local ecological conditions, and selection pressures by population.

Committee:

Patrick Lorch, PhD (Advisor); Christopher Vinyard, PhD (Committee Member); Mark Kershner, PhD (Committee Member)

Subjects:

Animals; Behaviorial Sciences; Biology; Biostatistics; Ecology; Entomology

Keywords:

Orthoptera; Tettigoniidae; Mormon crickets; Allometry; Geometric mean; Shape ratios; Morphological integration

Breidenbaugh, MarkTesting Effects of Aerial Spray Technologies on Biting Flies and Nontarget Insects at the Parris Island Marine Corps Recruit Depot, South Carolina, USA
PHD, Kent State University, 2008, College of Arts and Sciences / Department of Biological Sciences
Biting flies are pests and potential vectors at the Marine Corps Recruit Depot, South Carolina (PIMCRD). To prevent the disruption of military training, aerial pesticide applications using a US Air Force (USAF) C-130H are made. Biting midge (Ceratopogonidae) and mosquito (Culicidae) seasonal abundance and diel activity patterns were analyzed on the PIMCRD using CO2-baited suction traps from November 2001 – November 2004. Eighteen mosquito and 3 biting midge species were collected with Aedes taeniorhynchus the most abundant mosquito (42.7% of total) and Culicoides furens the most abundant (86.2% of total) biting midge. Activity of most biting midges and mosquitoes were highest the first 2 hours following sunset. Species of biting flies were present in all months. A new fuselage boom configuration on the USAF C-130H aircraft was characterized to determine the droplet spectra produced with flat-fan nozzles (8001, 8005). Across all trials, median droplet diameter for 8001 and 8005 nozzles were 11.4 µm and 54.3 µm, respectively. In addition, biting midge and mosquito mortality were analyzed with public health insecticides. Mosquito mortality was 100% 639 m downwind in single pass trials using bioassay cages and Dibrom. In wide-area applications of Dibrom, an 83-86% reduction of biting flies was observed. Overall, these field trials indicated that this new fuselage boom configuration creates effective droplet sizes and swath widths (i.e., 610 m) for USAF aerial vector control at the PIMCRD and elsewhere. Responses of nontarget insects to aerial pesticide applications were also studied. Malaise traps and yellow pan traps were used to determine nontarget insect diversity and abundance with before and after impact analysis. Total nontarget insect abundance was lower after sprays in Malaise trap collections in 2003 (P < 0.025), with these numbers decreasing by about 50%. However, there were no differences in total numbers after sprays in pan traps in 2005 (P = 0.756). Shannon diversity indices were not different after sprays in either year indicating that sprays had minimal impact on overall community biodiversity. Results indicate that there are some impacts on nontarget species from aerial sprays but applying sprays at dusk helps minimize these impacts while still controlling biting flies.

Committee:

Ferenc de Szalay, PhD (Committee Chair); Benjamin Foote, PhD (Committee Member); Mark Kershner, PhD (Committee Member); Scott Sheridan, PhD (Committee Member)

Subjects:

Ecology; Entomology; Public Health

Keywords:

vector control; biting midges, mosquitoes, Culicidae, Ceratopogonidae, Culicoides, adulticiding; AGDISP; droplet characterization

Hwang, Kai-Lun H.Physiological diversity and temperature hardening in adult tick dermacentor variabilis (ACARI: IXODIDAE)
Master of Arts, The Ohio State University, 2006, Entomology
Ticks employ an array of survival traits in response to adverse environmental conditions including behavior, active water-vapor uptake, integumental restriction of water loss, slow metabolism/respiration, and tolerance of temperature extremes. This dissertation studied the rapid heat hardening and rapid cold hardening traits, which increase tolerance to temperature extremes in Dermacentor variabilis. An unexpected physiological diversity was found in our studies, which added an interesting dimension to the project. Ultimately, survival experiments demonstrated that there was a seasonal (summer vs. winter) or ‘batch’ effect, apparently caused by when ticks were laboratory reared. In high temperature (45 °C) survival studies, high and low temperature cross-tolerance was ambiguous in summer-acclimated ticks whereas it was clearly demonstrated in winter-acclimated ticks. Likewise, in low temperature (-10 °C) survival studies, the high and low temperature cross-tolerance was clearly demonstrated in summer ticks, but not in winter ticks. Seasonal acclimation seems to play a principle role, while rapid hardening adds supplemental benefits by protecting D. variabilis against high and low temperature injuries. Two clones of Hsp70 were identified and characterized in D. variabilis and named Hsp70S (short form, 1540 bp) and Hsp70L (long form, 1727 bp). Hsp70S and Hsp70L share 95% nucleic acid sequence identity with the differences at their 3’ ends. They share 81% nucleic acid identity and 87% amino acid similarity with an Hsp70 of the deer tick, Ixodes scapularis. The Northern expression of Hsp70S was much higher compared to Hsp70L in response to high temperature exposures. Synthesis of Hsp70 in response to cold- and desiccation-acclimation was slight and delayed. Neither the field collected natural population (in summer) nor the outdoor acclimated (in winter) lab-reared ticks showed any higher level of Hsp70 expression than the controls. Rapid hardening correlates with concomitant increases in hemolymph osmotic pressure, glycerol and sorbitol concentrations in D. variabilis. Glycerol plays a significant protective role for D. variabilis against low and high temperature injuries. Sorbitol might play a secondary role, but its concentration is only thousandth of glycerol. This study increases our understanding of this tick’s survival traits and helps explain its impressive diversity in northern temperate America.

Committee:

Glen Needham (Advisor)

Subjects:

Biology, Entomology

Robich, Rebecca MMolecular characterization of adult diapause in the northern house mosquito, Culex Pipiens
Doctor of Philosophy, The Ohio State University, 2005, Entomology
One of the primary avian vectors of West Nile virus in the northern United States, Culex pipiens (L.), enters an adult diapause in late summer and early fall in response to short daylength and low temperature. The mosquitoes first appear in overwintering sites such as caves, culverts, and unheated basements as early as August and remain there until spring when environmental conditions again become favorable for development. Only females enter diapause and most are inseminated prior to entering the hibernation site. In preparation for diapause, females increase their lipid reserves by feeding on sugar-rich sources such as nectar and rotting fruit. Although females programmed for diapause can be enticed to take a blood meal by being placed in close proximity to a host, it appears this rarely, if ever, happens in the field. Failure of diapausing females to take a blood meal is presumably the reason that so few of the overwintering females harbor West Nile virus. Many aspects of diapause in Cx. pipiens have been well documented. There is a good database that describes the physiological features of this diapause, its environmental regulators, and the hormonal control mechanism. What is currently lacking is an understanding of its molecular underpinning. In this study, suppressive subtractive hybridization (SSH) is used to identify genes that are differentially expressed during the adult diapause of Cx. pipiens. Expression patterns are confirmed by northern blot hybridization, and the regulated genes that have been identified are discussed in the context of their possible functional contributions to diapause.

Committee:

David Denlinger (Advisor)

Subjects:

Biology, Entomology

Keywords:

Culex pipiens; mosquito; adult diapause; overwintering; gene expression

Bell, Ryan D.Impact of Relative Humidity on the Biology of Pardosa milvina Hentz, 1844 (Araneae: Lycosidae)
Master of Science, The Ohio State University, 2009, Entomology

Pardosa milvina is a small wolf spider commonly associated with agricultural ecosystems. P. milvina produces dragline silk that is attached to the substrate over which it moves, but is not used in capturing prey. The effect relative humidity on P. milvina behavior and biology was examined through a series of experiments. The water balance constraints of P. milvina were studied to determine its body water content and its water loss rate at 0% RH. The calculated water loss rate is comparable to that of other terrestrial arthropods, and body water content was similar to other Pardosa spp. To examine the degree to which prey items are utilized as a water source, a study was conducted to determine if dehydrated spiders were more likely to take prey than hydrated spiders of comparable satiation levels. The individuals tested did not show an increase in prey taking when under water stress, as no spiders in either treatment took prey. Although they did not take prey, the dehydrated spiders regained a significantly greater mass when presented with water, indicating that free-standing water sources are preferred over prey if the spider is not hungry.

The effect of relative humidity on silk deposition was examined, which necessitated the development of a technique for visualizing the silk. A difference in silk production between spiders maintained at different relative humidity levels was not found. Although there was no difference between relative humidity treatments, an analysis of a subset of individuals by mating status did reveal a difference in silk deposition between mated and virgin females. Virgin females deposited significantly more silk than mated spiders.

Committee:

Glen Needham (Advisor); David Horn (Committee Member); Richard Bradley (Committee Member)

Subjects:

Entomology

Keywords:

desiccation; water balance; wolf spider

Smith, Chelsea A.Testing an Interference Competition Hypothesis to Explain the Decline of the Convergent Lady Beetle, Hippodamia convergens (Coleoptera: Coccinellidae), in Ohio
Master of Science, The Ohio State University, 2012, Entomology
A significant decline in the abundance of the native coccinellid, Hippodamia convergens, coincides with the establishment and population increase of exotic coccinellids in Ohio. This pattern has lead to the hypothesis that intraguild predation by exotic lady beetles explains this decline. Several laboratory experiments demonstrating the propensity of exotic lady beetles to act as predators of native coccinellid eggs provide support for this hypothesis. The goal of this research was to determine the extent that exotic lady beetles predate on native coccinellid egg masses in the field. Two studies conducted over the course of three field seasons (2009-11), are presented in Chapters 2 and 3. Chapter 2 examines the extent of predation on coccinellid egg masses, and the role of coccinellids as egg predators. The objectives were to 1) compare the extent of egg predation experienced by three coccinellid species: H. convergens, Coleomegilla maculata, and Harmonia axyridis; 2) examine the levels of egg predation occurring across three habitats; and 3) determine the guild of predators responsible for coccinellid egg predation. To address these objectives, egg predation experiments were conducted in habitats where coccinellids are commonly found foraging: grassland, alfalfa, and soybean. Eggs of each focal coccinellid species were placed in the fields for 48 hours. The proportion of eggs remaining was compared among coccinellid species and habitats. Egg masses from the increasingly-rare native coccinellid, H. convergens, incurred significantly greater predation than eggs from the common exotic coccinellid, H. axyridis. Predation of the egg masses from the three species varied across habitats with the greatest amount of predation occurring in grasslands and the least in alfalfa. These egg predation experiments provided supporting evidence for the IGP hypothesis. Video surveillance systems were placed in the field and focused on coccinellid egg masses. These preliminary video experiments provided evidence that exotic coccinellids are not common predators of the egg masses. Chapter 3 details video experiments conducted to determine patterns among the predators contributing to coccinellid egg predation. The objectives of this study were to 1) measure the relative abundance and activity density of coccinellid egg predators present within the focal habitats 2) document the contribution of predator taxa to native and exotic lady beetle egg predation within each foraging habitat; and 3) determine if the relative abundance of aphids affects the intensity of egg predation. To address these objectives, video systems were used to observe predation of H. convergens and H. axyridis egg masses in soybean, alfalfa, and grassland habitats. The relative abundance and activity density of aphids and egg predators was also determined using quadrats, sweep samples, and pitfall traps. From the video observations, the guild of predators detected included Stylommatophora, Opiliones, Oniscidea, Coccinellidae, Gryllidae, Neuroptera, Tettigoniidae, Acrididae, Formicidae, Nabidae, Thripidae, Syrphidae, Araneae, Staphylinidae, and Diplopoda. This guild varied in diversity across the habitats, with the greatest diversity found within grassland habitats. Redundancy analysis revealed two egg predators that maintained a constant pattern of predation across both 2010 and 2011: Formicidae and Oniscidea.

Committee:

Mary Gardiner, PhD (Advisor); John Cardina, PhD (Committee Member); Daniel Herms, PhD (Committee Member); Andrew Michel, PhD (Committee Member)

Subjects:

Biology; Conservation; Ecology; Entomology

Keywords:

intraguild predation; egg predation; biological control; Hippodamia convergens; Harmonia axyridis; Coccinellidae

Cusser, SarahThe restoration of plant-pollinator mutualisms on a reclaimed strip mine
Master of Science, The Ohio State University, 2011, Evolution, Ecology and Organismal Biology
Plant-pollinator mutualisms are one of several functional relationships that must be reinstated to ensure the long-term success of habitat restoration projects. However, these mutualisms are not likely to reinstate themselves until the very particular resource requirements of pollinators have been met. By giving special attention to these requirements, habitat restoration projects are more likely to be successful in the long-term. I used network analysis to determine how aspects of the restoration effort itself influence the reestablishment and organization of plant-pollinator communities at an experimentally restored site in Central Ohio. Specifically, I investigate the influence of landscapes factors, floral diversity and the role of non-native plants on the structure and stability of plant-pollinator networks. I found that the diversity and distribution of floral resources affect the organization and stability of plant pollinator networks. Plots with high floral diversity far from remnant habitat compensated for loses in pollinator diversity by attracting generalized pollinators, which increase network redundancy and robustness. I also found that non-native plants play a central role in the structure of networks. I conclude that aspects of the restoration effort itself can be successfully tailored to incorporate the restoration of pollinators.

Committee:

Karen Goodell (Advisor); Elizabeth Marschall (Committee Member); Allison Snow (Committee Member); Mary Gardiner (Committee Member)

Subjects:

Ecology; Entomology

Keywords:

Pollination; Restoration; Strip mine; Network Analysis

Medina-Ortega, Karla JacquelinePoinsettia (Euphorbia pulcherrima Willd. ex Klotzsch: Euphorbiacea) Resistance Mechanisms against the Silverleaf Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Biotype B
Doctor of Philosophy, The Ohio State University, 2011, Entomology
The silverleaf whitefly (Bemisia tabaci biotype B) is the main insect pest of poinsettias (Euphorbia pulcherrima). Among potted plants, poinsettias rank first in sales across the nation. Control of whiteflies in greenhouses is primarily with insecticides; therefore, mechanisms of resistance in poinsettias are not well understood and have not been thoroughly studied. The goal of this research was to determine if poinsettia cultivars possess physical and chemical factors/traits affecting the behavior and physiology of the silverleaf whitefly and to some extent evaluate tritrophic interactions. The objectives were to (1) determine silverleaf whitefly behavioral preference for, and performance on different cultivars through choice and no-choice assays; (2) evaluate physical traits possibly mediating resistance, including visual cues by excluding light, leaf thickness, and leaf color indirectly via chlorophyll content using a SPAD meter, and with the use of a color reader; (3) determine free amino acids and phenolic compounds potentially involved in mediating resistance to B. tabaci; (4) evaluate tritrophic interactions by comparing Eretmocerus mundus parasitism preference between B. tabaci nymphs from a more and a less susceptible poinsettia cultivars. Behavioral preference of B. tabaci varied among cultivars, but cultivars with light green leaves were preferred than cultivars with dark green leaves. Leaf color appeared to be influenced by chlorophyll content and leaf thickness. Cultivars with light green leaves had less chlorophyll and had thinner leaves. Trichome density was not significantly different among the cultivars. Visual cues were important in recognition of a more susceptible host in the presence indicating leaf color of poinsettia plants plays a key role in recognition by B. tabaci. Cultivars were similar in the composition and concentration of amino acids, and cultivars with light green leaves averaged a higher concentration of amino acids. Concentration of individual phenolic compounds, in both leaf and petioles, were higher in a less susceptible cultivar (cv [‘Freedom Red’]) with dark green leaves, and where fertility of B. tabaci was lower, than on a more susceptible cultivar (‘Monet Twilight’) with light green leaves where fertility of B. tabaci was higher. Concentrations of over 45 % of individual phenolics shared between the two cultivars were higher in ‘Freedom Red’. While ‘Freedom Red’ had four unique compounds, only one compound was unique to ‘Monet Twilight’. Compounds unique to, and in higher amount in ‘Freedom Red’ included galloyl quinic acids, digalloyl glucose, apigenin diglucoside, apigenin glucoside, kaempferol hexoside, and quercetin pentose rutinoside, and rutin. These compounds have been associated with resistance to herbivores, prolonging developmental times, acting as antifeedants and toxins. Higher parasitism of B. tabaci nymphs on cv ‘Monet Twilight’ was observed than on cv ‘Freedom Red’. More studies are needed to determine if preferences of parasitism are due to the host plant or the nymphs to understand the dynamic interactions of bottom-up and top-down factors; also more in-depth analysis comparing the ratio of amino acids and phenolic compounds in less and more susceptible poinsettia cultivars in relation to whiteflies and its parasitoids needs to be conducted to better understand their ecological role.

Committee:

Luis Cañas (Advisor); Larry Phelan (Committee Member); Daniel Herms (Committee Member); Claudio Pasian (Committee Member)

Subjects:

Entomology

Keywords:

Plant defenses resistance plant-insect interactions phenolics amino acids

Lubbers, Hannah R.Impacts of Urbanization and Flow Permanence on Headwater Stream Macroinvertebrates (Hamilton County, Ohio)
MS, University of Cincinnati, 2009, Arts and Sciences : Biological Sciences
Through extensive research, stream ecologists have continuously strengthened their understanding of the importance of headwater streams and watersheds in stream health. Contrarily, United States policy makers have reversed such progress by reducing protection of many headwater streams. These contrasting trends have contributed to recent research in temporary headwater stream systems and the role that these streams have in the greater stream network. Despite numerous studies, researchers have not found consistent differences in macroinvertebrate assemblages between intermittent and perennial streams. Additionally, there is limited knowledge on how anthropogenic factors influence headwater streams that are naturally disturbed by drying. The objective of this study was to determine how urbanization interacts with stream permanence to shape headwater stream macroinvertebrate assemblages and salamander communities in Southwest Ohio. During spring (high flows) and summer (low flows) of 2007, we examined 20 intermittent and perennial reaches in ten streams along a gradient of watershed urbanization (range: 9 - 97% urban land cover). Macroinvertebrate richness ranged from 5-33 genera across all reaches, and the most abundant taxa were, in descending order, Oligochaeta, Lirceus fontinalus (freshwater Isopoda), and Chironomus spp. Urban land cover, temperature, nitrates, and substrate heterogeneity may have been important in structuring macroinvertebrate assemblages based on their strong correlations with the ordination axes. Duration of flow (permanence) did not explain differences in macroinvertebrates across sites based on the ordination. However, flow permanence was positively related to spring Chironomidae abundances (R2 = 0.11, P<0.05) and summer Eurycea bislineata (Northern two-lined salamander) abundances (R2 = 0.19, P<0.10). Few relationships with permanence and macroinvertebrate assemblages indicated that macroinvertebrates generally have life history traits enabling survival during dry conditions and/or the ability to recolonize intermittent streams once flow resumes. These results suggest that catchment urbanization and associated stressors are important drivers of macroinvertebrate assemblages, and headwater stream biota are not exclusively controlled by seasonal drying.

Committee:

Michael Miller (Committee Chair); Eric Maurer (Committee Member); Allison Roy (Committee Member)

Subjects:

Biology; Ecology; Entomology

Keywords:

headwater; intermittent; perennial; temporary; permanence; Rapanos; urbanization; land cover; imperviousness; macroinvertebrates; salamander larvae

Doyle, Annie LynnEffects of Forest Fragmentation and Honeysuckle Invasion on Forest Lepidoptera in Southwest Ohio
Master of Science (MS), Wright State University, 2008, Biological Sciences
Habitat loss and exotic species invasion is a rapidly growing threat facing forest animal communities worldwide. The goal of the current study is to assess the impact of forest fragmentation and the associated invasion of honeysuckle on immature tree-feeding Lepidoptera communities in southwestern Ohio. Caterpillar abundance, richness, and honeysuckle density were sampled along 100 meter transects conducted in ten forest fragments. Generalized linear models were developed to determine the effects of fragment area, landscape forest cover, and honeysuckle density on caterpillar abundance and richness. Caterpillar abundance and richness was positively related to landscape forest cover and fragment area. However, these effects were strongly dependent on honeysuckle densities within fragments. These results indicate that habitat fragmentation and invasive species interact to influence forest Lepidoptera communities. In an examination of the effects of honeysuckle on arthropod herbivory, honeysuckle appears to cause associational susceptibility of tree saplings.

Committee:

John O. Stireman III, PhD (Advisor); Don Cipollini, PhD (Committee Member); James Runkle, PhD (Committee Member)

Subjects:

Biology; Ecology; Entomology

Keywords:

HONEYSUCKLE; Caterpillar; Caterpillar abundance; richness; FOREST; honeysuckle density; fragments

Linkous, Emily KathrynIntegrating biological control and chemical control of cabbage caterpillar pests
Master of Science, The Ohio State University, 2013, Entomology

Lepidopteran pests Plutella xylostella, Pieris rapae, and Trichoplusia ni are the major species that attack crops in the family Brassicaceae. They are typically controlled by insecticide application, but there are parasitoid species that contribute to mortality. However, parasitoids alone are typically unable to exert sufficient control to reduce pest numbers below economic thresholds. Pest density tends to be lower in more diverse systems, including those that integrate flowering plants that parasitoids use as food resources. These resources are lacking in most agricultural landscapes. Parasitoids tend to be negatively impacted by exposure to broad-spectrum insecticides.

The first goal of this research was to investigate the integration of habitat manipulation and insecticide treatment through the planting of floral resources and use of selective microbial insecticides. The integration of sweet alyssum (Lobularia maritima) insectary strips and the insecticide Bacillus thuringiensis (B.t.) was investigated in a cabbage field trial conducted in 2011 and 2012. The results of this study are discussed in Chapter 2. The objectives of this study were: 1) to determine the effects of insectary strips on parasitism rates and pest density; and 2) to determine the effects of insecticides on parasitism rates and pest density. The main plot treatment was the presence or absence of insectary strips and the subplot treatment was insecticide. Plots were sampled weekly. Insectary strips were found to have no significant effect on pest density in or parasitism in 2011. In 2012, insectary strips were found to have increased pest density but also increased parasitism. Parasitism rate was lower in subplots treated with B.t. than in untreated subplots. Pest density in subplots treated with B.t. was not significantly different from subplots treated with cyfluthrin. These findings indicate that insectary strips can increase parasitism but may also increase pest density in some circumstances. The use of microbial insecticide did not increase parasitism but did keep pest density low. Because parasitism appeared to be density dependent, use of lower rates or longer intervals of B.t. may increase parasitism while maintaining low pest density.

Another goal of the research was to determine what parasitoid species were present in Ohio. The diversity and relative abundance of parasitoid species found in the survey are discussed in Chapter 3. The objectives of this study were: 1) to determine parasitoid diversity and parasitism rate on commercial farms; and 2) to determine whether differences in parasitism rates among farms are associated with differences in insecticide use as measured by the environmental impact quotient (EIQ). Ten commercial fields were used for the surveys in 2011 and 2012. Caterpillars were collected and held until the emergence of parasitoids or pests. Eleven parasitoid species were found. Species abundance varied between years. Farms with a higher EIQ rating tended to have decreased species abundance and percent parasitism, but this correlation was not significant. These findings indicate that many species of parasitoids are present in Ohio and that insecticide usage can impact parasitoid species diversity and abundance. Diadegma insulare and Cotesia rubecula should be the primary target of conservation biocontrol tactics within integrated pest management programs.

Committee:

Celeste Welty (Advisor); Mark Bennett (Committee Member); Mary Gardiner (Committee Member); Luis Canas (Committee Member)

Subjects:

Entomology

Bai, XiaodongInsect transmitted plant pathogenic mollicutes, Spiroplasma kunkelii and aster yellows witches' broom phytoplasma: from structural genomics to functional genomics
Doctor of Philosophy, The Ohio State University, 2004, Entomology
I employed various approaches, including genome sequencing, comparative genomics, functional genomics, and conventional molecular techniques, to study the biology and pathogenicity mechanisms of S. kunkelii and AY-WB phytoplasma. The economically important insect-transmitted plant pathogenic mollicutes, Spiroplasma kunkelii and aster yellows witches' broom (AY-WB) phytoplasma, invade and replicate in various insect tissue cells, and inhabit and replicate in plant phloem tissues. The partial genome of S. kunkelii and the complete genome of AY-WB phytoplasma were sequenced. The genome sequence data provide genetic basis for the study of the biology and pathogenicity mechanisms of these organisms. Comparative genome analysis among mollicutes was conducted, and resulted in the identification of four genes that are present in the genomes of all plant-pathogenic mollicutes sequenced so far, but missing from the mycoplasmas. Another gene within both genomes might have been derived by horizontal gene transfer between spiroplasmas and phytoplasmas. Four traE gene homologs were identified as membrane-bound ATPases in S. kunkelii M2 strain and are possibly involved in spiroplasma conjugation and adhesion. The AY-WB phytoplasma genome sequences were mined for potentially secreted proteins that may directly interact with host cell components and hence are candidate effector proteins. High-throughput functional assays resulted in the identification of 17 candidate effector proteins. Plant localization studies with the YFP fusions of two NLS-containing proteins (A11 and A30) revealed their localization in the plant nuclei and confirmed the dependence of A11 on plant importin a proteins for nuclear import. Transcripts corresponding to the phytoplasma proteins were detected in AY-WB phytoplasma-infected insects and plants. Microarrays demonstrated that phytoplasma A11 protein could affect the expression of 53 tomato genes, supporting the hypothesis that A11 is an effector protein involved in plant pathogenicity. The importance of the research lies in the application of high throughput bioinformatics, genomics and molecular approaches in the study of agriculturally important organisms for which little information is available. The described research and approaches might be useful for other pathogenic mollicutes that are recalcitrant to in vitro manipulation, including the economically important mycoplasmas that impact human health and livestock industries.

Committee:

Saskia Hogenhout (Advisor)

Subjects:

Biology, Entomology

Keywords:

PHYTOPLASMA; SPIROPLASMA; KUNKELII; AY-WB; proteins; genome; MOLLICUTES

Martin, Kirsten HopeThe Transition Zone: Impact of Riverbanks on Emergent Dragonfly Nymphs. Implications for Riverbank Restoration and Management
Ph.D., Antioch University, 2010, Antioch New England: Environmental Studies
The use of riprap in the restoration and stabilization of riverine landscapes is an issue of concern for many ecologists. While current methods of bank stabilization, especially those involving the placement of rocks (riprap) along the waterline, are effective in controlling erosion their presence changes habitat components (slope, substrate composition, near-shore river velocity) at the river-land interface. The additional impacts of river current, water temperature, soil composition, slope, and water level fluctuation, may further imperil emerging nymphs. The purpose of this research is to document the effects of riprap, location (upriver or downriver of hydroelectric intake/outtake facilities), water level fluctuation, river velocity, air temperature, water temperature, substrate temperature, and soil composition on the distance traveled to eclosure site by G. vastus and S. spiniceps, and the density of S. spiniceps, G. vastus, N. yamaskanensis, D. spinosus, O. rupinsulensis, M. illinoiensis, and E. priniceps. Knowledge of the conservation status of these species is fairly limited, although S. spiniceps (threatened), G. vastus (species of special concern), and N. yamaskanensis (species of special concern) are all currently listed on the Massachusetts Endangered Species list. Species density was determined through exuviae collection, and emergence distance was recorded from the edge of the waterline to the site of attached exuviae. Results of the study indicate that nymphal response to the observed abiotic features varies both with location and species. The presence of riprap had no significant effect on densities of S. spiniceps, G. vastus, N. yamaskanensis, D. spinosus, O. rupinsulensis, M. illinoiensis, and E. priniceps, but did significantly reduce the distance traveled from the waterline by both G. vastus and S. spiniceps.

Committee:

James Jordan, PhD (Committee Chair); Charles Curtin, PhD. (Committee Member); Mike Sutherland, PhD (Committee Member)

Subjects:

Animals; Ecology; Entomology; Environmental Science

Keywords:

dragonfly ecology; restoration ecology; riprap; riverbanks

Burington, Z. L.Evolution and Biogeography of the Tachinid Flies with Focus on the Tribe Blondeliini (Insecta: Diptera: Tachinidae).
Doctor of Philosophy (PhD), Wright State University, 2017, Environmental Sciences PhD
1. The large Diptera family Tachinidae is a diverse and recent group of koinobiont endoparasitoids feeding on a wide range of insects and some other arthropods. 2. Unfortunately, taxonomic confusion and poor understanding of tropical faunas has made difficulties for both basic and derived ecological research on tachinid flies. 3. Here I present evolutionary and ecological hypotheses for tachinid flies, with focus on the large tribe Blondeliini. Chapter 2 summarizes evidence for a latitudinal gradient in tachinid fly species richness within the Americas, using 7 survey data sets within both the temperate zone and tropics. In Chapter 3, I use several nuclear genes to construct a phylogenic framework for the tribe Blondeliini. Despite overall low support values, it was possible to infer several genus groups as well as describe overall evolutionary trends in host use and biogeography in the tribe. Chapter 4 is a conspectus of the Blondelia group of genera, which are distinctive for the female “keel and piercer” oviposition device. Both genetic and morphological evidence were used to delimit the included genera and species groups of Eucelatoria. Chapter 5 is a revision of the Eucelatoria ferox species group, the females of which are distinctive for their elongate piercers. Total ecological, morphological, and genetic evidence were used to describe previously named species as well as 17 species new to science.

Committee:

John O. Stireman, III, Ph.D. (Committee Chair); Thomas P. Rooney, Ph.D. (Committee Member); Jeffrey L. Peters, Ph.D. (Committee Member); John K. Moulton, Ph.D. (Committee Member); James E. O'Hara, Ph.D. (Committee Member)

Subjects:

Biology; Ecology; Entomology; Evolution and Development; Systematic

Keywords:

Blondeliini; Eucelatoria; Blondelia group; Tachinidae; tachinid flies; latitudinal diversity; taxonomy; new species; morphology; sword flies; phylogeny;

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