Master of Arts, The Ohio State University, 1922, Graduate School

Committee: Not Provided (Other) Subjects:

PhD, University of Cincinnati, 2024, Arts and Sciences: Biological Sciences

Sensory systems have evolved to provide organisms with practical information about their environments, rather than veridical reconstructions of reality. These systems interact with and attend to signals and cues that can affect behavior and fitness outcomes, leading to the crafting of a pragmatic, relevance-based perception of the world, uniquely tuned to the ecology of each organism/species. A compelling case study of this phenomenon is the experience of color. Color is a function of perception—an emergent property arising when a viewer interacts with light. It exists when an observer distinguishes between objects, fields, or lights based on the relative composition of wavelengths. Because color is inherently a perceptual comparison, its existence is relative to the perceiver. This requires that investigation into the use and evolution of color be considered in the context of the viewer. Psychophysical methods allow for intimate analyses of the behaviors employed by animals during discrimination tasks. This work studies both achromatic and chromatic perceptual thresholds, as displayed by two distinct behavioral responses, and in two species of jumping spiders with different color vision capabilities. These experiments build on each other in order for us to truly probe the thresholds of perceptual reality in these animals. In Chapter 1, I characterized achromatic contrast thresholds using whole-body reorientation responses in a trackball paradigm as well as retinal tracking through a customized ophthalmoscope in Phidippus audax and Habronattus pyrrithrix jumping spiders. In the trackball paradigm I found that P. audax responded to achromatic contrasts as low as 3.6%, whereas H. pyrrithrix demonstrated a greater threshold at 17% contrast. Gaze-tracking behaviors revealed a corroborating threshold for P. audax, at 3% achromatic contrast, but revealed a much more sensitive threshold of 7.8% achromatic contrast for H. pyrrithrix. These results indicate that the l (open full item for complete abstract)

Committee: Nathan Morehouse Ph.D. (Committee Chair); John Layne Ph.D. (Committee Member); Laura Kelley Ph.D. (Committee Member); George Uetz Ph.D. (Committee Member); Elke Buschbeck Ph.D. (Committee Member) Subjects: Biology

Master of Arts, The Ohio State University, 1913, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1963, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Arts, The Ohio State University, 1904, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, Miami University, 2021, Biology

Invasive Amur honeysuckle and overabundant white-tailed deer affect the vertical plant cover and standing litter biomass of southwestern Ohio forests, causing invertebrate habitat quality and quantity changes. Increasing plant structure caused by honeysuckle invasion were hypothesized to provide more habitat for above-ground invertebrates. White-tailed deer were hypothesized to negatively affect litter-dwelling invertebrates due to indirect effects on litter biomass, which reduces litter habitat for invertebrates. We analyzed the long-term responses of litter spiders to experimental exclusion of deer and the removal of honeysuckle over time, 2011-2019, and shrub layer spiders in 2019. Winkler extraction of litter samples was used to collect litter-dwelling spiders, and systematic visual searches were used to collect above-ground spiders. All spiders were identified to guild and the lowest possible taxonomic class. Deer exclosure treatments and greater litter biomass were associated with increased species richness and abundance of litter spiders over nine years. Shrub layer spiders had reduced abundance when honeysuckle was removed, and space and sheet weavers had greater abundance in plots with higher foliage height diversity. Litter spider communities diverged over time based on site and deer treatment, while differences in the 2019 above-ground spider community were caused by honeysuckle treatment and site differences.

Committee: Thomas Crist (Advisor); Melany Fisk (Committee Member); Ann Rypstra (Committee Member) Subjects: Ecology

Doctor of Philosophy, The Ohio State University, 2021, Environment and Natural Resources

Biological invasions threaten biodiversity and ecosystem functions. Stream ecosystems and their adjacent riparian zones are connected via a complex network of direct and indirect linkages, presenting a unique setting for the study of invasion. I investigated the effects of two different riparian invaders on stream biota and stream-riparian trophic linkages: an invasive insect (hemlock woolly adelgid Adelges tsugae; hereafter HWA) and an invasive shrub (bush honeysuckles Lonicera maackii and L. tatarica). Both sets of studies used the same basic approach at >20 streams across a gradient of invasion intensity: record geomorphology and water chemistry, collect and assess in-stream biota, quantify reciprocal subsidies, and determine riparian spider density, relative reliance on aquatically-derived energy (i.e., nutritional subsidies originating from periphyton), and invertebrate food-chain length (using naturally-abundant stable isotopes) at each study reach. I also conducted a before-after, control-impact (BACI design) honeysuckle removal experiment. My results suggest that in-stream physical and chemical alterations (i.e., large-wood characteristics and nutrient concentrations) associated with HWA invasion and subsequent hemlock decline drove changes in stream invertebrate diversity and trophic relationships. Evidence for ecological consequences of this invader was strongest at lower trophic levels. For example, periphyton biomass was greater at uninvaded reference sites than at severely invaded sites (x = 1.37 vs 0.52 mg cm-2), while relative abundance of herbivorous macroinvertebrates increased from 4 to 23% at the severely invaded sites. Spider (family Tetragnathidae) densities were 3.2 times higher at sites with severe hemlock decline and although density was not linked to emergent insect density overall, δ15N signatures of Araneidae and Pisauridae spider families tracked emergent insect δ15N (r2 = 0.42 and 0.78, respectively), suggesting a trophic linkage. (open full item for complete abstract)

Committee: S. Mazeika Sullivan (Advisor); Lauren Pintor (Committee Member); P. Charles Goebel (Committee Member) Subjects: Ecology; Environmental Science; Freshwater Ecology

Doctor of Philosophy, The Ohio State University, 2020, Entomology

Urban areas are often considered adverse environments for wildlife communities given that the colonization and establishment of local species pools are disrupted by biotic and abiotic changes at different spatial scales such as the introduction of invasive species, periodic mowing, and changes in soil and air quality. Although the number of people residing in cities has increased in the last century, over 300 cities worldwide have shrunk due to prolonged economic decline and population loss, resulting in thousands of newly available greenspaces scattered throughout cities. Consequently, interest in urban greenspaces as sites for conservation has grown considerably, raising questions about the ability of these habitats to support wildlife. As novel ecosystems, urban areas represent a set of new challenges for local species pools, yet the mechanisms driving community assembly processes within cities is a major knowledge gap. My work focused on identifying species distributions, patterns, and processes leading to the successful establishment arthropods in cities. For this, I chose to work with beetle and spider assemblages as they are considered biological indicators of environmental changes at small and large spatial scales and are taxonomically and functionally diverse predatory groups. In Chapter 1, my objective was to determine how urban greenspaces management and design impacts Carabidae and Staphylinidae beetles using taxonomic and life-history trait approaches. I found that ecological and morphological traits were good indicators of how beetles were responding to greenspace management strategies. Most species were negatively associated with building structures, while undisturbed habitats supported more hygrophilous and brachypterous beetle populations. In Chapter 2, I investigated the importance of local and landscape characteristics on spider communities using taxonomic and functional diversity approaches. I found that Pardosa milvina (Lycosidae) was the mo (open full item for complete abstract)

Committee: Mary Gardiner PhD (Advisor); Luis Cañas PhD (Committee Member); Andrew Michel PhD (Committee Member); Robert Gates PhD (Committee Member); William Symondson PhD (Committee Member) Subjects: Agriculture; Animals; Behavioral Sciences; Biology; Biostatistics; Ecology; Entomology; Environmental Science; Forestry; Molecular Biology; Soil Sciences; Urban Forestry; Urban Planning; Wildlife Conservation; Wildlife Management

Master of Science (MS), Bowling Green State University, 2019, Biological Sciences

Predators of crop insects are influenced by a number of variables which affect their foraging in agroecosystems. Though many of these predators, and their movement between crop and non-crop habitats, has been documented, the impact of variation in non-crop habitats is less understood. Here, we sought to understand how ditch geomorphology and prey availability at ditches and cornfields influences the potential spillover of web spiders, ground spiders, and bats. We examined 10 farms across Northwest Ohio, each possessing either a narrow conventional ditch, wider two-stage ditch, or very wide self-forming stream ditch. At each site, we surveyed and collected prey and predators along a transect extending from the ditch up to 200m into the adjacent cornfield, and conducted stable isotope analysis on samples. Stable isotope analysis (δ13C & δ15N) revealed that both web and ground spiders along ditches consume more prey that ate C3 vegetation (e.g. possibly emergent insects or ditch herbivores), while spiders in the fields consume mostly prey that ate C4 vegetation (possibly pests of corn). Guano isotopes indicate bats have highly variable prey consumption (median value around 38.3% of diet made up of C4,with large credible intervals). Web spiders were more abundant along ditches but increased in fields over the course of the season (p=0.001). Bat activity was higher at ditches than in adjacent cornfields in July-August, with both high and low aquatic insect emergence. However, August-September bats showed higher activity deep within the fields during periods of high aquatic prey availability at ditches (p=0.032). Isotopes suggest that spiders do not spillover between ditches and fields, but they were abundant in fields and ate prey with a C4 (corn-based) diet. Recording data and isotopes together suggest bats do consume prey from both ditches and cornfields. Ditch geomorphology was not found to have an effect on the response of abundance or activity of predators and prey (open full item for complete abstract)

Committee: Kevin McCluney PhD (Advisor); Jessica D'Ambrosio PhD (Committee Member); Karen Root PhD (Committee Member) Subjects: Agriculture; Biology; Ecology

Master of Science (MS), Bowling Green State University, 2019, Biological Sciences

Understanding responses of food webs to climate change is vital, especially when those food webs influence important ecosystem services, like pollination, valued at over $3 billion globally. Historically the focus has been on single factors (e.g. temperature) and mechanisms (e.g. change in mortality). However, global climate change is predicted to alter temperature and moisture simultaneously. Additionally, thermal and hygric physiological performance and species interactions are both likely mechanisms underlying food web responses to changing climate. The current lack of a synergistic, mechanistic understanding of how food webs respond to key aspects of global climate change is a major research gap. Here we questioned how changes in temperature and moisture may alter food web composition through filtering of sensitive taxa (physiological limits) or by modifying consumption (trophic interactions). We placed bumblebees (Bombus impatiens) and tomato plants (Solanum lycopersicum) in 32 mesocosms within a greenhouse in Bowling Green, OH in July 2018. We explored differences in fruit set and tomato quality by excluding half of the flowers from buzz-pollination via bags. Additionally, all mesocosms were categorized in four abiotic treatments (cool/dry, cool/moist, hot/dry, hot/moist), and were paired based on predator presence (with or without Green Lynx spiders (Peucetia viridans)). We found that predatory spider body temperature was significantly higher when more moisture was available in the environment (SE=0.779, df=28.0, t-ratio=-3.661, p=0.005). Our findings also indicate that if predatory spiders are more hydrated, they change their behavior and expose themselves more to heat (χ2=4.028, df=1, p= 0.045). Furthermore, this behavioral change influences spider consumption of bumblebees. When more moisture was available in the environment, spiders ate significantly more bumblebees (χ2=8.924, df=1, p=0.003). However, there were no significant differences between the h (open full item for complete abstract)

Committee: Kevin McCluney Dr. (Advisor); Helen Michaels Dr. (Committee Member); Daniel Wiegmann Dr. (Committee Member) Subjects: Behavioral Sciences; Biology; Climate Change; Conservation; Ecology; Entomology

Master of Science (MS), Wright State University, 2019, Biological Sciences

In this study, I examined how the spatiotemporal distribution of spider webs and diet changed in a lake riparian zone with increasing distance from an aquatic resource. I surveyed twenty, one-hundred meter transects along the perimeters of Sanford and Escanaba lakes (Wisconsin). Overall, spider web abundance was highest near the lakes and decreased moving into the adjacent forest. Horizontal orb webs, vertical orb webs, and mesh webs showed strong negative relationships with distance from the lakes. Aquatic insects composed an average 36-64% of spider diet for all spider families throughout the riparian zone, suggesting that some spider families are selecting habitats where aquatic prey availability is high. However, all are passively capturing aquatic prey as an abundant resource. These results demonstrate the value of riparian habitats to terrestrial communities and show that spiders could provide a model for assessing the reciprocal flow of allochthonous inputs between aquatic and terrestrial communities.

Committee: Thomas Rooney Ph.D. (Advisor); Katie Hossler Ph.D. (Committee Member); John Stireman III Ph.D. (Committee Member) Subjects: Ecology

MS, University of Cincinnati, 2018, Arts and Sciences: Biological Sciences

Recent studies have shown that animal “personality” demonstrates consistent behavioral variation at the individual level that persists across lifestages and contexts. The most commonly measured behavioral syndrome involves a “bold” to “shy” continuum, in which individuals are evaluated based on their willingness or latency to engage in risk-taking behaviors. I examined bold-shy behavioral syndromes in the brush-legged wolf spider, Schizocosa ocreata. Spiders were repeatedly given open field tests and later exposed to simulated predator stimuli. All spiders were tested as juveniles and adults. Results of open field tests showed individual S. ocreata exhibit consistent behavioral patterns associated with either end of the continuum of bold (exploratory) to shy (freeze) behavioral syndromes. These differences persisted across contexts, as well as lifestages (juvenile, adult). Bold spiders exhibited shorter latency to explore in an open field and to resume exploration after a simulated predator than did their shy counterparts, but also showed more variation in latency to resume exploration after a simulated predator. After reaching maturity, females were given a two-choice test using video playback of male courtship to analyze differences in mate choice, while males were exposed to female cues to assess courtship vigor. While open field behaviors and responses to simulated predators were correlated, personality type did not show significant effects on male courtship in the presence of female cues or female mate preference in the context of video playback. Males and females of differing personality types were also paired in a two-by-two factorial design to assess the effect of personality on overall mating success. No differences in mating success were found, suggesting that personality type measured using bold-shy attributes may affect somatic traits but not reproductive traits in this study.

Committee: George Uetz Ph.D. (Committee Chair); Elke Buschbeck Ph.D. (Committee Member); Nathan Morehouse (Committee Member) Subjects: Behavioral Sciences

Master of Science (MS), Bowling Green State University, 2018, Biological Sciences

Navigation in arthropods has been well studied in terrestrial model organisms such as ants, fiddler crabs, and spiders and there is an emerging understanding that arthropods are much more complex in their spatial abilities than once thought, based on their relatively small nervous systems. Whip spiders (Order Amblypygi) are of interest because, unlike most well-studied terrestrial arthropods, they are nocturnal and live in spatially complex habitats. In addition to the dense terrestrial substrate that creates navigational challenges, navigation at night adds seemingly more adverse conditions for goal-oriented spatial behavior. The integration of multimodal sensory information is hypothesized to facilitate navigation under these conditions, where odor cues are apparently crucial. The goal of this project was to establish a rich dataset of spatial movements of amblypygids under controlled laboratory conditions and determine the relative salience of sensory cues in a multimodal, navigational context. This study used an automated video tracker to record the return paths of amblypygids displaced from a shelter in an arena with a spatially heterogeneous array of sensory cues, where light and odor sources were experimentally manipulated. We found that removal of the light or odor cue did not affect their ability to home to a shelter, but in the absence of the light cue return paths were more circuitous and contained more pauses. Surprisingly, removal of the odor source from the arena had no effect on trajectory kinematics. In addition, our analyses revealed general species differences in return paths.

Committee: Daniel Wiegmann PhD (Advisor); Verner Bingman PhD (Committee Member); Paul Moore PhD (Committee Member) Subjects: Biology

Master of Science (MS), Bowling Green State University, 2017, Biological Sciences

Displacement experiments with amblypygids, nocturnal arachnids that inhabit the tropics and subtropics, revealed that they are rather extraordinary navigators and that their abilities are severely impeded when access to olfactory information is experimentally abolished. These results and the fact that amblypygids possess exceptionally large mushroom bodies, brain regions that process olfactory and, perhaps, spatial information led to the hypothesis that olfaction facilitates their navigation behavior. The amblypygid Phrynus marginemaculatus wanders nightly and shows strong shelter fidelity in a laboratory arena. Here, individual subjects were trained over a 26-night session in a square arena that contained two shelters to determine the extent to which shelter recognition is dictated by odor. The target shelter was positioned at a specific location in the arena near an acrylic well that contained 15 µl of geraniol. The other shelter was likewise positioned at a particular location in the arena, but near an acrylic well that contained 15 µl of water. The session consisted of nights on which the entrance to the target shelter was open and the entrance to the other shelter was closed, referred to as forced choice trials, and nights on which a subject had access to both shelters, referred to as probe trials. Probe trials involved manipulations of the locations of the shelters and their associated acrylic wells after a subject emerged from the target shelter. The probes consisted of three types of manipulations: control manipulations in which the shelters and associated acrylic wells were removed and replaced with identical shelters and dishes in their original locations; manipulations in which the positions of the two acrylic wells were swapped; and manipulations in which both shelters and their respective acrylic wells were moved from their original, trained locations. The odor-cued shelter was chosen in more than 90 percent of the control probes, but in the other two p (open full item for complete abstract)

Committee: Daniel Wiegmann (Advisor); Verner Bingman (Committee Member); Paul Moore (Committee Member) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1970, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Master of Science, Miami University, 0, Biological Sciences

Contests over limited resources frequently occur when species occupy the same area. Certain behaviors may predispose some species to have a competitive advantage during these contests. The cellar spider, Pholcus manueli, recently expanded its range and appears to have displaced local populations of Pholcus phalangioides. I quantified activity differences between these species and investigated whether the success of P. manueli is due to its competitiveness. In my first experiment, P. manueli displayed more activity and web deposits than P. phalangioides, but P. phalangioides deposited webbing at a faster rate. Next, I staged interspecific contests over territory—an empty web site or a site occupied by a web (higher resource value) of one species. Pholcus manueli did not win any contests and retreated from interactions more often. The success of P. manueli is not due to its ability to take over territory but may be related to its active nature.

Committee: Ann Rypstra (Advisor); Alan Cady (Committee Member); Nancy Solomon (Committee Member) Subjects: Animals; Behavioral Sciences; Biology; Ecology; Zoology

Doctor of Philosophy, The Ohio State University, 2014, Psychology

The current studies apply reverse correlation image classification (RCIC) techniques to estimate the mental representation of a spider among participants who vary in their fear of spiders. This is the first attempt that we know of to use RCIC techniques to both estimate individuals' mental representations of a complex, non-facial object and to test whether those representations vary in a meaningful way. We find evidence in a pilot study that the RCIC technique is adaptable to non-facial, but complex, stimuli (spiders). In Study 1, we find that the mental representation of a typical spider among participants higher in fear of spiders is rated by objective judges as looking scarier and more threatening than the mental representation among participants lower in fear of spiders. In Study 2, we find evidence of this effect for a specific spider image to which participants were exposed earlier in the study. Methodologically, our findings suggest that RCIC techniques can be used to understand individual differences in the representations of complex, non-facial stimuli. At a more theoretical level, the findings illustrate how perceptions can be influenced by the emotions and evaluations that individuals associate with an object.

Committee: Russell H. Fazio (Advisor); Richard E. Petty (Committee Member); Duane T. Wegener (Committee Member); J. Andrew Roberts (Committee Member) Subjects: Psychology; Social Psychology

Master of Arts, The Ohio State University, 2013, Psychology

Evaluative conditioning (EC) involves developing or changing attitudes, i.e. evaluations of objects, by the mere pairing of a target object with other objects of a given valence. Our aim is to better understand evaluative conditioning and its underlying mechanisms so as to develop applications for changing negative attitudes. One mechanism by which evaluative conditioning is known to work, implicit misattribution, posits that evaluations of the unconditioned stimulus (US) are mistakenly viewed as having been evoked by the conditioned stimulus (CS) when they are paired together. The experiment examined conditions under which evaluative conditioning regarding spiders might be effective and ineffective from the perspective of the implicit misattribution model. An EC procedure paired spider images with positive pictures and words. However, inducing implicit misattribution was likely to be difficult, due to generally strong negative attitudes toward spiders. That is, the source of the positive evaluation would obviously not be the spider. To promote source confusion, the CS in one condition were spider images that were previously rated as relatively more appealing. Comparison conditions included one in which CS were relatively unappealing spider images and a control condition in which no US-CS pairs appeared. 130 undergraduates participated for course credit. The main dependent variable of interest was pleasantness ratings of photos of spiders. Regression analyses examined main effects and interactions between condition and scores on a commonly-employed questionnaire assessing Fear of Spiders. More positive attitude change occurred in more-pleasant spider condition than in the condition involving less-pleasant spider images or the control condition. However, this effect was moderated such that only participants with lower fear of spiders showed attitude change relative to control. The effect also was observed for ratings of new spiders not previously seen d (open full item for complete abstract)

Committee: Russell Fazio PhD (Committee Chair); Richard Petty PhD (Committee Member); Michael Vasey PhD (Committee Member) Subjects: Psychology

MS, University of Cincinnati, 2001, Arts and Sciences : Biological Sciences

Courtship behavior has been studied extensively in the wolf spider Schizocosa ocreata (Araneae: Lycosidae). While much research has tested predictions of sexual selection theory regarding male traits used in female mate choice, some critical assumptions about female behavior remain untested. Because variation in female mating behavior is critical in sexual selection, I studied several aspects of mate choice from the females' perspective: (1) Do females mate more than once? (2) Is female preference for male characters (leg tufts and visual courtship displays) repeatable? (3) Does female receptivity vary with age (post-adult)? Females were paired with multiple males, and re-mating by females was rare (6%) implying that females are primarily monogamous. Males in contrast seem to be polygamous, 62% of males that were paired with more than one virgin female mated more than once. Sexual conflict over optimal mating rate may be inevitable resulting in different mating strategies. To determine repeatability of ma le preference, females were shown videos of courting males (identical in behavior and size, but different tuft sizes) simultaneously in a choice chamber once/day over 4 days. The repeatability of female preference varied with the nature of the choice. Female preference for larger tufts was significant and repeatable (r = 0.65) when choosing between an average male and one with reduced tufts, but not when choosing between an average male and one with enlarged tufts. This may be an indication of a threshold trait. To examine variation in receptivity with age post-adulthood, I studied responses of females to a courting male video. Receptivity varied significantly with age post-adulthood: females were more aggressive and less receptive to video images of courting males in the first week, became significantly more receptive after 3 weeks, and less thereafter. Correlated changes in aggressive and receptivity behavior may suggest a physiological linkage. These studies dem (open full item for complete abstract)

Committee: George Uetz (Advisor) Subjects: