Master of Science, Miami University, 2020, Biology

The ability to learn about the surrounding environment is advantageous for many arthropods when searching for mates, avoiding predators, or foraging. It has been demonstrated that arachnids are capable of both simple and complex forms of learning within these situations. Simple forms of learning, such as classical conditioning have been well explored in arachnids, but studies on more complex learning, such as contextual associations, are still needed. Here I present data on learning by the wolf spider Pardosa milvina (Araneae, Lycosidae) in connection with foraging. Spiders underwent training to learn either a simple or complex association. During training subjects were exposed to either unpalatable (quinine-coated), palatable (sucrose-coated), or neutral (water-coated) prey within either a maple or peppermint scented environment. After training, P. milvina was tested in a novel two-choice maze where individuals selected to travel either towards peppermint or maple cues to investigate potential preferences resulting from learning. Some significant effects of treatment and time on spider attack behaviors were found during the training period, though these factors yielded no significant effects on behavior during maze testing. Overall, some behavioral trends of complex groups during training and simple groups during testing align with expected results of learning these association types.

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

Doctor of Philosophy, The Ohio State University, 2022, Evolution, Ecology and Organismal Biology

Many animals live in a heterogeneous landscape of predation, with consequences that include changes in behavior, morphology, and physiology. While we understand much about how predation directly impacts prey phenotypes, our understanding of its indirect effects on the phenotypic attributes of prey are quickly becoming a subject of intense study. It has been shown that merely the risk of predation could alter the behavioral phenotype of prey, which in turn, could influence their reproductive fitness. Thus, the behavioral phenotypes in the parental generation are a potential target for natural selection. Because such traits are often heritable, predation risk could indirectly shape the phenotype of subsequent generations of prey through genetic change. Prior work has focused on the ability of organisms to evolve or alter the expression of traits (phenotypic plasticity) in response to environmental changes. Yet, there is now copious evidence that demonstrates how the environment can induce non-genetic phenotypic changes that span multiple generations. Such ‘transgenerational plasticity' occurs when the environment experienced by parents alters the phenotypes of subsequent generations. Transgenerational responses have been documented in many organisms for a variety of environmental factors and are postulated to have far-reaching consequences for population dynamics, community interactions and the rate and direction of evolutionary change. Nonetheless, despite widespread attention on the existence of transgenerational plasticity, our understanding of how behavior can be altered transgenerationally in responses to predation risk in the parental generation remains limited. My research has sought to test the hypothesis that predation risk in the maternal environment can drive transgenerational behavioral plasticity through maternal effects. I used an intraguild predator-prey system consisting of two wolf spiders. Tigrosa helluo served as the predator, with Schizocosa ocr (open full item for complete abstract)

Committee: Susan Gershman (Advisor); Stuart Ludsin (Committee Co-Chair); Ian Hamilton (Committee Member) Subjects: Behavioral Sciences; Biology; Ecology

Master of Science, Miami University, 2018, Biology

Invertebrates provide a key link in moving toxic heavy metals from the environment into the vertebrate food web. Studying the uptake and accumulation of metals in invertebrates can help explain bioaccumulation of metals further up the food web. In this study, I decoupled dietary and substrate exposure to heavy metals and quantified accumulation of cadmium, copper, lead, and zinc in the epigeic wolf spider Pardosa milvina. I also looked at how foraging and lifespan might change in response to heavy metal exposure. I found that P. milvina absorbs and accumulates all four of these heavy metals through its cuticle. However, only metals that also are micronutrients (e.g. zinc) were accumulated from dietary consumption; non-nutritive metals were excreted without accumulation. Female mortality was not affected by heavy metal exposure, while male mortality was negatively affected by substrate exposure to metals but not by dietary exposure. As P. milvina is a common prey item for a variety of vertebrate and invertebrate species, it likely provides a vector for heavy metals to move from the soils into the vertebrate food web.

Committee: Ann Rypstra Dr. (Advisor); Alan Cady Dr. (Committee Member); Melany Fisk Dr. (Committee Member) Subjects: Ecology

Master of Science, Miami University, 2018, Biology

Females often use male signals and cues to locate potential mates and assess their quality. These male signals can be transmitted across one or multiple signaling modalities. In the wolf spider Pardosa milvina, males use a visual courtship display to attract female attention and encourage sexual receptivity. However, whether or not other signaling modalities influence female mate choice in this species is poorly understood. I hypothesized that male chemical cues may play a role in female mate choice in addition to visual cues. I tested females for their ability to detect and assess males based on their chemical cues, both isolated and when combined with a visual signal. Females did not change their activity in the presence of isolated male chemical cues. When presented with males either surrounded by or lacking their chemical cues, I found that while male courtship played a major role in female detection and attraction, females tended to spend less time near males when their chemical cues were present. This research suggests that while male courtship displays are necessary and sufficient for mate attraction, chemical signals may play a limited role by helping females more quickly assess a male's visual display.

Committee: Ann Rypstra PhD (Advisor); Nancy Solomon PhD (Committee Member); Brian Keane PhD (Committee Member) Subjects: Animals; Biology; Zoology

PhD, University of Cincinnati, 2017, Arts and Sciences: Biological Sciences

Animals communicate across any number of diverse modalities, including multiple modalities simultaneously. Investigating the evolution of differing modalities often requires unique models and a thorough dissection of the pressures that shape the emergence and continued changing of conspecific signals. Vibration, as a modality for communication, is both incredibly widespread (particularly in insects and spiders) and poorly investigated relative to its most closely associated modality, airborne sound. Spiders, in particular, are an excellent model for studying vibration, and they uniquely do not seem to directly perceive airborne sound. This is especially intriguing when considering certain species, such as the `purring' wolf spider Gladicosa gulosa, that produce an audible sound during courtship interactions, raising questions about both how and why this sound exists. This thesis sets out to provide quantitative demonstrations of the nature and structure of the courtship signal, investigate the possible mechanisms and value of producing and receiving this signal, and suggest a potential explanation for the evolution of this signaling phenomenon. I recorded and characterized the male courtship signal in this species in both vibratory and acoustic modalities, and identified behaviors that were significantly predictive of mating success for both males and females, as well as their relative correlations to one another. I also measured the role of the substrate in both signal production and reception of the acoustic signal, and provided evidence of behavioral shifts in response to isolated conspecific acoustic signals. Finally, I set these data within a broader context of North American wolf spiders and suggest an evolutionary framework for the evolution of the G. gulosa signal. I found that this species is unique in the strength of its signal relative to other species, but not in the mechanisms it uses for production, and the airborne signal appears to be largely a bypro (open full item for complete abstract)

Committee: George Uetz Ph.D. (Committee Chair); Elke Buschbeck Ph.D. (Committee Member); John Layne Ph.D. (Committee Member); Michal Polak Ph.D. (Committee Member); Peter Scheifele Ph.D. (Committee Member) Subjects: Biology

PhD, University of Cincinnati, 2017, Arts and Sciences: Biological Sciences

All taxa must cope with assault from parasites and pathogens, and have thus developed an immune system that may require resources that would otherwise be invested in life history traits, such as those used in mating and reproduction. Consequently, male sexual signaling traits that are costly to develop and maintain can act as honest signals, since only the highest quality males can cope with the energetic demands required to both express these traits and maintain an effective immune system. In this study, I investigated the tradeoffs between immunity and sexual signaling in the brush-legged wolf spider Schizocosa ocreata. First, I sought to determine whether male multimodal sexual signals are an honest indicator of male health and immunity, and whether females can acquire information about male health status through the evaluation of these traits in a live mating context. While I found evidence that females avoid the chemical cues of infected males, there was no difference in vibratory sexual signals or in overall mating success between infected and healthy males. However, these were males that were infected as adults, after sexual signaling traits were fixed, and may not accurately reflect a change in male health. Therefore, I infected males as juveniles during the penultimate stage of development, when the most resources should be allocated toward the development of sexual signals. These juvenile infected males had higher immune function as adults, but had more asymmetrical visual traits, lower quality vibratory signals, and overall lower mating success.

Committee: George Uetz Ph.D. (Committee Chair); Joshua Benoit Ph.D. (Committee Member); Richard Karp Ph.D. (Committee Member); Eric Maurer Ph.D. (Committee Member); Alison Weiss Ph.D. (Committee Member) Subjects: Biology

PhD, University of Cincinnati, 2015, Arts and Sciences: Biological Sciences

Studies have revealed that in many animals, females use various male traits in mate choice to assess a male's ability to provide direct and/or indirect benefits. While it is easy to assume that females should always prefer to mate with males with these traits, increasing evidence suggests that females demonstrate plasticity in their mating preferences based on intrinsic and extrinsic factors. This dissertation focuses on how variation in the social environment results in variation in the mating preferences of the brush-legged wolf spider, Schizocosa ocreata. I used video and vibratory playback to simulate variation in the social environment of juvenile female S. ocreata and measure how that affects adult mate preferences. First, female S. ocreata were provided experience during their penultimate instar stage, manipulating the number of courting males per encounter (one or three males) and the encounter rate (every other day or twice per day). When given a choice between a lower quality (small-tufted) and higher quality (large-tufted) male in their adulthood, females were increasingly more selective depending on exposure to cumulatively more mature males during their penultimate social experience. Second, females were provided varying social experience with courting males of various tuft sizes during their penultimate instar stage. In both no-choice and two-choice designs, adult females were more receptive towards small-tufted and large-tufted males, respectively, if they saw small-tufted or large-tufted males during their penultimate stage. Third, female S. ocreata were provided variable sensory experience during their penultimate stage. Specifically, females in this study were provided playback of male courtship using vibratory signals, visual signals, multimodal signals, or no experience at all. When measured for unimodal preferences in no-choice presentations as adults, females demonstrated more receptivity displays towards the `familiar' signal modality. Two add (open full item for complete abstract)

Committee: George Uetz Ph.D. (Committee Chair); Ann Rypstra Ph.D. (Committee Member); John Layne Ph.D. (Committee Member); Stephen Matter Ph.D. (Committee Member); Michal Polak Ph.D. (Committee Member) Subjects: Biology

MS, University of Cincinnati, 2015, Arts and Sciences: Biological Sciences

Across animal species, males convey important information to potential mates through signals in multiple sensory modalities. In order to choose the best possible mate, female receivers must accurately perceive and assess male multimodal signals, especially when those signals occur simultaneously with those of other males. Cross-modal integration, i.e., cognitive binding of information transmitted in more than one sensory signal mode, is therefore important in animal communication, especially in complex, noisy environments in which many signals overlap. However, it is currently unknown how perception of multiple, disparate male signals plays a role in female mate choice decisions, especially for invertebrates. Males of the brush-legged wolf spider Schizocosa ocreata (Hentz) use multimodal communication (visual and vibratory signals) in courtship. Because female S. ocreata may be courted by multiple males at the same time, they must evaluate co-occurring male signals originating from separate locations. Moreover, due to environmental complexity, individual components of male signals may be occluded, altering detection of sensory modes by females. While experiments with live spiders and video playback have shown that female Schizocosa ocreata wolf spiders display receptivity to males courting in either isolated signal mode and show increased receptivity for multimodal courtship, it is unknown whether this is the case when females are presented with a choice between multimodal vs. isolated unimodal male courtship signals, and how these preferences are affected by disparity between signals. I first used digital multimodal playback to present females with a choice between 1) isolated unimodal (visuaI or vibratory), 2) multimodal vs. vibratory, and 3) multimodal vs. visual male courtship signals. I next used digital multimodal playback to investigate the effect of spatial and temporal disparity of visual and vibratory components of male courtship signals on femal (open full item for complete abstract)

Committee: George Uetz Ph.D. (Committee Chair); John Layne Ph.D. (Committee Member); Eric Maurer Ph.D. (Committee Member) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 2015, Evolution, Ecology and Organismal Biology

Communication between potential mates is of vital importance to the fitness of many taxa, allowing individuals to find one another, as well convey and receive information important in assessing a suitable mate. Signals involved in sexual communication can be transmitted through visual, vibrational and chemical modalities, with chemical communication being the oldest and most widespread. The ability to detect visual and vibrational cues often occurs across a range of inputs, while chemical communication has the potential for much higher specificity, as only those receivers possessing chemosensory cells attuned to the compounds used will be able to detect their presence. The detection and integration of multimodal signals into a behavioral response has been extensively studied in the Schizocosa ocreata (Hentz 1844) wolf spider (Lycosidae) model system. In this ground dwelling species, males respond to substrates containing female chemical signals with visual and vibratory courtship displays. While this response has been well characterized, the chemical identity of these signaling compounds is currently unknown, and pheromone identity has been understudied across spiders as a whole. The behavioral response of male S. ocreata to conspecific chemical signals has primarily been studied in the context of substrate bound female cues, though past studies have suggested that chemicals produced by conspecific male competitors may inhibit male courtship behavior, and have even suggested a role for olfaction.We further examined the role olfaction plays in male detection and location of females, and while we found no evidence that males are utilizing olfaction to find mates, we did observe behavioral changes to conspecifics of both sexes, and a reduction of activity in the presence of volatile cues from a predator. At levels of competitor cues that males are expected to encounter in nature, we found no evidence that male-male inhibition occurs in this species. In examining male r (open full item for complete abstract)

Committee: J. Andrew Roberts (Advisor); Susan Gershman (Committee Member); Roman Lanno (Committee Member) Subjects: Behavioral Sciences; Biology; Ecology

PhD, University of Cincinnati, 2010, Arts and Sciences: Biological Sciences

Animals communicate with each other to convey messages containing information used in many contexts (e.g., mating, territory defense, predator defense, foraging). Communication occurs within visual, auditory, chemical, electrical, or mechanical (seismic) channels or with a combination of these – multimodal signaling. During communication, aspects of the environment may interfere with the transmission of the signals, which may affect the behavior of the animals that are sending and receiving the messages. The work embodied in this dissertation examines how different types environmental interference affect courtship and mating behavior of the wolf spider, Schizocosa ocreata (Hentz) through a series of experimental studies. Interference may not only affect the outcome of communication (mating success) but influence behavior during the sending and receiving of messages. The types of environmental interference examined here reflect aspects of the natural environment, including substrates with different signal transmission properties (e.g., leaves vs rocks), noises that may occur during signaling (low frequency anthropogenic noise, bird calls, cicada calls), and interference from other conspecifics signaling within the communication network. In aiming to understand the effects of these potential disturbances, the work also explores several theoretical frameworks concerning communication: multimodal signaling, signaling with noise, and signaling within a communication network. In Chapter 2, I found differences in transmission effectiveness of seismic signals among natural substrates (leaves, rock, soil, wood) and a lower overall mating success on those that attenuate vibration (rock, soil, wood). Male spiders also exhibited an increase in visual signaling when on less effective substrates. These findings provide support for the backup signaling hypothesis and potentially the alerting/enhancing/amplifying hypotheses for the function of multimodal signaling. Chapter 3 is amo (open full item for complete abstract)

Committee: George Uetz PhD (Committee Chair); Elke Buschbeck PhD (Committee Member); John Layne PhD (Committee Member); Michal Polak PhD (Committee Member); Alan Cady PhD (Committee Member) Subjects: Biology

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

Master of Science, Miami University, 2005, Biological Sciences

Organisms constantly make behavioral decisions regarding reproduction and predator avoidance. To aid this process, males can benefit by detecting high-quality females and by using cues in the environment. Male wolf spiders (Pardosa milvina) adjusted their activity in response to chemical/tactile cues from female Pardosa. When confronted with two females simultaneously, males showed a stronger activity response to cues from females with high than low-quality body conditions. Overall, males displayed a stronger response to the cues deposited by a predator as compared to cues deposited by female Pardosa. When confronted with female and predator cues simultaneously, the graded behavioral response to cues from the high and low-quality females disappeared. Courtship and copulation behaviors of males were affected by female cue presence and body condition. However, predator cues did not affect these behaviors. These results suggest that multiple factors may affect the reproductive decision-making processes of Pardosa.

Committee: Ann Rypstra (Advisor) Subjects: Biology, Zoology