Doctor of Philosophy, The Ohio State University, 2024, Entomology

Oyster mushrooms (Pleurotus spp.) are a highly nutritious mushroom genus favored for use in the fresh market and at fine dining restaurants. Furthermore, their nutrition is especially important for those who have food restrictions and for anyone eating a vegan diet as it provides most B vitamins, is high in protein by dry weight, and is one of the only non-animal sources of vitamin D when consumed. The oyster mushroom cultivation system is highly sustainable, utilizing agricultural byproducts such as mulch and straw, though many growers import inoculated substrate from China since the cost of sterilization equipment can be prohibitively expensive. The oyster mushroom is the second most produced mushroom in the world, with the United States production ranking second only to China. Pest management is important to produce a high-quality mushroom, but little information exists regarding the pest management of this mushroom species. Fungus gnats in the genus Lycoriella are one of the major pests for oyster mushroom production. The larvae cause direct damage of up to 30% crop loss through feeding on the mycelium. The adults cause indirect damage through vectoring green mold, Trichoderma spp., spores which can cause up to 100% crop loss. With such high potential for crop loss, the action threshold for this pest is 1 adult female per grow room and 1 larva per 125 g. To improve pest management on oyster mushrooms and to identify effective control strategies, four key questions were explored. Are there differences in infestation rates for fungus gnats in different species of oyster mushrooms? How effective are the current organic pesticide options for management of fungus gnats across different oyster mushroom species? What species of fungus gnat is present on oyster mushroom farms in the U.S. and what is the phenology of these infestations? To address the first question, two sets of bioassays were performed. The first (Chapter 2) was done with inoculated straw to deter (open full item for complete abstract)

Committee: Luis Canas (Advisor); Christopher Ranger (Committee Member); Reed Johnson (Committee Member); Sanja Ilic (Committee Member); William Hendrix (Committee Member); Andrew Michel (Committee Member) Subjects: Agriculture; Biology; Entomology; Genetics; Organismal Biology; Toxicology

Doctor of Philosophy, The Ohio State University, 2017, Environmental Science

The cryosphere is shrinking as a result of climate change. Mountain glaciers, a key component of the cryosphere, serve as headwaters to glacier meltwater streams which support communities of stenothermic organisms. The Tibetan plateau is known as "the Third Pole" for its high number of glaciers, yet very few scientific papers have been published on aquatic invertebrate ecology of glacier-fed streams in the region. On the edges of the Tibetan Plateau in Southeast Tibet's Hengduan mountains, monsoonal temperate glaciers extend well below the treeline as valley glaciers, and are perhaps the most endangered cryosphere-dominated streams in the world due to their low latitudes and altitudes, which makes them sensitive to atmospheric temperature changes. The glaciated headwaters of the Mekong and Yangtze Rivers comprise a small fraction of the annual river discharge, yet at a local scale provide glacial meltwater that supports endemic and potentially rare species. Water temperature and channel stability differ between seasons due to the torrential flow from glacial meltwater during the summer melt season. The Milner & Petts (M&P) model of macroinvertebrate presence in glacier streams was based on the environmental factors of water temperature and channel stability during the summer melt season. In low temperature water close to the glacier, the macroinvertebrate communities are generally limited to Diamesinae chironomids, and further downstream more taxa are found where water temperature and channel stability increase. Therefore, temperature and channel stability are examined as potential limiting factors on the distribution of invertebrate communities, with the goal to compare the insect communities in Southeastern Tibet's glacier-fed streams with the widely-accepted M&P model of invertebrate community structure. Since discharge and hydrology may influence invertebrate distribution in glacier streams, hydraulic characteristics and invertebr (open full item for complete abstract)

Committee: Lanno Lanno Dr. (Advisor); David Denlinger Dr. (Committee Member); Richard Moore Dr. (Committee Member); Donald Dean Dr. (Committee Member) Subjects: Environmental Science

Master of Science, Miami University, 2013, Zoology

This thesis examined photo-induced toxicity and toxicokinetics for acute exposure to polycyclic aromatic hydrocarbons (PAHs) in fish. Co-exposure of ultraviolet radiation (UV) and PAHs enhances the toxicity at PAH concentrations orders of magnitude below effects in the absence of UV. Because environmental exposure to PAHs is in the form of complex mixtures, this study examined both single compounds and mixtures. The sensitivity of two species of larval fish (zebrafish and sheepshead minnow) to fluoranthene was identified by derivation of acute 96hr median lethal concentrations (LC50s). Differential sensitivity was explained by differences in toxicokinetics. In the zebrafish, 96hr LC50s were derived for four additional PAHs to examine the hypothesis that phototoxic (anthracene and pyrene) and non-phototoxic (carbazole and phenanthrene) pathways could be predicted. Anthracene and pyrene were phototoxic; however, carbazole exhibited moderate and phenanthrene exhibited weak photo-induced toxicity. Individual toxicity was used to compare the toxicity of mixtures in binary, tertiary, and quaternary combinations using a Toxic Unit approach. Toxicity was predicted to be additive, regardless of the level of photo-induced toxicity. Genetic analysis of biomarkers indicative of toxicity pathway for individual exposures and mixtures was investigated. Due to limitations of the results, no final conclusions were able to be made.

Committee: James Oris (Advisor); Michelle Boone (Committee Member); Andor Kiss (Committee Member) Subjects: Aquatic Sciences; Biology; Environmental Science; Experiments; Toxicology; Zoology