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Undergraduate Special Problem

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Adviser: search.filters.advisor.Yunque, Nestor G.Committee Chair: search.filters.chair.Tayo, Gilma T.

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    Molluscicidal activity of tabaco dust against the brackishwater pond snail Telescopium telescopium (Gastropoda: Potamididae)
    Azucena, Paulene C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    Telescopium telescopium, a molluscan potamidid snail thrives in the muddy substrates of brackishwater ponds in the Philippines. It occurs in considerable numbers but uncontrollable increases in its population poses serious threats to pond production. Tobacco dust is considered as a potential biomolluscicide that is able to control pond snail infestation. A short-term bioassay was conducted to know the effectiveness of tobacco dust as a molluscicide against T. telescopium by determining its median lethal concentration (LC50) after a period of 96 hours. Twenty-five telescope snails were subjected to varying concentrations of tobacco dust, from 0 to 1.0 kg/L at 0.2-kg increments. Three replicates were done for every treatment. Counting of dead snails was done after 48 and 96 hours of exposure. Snails exposed to varying concentrations of tobacco dust exhibited several defense mechanisms such as avoiding the toxic solution by crawling out of the area, closing their operculum and retracting their bodies toward their shell. Highest snail mortality was observed at the 1.0-kg/L treatment. After the 96-hr. exposure time, the concentration of tobacco dust that proves to be lethal to 50% of the snails was computed to be 0.5849 kg/L. Indeed, tobacco dust is an effective molluscicide against brackishwater pond snails, particularly T. telescopium.
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    A preliminary investigation on the physico-chemical parameters of the habitat and associated flora of Rafflesia sp. along the western side of Sibalom Natural Park
    Alacapa, Lilluck F. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    Rafflesia, bearing the largest flowers in the world, was found to exist in Sibalom Natural Park. In view of efforts to conserve the Rafflesia site, this study entitled, “A preliminary investigation on the physico-chemical parameters of the habitat and associated flora of Rafflesia sp. along the western side of Sibalom Natural Park”, aims to come up with information as to what conditions do these flowers grow and their associated flora. This study hopes to help strengthen biodiversity conservation efforts of the Department of Environment and Natural Resources. The study had ten sampling sites, five of which with the existence of Rafflesia sp. and five of which without Rafflesia sp.. In each of these areas the data gathered were girth of trees, saplings and seedlings, list and number of existing flora within the area, soil pH, soil texture, soil and air temperature, and relative humidity. The study found that the Rafflesia sp. in the Sibalom Natural Park grows at high relative humidity, relatively cool air and soil temperature, in soil with high amounts of clay and nearly neutral pH. The Rafflesia sp., aside from its host vine, exists with the plant locally known as ban-ban. No species of plant was found to dominate the areas where Rafflesia sp. exists.