Browsing by Author "Kigenyi, Erisa"

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    Bioinsecticidal Activity of Eucalyptol and 1R-Alpha-Pinene Rich Acetonic Oils of Eucalyptus saligna on Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae)
    (Journal of Health and Environmental Research, 2018) Omara, Timothy; Kizza Kateeba, Fredrick; Musau, Bashir; Kigenyi, Erisa; Adupa, Eddie; Kagoya, Sarah
    Exploration of plants, animals, microbes and their products for green pesticides have been the mainstay of modern agriculturalists. Plant bioactive oils have been utilized in formulation of green pesticides, which are less toxic, least deleterious on biocontrol agents, readily biodegraded and have no or few ecological effects as compared to synthetic equivalents. This study evaluated the bioinsecticidal activity of Eucalyptol and 1R-Alpha-Pinene rich acetonic essential oils of dry leaves of the Sydney Blue gum (Eucalyptus saligna Smith) on common granivorous maize weevil. Fresh leaves of Eucalyptus saligna were harvested and the essential oils extracted from its dry powder by hydrodistillation. The chemical composition of the essential oil was analyzed by tandem GC/MS. Twelve components were identified, and the main components were Eucalyptol (34.36%) and 1R-alpha pinene (17.92%). Acetonic essential oils of 2μL, 4μL, 6μL and 8μL in 1ml acetone were used in contact toxicity, fumigant and repellent bioassays. In contact toxicity, 8μL/ml oil exerted a rapid effect on the weevils giving 100% mortality in the first day of exposure; 6μL/ml achieved 100% mortality 96 hours after treatment. Both fumigant and repellent activities showed a gradual increase in insect mortality and repellency with time of exposure as the concentrations of the essential oils were increased; 100% repellency was achieved at 8μL in the second hour and this remained constant with time. The lowest repellency of 20% was obtained at 2μL. In fumigant toxicity, the highest mortality was 70% recorded at 8μL on the third day of exposure. The results indicated that the acetonic essential oil of dry Eucalyptol and 1R-Alpha-Pinene rich Eucalyptus saligna leaves can be developed into a bioinsecticide for controlling maize weevil as a repellent, toxicant and fumigant candidate.
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    Spectroscopic Analysis of Selected Priority Trace Metals in the Extant East African Gilled Lungfish (Protopterus amphibius) in Lira Municipal Lagoon and Its Edibility Health Risk
    (Science Journal of Analytical Chemistry, 2018) Omara, Timothy; Ogwang, Remish; Ndyamuhaki, Sarah; Kagoya, Sarah; Kigenyi, Erisa; Musau, Bashir; Adupa, Eddie
    This investigation analyzed the concentrations of three trace metals in gilled lungfish of Lira Municipal lagoon of Lira District and estimated the health risk associated with its consumption. Three fresh lungfish samples from the down, middle and up sluices of the lagoon were caught, eviscerated, washed and sundried. Edible muscles of the samples were oven dried at 105°C, desiccated and pulverized. 2.0 ± 0.1g of the fine fish powders were ashed at 550°C, acid digested, and the filtrates used to prepare 1 litre sample solutions. The sample solutions were analyzed for Lead, Zinc and Cadmium by Atomic absorption spectrometry. Spectroscopic results showed that no Cadmium was detected while the statistical mean concentrations of Zinc and Lead in the fishes from down, middle and up streams in mg/kg were 157.8 ± 0.01, 160.2 ± 0.02, 158.2 ± 0.01 and 6.84 ± 0.01, 1.69 ± 0.03, 5.12 ± 0.01 respectively. The above results showed that the trace metals in the investigated fish samples are deleteriously above the maximum permissible Zinc (0.7mg/kg) and Lead (0.3mg/kg) levels in fish indicated by CODEX STAN 193-1995. The statistical Estimated Daily Intakes were from 26.27 to 26.66 mg/kg/day for Zinc and 0.28 to 1.48 mg/kg/day for Lead. A heightened Health Risk Index value of 88.67 for Zinc was observed in the middle stream lungfish samples while Lead had the lowest Health Risk Index value of 2.00 in the middle stream fish from the lagoon. All the Health Risk Index values were greater than unity except for Chromium that was undetected in the fish muscles thus the lungfish of the lagoon is unsafe for human consumption and continuous consumption will impact human health. The immediate strategy lies in fencing the lagoon area and putting a stringent restriction against fishing from the lagoon.