Browsing by Author "Kongoro, Jedida"

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    Laboratory Evaluation of Selected Medicinal Plant Extracts in Sugar Baits and Larval Food Against Phlebotomus Duboscqi Neveu Lemaire (diptera: Psychodidae), A Vector for Cutaneous Leishmaniasis in Kenya
    (WebmedCentral, 2011-12-28) Ireri, Laban N.; Kongoro, Jedida; Ngure, Peter Kamau; Tonui, W
    Introduction; The efficacy of Tagetes minuta (Asteraceae), Acalypha fruticosa (Euphorbiaciae) and Tarchonanthus camphoratus (Compositae) extracts were evaluated for the control of Phlebotomus duboscqi while incorporated in sucrose. This is the first time plant extracts have been used in sucrose baits against sand flies as opposed to environmentally unfriendly synthetic insecticides. Materials and methods; The plants were collected from Marigat area, Baringo district in the Rift Valley Province of Kenya, an endemic area for leishmaniases. Extraction was done using N-hexane, dichloromethane, ethyl acetate and methanol. Results; The extracts showed significant mortality (P< 0.05) to both males and females and had comparable LD50 values in Tagetes minuta and Acalypha fruticosa extracts bioassays. The lowest LD50 value for females was 10.6mg/ml in ethyl acetate bioassays in Tagetes minuta and Acalypha fruticosa extracts, while the highest was 12.0 mg/ml in Tagetes minuta methanol extract. Males had the lowest value of 9.9mg/ml in Tagetes minuta methanol extract, while the highest was in Acalypha fruticosa methanol extract with a value of 15.5mg/ml. Results however showed that there was no significant mortality (P> 0.05) difference between males and females but mortality significantly differed (P<0.05) at various concentrations. Tarchonanthus camphoratus and combined extracts however showed weaker insecticidal properties than from separate extracts. Feeding the larvae usingextracts in larval food and plain powders nonetheless revealed no larvicidal properties in the plant samples. Conclusion; The results showed potent properties and may guide future research initiatives aimed at controlling sand flies using sugar baits as alternative approaches to conventional methods. Acalypha fruticosa Forssk (Euphorbiaciae), botanical compounds, Tagetes minuta Linnaeus (Asteraceae), Tarchonanthus camphoratus L (Compositae), phlebotomine sand flies
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    The potential of the extracts of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae), the vector for Leishmania major Yakimoff and Schokhor
    (Journal of Vector Borne Diseases, 0201-09) Ireri, Laban N.; Kongoro, Jedida; Ngure, Peter Kamau; Mutai, Charles; Langat, Bernard; Tonui, Willy K.; Kimutai, Albert; Mucheru, Obadiah
    Background & objectives: Harmful effects of synthetic chemical insecticides including vector resistance, environmental pollution and health hazards have necessitated the current significance in the search for plant-based insecticide products that are environmentally safe and effective to leishmaniases control. The insecticidal activity of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) extracts were investigated against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae). Methods: The extracts were prepared from dried aerial parts soaked in methanol and ethyl acetate twice until the filtrates became clear, filtered and dried out by rotary evaporation at 30–35oC. The solid extracts obtained were later prepared into 2.5, 5 and 10 mg/ml. Two millilitres of the solutions were blotted on filter papers, which were dried overnight and placed into jars where adult sandflies were aspirated. Males and females were assayed separately. Results & conclusion: The extracts had significant mortality (p<0.05) in both males and females bioassays but were not significantly different between sexes. The extracts of Acalypha fruticosa and Tagetes minuta had significantly higher mortality rates than those of Tarchonanthus camphoratus and the different concentrations used showed significantly different mortality rates and 10 mg/ml was the most effective concentration. Cent percent mortality was obtained at 96 h of exposure to 5 and 10 mg/ml concentrations except for Tarchonanthus camphoratus which had a mortality of only 46.7% in 10 mg/ml bioassay. These extracts were found to be insecticidal to adult sandflies.