Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-24T08:12:15.727Z Has data issue: false hasContentIssue false

Effects of a biologically active fraction from Melia volkensii on Culex quinquefasciatus

Published online by Cambridge University Press:  19 September 2011

L. W. Irungu
Affiliation:
Department of Zoology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
R. W. Mwangi
Affiliation:
Department of Zoology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
Get access

Abstract

A chromatographically enriched fraction designated Fraction B from dry fruits of the plant Melia volkensii (family Meliaceae) was evaluated with the objective of determining its toxic and growth inhibiting effects on the larvae and adults of Culex quinquefasciatus mosquitoes. The fraction was purified from a crude methanolic extract by cold precipitation and elution of the precipitate dissolved in a hexane-ethyl acetate solvent system through a silica gel column. Larval treatments involved rearing the larval stages in water containing the fraction at concentrations of between 5 and 200 ppm. The LC50 for this fraction was found to be 34.72 μg/ml in 48 h. Second instar larvae were found to be more susceptible to fraction B when compared to fourth instar larvae. All fourth instar larvae that survived the treatment moulted into larval-pupal intermediates that were short-lived. The extract was also found to be an oviposition deterrent at a concentration of 20 ppm and above. It is concluded that M. volkensii extract has potential in the control of Culex quinquefasciatus.

Résumé

Une fraction enrichie chromatographiquement et designée Fraction B des fruits secs de la plante Melia volkensii (famille Meliaceae) a été évaluée pour déterminer sa toxicité et ses effets inhibiteurs de croissance sur les larves et adultes de Culex quinquefasciatus. La fraction a été purifiée à partir de l'extrait méthanolé brut par précipitation à froid et elution du précipité dissoit dans un mélange de solvent hexane-ethyl acetate à travers une colonne de silica gel. Des traitements destinés aux larves impliquaient l'élevage des stades larvaires dans le l'eau contenant la fraction aux concentrations comprises entre 5 et 200 ppm. La DL50 pour cette fraction a été de 34.72 μg/ml en 48 heures. On a trouvé que les larves du 2nd instar ont été les plus susceptibles à la fraction B, comparées aux larves du 4ème instar. Toutes les larves du 4ème instar qui ont survécu au traitement ont mué en intermédiares larve-pupe dont la durée de vie a été écourtée. L'extrait s'est aussi révélé un dissuadant de l'oviposition à la concentration de 20 ppm et au dessus. On en a conclu que l'extrait de M. volkensii offre un moyen potentiel de lutte contre Culex quinquefasciatus.

Type
Research Articles
Copyright
Copyright © ICIPE 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Al-Sharook, Z., Balan, K., Jiang, Y. and Rembold, H. (1991) Insect growth inhibitors from two tropical Meliaceae. Effect of crude seed extracts on mosquito larvae. J. Appl. Entomol. 111, 425430.Google Scholar
Finney, D. J. (1971) Probit Analysis, Third edition. Cambridge Univ. Press.Google Scholar
Hsieh, M. Y. and Steelman, C. D. (1974) Susceptibility of selected mosquito species to five chemicals which inhibit insect development. Mosq. News 34, 278282.Google Scholar
Mwangi, R. W. (1982) Locust antifeedant activity in the fruits of Melia volkensii. Entomol. Exp. Appl. 32, 277280.Google Scholar
Mwangi, R. W. and Kabaru, J. M. (1991) Insect antifeedant and growth regulator compounds in different parts of Melia volkensii. In 4th Napreca Symposium on Natural Products. Extended abstracts. Addis Ababa, Ethiopia, pp. 1314.Google Scholar
Mwangi, R. W. and Mukiama, T. K. (1988) Evaluation of Melia volkensii extract fractions as mosquito larvicides. J. Am. Mosq. Control Assoc. 4, 442447.Google Scholar
Mwangi, R. W. and Rembold, H. (1987) Growth-regulating activity in Melia volkensii extracts on the larvae of Aedes aegypti. In Natural Pesticides from the Neem Tree and Other Tropical Plants (Edited by Schmutterer, H. and Ascher, K. R. S.), pp. 669681. Schriffenreice der GTZ, No. 206, Eschborn.Google Scholar
Mwangi, R. W. and Rembold, H. (1988) Growth-inhibiting and larvicidal effects of Melia volkensii extracts on Aedes aegypti larvae. Entomol. Exp. Appl. 46, 103108.Google Scholar
Rajab, M. S. and Bentley, M. D. (1988) Tetranortriterpenes from volkensii. J. Natural Products 551, 640844.Google Scholar
Rajab, M. S., Bentley, M. D., Achford, A. R. and Mendel, M. J. (1988) A new limonoid insect antifeedant from the fruit of Melia volkensii. J. Natural Products 51, 169171.CrossRefGoogle Scholar
Sukumar, K., Perich, M. J. and Boomar, L. R. (1991) Botanical derivatives in mosquito control: A review. J. Am. Mosq. Control Assoc. 7, 210237.Google Scholar
Zebitz, C. P. W. (1984) Effects of some crude and azadirachtin enriched neem Azadirachta indica seed kernel extracts on larvae of Aedes aegypti. Entomol. Exp. Appl. 35, 1116.Google Scholar
Zebitz, C. P. W. (1986) Potential of neem seed kernel extracts in mosquito control. Proc. 3rd Int. Neem Conf., Nairobi, pp. 555573.Google Scholar