Research Article | Volume: 3, Issue: 2, February, 2013

Larvicidal activity of Kotschya uguenensis plant powders and methanol extracts against Anopheles gambiae s.s. larvae in the laboratory and in simulated ponds

Innocent E Nkunya MHH and Hassanali A   

Open Access   

Published:  Feb 27, 2013

DOI: 10.7324/JAPS.2013.30221
Abstract

Polar constituents of Kotschya uguenensis Verdc. (Fabaceae) do not exhibit acute toxicity but cause growth disruption of Anopheles gambiae s.s. Gile (Diptera: Culicidae) larvae with eventual death. Time-course larvicidal effects of powders of root and stem barks and their crude methanol extracts in form of emulsions were compared in the laboratory and in artificial semi-field ponds. Kotschya uguenensis powders of root and stem barks and emulsions of their crude methanol extracts were assayed against A. gambiae s.s according to protocols of WHO 1996 & 2005. All formulations were equally effective under laboratory conditions giving 100% larval mortality within three days at a dose of 50 μg/ml of the extracts or concentrations of powders corresponding to the same level of extractable material. Under semi-field conditions, suspensions of the powder materials appeared to perform better than emulsions of methanol extracts. Time taken to give 80% mortality (LT80) of larvae and pupa at 0.1% w/v was 6.06 days for powders of root bark and 5.60 days for powders of stem bark. The LT80 for the root bark extract at 200 μg/ml was 8.28 days while that for the stem bark methanol extract was 12.47 days. No residual effects of the test materials on the larvae or pupae were evident in semi-field ponds 14 days after the re-introduction of the test materials. Our results suggest that, for the control of anophelines in the field, a weekly application of appropriate amounts of powders of K. uguenensis may be effective.


Keyword:     Kotschya uguenensis Verdc. Fabac


Citation:

Innocent E, Nkunya MHH, and Hassanali A., Larvicidal activity of Kotschya uguenensis plant powders and methanol extracts against Anopheles gambiae s. s. larvae in the laboratory and in simulated ponds. J App Pharm Sci. 2013; 3 (02): 122-126.

Copyright:The Author(s). This is an open access article distributed under the Creative Commons Attribution Non-Commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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