African Journal of Biotechnology Vol. 6 (3), pp. 307-311, 5 February 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Larvicidal effect of Hemidesmus indicus, Gymnema sylvestre, and Eclipta prostrata against Culex qinquifaciatus mosquito larvae

V. Gopiesh Khanna and K. Kannabiran*

School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore-632014, India.

*Corresponding author. E -mail: kkb@vit.ac.in or kkb_67@yahoo.com.  Tel: +91-0416-2202473. Fax: +91-0416- 2243092 / 2240411.

Accepted 29 December, 2006

The larvicidal effect of aqueous extracts of Hemidesmus indicus roots, Gymnema sylvestre and Eclipta prostrata leaves were tested against Culex quinquefasciatus larvae at the concentrations of 1, 2, 3, 4 and 5% up to three days. All extracts showed larval mortality. Larval mortality was 100% with the use of 5% concentration of root extract of H. indicus, leaves extracts of G. sylvestre and E. prostrata after 2 days. Qualitative analysis of the phytochemicals of aqueous extracts revealed the presence of carbohydrates, saponins, phytosterols, phenols, flavonoids and tannins in all the plants. Quantitative analysis showed that the crude saponin was the major phytochemical constituent present in highest percentage followed by crude tannin in all three plants. It is suggested that all the three plants possess larvicidal properties that could be developed and used as natural insecticides for mosquito control.

Key words: aqueous extract, larval mortality, qualitative analysis, phytochemicals, natural insecticides