African Journal of Biotechnology Vol. 5 (9), pp. 761-765, 2 May 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Larvicidal properties of Lepidagathis alopecuroides and Azadirachta indica on Anopheles gambiae and Culex quinquefasciatus

OBOMANU , F. G.¹*, OGBALU, O. K.², GABRIEL, U. U.³, FEKARURHOBO, G. K.¹, and ADEDIRAN, B. I.¹

¹Department of Chemistry, Rivers State University of Science and Technology, Port Harcourt, Nigeria.

²Entomology Unit, Department of Applied and Environmental Biology, Rivers State University of Science and Technology, Port Harcourt, Nigeria.

³Department of Fisheries, Rivers State University of Science and Technology, Port Harcourt, Nigeria.

*Corresponding Authors E-mail: faithwinobomanu@yahoo.com.

Accepted 31 March, 2006

Comparative analysis of the larvicidal properties of aqueous extracts of leaves of Lepidagathis alopecuroides and Azadirachta indica (neem) was carried out on Anopheles gambiae and Culex quinquefasciatus. Assays showed that L. alopecuroides was more toxic to both larvae, while C. quinquefasciatus was more susceptible to extracts of both plants. For extracts from 500 mg of leaves in 1 L of water, the lethal time (LT₅₀) for C. quinquefasciatus and A. gambiae with L. alopecuroides extract was in the ratio 1:4.5, while it was 1:21.8 with neem extract.  No mortality was recorded in A. gambiae exposed to neem at all the concentrations until the emergence of the adult.  The results suggest that L. alopecuroides is more potent than neem and could be developed as a cheap, effective and renewable resource that could be incorporated into the Roll Back Malaria program in Nigeria and other countries.

Key words: Lepidagathis alopecuroides, Azadirachta indica, Culex quinquefasciatus, Anopheles gambiae, larvicide.