Abuja Journal of Agriculture and Environment (AJAE)

LARVICIDAL EFFECTS OF THE CRUDE ETHANOL EXTRACT AND FRACTIONS OF LAGGERA AURITA(D.C) SCH.BIP AGAINST ANOPHELES GAMBIAE
Author(s): Dantanko, F., Malann, Y. D., Ameh, U. C., Oyerinde, A. A. and Gywa, G. D.
Volume/Issue: Volume 1 , Issue 2 (2021)

ABSTRACT:

Anopheles gambiae is an important vector of malaria parasites in Nigeria. Vector control using plant extracts is one of the methods. The crude ethanol extract and fractions of Laggera aurita (D.C) Sch were investigated against the fourth instar larva of the malaria vector, Anopheles gambiae. The tests were carried out following the standard World Health Organisation larval susceptibility test. Three replicates comprising of 20 larvae each were exposed to various concentrations of the extracts. Larval mortality was observed after24 and 48 hours respectively. The results showed that mortality increased with an increase in concentration and period of exposure. Fractions P4 (dichloromethane: methanol ratio 1:1) and P3 (methanol: water ratio4:1) were found most effective with LC values of 2922 and 3284 mg/L respectively. The Nuclear Magnetic 50Resonance (NMR) results of the active fractions revealed the presence of thymol, carvacrol, triterpenes of sitosterol, stigmasterol and amyrin type. The study shows that these naturally occurring compounds could have potential applicability in the control of Anopheles gambiae.

KEYWORDS:

Laggera aurita; ethanol extract; fractions; Anopheles gambiae; larvae.