LARVICIDAL ACTIVITIES OF Ocimum basilicum AND Mentha piperita EXTRACTS AGAINST AEDES MOSQUITO LARVAE

Abstract

Mosquito borne diseases are major health problems in tropical and subtropical countries. In addition to development of resistance in mosquito species, control measures using synthetic insecticides have led to several environmental hazards. This study investigated the larvicidal potential of Ocimum basilicum and Mentha piperita, against the Aedes mosquito larvae. Fourth instar larvae were used for larvicidal bioassay. The aqueous plant extracts of M. piperita and O. basilicum were used singly and in combination and water was used as control. The larvae were exposed to a range of concentrations of each extract under laboratory conditions and larval mortality was assessed after 24 and 48 hours exposure. After 24 hours, M. piperita extracts had the highest larvicidal activity (90%) at 2.0ml followed by a combination of the two extracts (76.67%). At 48 hours, M. piperita maintained the highest larvicidal activity. M. piperita and O. basilicum had LC50 of 0.01mg/ml and0.14mg/ml respectively after 48 hours of exposure. The results indicated that M. piperita and O. basilicum may play an important role in reducing the use of chemicals for mosquito control. In-depth investigations to elucidate the active ingredients of the extracts should therefore be conducted.