Abstract

LARVICIDAL ACTIVITY OF A FEW INDIGENOUS PLANT EXTRACTS ON CULEX PIPIENS (DIPTERA: CULICIDAE)

Pushpalatha E.*, Aiswarya D. and Sharihan E.K.

ABSTRACT

Larvicidal activity of the acetone extracts of Acalypha fruticosa (leaf), Quassia indica (seed), Anamirta cocculus (fruit) and Sphagneticola trilobata (stem with leaf) on III instar larvae of Culex pipiens were estimated. Among the four selected plants, Anamirta cocculus fruit extract showed highest activity. The 24 hr LC50 is ranged from 29.57 ppm for acetone extract of A. cocculus and 461.23 ppm for acetone extract of A. fruticosa. 48 hr and 72 hr LC50 were also estimated and provided in the present study and A cocculus exhibited a very low concentration of 19.96 ppm. The data on 48 hr LC50 also decreased significantly to 47.13 ppm for the acetone extract of S. trilobata. a very low. Treatment with acetone extracts of the selected plant extracts also exhibited larval-larval, larva-pupal and pupal-adult malformations. However the acetone extract of Anamirta cocculus fruit did not exhibit any malformation in the treated concentrations as the larvae ever survived beyond III instar stage so as to develop any malformations and the plant extract caused complete death of the treated larval populations. The investigation further confirms the possibilities of developing a potent biocontrol agent based on A cocculus.

Keywords: Acalypha fruticosa (leaf), Quassia indica (seed), Anamirta cocculus (fruit) and Sphagneticola trilobata.