LARVICIDAL PROPERTIES OF FOUR ETHIOPIAN ME()ICINAL PLANTS AGAINST CULEX QUINQUEFASClATUS

Abstract

The emergence and spread of insecticide resistant mosquitoes necessitated the;! search for
plant derived insecticides. A study was conducted to investigate the larvicidal properties of four
EtJ;riopian maUcinal plants against second instars of laboratoty reared Culex quinquefasciatus. Finely
ground powders of Chrysanthemum coronariurn inflorescence, Melia azadirach seeds, Azadiractha indica
seeds and Phytolacca dodecandra berries were tested for their larvicidal effect. The tests were conducted
by exposing 20 mosquito larvae per cup to plant materials diluted in distilled water at different test
concentrations (400, 200,'100, 50 and 25 mg/ml). P. dodecandra (LCso=.90.21 mg/lit) and C. coronarium
(LC50 = 96.21 mg/lit) showed better leilial effect compared to M. azadirach (LCso= ;w3.06 mg/lit) and A.
indica (LC50= 229:86 mg/lit). Larvicidal properties of these plants decreased in the order P. dodecandra
berries, C. coronarium inflorescence, M. azadirach seeds and A. indica seeds