Larvicidal activity of latex and stem bark of Euphorbia tirucalli plant on the mosquito Culex quinquefasciatus

Abstract

The methanolic, chloroform and ether extracts of Euphorbia tirucalli latex and stem bark were evaluated for larvicidal activity against laboratory-reared larvae of Culex quinquefasciatus (Diptera: Culicidae), vector of the brancroftian filariasis and worst urban nuisance mosquito. The latex extracts contain more potent larvicidal components (177.14 mg/L-326.37 mg/L) than the stem bark extracts (237.663 mg/L-513.39 mg/L). The order of toxicity (LC50) for the latex extracts was Methanol extract (177.14 mg/L) > Chloroform (200.76 mg/L) > Ether (326.37 mg/L) while the rank of order of toxicity (LC50) of stem bark extracts was Ether (237.66 mg/L) > Chloroform (343.515 mg/L) > Methanol (513.387 mg/L), Higher doses (LC90 24 h of mosquito larvae) of each extract did not cause any mortality among fishes after 24 h. The study gave a weight into the possibility of formulating suitable preparation from the latex and stem bark extracts of the plant for use in mosquito control programme.