TOXICITY OF NERIUM INDICUM AND EUPHORBIA ROYLEANA LATTICES AGAINST CULEX QUINQUEFASCIATUS MOSQUITO LARVAE

Different dilutions of aqueous and methanolic extracts of lattices of Nerium indicum (Apocynaceae) and Euphorbia royleana (Euphorbiaceae) were administered for 24h and 48h to the Culex quinquesfasciatus (Diptera: Culicidae) larvae in order to test their lethality. The larvicidal activity of lattices of both plants, were time and dose dependent respectively. There was a significant negative correlation between LC values and exposure periods. The result also indicates that the different dilutions of the lattices of both plants also significantly delayed the post-embryonic development of Culex larvae. Methanolic extract of N. indicum is 1.8 times more toxic than aqueous extract while in case of E. royleana, the methanolic extract was 16 times more toxic in comparison to aqueous. Key Words: Nigerian Journal of Natural Products and Medicine Vol.7 2003: 61-6