Mosquito larvicidal and ovicidal activity of Delonix elata (L.) Gamble against Culex quinquefasciatus Say (Diptera: Culicidae)

To determine the larvicidal and ovicidal efficacy of different solvent leaf and seed extract of Delonix elata (D. elata) against filariasis vector Culex quinquefasciatus (Cx. quinquefasciatus). Twenty five early third instar larvae of Cx. quinquefasciatus were exposed to various concentrations and were assayed in the laboratory by using the protocol of WHO 2005. The larval mortality was observed after 24 h of treatment. The ovicidal activity was determined against Cx. quinquefasciatus mosquito to various concentrations ranging from 75-600 mg/L under the laboratory conditions. Among five solvent extracts tested the maximum efficacy was observed in the leaf and seed methanol extracts. The LC50 and LC90 values of D. elata against early third instar of Cx. quinquefasciatus were 124.84, 147.86 mg/L and 213.88, 289.43 mg/L, respectively. No mortality was observed in controls. The Chi-square values were significant at P<0.05 level. Among five tested solvent, methanol extract was found to be most effective for ovicidal activity against Cx. quinquefasciatus mosquito. 100% mortality was observed at 375 mg/L . From the results it can be concluded the crude extract of D. elata was an excellent potential for controlling Cx. quinquefasciatus mosquito larvae and eggs.