Larvicidal activity of Wrightia tinctoria R. BR. (Apocynaceae) fruit and leaf extracts against the filarial vector Culex quinquefasciatus Say (Diptera: Culicidae)

To determine the larvicidal activity of crude aqueous and petroleum ether extracts of Wrightia tinctoria fruits and leaves against the filarial vector, Culex quinquefasciatus. The larvicidal activity was evaluated at concentrations of 0.06%, 0.12%, 0.25%, 0.50% and 1.00%. Larval mortality was observed for 24 and 48 h. Among the plant parts tested, aqueous fruit extract exhibited highest larvicidal activity followed by aqueous leaf extract with LC50 values of 0.17% and 0.09%; 0.21% and 0.11% after 24 and 48 h respectively. Further investigations are needed to elucidate this activity against a wide range of all stages of mosquito species and also the active ingredient(s) of the extract responsible for larvicidal activity should be identified.