This study investigated the mosquitocidal activities of marine algae collected from Gulf of Mannar. The larvae Aedes aegypti and Culex quinquefaciatus tested against Padina gymnospora and Caulerpa racemosa were extracted using different solvents like Chloroform, Methanol, Petroleum ether and Acetone. The two different seaweed extracts using four different solvents were proved statistically significant (p<0.05). The seaweed extract used for the LC50 assay against II and III instar larval mortality was recorded. The overall results was observed all the solvent extract against Padina gymnospora especially more toxic in acdtone and chloroform of Culex quinquefaciatus (II & III -100%) followed by chloroform in Aedes aegypti (II & III -83%). Likewise the similar species of mosquito larvae (Aedes aegypti) against Caulerpa racemosa extract in Chloroform, acetone and methanol showed the high mortality was noted. These findings may help in developing a prospective alternative source to control the mosquitoes.
