Larvicidal activity of two seaweeds, Ulva fasciata and Grateloupia lithophila against mosquito vector, Culex quinquefasciatus

The frequent use of systemic insecticides to manage insect pests leads to a destabilisation of ecosystem and enhanced resistance to insecticides and pests suggesting a clear need for alternatives. In addition, increasing documentation of negative environmental and health impact of synthetic insecticides and increasingly stringent environmental regulation of pesticides have resulted in renewed interest in the development and use of bio insect management products for controlling mosquitoes and pest. The present study focuses on larvicidal activity of methanol, acetone and benzene extract of seaweeds (Ulva fasciata and Grateloupia lithophila) against Culex larva. Of the two algae screened G. lithophila was found to effective against the larva Culex in all the 3 extracts. There is no previous report on the mosquito larvicidal activity of U.fasciata and G. lithophila from the Kovalam coast of Tamil Nadu, India.