Bio-efficacy of two sea weeds methanol extract on growth and development of Spodoptera litura Fabricius

Two algal sea weeds viz., Chaetomorpha antennina and Ulva fasciata collected from Puducherry coast, India were investigated for their larvicidal, growth and developmental effects on Spodoptera litura. Larvicidal action of methanol extract of sea weeds, noticed no effect up to 24 hrs of treatment. However, treatments exhibited gradual increase in mortality up to 7^th day. Both seaweeds methanol extracts at 10% concentration resulted larval mortality upto 66.6%. Eventhough the larval mortality was gradual among the treatments, pupation was indifferent among the treatments and the pupal to adult conversion was comparatively lower in all the treatments. Adult emergence data on the effect of C. antennina and U. fasciata (10%) exhibited similar pupal: adult conversion ratio of 1: 0.40 whereas in control and solvent control the ratio was 1: 0.92.