R. KANNAN* AND R. BHARATH KUMAR
Department of Entomology, Annamalai University, Annamalai Nagar-608 002 (Tamil Nadu), India *(e-mail : kaninsect@yahoo.co.in; Mobile : 9944030789)
(Received : March 5, 2019; Accepted : May 15, 2019)
ABSTRACT
Ulva fasciata Delile, a green algal seaweed, collected from Puducherry coast, India was investigated for its effect on Spodoptera litura Fabricius in Department of Entomology, Faculty of Agriculture, Annamalai University. Experimental results on the larvicidal action of acetone extract of seaweed, U. fasciata revealed no effect up to 24 h of treatment. In U. fasciata treatments, gradual increase in mortality was noticed up to 7th day and on the 7th day observation, acetone extract at 10% concentration exhibited larval mortality of 66.67%. Even though the larval mortality was gradual among the treatments, pupation was at variable level among the treatments and the pupal to adult conversion was comparatively lower in all the treatments. Adult emergence data exhibited pupal : adult conversion ratio of 1 : 0.40 in U. fasciata 10% treatment, whereas in control the ratio was 1 : 0.92.
Key words :Ulva fasciata, seaweed, acetone extract, Spodoptera litura, larvicidal activity