Study on larvicidal activity of weed extracts against Spodoptera litura.

Larvicidal activity of various concentrations of crude aqueous leaf extracts of E. triplinerve were studied against S. litura following the treatment on fourth instar larvae. The results of the total percent mortality (from fourth instar to adult) demonstrated that the mortality rate progressively increased (41.42, 58.57, 69.80, 84.49, 86.77, 90.55, 91.30, 90.54) as the extract concentrations increased (1, 2, 3, 5, 7.5, 12.5, 15, 17.5%). The maximum of 92% total mortality was observed at 15% concentration of the extract. It was significant to note that the percent mortality observed from 5% onwards was more than 85%. Results of adult emergence inhibition indicated that the EI50 of E. triplinerve was more effective at 4.07%. Interestingly the calculated EI90 value was 14.10%. This is an ideal eco-friendly approach for the control of agricultural pest, S. litura.