Bioefficacy of violacein against Asian armyworm Spodoptera litura Fab. (Lepidoptera: Noctuidae)

The aim of the study was to assess the bioefficacy of violacein isolated from Chromobacterium violaceum against Spodoptera litura, an important field pest. Antifeedant, larvicidal and pupicidal activities of violacein were evaluated for its bioefficacy against the third instar larvae of Spodoptera litura at 125, 250, 500 and 1000 ppm concentrations. After 24 h of treatment, violacein treated larvae showed maximum antifeedant activity of 72.46% at 1000 ppm concentration with LC50 of 392.25 ppm. Four days after treatment, violacein treated larvae showed a mortality of 77.10% at 1000 ppm concentration with a LC50 value of 255.06 ppm. Violacein treated larvae recorded 20–24% pupicidal activity at 125–1000 ppm concentration. The antifeedant and larvicidal activities were increased with increasing concentration. Violacein could also be considered for use in the management of pests.