Insecticidal Toxicity of Spilanthol from <i>Spilanthes acmella</i> Murr. against <i>Plutella xylostella</i> L.

Abstract

The present study explored the Spilanthes acmella Murr. for insecticidal principle, a plant of high value. The seed extract showed insecticidal activity against Plutella xylostella. Further, bioassay guided isolation of bioactive compounds resulted in insecticidal active molecule, which was identified with the help of ESI-MS and NMR. Highest activity of 95 - 100 percent was observed at low dose of 2 g/l with spilanthol, while 60 - 70 and 80 - 90 percent mortality at 5 g/l in crude seed extracts prepared in methanol and hexane after 48 hours exposure, respectively. LC50 of 1.49, 5.14, 5.04, 11.75 g/l was observed with spilanthol, crude seed extract of methanol, hexane, deltamethrin, respectively. The findings indicate the potential of S. acmella with potent insecticidal toxicity for the management of P. xylostella and other insects of agricultural importance.