Bioactivity of Some Plant Extracts against Mustard Aphid, Lipaphis erysimi (Kalt.) and its Predator Coccinella septempunctata (Linn.)

Insecticidal activity of chloroform, methanol extracts and oils from nayantara, Vinca rosea and bottle brush, Callistemon lanceolatus were tested against mustard aphid, Lipaphis erysimi and its predator lady bird beetle Coccinella septempunctata under laboratory condition by direct spray and leaf residue methods. Chloroform extract of V rosea (LC50=0.409%) was found to be the most toxic when applied by leaf residue method followed by methanol (0.613%) and oil (1.031%). In case of C. lanceolatus, the descending order of toxicity was methanol (0.965%), chloroform (0.987%) and oil (1.807%). Similar trend was also observed when these extracts and oils were applied by direct spray method and the descending order of toxicity were as follows chloroform (0.465%), methanol (0.465%) and oil (1.622%) for V. rosea and methanol (1.104%), chloroform (1.200%) and oil (2.487%) for C. lanceolatus. None of the extracts and oil have shown any mortality to its predator Coccinella septempunctata up to ten days after feeding the treated aphid.