Studies on the Effectiveness and Biological Activities of Strophanthus divaricatus Against Imported Cabbage Worm

s: Results of experiments in laboratory indicated that the extracts of fruits, leaves and stems from Strophanthus divaricatus possessing strong antifeedant and insecticidal properties on the 4th instar larvae of the imported cabbage worm Pieris rapae. It was found that the LC50 and LC95 of D-strophanthin isolated from Strophanthus divaricatus were 32.046 8 mg/L and 379. 718 1 mg/L respectively, against 4th instar larvae of Pieris rapae. Results in field trials showed that the good effectiveness was obtained with 0. 05% commercial products of Strophanthus divericatus against imported cabbage worm.