Investigation of killing and antifeedant effects on pieris rapae larva of extracts from some potential plant species

Abstract

An investigation on killing and antifeedant effects on Pieris rapaelarvae of extracts from 10 different potential plant species was carried out. The extracts from leaves and immature fruits of Melia azedarach, mature Momordica cochinchinensis seeds, mature Sophora japonica seeds, Capsicum annuum fruits were found to have very strong antifeedant activities. The extracts from leaves of Elsholtzia ciliate, Ocimum bacilicumand young seeds of Sophora japonica exhibited a moderate antifeedant activities. Antifeedant activities of seeds of Momordica cochinchinensis and Sophora japonicamight be attributable to trypsin inhibitors. The extracts from fruits ofCapsicum annuumhad a very strong killing effect on the insect. Pieris rapae - killing effects of extracts from  Sophora japonica mature seeds, Melia azedarach leaves, and Momordica cochinchinensis seeds were quite strong, and the activities were enhanced when the 3 extracts were applied on Pieris rapaelarva previously sprayed with the diluted Capsicum annuumfruit extracts.