Use of plant derivatives for insect pest control was common in the tropics before the advent of synthetic pesticides. Plants such as neem, Azadirachta indica A. Juss, chinaberry, Melia azedarach L., and Warburgia spp., have been known for insect repellent and antifeedant properties in addition to other plants possessing insecticidal and growth regulating properties. Practical usefulness of antifeedants derived from plants for management of insect pests in selected field crops and stored grains is discussed. These products would, however, require some definitions of quality control and standardization of biological properties for large-scale use.
