After various crop plants, grown on insecticide-free soil were screened for the presence of biologically active substances, a few were selected for further studies. During the coming year, efforts will be continued to isolate and identify compounds which have insecticidal and/or synergistic properties. Previously isolated materials, some of them identified, will be tested for their acute and chronic toxicities. Their effects on biological systems, especially with rats and insects will be further investigated.