INSECTICIDAL ACTIVITY AND DITERPENE CONTENT OF PERSEA-INDICA

Extracts of Persea indica were toxic against Macaronesia fortunata (Lepidoptera: Lymantriidae) and Heliothis armigera (Lepidoptera: Noctuidae). Two insecticidal diterpenes, ryanodol and cinnceylanol, were present in the plant's petrol, methanol and water extracts. The methanol extract produced the highest larval mortality and growth reduction against M.fortunata, and also had a negative effect against H. armigera larvae. The reduction in both larval weight and development brought about by the components of the petrol extract can be partially attributed to the presence of the two diterpenes, but these products alone, however, do not explain the high toxicity of the methanol extract. The differential effect of the methanol extract and the potential use of P. indica for pest control are discussed.