G. Schmeda-Hirschmann, P. Román , C. Theoduloz. Departamento de Ciencias Biológicas, Universidad de Talca, Casilla 747, Talca, Chile.The main secondary metabolites of Fabiana imbricata showed toxicity towards the greenbug Rhopalosiphum padi when administered in an artificial diet. A dose-dependent toxicity was observed for fabiaimbricatan-15-oic acid and oleanolic acid at doses up to 3.0 mM (p <0.01). Both compounds apparently act as antifeedants at higher doses. Rutin also showed a dose-related toxicity. Scopoletin and p-hydroxyacetophenone were toxic at 6.0 mM. None of the compounds tested were toxic towards the fifth instar Heliothis zea larvae.