Crude seed extracts of four forest tree species, Mora excelsa Benth, Carapa guianensis Aubl., Pentaclethra macroloba (Willd.) Kuntze and Clathrotropis brachypetala (Tul.) Kleinhoonte, from Guyana and Trinidad and Tobago were screened for their antifeedant activity against third instar larvae of Spodoptera frugiperda. All extracts tested exhibited antifeedant activity. M. excelsa had the highest antifeedant activity while C. guianensis, P. macroloba and C. brachypetala gave significantly lower activity. Maximum antifeedant activity (>75%) was recorded for acetone and ethanol extracts of M. excelsa seeds and intermediate activity (25-75%) for water extract of M. excelsa seeds. Low antifeedant activity (<25%) was recorded for all solvent extracts of C. guianensis, P. macroloba and C. brachypetala seeds which were not significantly different from each other. The overall antifeedant activity for seed extracts of all four tree species was comparable for samples from both Guyana and Trinidad and Tobago.