the effect of aqueous extracts of talisia esculenta (t.e.) and sapindus saponaria (s.s.), were evaluated on the development and mortality of 8-14th day-life spodoptera frugiperda, an important pest of maize. corn leaves were dipped in the aqueous extracts (1% w/v) and offered as food to the caterpillars. the treated corn leaves with the extracts caused larval mortality (26.71%/t.e.; 63.3%/s.s.) and also showed effect on the larval weight (237.50 mg/t.e.; 86.65 mg/s.s.) when compared with the control (11.3% and 293.45 mg), mortality and larval weight, respectively. the electrophoresis with gelatin (0.1%) showed two very clear white areas (trypsin activity) in the caterpillars midgut of all the treatments. only the caterpillar treated with s. saponaria presented significant differences, showing trypsin activity (10.59%). sapindus saponaria appeared better than talisia esculenta and showed good potential to be used as control agent for s. frugiperda.