Extracts from Calceolaria talcana exhibited strong bioinsecticidal effects against Drosophila melanogaster
and Spodoptera frugiperda. The most active extract was ethyl acetate and its majority compound verbascoside.
The highest lethal concentration to the larvae of S. frugiperda and D. melanogaster was 20.0 g/ml
of the ethyl acetate extract with 95.8% and 67.0% of mortality, respectively. Against D. melanogaster the
ethyl acetate extract showed the highest activity with 75.05% of antifeedant index at 25 g/ml, methanol
extract instead showed 100% to 100 g/ml. At very low concentrations ethyl acetate and methanol
extracts induce antifeedant and insect growth regulatory activity showing selective effects as deterrent
and on the sclerotization showing a pre-emergence effect on S. frugiperda. The results from these extracts
were better than showed by methanol extracts from Cedrela salvadorensis, Myrtillocactus geometrizans and
Yucca periculosa samples used as positive controls.