INSECTICIDAL DEFENSES OF PIPERACEAE FROM THE NEOTROPICS

Insecticidal and growth-reducing properties of extracts of 14 species of American neotropical Piperaceae were investigated by inclusion in diets of a polyphagous lepidopteran, the European corn borer, Ostrinia nubilalis. Nutritional indices suggested most extracts acted by postidigestive toxicity. Piper aduncum, P. tuberculatum, and P. decurrens were among the most active species and were subjected to bioassay-guided isolation of the active components. Dillapiol was isolated from the active fraction of P. aduncum, piperlonguminine was isolated from P. tuberculatum, and a novel neolignan from P. decurrens. The results support other studies on Asian and African Piper species, which suggest that lignans and isobutyl amides are the active defence compounds in this family.