Manduca sexta on a wild tobacco leaf (IMAGE) Max Planck Institute for Chemical Ecology Caption The larva of a tobacco hawkmoth Manduca sexta on a wild tobacco leaf: A detailed chemical analysis of larval frass (small black ball) revealed how toxins are activated in the caterpillars, thus providing clues to the biosynthesis of the toxins in the plant, the reversed process in comparison to digestion, or as the scientists called it: the "digestive duet". Credit Anna Schroll Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.