L-Dopa in Legume Seeds: A Chemical Barrier to Insect Attack

Seeds of the genus Mucuna display both a remarkable immunity to attack by seed-eating insects and an unustially high concentration of free L-dopa. When seed powders or pure L-dopa were incorporated into artificial diets and fed to southern armyworm larvae, mortality increased, and abnormal pupae and adults resulted. At higher concentrations L-dopa acted as a feeding repellent.