To improve our understanding of factors that affect intraplant distribution ofArtogeia rapae(L.) andTrichoplusia ni(Hübner) on cabbage, we exposed larvae to gradients of cabbage leaf age. Excised leaves from field-grown cabbage were arranged in a chamber to form the gradient of leaf age. Larvae in the third-fifth instar were allowed to feed on these leaves for 48 h, and leaf area consumed was measured. Larvae ofT. nishowed no preference for leaves of any particular age, eliminating one of a number of factors that were suspected of affecting their distribution on cabbage. Larvae ofA. rapaepreferred the youngest (head and wrapper) leaves, which helps explain observed intraplant distributions on these larvae in the field and allows us to predict the location of their feeding damage on the plant.