A MARROW-STEM kale (Brassica oleracea var. acephala) selection segregated on selfing for plants with and without cuticular wax on their leaves, and it was observed in a natural field infestation that the non-waxy plants were not colonized by the cabbage aphid (Brevicoryne brassicae L.), whereas the normal, waxy plants had large colonies. The resistance of non-waxy plants was confirmed in a field plot, artificially infested. In a severe attack of cabbage white fly (Aleuroides brassicae Walk.), which developed later in the year than the aphid attack, no larvae or pupae, and only occasional adult flies, were found on the non-waxy plants, whereas the lower sides of the leaves of the waxy plants were covered with white fly at all stages of their life-cycle.