This aphid feeds mainly on apply foliage, notably fruiting spurs, causing leaf chlorosis and curling. Their feeding indirectly stunts and deforms fruits in the cluster. This species is therefore considered the most economically significant of the aphid species that feed on apple in Ontario. Young nymphs are pale yellow or pink. Hatched nymphs are wingless females that are called stem mothers when they are mature.
Adults are a dark purple-pink colour and are found in colonies on extension and terminal growth.
Overwintering eggs of rosy apple aphid on twig. Colony of rosy apple aphids. The eggs begin to hatch as tree buds open in the spring and continue to hatch over a two-week period. Aphid nymphs feed on the outside of leaf and fruit buds until leaves unfold. Mature females usually produce live young shortly after or during bloom.