They are most commonly found on the undersides of plants in the vegetable garden, but may also be found on the actual heads of the cabbage family plants. In small numbers, you may notice very little plant damage, but in large numbers aphid damage will appear in the form of yellowing leaves which tend to wilt in a downward direction. This wilting often looks like a cup because the edges of the leaves curl inward toward each other. Gardens with aphid damage may also have plants which have a sticky coating on the leaves. Ants are also typically present when aphids are.
Aphid infestations can quickly multiply.
Actual cabbage plant damage occurs as the aphid feeds off of the plant, sucking out its juices. In it s wake, the cabbage aphid leaves a sticky coating on leaves known as honeydew or plant sap. This honeydew is a byproduct of the cabbage aphid s inability to digest all of the plant sugars. Ants are usually present, because they feed on this sticky substance. Aphids can reproduce rapidly, so once infestation begins it is likely to get severe.