Two species of aphids attack pecans. Yellow and black aphids feed on leaves. Honeydew is deposited on the foliage and black sooty mold fungi develops. Damaged leaves may appear speckled or have patches that often turn brown and then die. Adult aphids are either yellow or black and have soft bodies with delicate wings and a pair of tubes projecting from their abdomen.
Adults have wings and immatures are wingless and usually appear in colonies.
Both species overwinter as eggs deposited in bark crevices. Nymphs are active in the spring. There may be 10 or more generations a year. Damaged leaves may appear speckled or have yellow patches that often turn brown and then die. Such feeding can cause leaves to drop prematurely.