Adult woolly apple aphids are wingless until a generation is produced that can migrate to a different host. Wingless adult females bearing live young are found on apple trees during the summe. This adult form is dark brown to purplish, and 1.8 mm (.07 in.) long. In aerial colonies, it has a long, white, filamentous waxy secretion. In underground colonies it has a more bluish-white, rodlike secretion.