Tuliptree aphids are out in full force attacking their favorite host, tuliptree or yellow poplar, Liriodendron tulipifera. These insects are found throughout Illinois from mid-June to October.
Tuliptree aphids are generally light green to pink. They feed on the undersides of leaves where they cause leaf yellowing. Heavy infestations can cause leaves to turn brown and drop prematurely. They are more of a problem on trees that are under some type of stress, such as drought, compacted soil, or construction damage. The major concern with tuliptree aphid is the large amount of honeydew produced from their feeding. Honeydew dropping from trees can create a sticky mess on sidewalks and on cars parked beneath infested trees. In addition, honeydew can attract bees and stinging wasps. Tuliptree aphids overwinter as eggs in the bark crevices of trees. In the spring, eggs hatch into young aphids. Winged and wingless forms appear in June and July.
Management involves keeping trees healthy through proper watering and fertilization practices. Heavy rains throughout the summer wash aphids off trees. High-volume sprays of water may also reduce aphid numbers. Low populations of tuliptree aphid can be managed with foliar applications of insecticidal soap. These applications also help preserve natural enemies such as parasitic wasps and predators. Because tuliptree aphids are generally exposed while feeding, they are subject to attack by many parasitic wasps, which turn the aphids into brown mummies. Predators such as the two-spotted ladybird beetle also feed on tuliptree aphids. Heavy tuliptree aphid populations that are causing aesthetic injury can be managed with foliar sprays of either insecticidal soap or acephate (Orthene).