Tulip tree scale

The tulip tree scale (Toumeyella liriodendri) belongs to the family Coccidae and is considered one of the largest soft scale insects. It is a notorious pest that primarily targets specific deciduous trees, causing significant stress to the host plant through its intense feeding habit.

Its main host is the tulip tree (Liriodendron tulipifera), though it frequently infests various species of magnolia and other ornamental trees. The insects prefer to colonize the lower branches and stems, forming distinct, dark-colored, bumpy masses that are often mistaken for part of the bark.

The life cycle is univoltine. In late summer, females give birth to nymphs, which then move to twigs to feed and overwinter. In spring, they resume growth rapidly. The mature females become large and convex, secreting honeydew while protecting the developing eggs underneath their bodies.

Damage is twofold: direct extraction of plant sap leads to wilting and branch dieback, while the secretion of sticky honeydew promotes the growth of black sooty mold. This mold covers leaves and stems, significantly reducing the efficiency of photosynthesis and causing premature leaf drop.

Control strategies require timely intervention. Systemic insecticides are the most effective method, especially during the crawler stage. Cultural practices, such as removing heavily infested branches and ensuring the plant receives adequate water and nutrients, are crucial for recovery and long-term protection.

• Monitor for crawler activity in late summer.
• Apply systemic insecticides during the peak growth season.
• Use dormant oils in early spring to kill overwintering scales.
• Prune and destroy heavily infested plant parts.