Sycamore Scale – Stomaoccus platani

Sycamore Scale – Stomaoccusplatani

Common Name: Sycamore Scale

Latin Name: Stomaoccusplatani


The scale is exceedingly minute, measuring just 1/16 inch long, and the greatest evidence is the appearance of yellow dots on the undersides of sycamore leaves. Close inspection exposes the scale inside the area. The scales change colour from orange to brown as they age, and mature females have little white tufts of wax emerging from the wax shell’s edges.

Host plant:     

Sycamore and London planetree is a host plants.


Each year, the sycamore scale has numerous generations.

Damages caused by Sycamore Scale:

The sycamore scale is a major pest of London plane trees and other sycamore trees. Sycamore scale is a significant pest of native and imported sycamores in California and Arizona, limiting their utility as landscape ornamentals.

Life history and habits:

Sycamore scale can be seen on the leaves from leaf flush to fall and on the delicate bark all year. The crawlers migrate from the bark to leaf buds, leaf petioles, and the undersurface of leaf blades, where they settle and eat using strawlike mouthparts. Each female scale lays 50 to 100 eggs in a single clump. Females who evolved from immatures fed on leaves frequently migrate and place their eggs on the bark. Other females deposit their eggs on the leaves. If the eggs were deposited on bark and leaves were present, many crawlers may migrate off the bark to settle and eat on foliage after they hatch. As autumn approaches, scale concentrations on leaves decrease, and a greater proportion of the scale population is found on the bark. Each year, the Sycamore scale has several generations.