Landscape - White Prunicola Scale

The following is information on the white prunicola scale that affects many woody plants in the landscape.

WHITE PRUNICOLA SCALE.

This armored scale feeds on a number of hosts including: Acer, Alunus, Aucuba, Buxus, Forsythia, Ilex, Ligustrum, Malus, Prunus, Rhododendron, Syringa, and others. Crawlers of the second generation are active at 2314 3586 [3010 peak] GDD. This insect is often confused with white peach scale and is a serious pest on Prunus. Male scales are elongate, felted, white and light yellow at one end; whereas females are round with light yellow slightly off center. Scales are usually on bark and fruits, although occasionally found on leaves. Male scales are often in conspicuous white masses on the undersides of branches when trees are heavily infested. Parasitoids and predators provide some natural control. Chemical control options include horticultural oil, insecticidal soap, dinotefuran (Safari), pyriproxyfen (Distance) or one of the pyrethroids.

White prunicola scale. Photo from the June 3, 2005 edition of the Branching Out newsletter from Cornell Cooperative Extension.

Information from Brian Kunkel, Ornamental IPM Specialist, UD