Euonymus scale, gloomy scale, juniper scale, peony scale, pine needle scale, tea scale, and white peach scale are our most frequently-reported armored scale insects in the landscape and nursery. Horticultural oils are essentially the same chemical as plant shine oil, baby oil or mineral oil except that horticultural oils often have a surfactant that helps keep the oil in suspension. No. 45 has additional information on horticultural oils and rates for use on scales as well as aphids, mealybugs, mites and whiteflies. Euonymus Scales Euonymus scale insects are common and sometimes very damaging pests of euonymus and a few other ornamental plants. Male euonymus scales have snowy white armor and are sometimes quite conspicuous against the leaves.
Females have gray, oyster-shaped armor and are less conspicuous.
Females and males can be found on stems as well as on leaves. Note No. 15 provides information on the euonymus scale and its control. Horticultural oil or Cygon used for euonymus scale suppression should also control spider mites and other pests of euonymus. Gloomy Scales Gloomy scales make the bark of infested maples rough, dark and unsightly . They also cause twig dieback.