University of Kentucky -- College of Agriculture -- Department of Entomology

Scale Insects in Kentucky


Scale Host Appearance Crawlers Active in Kentucky
Cottony Maple Scale maples, other woody plantsflat, oval, brown, 1/8 inch long with large white cottony egg sac protruding from under bodyearly September
Euonymus ScaleEuonymus spp., Pachysandra, Bittersweet females: dark brown or gray, 1/16 inch long, resemble oystershell scales, pear-shaped; males: smaller, narrow, white.First brood: late May; Second and third broods: late July to early September
Juniper ScaleJuniper, Arborvitaefemale: circular, flat, dirty white, 1/20 inch, yellow exuviae off-center (looks like a fried egg); males:smaller, narrow, exuviae located at end of shellmid-May
Lecanium ScalesArborvitae, Sweetgum, Zelkova, other hostsmostly hemispherical or turtle-shaped, brown, 1/8 to 1/6 inch.varies with species
Magnolia ScaleMagnolia, Tuliptree broadly oval, convex, 1/2 inch long early September
Obscure ScalePin Oaks, Hickory, Walnutroughly circular, flat, 1/8 inch, exuviae form a central spot surrounded by a gray ringJune through August; late July is best time for a single treatment
Oystershell ScaleLilac, Maple, Willow, other hostsoyster-shaped, gray, 1/8 inch, exuviae accumulated at narrow endearly May when hawthorn blooms
Taxus MealybugTaxus, (apple, cedar, linden, maple)adult mealybug is approx. 8 mm long, they cluster in crotches of twigs and branches; white-gray in colorlatter half of May, summer
Tuliptree ScaleTuliptree, Walnut, other plantshemispherical, 1/3 inchlate August
Walnut Scalewide variety of deciduous trees and shrubs, rarely on conifersnearly circular, flat, gray with a reddish-brown spotmid-June, late August to early September


Revised: 7/96

Cooperative Extension Service: University of Kentucky, Kentucky State University, U.S. Department of Agriculture, and Kentucky Counties, cooperating