Know how to use "fewer" and "less"? Find out.
a species of insect in the armoured scale family, Diaspididae (order Homoptera), that is found on woody plants and secretes a hard, tough protective covering that resembles a miniature oystershell. Despite its small size, the oystershell scale can inflict great damage on the trees and shrubs on which it lives. Control is by dormant, or horticultural, oil spray and natural enemies such as birds, mites, and parasitic wasps.