(Length: 1/16″- 3/8″) Scale insects are common pests to many trees and shrubs, are less than 1/8″ long and generally blend in with the host plant. Heavily infested plants are often covered with small disk-like or waxy coverings which look like tiny bumps on the plant leaves or stems. The scale is underneath each covering feeding on the juices of the plant. Plants heavily infested with scale may look water stressed. Leaves turn yellow, twigs may drop and limbs may die. Keeping your trees and shrubs well watered and fertilized will help prevent scale problems.