Scale insects are troublesome pests of perennial plants and woody ornamental trees and shrubs. Almost all scale insects are small and highly concealed. Thus, they often cause significant damage to ornamental plants before they are found.
Scales occur on nearly all pats of host plants including leaves, branches, trunks, fruits and roots. They sometimes occur under bark and may cause various kinds of plant deformities. Scale insects feed as either nymph and/or adult.
Scales damage plants by removing plant sap and slowly reducing vigor. Heavily infested plants grow poorly and may suffer dieback of twigs and branches, discoloration an leaf drop.
Target control measures at unprotected crawlers since waxy coverings protect adult scales. Apply horticultural oils during the dormant period to control the overwintering stages of most species.