Lace bugs are common pests of azalea, rhododendron, sycamore, broad-leaved evergreens and many deciduous trees and shrubs. Lace bugs feed on the underside of leaves causing stipples on the upper leaf surface.
Leaves turn yellow, then brown along with dieback that can lead to shrubs being killed. The life cycle of this insect allows for several generations in a year so proper monitoring along with control strategies such as soil injections and/or foliar applications are often highly successful.
Image via Kansas State University