LACE BUG This is a common pest of azaleas, especially those growing in sunny locations. The adults and nymphs have piercing-sucking mouthparts for sucking sap from the undersides of the leaves. Injury by their feeding results in stippled or blanched areas on the upper leaf surface.
Heavy infestations cause the leaves to turn pale green or yellow and fall off.
On evergreen azaleas the eggs overwinter in the leaf veins or on the leaves themselves. If your azaleas are deciduous, they will overwinter on fallen leaves. If there is no rain to wash off the leaves, then do not exceed three applications or you may damage the plants. Other insecticides are available.