Most of them are placed irregularly along the midrib. Nymph -Commonly found on the underside of a leaf, the nymph is almost colorless at birth but soon turns black and spiny. It molts six times and ranges in size from 0.4 mm to 1.8 mm before becoming an adult. After the fourth molt, wing pads show distinctly. The evergreen azalea varieties are preferred by azalea lace bugs, although the deciduous varieties may be attacked.
Mountain laurel is also subject to infestation.
Damage - Injury is caused by the nymphs and adults as they extract sap from the undersurfaces of the leaves. In severe infestations, the leaves become almost white, many of them drying completely and dropping off. The undersides of the leaves are also disfigured by the excrement and cast skins of the insects. Life History - Since its introduction from Japan in the early 1900's, the azalea lace bug has been recognized as an important pest of azaleas. Female lace bugs lay groups of eggs on the undersides of the leaves, most often along the midribs.