Lace bugs use their sucking mouthparts to feed on plant sap. Damage ranges from a few scattered tiny white-to-yellow spots on upper surfaces of leaves to bleached-white leaves that drop prematurely in late summer (Figure 1). Common species in Kentucky feed on azalea (azalea lace bug); hawthorn, cotoneaster, pyracantha, Japanese quince (hawthorn lace bug); rhododendron and mountain laurel (rhododendron lace bug); and hickory, mulberry, and sycamore (sycamore lace bug).
Confirm Lace Bug Damage
Lace bugs can be confirmed as culprits by looking at undersides of spotted leaves for the insects, white cast skins, tarry waste spots, or eggs (larger dark spots along leaf midribs) (Figure 2). Adults are about 1/8 inch long with lace-like wings that cover the abdomen. Nymphs are dark and spiny (Figure 3).
Heavily-infested leaves may drop prematurely. However, late season leaf loss should not affect healthy trees, so no control is needed.
By Lee Townsend, Extension Entomologist