Lacebugs

Many oaks and several other trees and shrubs have developed tan to brown or yellow leaves from damage by lacebugs this month. These color changes will become more prominent in August and September. A check of the lower sides of such leaves will reveal the presence of lacy-winged adult insects, their black nymphs (immature adults), black frass (waste) and vase-shaped eggs. Piercing-sucking mouth parts are used to feed on the soft green leaf tissues which causes the color change. The adults are easily recognized by their transparent wings held horizontally over their backs. Prominent veins cause these wings to resemble lacy networks. Twenty seven species of lace bugs in the genus Corythuca feed on deciduous trees and shrubs in the United States. Control is usually not warranted on oaks and other trees because next year?s leaf buds are well formed before this year?s leaves are severely damaged. Chemical control on ornamental trees is an option, but a labeled insecticide should be applied in early June when lace bugs numbers are small and before ?bronzing? of leaves starts.