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FS ShieldForest Health Protection, Southern Region


Corythucha spp.

Importance. - Adults and nymphs of lace bugs feed on the leaves of many species of hardwoods throughout the South. Some of the more common species affected are sycamore, oak, elm, hackberry, and basswood. By the end of August, leaves attacked by these insects may be discolored and perform little photosynthesis, and may even fall from the tree.

Identifying the Insect. - Nymphs are usually dark colored and covered with spines. Adults have broad, transparent, lacelike wingcovers. They are flattened, and about 1/4 inch (6 mm) long. Some species are beautifully colored.

Adults on sycamore

Adults on sycamore. (Click for detail. JPG 39K).

Identifying the Injury. - Infested leaves have chlorotic flecks or tiny chlorotic spots on the upper side. Heavily infested trees may be partially or full defoliated, especially during dry weather.

Biology. - Adults overwinter in bark crevices and similar protected areas of their host. The adults become active during the spring and lay eggs on the underside of leaves. After the eggs hatch, the nymphs begin feeding on the underside leaves. They feed by inserting their mouth parts into leaf tissue and sucking the plant juices. A complete life cycle, from egg to adult, may take in 30 to 45 days; several generations may occur each year. In late summer, both adults and nymphs will be feeding at the same time.

Control. - Natural enemies are usually effective in maintaining populations at a low level and bringing outbreaks under control. Chemical controls are usually only used on shade and ornamental trees.