Sycamore Lace Bug, Corythucha ciliata (Say)

Leininger, T.D; Solomon, J.D.; Wilson, A. Dan; Schiff, N.M. 1999. A Guide to Major Insects, Diseases, Air Pollution Injury, and Chemical Injury of Sycamore. Gen. Tech. Rep. SRS-28. Asheville, NC: USDA Forest Service, Southern Research Station. 44 p.

Importance.-One of the most common insects found on sycamore foliage, lace bugs may occur in large numbers on shade or ornamental trees in urban areas, especially in late summer or during dry periods. Corythucha ciliata is a problem throughout the Eastern United States.

Identifying the Insect (fig. 6a, b).-The adult is a pale, flattened insect about 3 mm long whose wing covers are extended and so intricately ornamented that they appear to be made of a piece of lace. Immatures are also flattened but are black and covered with spines.

Figure 6a. - Adult lace bugs feeding on underside of leaf. Photo by James Solomon, USDA Forest Service

Identifying the Injury.-The lace bug pierces the epidermis and withdraws fluids and cell contents, which results in chlorotic flecking on the upper surface of leaves. Late in the growing season the leaf’s lower surfaces may appear messy, having been varnished with lacebug excrement and shed skins. Large populations of lace bugs may cause leaves to turn brown and drop prematurely.

Biology.-Adults overwinter under bark and become active when leaves start to develop. Eggs are glued to the pubescence on the undersides of leaves. Both adults and nymphs feed on the undersides of leaves by sucking sap with piercing mouthparts. Nymphs seldom move to another leaf until they are almost mature. The complete life cycle from egg to adult takes about 30 days, and there may be 2 to 5 or more generations per year. Late in the year, synchrony of generations breaks down, and all life stages may be found on the same leaves.

Figure 6b. - Lace bugs nymphs feeding on underside of leaf. Photo by James Solomon, USDA Forest Service

Control.-Predators usually keep lace bug populations small. Chemical control may be required in late summer and fall when populations are largest.