CLB larvae and adults feed between the veins of the newest leaves on host plants. Larvae cause the most damage by removing long strips of tissue from the upper leaf surface, while leaving the translucent cuticle of the lower surface intact. This feeding pattern produces a characteristic “frosted” appearance. Tips of damaged leaves frequently turn white, giving heavily infested fields a frost-damaged appearance. Adults will chew completely through the leaf, which results in narrow slits, although the damage they cause is usually insignificant. Yield losses of 25% have been reported in irrigated spring wheat in Washington State. Yield loss is influenced by crop vigor and the timing and duration of the CLB infestation. Stressed growing conditions or poorly developed plants may increase potential damage.
Effective cultural controls for the CLB rely on agronomic practices that favor well established stands with vigorous, well-tillered plants that can tolerate damage by CLB populations that are below threshold levels. Border strips (1–2 drill strips 45–60 ft wide) seeded to oats 2 weeks after spring wheat are an effective trap crop management strategy. The oats then provide areas of refuge that enable the survival and proliferation of parasitoid wasps and other predators