Lace Bugs
lacebug nymphs and adult on sycamore leaf
Lace bugs are common pests of a variety of ornamental trees and shrubs. They feed from the underside of host plants by sucking out plant juices with piercing, sucking mouthparts. Common hosts include Azalea, Rhododendron, Sycamore, many broad-leaved evergreens, and many deciduous trees and shrubs.
Identification & Life Cycle
Adult lace bugs are about 1/8” to 1/4” long. The entire wing surface is covered with veins that look similar to lace, giving these pests their name. In addition, the wings are dotted with brown & black colors. Immature lace bugs, called nymphs, are similar in appearance, but are smaller and often have spines.
Lace bugs can be divided into two groups – those that attack deciduous plants and those that attack evergreens. Lace bugs that attack deciduous trees and shrubs spend the winter months in the adult stage by hibernating on the plant under loose bark or in nearby leaf litter. The adults emerge from their protective places in the spring, feeding and laying eggs on the new leaves. Lace bugs that attack evergreens overwinter in the egg stage attached to the host plant’s leaves. The nymphs emerge from the eggs in the spring after danger of frost has passed. They then feed and molt until they become adults and the cycle repeats itself.
Feeding damage on azalea
Damage
Most plants with lace bug feeding damage turn yellow or have whitish spots that are evident on the upper leaf surfaces. Broadleaf evergreens often keep damaged leaves from one season to the next. As lace bugs feed, they produce dark varnish-like droppings that are scattered throughout the lower leaf surface. If large numbers of lace bugs are present, cast skins can frequently be found attached to the underside of leaves.
Control
Plants that attract lace bugs should be monitored early. In order to avoid visual damage, the first generation of lace bugs must be eliminated. Damage to leaf tissue cannot be reversed once populations are under control. Treatments should be applied when the insects are found on the foliage. It is very important to treat the undersides of the leaves since this is where they feed. In addition to chemical controls, there are a few cultural control methods that can help prevent and control small infestations.
Most lace bugs prefer bright, sunny areas. Susceptible plants should be planted in shady areas of the landscape. In addition, a hard jet of water to dislodge young nymphs as they hatch in the spring can help control populations as they often die before they can find their way back to suitable leaves.
Contact your RYANPro to learn more about lace bug control options. A systemic control applied early in the spring can often control infestations and prevent unsightly damage.