When a tree is being attacked by lace bugs, the upper surface of the leaves appears speckled white and green. The mottling can be mistaken for damage caused by mites or leafhoppers. The presence of lace bugs can be distinguished from other insects by the shiny, hard, brown droplets found on the undersides of damaged leaves. The lace bug is a small insect, about 1/8 inch in size, brown in colour, with lacy wings.
The lace bug can often be found in large numbers on the undersides leaves and they are very fond of oak trees. They suck sap from the leaves, causing the leaves to lose their green color and, in doing so, substantially reduces the tree’s ability to produce food.
The adults over-winter in the bark crevices and, in the spring, emerge to attach their eggs to the underside of leaves, using a brown sticky substance. When the eggs hatch, the juveniles emerge and begin sucking sap from the leaves until late summer.
Recommended Steps to Control Lace Bugs
After leaf drop in the late fall and in early spring, spray the tree’s trunk and branches with Horticultural Oil Insect Spray to kill the bugs that are over-wintering on the bark. In the spring, at the first sign of the lace bugs, spray the tree with Take Down Garden Spray to kill the adults and prevent the eggs hatching. Spray Take Down throughout the season, as needed.
If the tree is too tall to spray, in the early spring apply Once-A-Year Insecticidal Drench w/Merit, to provide insect protection for the full growing season.