WSU Island County Extension programs connect the people and communities of Island County with the knowledge base of Washington State University to promote quality of life and advance economic well-being through fostering inquiry, learning, and the application of research.
The Meerkerk Garden Staff recently observed an outbreak of lace bug at the garden. This significant pest of Rhododendrons and Azaleas becomes active in May. As the insect feeds on the underside of the leaves, the upper side of the leaves become yellow and stippled. The business end of things happens on the underside of the leaves where the insect feeds and lays its eggs in dark brown tar-like excrement.
The eggs and nymph stages are protected by the tar-like substance making it difficult to see the extent of the infestation. Infestation is worse on water-stressed plants and on those exposed to the sun.
Lace bug has been a major problem on Rhododendron and Azalea on the mainland for some time where control has proved difficult, especially in larger landscapes.