Lacebugs on rhododendrons and azaleas

Asked March 18, 2019, 12:15 AM EDT

Hello, We have lacebug infestation on our rhodies I have tried horticultural spray, but they are still there. What can I do? I want to prevent spread to the healthy ones Also, what are local and drought tolerant alternatives to these trees? Thank you!

Clackamas County Oregon

1 Response

Thank you for your question. Azalea lacebug infestations typically evidence themselves by yellowing (chlorosis) of the leaves. Without a photo of the plant, I am not certain this is the problem since rhododendron leaves are ‘tougher’ than azalea leaves. The telltale sign is black dots on the underside of the leaf, which is insect excrement. Control is difficult, sine the insecticide needs to be applied to the underside of the leaf—where the insects are—at the right time in their lifecycle. Hard to do! Here is the best resource we can provide to help: http://oregonstate.edu/dept/nurspest/Azalea_lacebug.pdf Good luck!