I have holly bushes that have some kind of pest. . . it is rectangular shaped and is scattered all over the underside of the leaves. Some of the leaves also look like they have powdery mildew on them, but these little geometric shaped pests are all over several of my holly bushes. Can you tell me what they are and how to deal with them?
Disease or Pest on Holly
Certified GKH Gardening Expert
It sounds like it might be mealy bugs or scale. These articles will help: