Garden Pests and Diseases: What IS this?, 1 by michaelangelo

michaelangelo wrote:
I am hoping someone can tell me if what I'm finding on the Hibiscus in this photo is contageous and someting to be concerned about. I know very little about plants and nothing about hibiscus. I had this one in a bright sunny window all winter in a room we leave vacant and very cool in winter. It developed these loose tiny specs on its leaves and now those specs are on the leaves of another nearby plant. They don't move so I don't think they are an insect. The biggest problem is I want that sunny window now for some young herb plants but I am afraid to place them in the window for fear of a contageous disease problem. Any information is much apprecuated.