I have a mulberry tree growing in front of my office. The mulberries are developing fast but still very green. Some turning slightly pinkish. I have noticed a curl of "smoke" coming from the berries every now and then - well I think that is where they are coming from. The smoke/powder is emitted and a few seconds later evaporates in the air. I have been unable to find out what this is and no nursery can help. Finding anything on mulberries on the websites - zilch! One horticulturist/gardener on the web thought it might be some kind of fungus releasing its spores but suggested I try this forum. Hope someone can shed some light on this very interesting phenomenon.