Could anyone tell me a little bit more about this picture? There are some small spots along the vine that showed up white in the camera but they are actually fairly clear. From looking at pictures on the internet it appears that it's just sap from the cane but my main concern are the larger black spots. Is this from an insect or is this normal? I don't think it's a fungus of any type. You may not be able to see it clearly in the picture but there are also smaller black spots along the vine which look to me like they may be insect droppings.
Just an update: I might have answered my own question. This looks like Grape Cane Gallmaker and from what I have read they don't usually cause enough damage to warrant any type of treatment. Has anyone else had any experience with this? http://www.oardc.ohio-state.edu/grapeipm/grape_cane_gallmaker.htm
