Was out looking at my 2nd year Concord grape vines this evening and found a red-tipped green thorn shaped growth on a few of the leaves. It looks like a thorn. I can't tell whether it is plant or insect matter. Anybody have any ideas? The largest one is maybe 1/4 inch long. I removed the affected leaves, but I'm wondering if I should be spraying them with something. Thanks, David
