Squirrels are capable of such damage. Got any of them around? And I suppose, since grape vine already has thin strips of bark that begin to peel on their own eventually, this could also be caused by nothing more than birds perching in that spot.

Exfoliating (peeling) bark is very common on many types of grapes and happens naturally. In some cases, grape growers/vintners actually peel off this bark on a routine basis (every 3-4 years) to remove habitat for overwintering insect pests.

Those look like pretty mature vines - I would expect this to be quite typical and nothing to be concerned about.

thank you - i will keep my eye on it

I live in Las Vegas And for the life of me this has me baffled. I know there are more than a hundred viruses that grape plants get. I am sure glad that isn't the problem here.

Does anyone know what those little yellow & black bugs are that turn the least in to lace