Pretty sure I was hit with the flea beetle this year. Total vineyard yield was down about 40%. I had whole rows without a single grape cluster. Next year, I’ll take a day off work the minute I see one of these devils. We have 3 acres of vines in central Wisconsin.
Have you tried Garden Tech Sevin (contains Zeta-Cypermethrin, not Carbaryl)? I have found it to be VERY effective.