Tiny worms eating grape leaves
Hi- these are grape flea beetle larvae. Th adults come our of hibernation near your grapevines and feed on buds which can greatly reduce flowering and fruiting. The larvae feed on buds and tender leaf tissue. The adults ar considered more damaging.
The first insecticide spray is done at bud swell (before new shoots emerge). Sevin (carbaryl) is recommended. You could use carbaryl now to clean them up. Organic insecticides may be effective if you can spray the larvae directly- neem oil, pyrethrins + oil, horticultural oil.
Please see the VA Tech home fruit spray schedule (3-18 and 3-19):
Thank you so much!