i have a grapevine growing up the side of the house, it has numerous amounts of small bunches of grapes growing. however i have just noticed that a lot of the grapes are missing is it birds or bugs that are eating it? They leave the stem and just eat the grapes (buds as it were) if anyone could tell me then perhaps I could buy some pesticides?
I suspect that you would be wasting your money with pesticides. It will probably be birds or squirrels. Netting the grapes might be a better solution. One morning ... early, why not sit and watch very quietly to see who your thief really is.