Something is eating my vines.....

[julesapple]

.....I have two vines, bought last year from at garden centre (feeling miffed that I missed out on the Morrisons bargains! mine don't have many bunches of grapes at all) and something is eating the leaves. Whatever it is is munching great holes in the leaves and seems to prefer young leaves. I've looked very carefully all over the vines and can't find anything creepy crawly or maggot like.....so maybe the culprit can fly?

I've sprayed with Provada (apparently the ultimate bug killer) but leaves are still being eaten.

Any help would be appreciated

[starloc]

Provado bug killer works by poisoning the plant so anything that eats it is killed but there is some evidence that it can effect bees, so best not to spray it on if the plant is flowering. it doesnt work for all pests though.
if theres nothing on the leaves of stems when you look closely then theres a chance that its something like a caterpiller, vine weavil or snail etc , some of these type of pests live in the soil and come out at night to eat your plants , try some copper tape around the stem of the plant to stop snails climbing up, check under the pot as slugs and snails live under there, but more likely its one of the weavils or a beetle
Some people can tell from the way the leaves are eaten what is eating them, sif you have a photo of the leaves it may help them to say what it is