Vine weevils

I have an infestation of vine weevils in my polytunnel this year - they have attacked my grape vine and the weevils are crawling on most of the plants and eating chunks out of leaves and nibbling the stems, causing the new shoots to keel over. I plan to use nematodes in the autumn to kill off the grubs in the soil but what can i do about the weevils? I have just been out and picked off about 20 weevils and squashed them! Is there anything I can use to spray them with? I will be eating the salad and vegetables and, hopefully the grapes...

Last year someone suggested a cup of vegetable oil should be placed at soil level and the weevils loved it and he caught lots using it. I was quite intrigued and plan to try it when it stops raining.

Anything is worth a try.... thanks