they look just like your picture, except they are not translucent, more of a solid cream colour.
is is possible that vine weevils would be hanging about in a pasture? we only began the garden in september, and these grubs were already here. there are no other veg plots within half a mile, just sheep and cows. and our weather is in no way mild as we are in the pennines.
something has been eating holes in the centre of my strawberry leaves though, and vine weevils like strawberries? 
thanks for your input