What grubs are these?

Others on here may be better than me, but the pale one with the brown nose looks live a vine weevil. The others could be leather-jackets from which daddy-long-legs develop.

The nearest one is almost certainly a cockchafer grub. Strangly enough these are sometimes called dock grubs. Anglers used to pull up docks to find these grubs for bait. These will eat your crops but probably not potatoes. More likely to knip off your lettuce.

Not sure about the other ones but the other white one may be a beetle lava, in which case it is a goodie as they eat slugs.

The small white grub with the brown head is a wire worm and unfortunately they love potatoes Ive got loads of them on my plot. they seem to prefer white potatoes so all i grow is Desiree. I've read on other forums that planting garlic disrupts the breeding cycle .

Our site has a major problem with something that tunnels into potatoes apparently (don't know the name, they are commonly referred to with only 4 letter words ) so most of them grow potatoes in bags and they don't have a problem