What are these larvae?

I believe they are Crane Fly grubs known as leather jackets, they eat roots of plants and are not good news, we all have them in our gardens, when I find them I give them to my chickens and of course wild birds love them. Here is more info http://www.just-green.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=50

Hi Norfolk, thanks for the link. Those grubs look a little more translucent, although mine were covered in mud which may have made them appear less so. Any that get eaten, get eaten but I don't have anything to feed them to and I don't want to kill them just for the sake of it. I'll hold of with the pesticides and hope they don't cause too much damage.

Hmm difficult to tell from a photo, only other I can think of is the Chaffer grub, more info here http://www.nemaslug.com/html/chafergrubs/chafer_main.html

..or vine weevil http://www.rhs.org.uk/advice/profiles0600/vineweevil.asp

Leatherjackets - they are baby craneflies - I normally give them to the birds on the bird table or deal with them like slugs (big boot) they eat the roots of plants especially grass

Leatherjackets - very partial to baby lettuces, loosing virtually one a day at the moment.

Either Chafers/Leatherjackets - we lost a big part of our lawn to them.