Base of Iris and outdoor cucumber being eaten

I have had a large iris for many years, this year the leaves looked a bit brown and unhealthy, I held one and it came out in my hand, when i inspected the base it seems to have been eaten by something, nearly half the leaves have the same problem, also growing outdoor cucumbers, they were growing really well with fruit set, then one day looked a bit wilted and the same thing had happened. Has anyone got any ideas of what it is and what I can do?

If something is being eaten in the garden -always suspect slugs or snails-have you taken any preventative measures?

Cucumbers will get neck rot where the stem meet the soil if it get too wet

So it may be either- or both- of those.

It was not slugs or snails as the chewing was on the inside of the iris leaves, seems more like a grub. Thanks for your help.