Green caterpillar URGENT HELP

Question

Hi again, sorry for continuous posts! Is it ok if I ask what kind of caterpillar this little guy is?

It's very soft, really sticky feet, kind of velvety, and it's matt (?) green with a white line down each side, slightly darker, vague arrows pointing all the way along its body and it has two small white spots at one end. 
 It was found on an arum lily leaf - is this its host plant? What will this fellow eat? Worried that it dies because of me not feeding it properly :-( 
 
 Thank you! 
 Take care,

Lil Wren

Ian Moth · Answer

I am glad you wanted to help him. I have exactly the same caterpillar. He was crawling across a large stretch of snow (January) and he's doing fine on lettuce, broccoli, a few cat biscuits and a light spray of water on the leaves. I've put clean tissue each day for him to cocoon on. It's very difficult identifying all-green caterpillars. Most sites simply see them as pests. As kids, my sister & me used to save endless bees and other creatures from getting stuck in water. I've always done so. I realise this is an old post, I think he's a cabbage moth caterpillar.