Euonymus fortunei 'Blondy'

Well here I go, dipping into the vast pool of knowledge hereabouts. Ive done a search about these but cant find anything. Last winter/early spring, I bought three Euonymus fortunei 'Blondy' plants. They seemed healthy enough and for a time were doing quite well. Then something took a fancy to them in a big way and started to scoff them.

I think it is slugs.

But I dont know for sure.... I did spot a caterpiller sneaking off once, it was grey, about 50mm 2" long, 10-15mm 2-3/5" in diameter with one or two pairs of false eyes on its back. Anyone know what it was? It looked a fat little blighter, probably full of my damn shrubs!!
Being a closet tree hugger,I started to spray the plants with "Growing Success Bug Killer" an organic pesticide, and they did perk up, but soon regressed. The photos show them today, the light wasnt brilliant, but you can see the damage. I think the first one is a bit far gone, but the other two might be able to be rescued.
Thanks for any help you can give me.

 

Sounds like it could have been one of the hawk moth caterpillars John, euonymus are very resilient leave them till spring when new growth appears cut them back by about a third they should thicken up again.

 

Thanks for that Walnut, I googled Hawk moth caterpiller and it was the beast. I will cut the plants back a bit this spring.

 

I agree slugs generally go for much softer leaved things than your euonymus. It would be the caterpillars. If it happens again I would simply go on a caterpillar hunt. With three bushes you might find it easier to do a search and remove them physically than go and get out the sprayer, mix it up and spray...and its cheaper. As soon as you see the same damage start looking before it gets bad.