Cavelo Death

The Cavelo Nero has come to the end of it's life and is dieing a failry undignified death. It has been completely savaged by cabbage moth caterpillers. I was going to pull them out and dump them in the compost, but I've noticed that they are always surrounded but wasps, hoverflies and ladybugs and the rest of the garden remains pretty much unscathed. They can stay there now as sacrificial plants while bringing in those other beneficial insects.