We planted pink powder puff calliandras to trail up the two patio support posts in our back yard. The one with the most new growth attracted tons of green caterpillars ... which quickly became big green caterpillars. None of them has gone into a cocoon yet. Once they get big the birds eat them. They are always replaced by new baby caterpillars.
I was picking the caterpillars off at first, because I did not want them to wreck my plant. But my mom -- who is a beneficial bug expert -- convinced me to let them do their thing. It's been fun for me and the kids to watch them get big ... and then become food for all the birdies in our yard.