Here is a small section of my backyard. From left to right, I've planted a Hibiscus, a Passion Flower Vine, and nice healthy little lime tree...yellow Mandevilla.
Last summer, all were flourishing, but now only the lime tree remains. I thought back to this summer and remembered lots of orange and black catterpillars, so this morning, I did a little Google search on them. Nothing like trying to save your plants after they're already dead, right?
I read in this article that I really should have washed them off the plants when they were still eggs. I'll keep a sharp eye out next summer. I also read that they shouldn't have killed the plants, even if they ate all the leaves. Someone should tell that to the dried out twigs in my yard. I'll leave them in place for a while and see if they show any signs of life, but I'm not holding out much hope. :-(