I have had a Purple Passion Flower vine since March of 2008 on a southwest exposure trellis here in Tampa. It has done wonderfully through all seasons. Every April, when the Gulf Fritillary caterpillars come, I spend about 10 minutes a day "eliminating" as many as I can find. This year, rather than give up at least an hour/week looking for these buggers, I decided to do some research on eradication methods, but what I found made me change course...for now.
Simple Google searches will return endless threads of Q&As. Everyone is looking for a way to decimate their invaders (usually with a preference for organic solutions...ha!) and someone always replies that the caterpillars and passion vines have evolved together....sure the vines will look "TERRIBLE", but they will come back stronger and your garden will burst with butterfies. Since I approach my garden with my sights set on the long-term, this symbiosis hit home.
So rather than find and smash this year, I'm going to let these prickly little creatures run their course, eat my vines and passion flowers, and watch them turn into butterflies. I hope for their sake that they are beautiful butterflies and my vine emerges healthy and vibrant later in the summer. If not, this will be their last spring getting fat off of my vines.
Click the link below to see one on my vine that I hope is about ready to morph.