I was having the same problem with a bougainvillea and a tibouchina. I even found the pest's scat, but never saw the pest. They must feed at night. I eventually found a bright green caterpillar about the size of a grain of rice that might be the culprit. They stripped my bougie bare! Try neem oil spray.I have been applying it to every flush of new growth with good results. I slacked off during the recent cold and noticed that the invisible pests have returned, so I guess diligence pays off.

Pipevine Swallowtail caterpillars defoliate the native Aristolochia here in the Sacramento area; not sure if it's too early for them in SoCal. Here the cats hatch out in early spring and are sometimes hard to see until they've grown a bit. I've never seen them on any of my exotic Aristolochias, but mine are losing a lot of leaves due to the extended cold spell we've experienced over the past couple of weeks...

Mike

You want to grow an Amazonian species in California? I hope you've got a good conservatory...

ifraser25, sorry, but we grow quite a few species outdoors here in SoCal. My A. elegans survived the frosts here, while two passifloras did not. I've also seen grandiflora and triloba grown outside in Encinitas [though I doubt the frost was kind to the grandiflora]