Hi, Kabby! You've come to the right place! And feel free to drop into the monthly butterfly thread at any time and ask a question. We all love pitching in!
I was once new and I read the same things. And it's bunk I tell you! Bunk!
What I have found is that Zebra Longwings show a strong preference for native passifloras, regardless of where they are planted. I grow P. lutea, P. suberosa, and a cultivar, P. 'Lavender Lady". I have them placed in different areas around the yard, and the P. suberosa has a tendency to reseed itself in odd places. I know it's not underground runners because there's concrete in between. The Zebras love P. suberosa and P. lutea. They seem to do better (survive more) on the P. suberosa. My "main" P. suberosa is right in front of my house, in full sun, bordered by concrete. I cannot keep the caterpillars off it. They strip the leaves and as soon as it starts sprouting again, I get eggs. The Gulf Fritillaries use it, too. It's definitely a competition.
That being said, I have moved Zebra Longwings over to the 'Lavender Lady' when I didn't have any other food and they ate it. They don't lay eggs on it, but the caterpillars will eat it. Another native is P. incarnata, but that can be fairly aggressive so I would only plant it if you have a lot of space.
Let us know if you have more questions!
