I have both in my yard and they use both equally. I have observed no preference.

I have Passioflora foetida in my yard, and the gulf frits thrives on it. I also bought "lilikoi" vine from home depot and they did laid eggs in it too. I guess anything that is on passioflora species that grow in your area, they will thrive in it:-)

I have Maypop (Passiflora incarnata) in my yard Nicholas, and they seem to love using that. I think that the butterflies have some regional preferences. It would be most interesting to know which works best for other people that live in your area and raise them.
Angie

There are certain "red" passion vines that are toxic to the butterflies - I've read on here that the fritillaries will lay eggs on it but the cats will not survive. Others who are more experienced can give you more details (or you can do a search here on garden web to find the info.)

If your purpose is to attract frits and caterpillars, please make sure you read up on that - how disappointing it would be to plant a species that is toxic.

~Laura

Although there are some red-flowering passionvines (like Lady Margaret) that aren't toxic and even some blue-flowering ones that are toxic, of the vines on the market, the red-flowering ones are usually the toxic ones. I think it's P. coccinea and P. vitifolia that you commonly see for sale that you shouldn't use.

P. incarnata/maypops is the best in this area. For whatever reason, P. caerulea won't last more than a few years here. I don't think it's the cold that slowly kills it, because it keeps some leaves all winter. Maybe it needs more cold, so it can rest in winter, you know, needs more of the famous chilling hours. Whatever it is, although maypops do better here, some people have better luck with P. caerulea.

I have a HUGE passsionvine that came from a seed from fruit from my P. 'Incense' vine. Incense doesn't make it's own pollen, so the male parent has to be one of the maypops that were growing near it. The flowers look more like Incense, but gulf frits lay their eggs on it readily, not as a last resort, like they do with Incense, so the chemical makeup of the leaves must be more like P. incarnata. It's grown into the gardenia next to its raised bed in my garden and over onto the other side of the fence!

Sherry

Thank you I just ordered some Maypops online. None of the nurseries nearby had either.
Laura, it's a interesting story how I got these eggs. There is a poisonous passionvine that I search for eggs on to save before they take a bite out of it. I've always been too late. But this time I found 2 eggs 1 on a dead tendril and another on another plant other than the vine so I'm hoping that I'll have luck this time.

I have one more question, does anybody know how to get an egg off of the leaf without damaging the egg so that next time this situation happens I may have a better chance of saving them?

Nicholas