That really sucks! I would be soo mad- they are greedy little suckers aren't they? I try to grow extra vines and pick the cats off and put them on them and keep them off the 'good' vines but they do seem to have thier own preferences lol. Hopefully the vines will grow back ok.

Are they Gulf Frittary caterpillars or Zebra Longwings? Orangish with dark stripe and spines or white with black spines? I have never had them destroy the vine, just munch on the leaves and there always seems to be plenty to go around.

These are Gulf Frits. I've yet to see a Zebra Longwing around here.

The plant itself is not in danger of dying--just the individual vine. I found a 10-inch section of my p. vitifolia that'd been almost completely girdled yesterday, but I found it soon enough so that I've attempted to root cuttings from it.

Normally, I transfer all the found caterpillars from the smaller, ornamental passis onto my huge Incense or one of its "daughters" that spring up here and there, but it's really, REALLY frustrating when I miss one and it skips the leaves and girdles a vine. We're in the middle of winter, but even though we had a very light freeze last night, there are still cats thriving on the Incense (not to mention scattered chrysalises (?) here and there). Temps will reach the upper 60s this afternoon, and if I was home I guarantee I'd count a handful of Gulf Frits come through to lay eggs. I *like* having the butterflies, but I wish their kids weren't so darn destructive!

Wonder if it's to make sure that the passies make new growth... I'm thinking this because you say that they are only doing this to part of the vine and not the whole lot... Make sense?

I dunno. They've done it occasionally all year--usually to my Incense--but the plants had been growing so vigorously that it didn't matter. But at this time of year, with the plant somewhat dormant (even with our warm days) such shenanigans are frustrating and noticeable.

Someone said there were some species of butterfly in which the caterpillar girdled a branch right before it went into pupa stage. This still doesn't explain why, but it makes sense as the cats that are guilty of this offense have been large ones.

I feel for ya had the same thing all year here had 24 passion plants eatin to ground. Got no seeds and not sure how many will come back this spring but its crazy to see them eat even the flowers I think im ganna have to find a away to keep them off long enough for my passion to get a good start this year.

WOW!!!
I hate to hear that!!! I know the white passi I grew always had loads of caterpillars mostly Black Swallowtails! We grow organically and live in the country so I guess I just expect it... I never lost a plant to them before.. We always grow Host plants like Rue, Dill and Parsley to give them something else to chew on..
Chena

Chena, are you sure those were black swallowtail caterpillars? Passiflora produce natural cyanide to discourage most insects from eating them--but helliconia butterflies have adapted, and absorb that poison to make them very nasty tasting indeed. Did it look like the caterpillar at the link below?

Here is a link that might be useful: Gulf Fritillary caterpillar

Welp.. I'm pretty sure.. We brought the chrysalis in and hacthed them in the house.. We have a Praying mantus pod we are trying to hatch right now..