The small white cats do little damage but the orange ones will eat a lot of your plants. You can pick them off if you wish (they are not dangerous)and put them on a wild plant or go to the butterfly gardening forum and see if someone wants them. I like the butterflies and the plants so it would be a tough choice for me. Your plants will survive but will not bloom with that many cats. I would suggest that you remove most of them so it keeps blooming.

If they are orange caterpillars, do not kill them as they will turn into beautiful Gulf Fritillary butterflies!

At the link below are some pics of the Gulf Fritillary butterfly and its caterpillars.

I would suggest caution when removing the caterpillars though..they have irritant spines & accumulate cyanogenic glycosides, alkaloids etc which they absorb from the Passiflora leaves. I would wear gloves therefore when removing them. The Gulf ones will only feed on Passiflora-some people grow a sacrificial plant that they put all the caterpillars on.
Myles

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

The spines are irritating perhaps to lizards and other predators but, generally speaking, people don't have much problem with picking these little guys up. My Kindergartners have touched them and have had NO ILL consequences. If you don't want to have them eating directly from you vines, you can pick them off and feed them the leaves you select yourself. :) The caterpillars won't kill your plants but will just eat the leaves, then go to find a place to pupate and become a lovely Gulf Fritillary butterfly.
{{gwi:1130468}}

Sorry I do not agree that it is a good idea to touch caterpillars. See the very good article below.
The Gulf Fritillary caterpillar looks dangerous from its colouring and has poisonous body fluids & irritant spines.
Caterpillar dermatitis is well known. Repeat contact can induce allergic reactions. Some caterpillars sting so children should be taught not to touch any caterpillar. The adult Gulf Fritillary butterfly is also poisonous-hence few predators.

Also if infestations are bad enough the caterpillars can sometimes kill the plants if they are not well established.
Myles

Here is a link that might be useful: Caterpillar Envenomations

Passionflow, I understand your concernÂthe majority of the problematic caterpillars are those of moths not butterflies. Your article mentions the silk moths (Saturnidae) and in my teaching, I go over the characteristics of various caterpillars and how they should be handled (actually the children learn they are not to handle anything unless they've been given the okay from an adult). I am very careful about teaching my students what is considered safe and what is not. :) Thanks for the link.

Actually, the only caterpillars I've seen do major damage are the 'looper' or 'inchworm' type...they work very hard at eating lots, quickly! They accounted for several attempts at catnip before I got smart and sprayed for one year, let the plant establish, then let em have at it.

From my own childhood experiences, teaching the kids what is okay to handle and what is NOT is probably one of the best things you can do to help them survive to adulthood. :) If it was fuzzy, we always used a piece of straw or small twig to examine it more closely--never ever did you get praise for petting one! LOL! I think Mom woulda killed us! :)

While some things can be dangerous, far better to teach how to make their own judgements--it really helps in later life.

PA
(often described as "Oh hey COOL! Can I do THAT?" :)

Ok so I am curious, I have this caterpillar Eating all the leaves off my Passion fruit of only 1 yr.. it is getting big but now has NO leaves left.. How can I get rid of these without Killing them..(I love butterflies) i'm in a dilemma??? what OTHER kind of plant will they eat.. any other besides fruit? Please help my Passion fruit has Only produce 3 fruitlings so far last season.. and I want MORE!!! HELP

Hello there,

My suggestion would be to buy another Passiflora, such as P. 'Incense', P. caerulea, or P. incarnata, that grows rapidly and is not used for fruiting. Then simply carefully transport the little munchers to the "host" plant that you are providing for them. This is basically just iterating what Myles said above about having a "sacrificial" plant for them to feed off of.

By the way, if Myles said "don't touch them with your hands", I would suggest you listen to him. I suspect he has more experience with them than most people. Thin, un-powdered vinyl or poly gloves are quite cheap in boxes of 100 on Amazon and elsewhere.

Obviously, this will take some diligence on your part to keep up on it, but I think it should be well worth the effort.

Happy gardening!
Eric Wortman

ok i dont wanna sound cold but my kid tried to get one of these Gulf Fritillary cause he said it looked like a gummy worm so they have to go. then my dog got interested well i dont want a poisoned kid or dog. what poisons would work?

I've heard that BT works.

Forget the poison. Pick them off with your hands. I have picked off hundreds, I mean hundreds over the years on my young plants. I let them go once the vine is established. If they eat all the leaves the stress may kill your vine. The younger they are the greater chance of dying.

I have handled lots of heliconius larvae over the years, the julia [flame] caterpillars spines can make the skin look like it has lots of air bubbles on the surface, when you have handled lots of them in a short time, so far they are the only ones that have, in the butterfly house where i worked we had them strip many of the passiflora, but they prefer decaloba section to anything else, and the Austrailian ones get covered with eggs. So if you can grow decaloba in the US, that should help keep them off your fruiting plants. P. lutea would be very useful for this as the flowers are so small and it can cope in most colder areas. The gulf fritillary i dont know what sections it prefers, but probably can be transfered, i usually use xerogona hybrids, as food for most. It seems that what the fully grown larvae eats effects what the resulting females will lay on for the next generation, so you can over several generations get them naturally on these alternatives.