How to know if a butterfly is about to pupae

[annlpz]

Yesterday I found this (I suspect) Papilio multicaudata
Walking on the floor in the middle of the street, I almost stept on it. So I took it home, and got some leaves of the trees near where I found it
But the caterpillar hasn't eaten and that making me nervous. Its right now hanging out like this
I don't want it to die, so I'm planning on putting it in some tree on the street
But I don't know if its not eating because maybe it could be about to pupae. If thats the case, I'd keep it until it becomes a butterfly. How should know if its about to pupae and if that's the reason it's not eating?

 

[sparticus]

Usually caterpillars have very specific food needs. Are you sure the tree is the right food for the caterpillar? I feel like a lot of the swallowtail species eat plants in the carrot family, not trees. Not eating and leaving the host plant can be signs they are getting ready to pupate, but I would confirm you are feeding it the right plants first. You should be able to find out what size they are at the last instar before they pupate with research, also. It's usually pretty standard for whatever species to pupate at a specific size.

 

[corydalis]

They usually behave like this when they are ready to pupating, then they spin a harness to support themselves. If I see it correctly the harness is already apparent.

 

[Ultum4Spiderz]

Yesterday I found this (I suspect) Papilio multicaudata
Walking on the floor in the middle of the street, I almost stept on it. So I took it home, and got some leaves of the trees near where I found it
But the caterpillar hasn't eaten and that making me nervous. Its right now hanging out like this
I don't want it to die, so I'm planning on putting it in some tree on the street
But I don't know if its not eating because maybe it could be about to pupae. If thats the case, I'd keep it until it becomes a butterfly. How should know if its about to pupae and if that's the reason it's not eating?

Looks like it’s going to pupate soon.

 

[annlpz]

I'm happy to say this day the caterpillar is now a pupae. Thank you all for the help!