I was told to try here and see if anyone can help.

This is something that is recent for me, and nothing I can seem to find online.
I am seeking help in either someone who may have an idea as to what is killing them, or perhaps finding a location that does study entomology and can do an autopsy to figure out their cause of death.
I only have 3 left and I am desperate to make sure these live or get themselves to cocoon.


Ok so let me give you the 4-1-1 on these guys.

I've had them since April.
Up till 3 months ago they were eating and thriving.
Up till three weeks ago (mid-Sept) there were no deaths.
I have been offering them romaine lettuce.
I have lost some to a fly parasite having been laid in a few of them.
Up till this month, the pet carrier they were in was kept inside.
Though around Sept 24th the caterpillars were brought back in side.
Avoiding most days that were above 90* and up.
I believe they are in their 5th instar (despite the size of a few).
I live in So-Cal.



I know they are not dying of a parasite (at least visible to the eye). They are not acting weird like the ones I have seen that have died of a parasite. IE they are not randomly arching their bodies and keeping them still in unusual positions (such as upward half circles) or constantly moving their mouth in an eating motion.
They aren't starving that I am aware of. When giving them the romaine lettuce it's washed off and patted dry on a clean towel. The ones that have died recently (seemingly suddenly) are all rather large looking and until their death they have not shrunken down in nature (like you would expect if they were living on reserves). I've seen them shrink down, like someone squeezing an accordion together.

These caterpillars are becoming limp, as the phrase goes 'like a limp noodle.' They aren't oozing anything out of their mouth or rear. And their death is, sudden. One day they are fine, moving or clinging tight to their location upon touch the next day, gone. Not even 24 hrs later.

Someone said it sounds like disease -which is really worrisome! I'd like to know if anyone knows of like listed or known diseases for caterpillars?

I know some might say release them but that's no something I plan to do, because I only see them being eaten then, starving or otherwise not making it.
If anyone knows of someone who to contact that perhaps can shed light on this problem, or who to contact on where I can send the few that have passed for an autopsy I'd be so grateful!