my Cecropia caterpillar is sick/dying

[auroborus]

my hyalophora cecropia caterpiller seems to be sick, I found him at the bottom of his container looking a little dehydrated (though there is plenty of humidity around) Also he isnt walking or gripping anything with his legs, Is there any way of rescueing my lil caterpillar? hes in the fourth instar, I separated him from my other caterpillars. Also my caterpillar is raised indoors, he has a few room mates that seem to be doing really well. I have them by a window so they get enough heat and humidity, as well there is no chance of parasites.

 

[Bugs In Cyberspace]

I keep mine in a well ventilated cage and dump out the frass every two days when they are young and everyday when they are older. Humidity spells disaster for these.