After 3 rainy days this caterpillar grew dramatically. It now measures at 6cm, and though I never measured it before I'm sure it was about 4.5 a few days ago.

Update: 2 days later it died, but I'm still unsure why. It didn't get below 50 that night, it had plenty of fresh food, I fed it from the same plant for weeks, and I couldn't find any signs of parasitism. What's really wierd is the white-lined sphinx I was raising died at the same time, which makes me almost sure it wasn't parasitoids. Any ideas?