This larva was clinging to the rear end of a planthopper which was well hidden in the vegetation. It was the white spot that caught my eye.

I took the hopper home in a ziplock bag because it looked so odd; the larva abandoned the planthopper and started crawling about. Its back was well covered by waxy, dusty material. It was holding a cottony web on its belly. I can't figure out what kind of larva it is. Please watch the short video; you get more of a sense of how it moves and what it looks like from it.
I removed all the stuff later on to observe more details of the anatomy. A day later it started forming a new cottony ball.