An ecdysiast is a very fancy term for a striptease artist.
This is a silkworm who has just transformed from the third to the fourth instar (larval stage) by shedding its skin. The transformation begins with extended prayer, then there is a lot of wriggling like a hoochy-kootch dance, and suddenly the shiny new caterpillar pops out as you see here. The shed skin is wadded up like a discarded sock, but you can see the old head on the top of the shed skin.
