Papilio Polyxene

Eastern Black Swallowtail (Papilio Polyxenes) larvae; late stage before pupation.

Seen here chillin' on its primary host plant, the herb fennel.

Photo with my finger on its back shows the expression of the orange y-shaped 'osmeterium', an organ which exudes a rather-unpleasant "stink-bug-like" odour in response to unwanted, aggressive attack.

After washing my hands four times, since, I can still smell it....