reflex bleeding
I am impressed. Several of you* figured out the mystery behavior: reflex bleeding, a defensive response employed by some arthropods with especially nasty hemolymph to deter predators. A couple of you even pegged the identity of the mystery arthropod, a blister beetle in the genus Epicauta. Here's the uncropped photo:
An Epicauta blister beetle reflex bleeds when grasped with forceps.
Five points each to Tim, Ainsley, Neil, and Dave. And, ten points each to Pete and TGIQ.
So. Um. Don't spend them all in one place...
Posing on a mesquite flower.
*what's up with all the guessers-of-mysteries…