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 being bloggers? Are bloggers just smarter?
Myrmecos Blog 
Maybe just geekier 😛
P.S. That is SUCH A COOL BEETLE. I want one.
Well clearly I need to bone up on my blister beetles and their biology.
Don’t feel bad, James. It’s a trick photo (see my comment to Ainsley, below).
Yep, I agree TGIQ… proud to be a geek!
You’re the only non-blogger among the participants. What gives? Is Peteblog.com taken already?
I’ve often thought about it, but the general standard of bloggery in the ento/bio fields is just so high it’s a little intimidating!
Maybe one day….
So the single claw WAS a red herring! CURSES.
That’s exactly why I cropped the photo that way. It’s the wrong angle to see the split tarsal claws, too.
I totally went down that one-claw road too…but it ended up nowhere, so I figured it had to be a trick.
Sneaky ant guy.
Oh well, it would be neat if there were a spider with reflexive bleeding, but at least you are one great arthropod photographer that doesn’t shoot jumping spiders.
Same thing that happens to me when I’m grabbed with forceps