*A Small Death

Today I went back to the tree from yesterday, to see if I might find that cicada nymph's discarded shell.  Sadly though, this is what I found instead:

 

It looks like the nymph did undergo the final molt and emerge as the imago, but it had been so weakened by the arduous climb that its strength gave out and it died without ever taking flight.

How can I be sure it was the same one from yesterday?  While I cannot be absolutely certain, the fact it was the only one left on the tree (I'd plucked the lower shell on the tree to take home);  it had begun to veer toward the right when I left;  and that when I discovered it, it was crawling away from the tree rather than climbing it, could have been a sign of some genetic defect, one that was affecting its navigation faculty and maybe some other functions as well.  Evolution at work, ruthlessly weeding out individuals that are not up to species' standards.

*"A Small Death" is the title of the short story I once wrote, described here.