What was that ornately sculptured mystery object?
It was the egg of the Question Mark butterfly, Polygonia interrogationis. I admit, I had an advantage over you folks. I identified the species watching the adult butterfly before she laid that egg on an elm leaf.
Although several of you put in solid guesses, I am awarding no points for this week’s mystery. The single correct entry- by lepidopterist and blogger Chris Grinter– provided no supporting information as per our more stringent rules, and the entries with supporting info didn’t arrive at the correct ID.
But don’t feel bad. This was an especially hard mystery, and one that I wouldn’t have gotten myself had I not spied the egg-layer in action.
Myrmecos Blog 
What supporting information were you looking for?
LOL! I’m with Chris on this. You didn’t give him credit for knowing?
Oh, I give Chris credit. Just not points.
We had some discussion a couple weeks back whether guesses should be accompanied by supporting rationale. Taxonomic characters, ecological context, that sort of thing. The idea is to prevent simple image-searching on bugguide and force more careful consideration of the identification.
So we implemented the new rule that naked answers were not sufficient. Rules is Rules.
Having said that, I am impressed Chris nailed it. I certainly wouldn’t have- not without the adult butterfly.
Ahhhh technicalities, guess I missed the change to that rule! I’ll elaborate on my gestalt next time…
I doubt that BugGuide browsing would have helped much in this case anyway, since the only egg image I saw there for this species was insufficiently detailed to really make out. I’ve noticed that, in general, egg images are kind of scarce on BugGuide, and those that are there tend to not have very detailed IDs (for obvious reasons). Since this image has both excellent provenance and high detail, are you considering contributing it to them?
I went back and looked at some plant hairs, and these are decidedly more elmy than nettley, though perhaps no less nettlesome for having tripped up MY Gestalt! Hah.
Tim – Good suggestion!
Alex,
I like that you took my suggestion – this makes for much more challenging mysteries! I’ve learned something new already, and I think that might be one of the great advantages of the new format. Insects rule! I missed this one but I’ll try for the next.