Tawny Emperor vs Hackberry Emperor Caterpillars

I see this come up every once in a while: somebody sees an Asterocampa caterpillar but doesn't know which one. It doesn't help that the definitive caterpillar guide, Caterpillars of Eastern North America, has an entry for Tawny Emperor but includes pictures of BOTH caterpillars and it's not immediately clear without a close reading of the text which is which.

Since I had one of each, the same age, I figured I would put them side by side for a comparison. Keep in mind there are subspecies for each and they can look very different in terms of body pattern (don't get me started on the ID tips for Tawny Emperors being exclusively for the Florida subspecies, sigh), so you want to look at the structure of the head and the relative size of the horns/hornlets.

L: Tawny Emperor R: Hackberry Emperor

L: Tawny Emperor R: Hackberry Emperor

Top: Tawny Emperor Bottom: Hackberry Emperor

L: Tawny Emperor R: Hackberry Emperor
NOTE: The color and pattern of the face will change with age (molting) and varies between individuals. That said, the patterns on striping on the faces are distinct between the two.

And the most important part:

L: Tawny Emperor R: Hackberry Emperor

Publicado el octubre 9, 2017 10:15 TARDE por nanofishology nanofishology


Fotos / Sonidos


Mariposas Emperatriz (Género Asterocampa)




Texas, US (Google, OSM)


A reference for those pesky caterpillar IDs!
Tawny emperor on left/top has lots of little horns
Hackberry emperor has shorter, subtler hornlets (???)


Really good write-up, Alysa! :) I'll look closer for these caterpillars now that I know how to tell the difference. :) Thanks! Also, as you ID caterpillars like this, you should link back to this journal entry so the observer can get this additional info.

Publicado por sambiology hace casi 7 años

Will do!

I think iNat should add a feature where each journal post that links to an observation should get added to a tab on the species page. The knitting/crochet website Ravelry does the same thing... if you write a post or comment in a discussion board and link to a pattern, your post will show up on the pattern page. Really easy to see interesting commentary on the page. Right now I feel like all the super useful information and discussion gets hidden in journals that nobody knows how to find without stumbling onto a link.

Publicado por nanofishology hace casi 7 años

Yeah, really interesting info does get hidden in journal entries, unfortunately... Our friend Chuck @gcwarbler has some incredible journal entries, and most of them I've just bookmarked!

I do like to go through the journal entries on iNat though:

Publicado por sambiology hace casi 7 años

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