Longwing Zebra Butterfly from Costa Rica

Butterfly Identification
Location: Osa, Costa Rica
October 21, 2010 7:57 pm
Not a bug, but maybe you can help.
I need an identification of this butterfly photographed in the Osa Peninsula of Costa Rica. I have included dorsal and ventral views.
Signature: Doug Goodell

Dear Doug,
Your butterfly is one of the Longwings in the subfamily Heliconiinae.  After a bit of searching, we believe we identified your species as Heliconius pachinus on the Butterflies of America website.  The Tree of Life website has a map which shows the distribution of Heliconius pachinus in Costa Rica and Panama.  The Wildlife Refuge website indicates its common name is the Longwing Zebra Butterfly and that:  “it is found in association with Rain forests from sea level to 1,600 meters on both slopes” and that when threatened “adults release a repugnant odor from glands located in the tip of the abdomen.”

Update
Hi Daniel
Thanks for your information. This identification certainly makes sense. BUT, I have two concerns:
First, How do you distinguish pachinus from hewitsoni (which was my conclusion), or from cyndo. Are there any specific identifying features?
Second, The reference in Wildlife Refuge website to the common name being “Longwing Zebra Butterfly” is most unfortunate.  It may be called that in some places but the name Longwing Zebra is, as I have seen it, is most often used to refer to Heliconius charithonia.  (It is the State butterfly of Flordia).
I realize that these identifications can be difficult.  Can you add any further clarification to these concerns?
Again, I greatly appreciate your efforts.
Thanks
Doug Goodell

Hi again Doug,
We cannot say for certain who is correct, and both possibilities seem plausible.  The Tree of Life website has a nice page on Heliconius hewitsoni.  Use of common names like Longwing Zebra Butterfly can obviously cause problems.  We have not seen the transposed name Longwing Zebra which is distinct from the Zebra Longwing, Heliconius charithonia, the species you cite which may be found on BugGuide.  The examination of the actual specimens by qualified specialists might be the only sure way of determining the exact species you have photographed.  We understand that modern DNA analysis is creating an entirely new means of determining taxonomy, and it may result in identifying more species, or perhaps fewer species, once the results are in.  DNA analysis may prove that Heliconius pachinus, H. hewitsoni and H. cyndo are distinct species, or subspecies, or perhaps the same species that evidences minor physical variations in individual populations.  The bottom line is that the butterflies know how to identify their own species, allowing for their perpetuation.  Good luck in seeking your answers.  Also, we just encountered a similar taxonomic problem in our effort to identify a Hornworm Caterpillar from Crete.

Hi again Daniel
Thanks again for your thoughtful response. You have nailed my problem. I will continue to seek information from Costa Rican entomologists, but I certainly appreciate your efforts.  Indeed, realizing how much time it takes me to try to track down these identifications, I don’t see how you can do so much, covering so many subjects. You are to be commended for the time spent and results obtained!
Doug
PS I will soon send you some bug photos that have been bugging me.

Additional Questions
November 9, 2010
Hi again Daniel,
At the risk of overextending my welcome, I’d like to ask you another question on this topic. I have recieved an independent suggestion from a Costa Rican enthomologist that my images are of H. hewitsoni.  But he also suggests that it should be called H. sapho hewitsoni because the two have been combined. The TOL site cladogram does indeed suggest that hewitsoni and sapho are very closely related. Web searching turns up a few, but very few, references to the mixed name. What puzzles me most is that the dorsal pattern of sapho and hewitsoni seem quite different (unlike the dorsal patterns of hewitsoni and pachinus which are very similar). With such different wing patterns are they likely to be combined? Or has the sapho name simply been added to both hewitsoni and leuce. Can you or anyone else help me to understand this issue. I am not a biologist; I’m simply trying to put the proper identification, with confirmation, on a picture that is to be published: should it be H. hewitsoni or H. sapho hewitsoni? I realize that there may not be a good answer for this, but I had to ask.
Again, I thank you for your time and comments.
Doug Goodell

Hi Doug,
We don’t really feel qualified to provide a conclusive answer, but we do know that taxonomy changes occur all the time.  Perhaps DNA analysis, which is the new tool for correct taxonomic classification, has been used to determine the identity of the species in question.  You can play safe and just identity it as Heliconius species.

Jeffrey Glassberg confirms identity:  April 5, 2017
Hi Doug and Daniel,
Daniel — thank you very much for your help in contacting Doug!