What's That Bug? does not endorse extermination

Subject: Tiger Swallowtail – Papilio glaucus or Pterourus glaucus?
Location: Naperville, IL
July 10, 2012 10:15 pm
Hi Daniel~
These photos are of a female Eastern Tiger Swallowtail, but do you know which genus name is correct? We’ve had some intense heat in Illinois over the past two weeks, which finally broke a few days ago, and I am thinking this might be why I’ve seen so few butterflies about. Is there any basis to this? All the best to you.
Signature: -Dori Eldridge

Eastern Tiger Swallowtail

Hi Dori,
You have proposed a very interesting theoretical question.  The reason we have scientific names for insects as well as all other known life forms on this planet is so that there is a universal name for the creature regardless of the language spoken by the person who is referring to the creature.  The common names are less widely used and often the same common name might be used for a number of creatures just as the same creature, especially if it has an extensive range, might have numerous common names.  There are also officially recognized common names as well as casually used common names that are not officially registered.  Since your question is regarding the scientific binomial name, we will confine the remainder of our response to that nomenclature.  How is a scientific name determined?  BioDiversity Explorer has a very extensive explanation on the process.  So, how can a species have more than one scientific name?  The first person who describes a species has naming rights, but in the days prior to the instantaneous mass communication we have at our fingertips today, it was possible to have more than one person simultaneously discover a species, or especially in the case of wide ranging species, to have a subsequent person believe that person has discovered a new species when it was previously described.  In that case, even if the second name came into wide use, the first naming trumped.  It is also possible that a species was originally placed in one genus and further scientific investigation caused the genus to be either split or lumped, necessitating a change in the genus name which is the first and capitalized part of the binomial.  Until your letter, we were unaware of any scientific name for the Eastern Tiger Swallowtail except
Papilio glaucus.  Your question caused us to do some research.  BugGuide still has the Tiger Swallowtail listed as Papilio glaucus, however, however it is indicated:  “Synonyms and other taxonomic changes
Papilio glaucus Linnaeus, 1758. Synonyms and taxonomic notes:
Pterourus glaucus–sometimes this and related species are split out from Papilio.
Large, spring-flying populations in the Appalachians have recently been recognized as a separate species,
Papilio appalachiensis (Pterourus appalachiensis).”
The North American Butterfly Association (NABA) still recognizes
Papilio glaucus.  The modern use of DNA analysis can have a significant bearing on the naming and renaming of new and known species.  Finally we turned up this online version of The Taxonomic Report of the International Lepidoptera Survey from 15 June 2002 that recognizes Pterourus appalachiensis as a new swallowtail butterfly from the Appalachian region of the United States.”  Perhaps the discovery of that species is responsible for splitting out the Tiger Swallowtails from the genus Papilio.  We must confess Dori, that we are not scientists and you should probably check with a noted expert in the field before trusting anything we have discovered.

Eastern Tiger Swallowtail

What's That Bug? does not endorse extermination
Location: Illinois

2 Responses to Eastern Tiger Swallowtail: What's In a Name???

  1. dorwageld@aol.com says:

    Goodness, Daniel, I was away for some time in July, shortly after I sent these Eastern Tiger Swallowtail shots to you, and I never noticed the comprehensive response you wrote. Thank you – and apologies for not thanking you earlier! After reading your request for clear photos of a Western Tiger, I went in search this evening for the differences between the Western and Eastern varieties, and I came upon an interesting, related tidbit from a web site called learnaboutbutterflies.com:

    “Back in the 18th century when Linnaeus created the System Naturae, the word Papilio was used as the genus name for every known species of butterfly in the world. Since then much has been learnt about the relationships between different species. Consequently most have been reassigned to new genera, and only about 215 of the 17600 currently known species are retained in Papilio.
    There are 30 Papilio species in the Australian region, 60 in the Oriental region, 40 in the Holarctic region, 54 in the Afrotropical region, and 31 in the Neotropical region ( the latter figure includes 28 that have recently been transferred to the genus Heraclides ). The 40 Holarctic species include 21 found in North America – excluding those found south of Mexico, on Caribbean islands, and species that have been transferred to Heraclides.
    Papilio rutulus was originally considered to be a subspecies of glaucus. Females of glaucus however are earthy brown in colour, with no trace of dark bands on the upperside, whereas rutulus females are identical in colour and pattern to the males.” (http://www.learnaboutbutterflies.com/North%20America%20-%20Papilio%20rutulus.htm)

Leave a Reply

Your email address will not be published. Required fields are marked *