Another "A-Hah!" Moment with Petrophila Moths

Since finishing my previous article clarifying Petrophila jaliscalis and P. santafealis (So. Lep. News 41(3):216-225, Sept. 2019), I have been working on a larger review of the identification of all of the North American members of this genus*. Happily, I have discovered some subtle ways of separating several of the most-often conflated species, especially in the “fulicalis-species group”. But I had been continually frustrated with the distributional patterns and wing patterns of the latter group across Texas and Oklahoma. There just seemed to be some unresolvable discord between assigned species names, wing patterns, biogeography, and DNA barcoding. So I let it all go for several months.

I recently began revisiting this entire mess, rereading original literature and pouring over imagery and barcode taxon trees. With the help of Occam’s Razor and a resounding believe in the constraints of biogeographic history and the fallibility of human endeavors, I came to a major realization this morning. A light-bulb went on. The skies parted and the sun shone. I figured it all out. (And if you believe that last statement, I have a bridge in London I’d like to sell you.) It’s a complex story that I will develop in full detail in my next manuscript, but here are the Cliff Notes, as I currently understand the situation:

  1. Contrary to my previous belief and assertions*, Petrophila fulicalis does in fact occur west of the Mississippi River, in Missouri, Oklahoma, and Texas—well down into central and south Texas in fact.
  2. Petrophila heppneri is primarily confined to the Texas Hill Country with one questionable outlier in Colorado County, TX, on the coastal plain.
  3. Petrophila heppneri and P. fulicalis may overlap narrowly in central Texas but to date I have only found one county (Hays) with valid records of both species. Heppneri basically occurs only on the southern half of the Edwards Plateau. Records of P. fulicalis essentially surround those of P. heppneri. I might expect that eventually this pair of species will be found to co-occur in places like Bexar, Blanco, Comal, Kerr, Val Verde, and Terrell counties.
  4. Petrophila hodgesi remains an Ozark ecoregional specialty but it occurs in close proximity to P. fulicalis in northeast Oklahoma and probably southern Missouri.
  5. Petrophila santafealis, heppneri, and probably hodgesi are all sister taxa to P. canadensis and with it represent a separate lineage (clade, if you will) to a fulicalis-confusalis lineage. The santafealis-hodgesi-heppneri group represents a southern offshoot of canadensis stock distributed patchily in limestone-derived watersheds in Florida, the Ozarks, and the Texas Hill Country. There are very scattered records of similar Petrophila moths in North Carolina and Alabama which to some degree bridge the gaps between the other “species” but the distribution of the group is not expected to be (and cannot be) continuous across the larger landscape. All of these southern populations are probably relictual from some previous wetter or cooler Holocene or late Pleistocene era.

Small footnote: The enigmatic barcode BIN BOLD:AAG9560 was part of the impediment to understanding all of this. Two of its 14 members (Mark Dreiling’s OK specimens) had been labeled “Petrophila hodgesi”. A search on BOLD for the latter taxon brings up images of 7 specimens: Mark’s 2 OK specimens and 5 from Washington Co., AR. Here’s the rub: Mark’s 2 specimens are actually fulicalis (both by wing pattern and by barcode analysis) and the 5 Arkansas specimens, which appear to be legitimate hodgesi, don’t have a BIN assigned to them. That leaves hodgesi without a verified, assigned barcode, as of today.

All of this will be set out in detail in my next manuscript. I will NOT be making any substantial moves or changes to identifications on iNaturalist.org or BugGuide.net until I have something resembling a completed manuscript, but there will be a substantial number of re-identifications at the appropriate moment.

I know you are all on the edge of your seats… ;-)

* See also: https://www.inaturalist.org/posts/27047-id-guide-6-notes-on-texas-petrophila-identification
https://www.inaturalist.org/journal/gcwarbler/40151-sorting-out-feather-edged-and-heppner-s-petrophila

Posted by gcwarbler gcwarbler, August 03, 2020 14:28

Comments

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Wow, you are certainly tackling a monumental task and making huge progress! Can't wait to see the next manuscript!

Posted by beschwar 9 months ago (Flag)
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Love a good taxonomic mystery!

Posted by pfau_tarleton 9 months ago (Flag)
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Have you ever thought about writing a murder mystery? I am pretty sure that you would only have to change up the characters' names.

Posted by centratex 9 months ago (Flag)
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The New Clue board game: "...Mr. Petrophila did it in the Study with Cyanide."

Posted by gcwarbler 9 months ago (Flag)
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Hahaha!!! :-)

Posted by beschwar 9 months ago (Flag)
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Keep up the great work!

Posted by zdufran 9 months ago (Flag)

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