Battus philenor hirsuta

[eurytides]

Compared to the nominate philenor, ssp hirsuta have slightly different adult morphology (hairy body, less pointed forewings), host plant detoxification ability (A. serpentaria is toxic to them), and different looking larvae (google).

Female hirsuta and male nominate philenor cannot successfully couple. The reverse cross produces viable eggs but all die after pupation. See here:
https://images.peabody.yale.edu/lepsoc/ ... v44_n2.pdf

So, why isn’t hirsuta a full species?

[adamcotton]

Thank you for pointing out this interesting short note. I guess that no-one has compared sequences of hirsuta and philenor, but it does sound as though they are probably distinct species.

Adam.

[Chuck]

So, why isn’t hirsuta a full species?

Well is it a genetic morph of the nominate species, or is the mother species from which they both sprang now extinct?

[eurytides]

But even if it’s a “genetic morph” (not quite sure how that’s being defined), if it’s so distinct from nominate philenor from which it is physically isolated, wouldn’t it be a good species? I mean, it seems to fit the biologic species concept.

[papiliotheona]

Speciation, especially in the swallowtails, is a funky thing. We call *hirsuta* and *philenor* subspecies despite this obvious genetic incompatibility; yet both combinations of pairing *Papilio zelicaon* and *polyxenes* result in fully fertile offspring of both sexes, and indeed there are probable wild hybrids where they meet in CO, etc.--so, go figure. The same is true of most of the other *machaon* complex members, albeit there is major Haldaning with M *rudkini* x F *zelicaon gothica*--very few males produced, albeit the ones that are are fertile.

[Chuck]

A subspecies is by definition is an offshoot of another, existing species. If they are descended from an extinct taxon, it is by definition a species.

Back in the olden days a unique group would be called a subspecies of a previously identified taxon. When canadensis was a ssp, how did we know that maybe canadensis was the mother species and glaucus was the subspecies? They didn’t. So the first found taxon was the species, and the next ones were called subspecies.

With genetics we often know the relationship of two groups, and know if the source taxon is extinct. And if it is, which it often is, they are then sibling species. And we’ve been seeing that in the elevation to species status.


So it probably is a species.

[eurytides]

Anyone out in north California in this group? Deserves further study!

[JVCalhoun]

A subspecies is by definition is an offshoot of another, existing species.

In the nineteenth century, a "subspecies" was loosely defined as a geographic variant of a species, but that didn't last long. It was soon seen as an equal division of a species. In other words, once a species was recognized as having one or more subspecies, then the taxon that was originally described became the nominate (now nominotypical) subspecies. As a result, all such taxa were then treated as equal subspecies, without suggesting which is the ancestral form.

When canadensis was a ssp, how did we know that maybe canadensis was the mother species and glaucus was the subspecies? They didn’t. So the first found taxon was the species, and the next ones were called subspecies.

This doesn't seem to be the case with canadensis. Its authors, Rothschild and Jordan, described it as "P. glaucus canadensis," with "P. glaucus glaucus" explicitly treated as a separate subspecies, similar to how we would do so today. They referred to them as "geographical forms" of the same species, which they considered to be the same as a subspecies. Because they referred to canadensis as a "small form," I suppose it could be inferred that they believed glaucus to be the ancestral taxon.

The ICZN Code currently defines a subspecies as "The species-group rank below species; the lowest rank at which names are regulated by the Code." This dates back to the first edition of the Code in 1961, which similarly defined as subspecies as "A category of the species-group subordinate to species; the lowest category recognized in the Code."

Neither of these definitions suggests that a particular subspecies is to be considered subordinate to another, especially because one was described earlier. That's a good thing, as that would really result in a mess!

[eurytides]

Someone should do some molecular tests on hirsuta vs nominate philenor. My gut feeling is that there is enough here to elevate hirsuta to a full species. There are larval, physiologic, adult differences, and documented issues with interbreeding. I wonder if anyone has looked at the genitalia? The lack of coupling ability mentioned in that article by Soukarov and Daniels makes me really wonder about that.

[Chuck]

Someone should do some molecular tests on hirsuta vs nominate philenor.

Therein lies the roadblock. You may remember that there are Papilio solstitius with the UK genetics lab sitting awaiting funding for analysis since 2022. Nick G is hit or miss, depending on what his focus is at any given moment. I can't imagine the backlog of questionable taxonomy awaiting even simple COI.

The lady who did the solstitius COI for me was looking for a collaborator to purchase 100 sample runs, cost was US$1200. You'd need fresh/ frozen legs, not dried specimens. I can connect you if that helps.

[eurytides]

Oh I know Chuck, not saying this would be easy. I just wanted to put the bug in someone’s ear (no pun intended) in case anyone here is within range of hirsuta. I would do it if I had any specimens or plans to travel to Cali.

[Chuck]

Oh I know Chuck, not saying this would be easy. I just wanted to put the bug in someone’s ear (no pun intended) in case anyone here is within range of hirsuta. I would do it if I had any specimens or plans to travel to Cali.

Good idea. And, it is "relatively" easy, it's already been flagged. Anyone could publish an elevation to species status; but even you would agree that said publication should rely on at least COI.

Papilio rutulus in (parts of) California, and eurymedon in AZ are also pretty well known to be "different" and there is COI bar coding on those. Just takes someone to start writing. I think there are so many subspecies in need of elevation that it's too much for the pros who have access to the labs and are already swamped writing.

Glad you flagged hirsuta, I wasn't even aware of it.