Taxonomical Changes

D.B. Thomas explains:

There is a third paper by Jay and Ahmad with the final bunch of species in which they transfer some of the species placed by Lariviere in Parabrochymena back into Brochymena. I was a reviewer and provider of specimens for all three papers, and Larivieres original paper as well.

That result is indicative of the problem.

1. About 1946 Herb Ruckes produced the first major revision of Brochymena. This was a seminal paper. Not perfect, but as a first approximation an excellent piece of work. Ruckes divided the genus which then included about 25 species into three "groups", not even subgenera: the quadripustulata group which had triangular humeri, the arborea group which had quadrangular (or "truncate") humeri and, a monotypic cuspidata group.

Subsequently another ten or so species turned up bringing the total number of described species up to around 35. The only problem I had with Ruckes paper, other than the fact that the key doesn't work, was that he was reluctant to sink some of the invalid species presumably because the people that named them were still around. The key didn't work because it relied on somatic characters when the genitalia are really the only sure way to identify things.

2. Marie Lariviere then published her doctoral dissertation which was another revision of the genus to include all of the new species. At the alpha-taxonomic level she did a very good job. For example she was able to show that "cuspidata" described from Panama was actually the southern most end of a cline of a common Mexican species haedula. The problematic part of her work was that she then proposed a genus name for the species that Ruckes called the arborea group. She claimed that she had done a cladistic study of the other Halyine genera and that her "Parabrochymena" was as distinct a genus as the others. But she has never produced such study (and I don't believe it). Lariviere also claimed that there was an an equivalent amount of morphological variation within the two genera, which was also not true.

3. The series of papers by McPherson and Ahmad show that this latter claim was not true. There is a large amount of variation in the Brochymena species with regard to the genitalic structure. Also there is a disconnect between male genitalia and the humeral character. So they align the species based on the genitalia.

Here is my problem with recognizing Parabrochymena. Parabrochymena is a little cluster of six closely related species which all share a suite of morphological characters. Thus I agree with Jay that it is a recognizable monophyletic group and in that narrow sense, "valid." But that leaves a big garbage bag genus Brochymena. One could take any large genus of insects and isolate out some cluster of closely related species. The only rationalization for giving it a name would be if one could show it is basal. If on the contrary, the ancestor of this Parabrochymena cluster shares an ancestor common to one of the groups inside Brochymena then it is not a valid taxon unless one breaks up Brochymena into its constituent species clusters and gives names to them. Until one or the other happens I am reluctant to recognize Parabrochymena.

… v belov, 20 January, 2011 - 12:54pm

Woolly Alder Aphid

I just discovered that Paraprociphilus tessellatus is now Prociphilus (Paraprociphilus) tessellatus, and probably has been for quite a while (it's even listed that way on Nomina Nearctica). Figured I'd announce the change here rather than leave a comment on every image.

… Charley Eiseman, 13 January, 2011 - 9:19pm

forum switch?

I'm wondering if all of these discussions aren't misplaced. Isn't there a Taxonomy proposals forum? It seems that each of these issues deserves a thread there, instead of throwing them all into this one thread on the General Forum.
I know a topic can be moved to a different forum somehow, but I think only the original poster of the thread at the top level can do that.

… Cotinis, 13 January, 2011 - 10:19pm

Yes

This is a very annoying "feature" of BugGuide. It makes it easier for editors to rearrange the guide, but people who come here looking for IDs never know that their previous "ID" has changed. Some editors also create this problem by making species pages for things that should be no taxon (UnknownSpecies1, YellowAndGreenSpecies) and then when they figure it out they just rename the page and the contributors NEVER get an ID because the last notification they recieved was a move to UnknownSpecies1.

… John R. Maxwell, 9 January, 2011 - 12:14am

i'm certainly guilty of the latter

i.e., creating those 'unnamed' species pages rather than 'no taxon' -- because otherwise we'll have to move everything manually to a new page after a valid name has been established, although i'm not aware of any actual examples of changes of such temporary 'names'
anyway, the notification system does need a lot of improvement, that's for sure

… v belov, 11 January, 2011 - 12:16pm

I know

it is extra work, but people looking for IDs get cheated if we just rename a page. Or worse we would have to post a comment on every series saying that they have an ID?

… John R. Maxwell, 11 January, 2011 - 12:18pm

you're right, of course

on a few occasions where species name changes have been introduced [all of them involved pages with 1 to 3 submissions tops] i did post comments about the update on every series, but i don't know of any instances where changes of that sort have been made unbeknownst to the contributors

… v belov, 11 January, 2011 - 12:31pm

I wonder

if the time it would take to leave comments on images is more work than the bulk "tag and move" to a new page once species were determined (for large numbers)?

… John R. Maxwell, 11 January, 2011 - 4:02pm

commenting takes more time, no doubt -- unless most pix on the page have been contributed by the same user, which is often the case

… v belov, 11 January, 2011 - 4:05pm

Parabrochymena has long been synonymized

the guide used obsolete taxonomy, now corrected

… v belov, 3 January, 2011 - 9:17am

BugGuide historical note from 2008...

OK, you young whippersnappers(;))--originally (like, 2004, 2005, et seq.) we had the species listed Brochymena arborea, which is one of the ID's I considered for our second-ever "Broch" back in 2004 (though this turned out to be quadripustulata):

Much later somebody said we should split arborea, etc., out to Parabrochymena, and that was recently, according to my feeble recollections. I can't recall who said we should make that change, but I believe it was discussed at the time. Looking at the Google cached version, I see the guide for Parabrochymena was written by by Ted Kropiewnicki on 11 February, 2008. So it hasn't been that long, and there was some discussion at the time. (Genus Parabrochymena was only erected in 1992, so it can't be radically obsolete, can it?)
I'm really fine with keeping one big happy genus Brochymena, but I think it would be nice to see some notation on what authority is being followed on that. I've been out of the loop lately--do we have a single recognized authority for Pentatomidae?
I'll make some notes on the guide for Brochymena to satisfy my own obsessiveness.

Additional note. We do have a listing for this family under the Master List of Online Taxonomic Resources, Dr. Rider's Pentatomoidea Home Page, and it does not list arborea, etc., under Brochymena, and it does list Parabrochymena Larivière, 1992, though does not list the species. So what is the authority for the inclusion of arborea under Brochymena?

… Cotinis, 11 January, 2011 - 5:07pm

thanks for the history, Patrick

Don Thomas who IDs/checks the bulk of BG stinkers, have always used Brochymena for arborea and its closest kin

… v belov, 11 January, 2011 - 5:34pm

OK...

Darn, I knew you'd get to it while I was making a revision. I found some more details on what authority we had listed for Pentatomids--see above.

Again, I'm happy with putting it back under Broch, but it would be nice to be able to point to a published list. Consult three taxonomists, you will get at least four opinions, I suppose!

… Cotinis, 11 January, 2011 - 5:39pm

i will specifically ask Don and Dave Rider...

...for the 'official' reference

i also know that Jay McPherson used to treat them all in Brochymena

… v belov, 11 January, 2011 - 5:45pm

References--seem to be maintaining Parabrochymena

Well, here are some interesting ones from 2005, 2007, by McPherson!
J. E. McPhersona and Imtiaz Ahmadb, 2005. Further Information on Male Genitalia of Parabrochymena Larivière and Brochymena Amyot & Serville (Hemiptera: Pentatomidae). Annals of the Entomological Society of America 98(3):282-290. 2005. doi: 10.1603/0013-8746(2005)098[0282:FIOMGO]2.0.CO;2 (link).
Abstract
In a previous article, we reported that the male genitalia of two species of Parabrochymena and four of Brochymena were distinct, particularly the shape and length of the vesica. Here, we present genitalic information on an additional four species of Parabrochymena and 10 species of Brochymena that further supports consistent differences between the two genera.

J. E. McPherson,1 and Imtiaz Ahmad. Redescriptions of Brochymena and Parabrochymena (Hemiptera: Heteroptera: Pentatomidae), Based Primarily on Male Genitalia, with Reclassification of Three Species and Description of New World Tribe (Halyini). Annals of the Entomological Society of America 100(5):673-682. 2007
doi: 10.1603/0013-8746(2007)100[673:ROBAPH]2.0.CO;2 (link).
In two previous articles, we reported that the male genitalia of six species of Parabrochymena and 14 species of Brochymena were distinct, particularly the shape and length of the vesica, thus supporting the establishment of Parabrochymena. Here, we present genitalic and nongenitalic information on four of the remaining five species of these two genera. Because of the results of these analyses, and in combination with similar analyses of species described earlier, we have transferred three of the four species [i.e., Parabrochymena enigmatica (Ruckes), Parabrochymena inbio Larivière, and Parabrochymena poeyi (Guérin-Méneville)] to Brochymena. Also, we have provided descriptions of Brochymena and Parabrochymena and the New World tribe (Halyini), which includes only these genera.

I don't have BioOne access, so I can't read the full text, but they seem to be maintaining Parabrochymena, though shuffling some species back to Brochymena. I don't see them referring to arborea, but it must be in one of the papers. Of course I'm sure all of this could be argued as to genus versus subgenus or whatever.

… Cotinis, 12 January, 2011 - 11:06am

exactly...

i referred to these very papers in my last night note to Don; i'm sure he'll reply soon and will provide detailed argument, as he always does

… v belov, 12 January, 2011 - 11:13am