Taxonomy

The Ants of Paraguay

Camponotus personatus

Paraguay may be the world’s most important country. Never mind that it is economically isolated and geopolitically forgettable. Rather, I measure importance by less trivial metrics, and by that of course I mean ants.

Paraguayan ants have changed the world. Many of the world’s worst pest species evolved on the broad plains of the Paraná river before hitchhiking with human commerce to points abroad. The infamous fire ants in the southern U.S. originated on the Paraná, as did the Argentine Ants that plague California and Europe, along with a rogue’s gallery of other trampy and invasive species. These invasives transform ecosystems and drive native species to extinction. Not to mention that some of them are champion stingers and are very good at getting into houses, greenhouses, and wherever else they can stir up trouble.

We do not know why ants from this region are so potent, but perhaps something about the Paraná acts as a cradle for pestilence. Sadly, we’re a pretty long way from finding out, as the ant fauna in that part of the world has been among the most poorly-documented anywhere. We know a fair bit about what happens to these ants after they arrive in Europe, Hawaii, Florida, and other places frequented by scientists, but what goes on in the native range is largely a black box. I’ve been slowly been chipping away at the problem by cataloging the ant species that live in Paraguay. You can check out the progress- accompanied by April Nobile’s amazing ant images- here:

The Ants of Paraguay

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For more details, the full catalog is here (full text is subscription only, sorry):

Wild, A. L. 2007. A Catalogue of the Ants of Paraguay (Hymenoptera: Formicidae). Zootaxa 1622: 1-55.

The Current State of Ant Taxonomy…

…reviewed by Phil Ward here:

Ward, P.S. 2007. Phylogeny, classification, and species-level taxonomy of ants (Hymenoptera: Formicidae). Zootaxa 1668: 549-563.

Abstract: The current state of ant systematics is reviewed. In recent years substantial progress has been made in identifying the major clades of ants and the relationships among them. Earlier inferences about ant phylogeny based on morphology have been refined and modified as a result of a recent influx of molecular (DNA sequence) data and new fossil discoveries. It is now apparent that much of the biological and taxonomic diversity of ants is contained within the “formicoid clade” which comprises 14 of the 20 extant subfamilies and about 90% of all species. Whether the remaining groups of extant ants (Leptanillinae and the poneroid subfamilies) represent a clade or a grade at the base of the ant tree remains unresolved. The fossil record for crown group ants extends back to 90–100 mya. Stem ants (sphecomyrmines, armaniines) were also present during this period. Molecular divergence date estimates that take into account the fossil record of both ants and other Hymenoptera suggest that crown group ants arose ~115–135 mya. Most of the extant ant subfamilies and genera are well defined morphologically and likely monophyletic, but there are some notable exceptions including the subfamily Cerapachyinae and several large and ambiguously delimited genera such as Pachycondyla. Several tribes in the large subfamilies Formicinae and Myrmicinae also represent artificial assemblages. Finally, while the specieslevel taxonomy of some ant genera is in a satisfactory state, taxonomic anarchy reigns in others, with numerous illdefined species and many names of uncertain applicability. Progress in this area of ant systematics will require sustained individual efforts, expansion of job opportunities, enlistment of new technologies, and a deeper understanding of the nature of ant species and the differences between them.

New Species: Trachymyrmex pomonae

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Trachymyrmex pomonae Rabeling & Cover 2007
Arizona
Nothing warms the heart more than a new ant species close to home! An all-star team of ant specialists, headed by Christian Rabeling at the University of Texas, describe the Arizonan species Trachymyrmex pomonae in Zootaxa this week. This spiny little red insect is part of a New World evolutionary radiation of agricultural ants, the attines, that cultivate a fungus in underground chambers. Trachymyrmex pomonae is one of several Trachymyrmex species in the United States, with dozens more occurring in Central and South America.

New species discovery is not so simple as finding a critter in the woods and declaring “Eureka!” A background knowledge of related species is essential for recognizing something novel. Trachymyrmex has been an especially challenging group of ants in this regard, as the published taxonomy of the group is limited and many of the species are confusingly similar. In the absence of a taxonomic synthesis, one is reduced to using isolated taxonomic papers written decades ago on individual species and going through endless drawers of museum specimens. Fortunately, Rabeling et al. do exactly that for the North American Trachymyrmex, and on top of it they throw in DNA sequence data from two loci sampled across multiple populations per species. Once the dust settled, they inferred the existence of nine species but had only eight valid, pre-existing names to apply to them. The extra species became the new T. pomonae.

Students of the biannual Ant Course in Arizona might recognize T. pomonae. It is not an uncommon ant around the Southwestern Research Station in Portal where the course is taught. If you’re an Arizona Ant Course alumnus, check your collection!

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Source: Rabeling, C., Cover, S. P., Johnson, R.A., and Mueller, U.G. 2007. A review of the North American species of the fungus-gardening ant genus Trachymyrmex (Hymenoptera: Formicidae). Zootaxa 1664: 1-53.

The Rogue Taxonomist

Warning: long ranty post to follow.

Taxonomy is an unusual discipline in the balance it strikes between legal and scientific concepts. There’s the obvious biology bit about discovering and defining taxa, but unlike any other science there’s a backbone of legalistic code that regulates the dynamics of names. If you’re the sort who really digs dry legal documents, you can read the zoological code here and the botanical code here. The codes are largely concerned with nomenclature, dealing with issues such as the proper hierarchy of ranks, and resolving conflict among competing names. For instance, the code decides what happens when two people independently describe the same biological species with different names. The short of it is that taxonomists, like courts, must deal with precedent. They are bound by the code to consider all relevant previous publications.

Because of the importance of precedent, taxonomy is uniquely vulnerable to crackpots. When such a person surfaces, the schlop he produces cannot just be dismissed as the rantings of some hare-brained loner. (more…)

New Species: Technomyrmex fisheri

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Technomyrmex fisheri Bolton 2007
Madagascar, line drawing by Barry Bolton

Last month, British myrmecologist Barry Bolton published the first ever global synthesis of the ant genus Technomyrmex. The tome describes 37 new species, including Technomyrmex fisheri from Madagascar, named after Brian Fisher of Antweb. I’m always keen to try out new taxonomic keys, so I tested Bolton’s out on several unidentified African and Australian species in my collection. As is nearly always the case with Bolton’s meticulous work, the key worked flawlessly. I only wish I had more Technomyrmex to key.

Perhaps the most notable finding of the study, aside from the plethora of new species, is one that might upset the Pest Control folks. Bolton has discovered that the infamous White-Footed Ant, previously thought to be the single species T. albipes, is a complex of similar species, only one of which is T. albipes. In the long run, the knowledge that there are multiple pesty species in the group will better help us determine where they came from and how to control them, but of course in the short term these are the sorts of discoveries that make people hate taxonomists. Changing names makes literature retrieval more difficult, and it’s always tricky to have to remember a new name.

The Technomyrmex causing problems in Florida can no longer be referred to as Technomyrmex albipes. It is now Technomyrmex difficilis. Perhaps appropriately, we can now call this pest the “The Difficult Ant”. In any case, it looks like this in the field.

Source: Taxonomy of the dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker cast. Barry Bolton. 2007. 150 pp. Contributions of the American Entomological Institute Volume 35, No. 1.

New Species: Idioneurula donegani

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Idioneurula donegani Huertas & Arias 2007

 

 

Huertas, B. and J. J. Arias. 2007. A new butterfly species from the Colombian Andes and a review of the taxonomy of the genera Idioneurula Strand, 1932 and Tamania Pyrcz, 1995 (Lepidoptera: Nymphalidae: Satyrinae). Zootaxa 1652: 27-40.

The online journal Zootaxa has hosted the publication of 6723 new animal species since its inception in 2001, averaging over 2.8 new species per day. And that’s just a single journal- there are scores of taxonomy journals out there. Taxonomy is an old science, but it remains on the frontiers of biological discovery.

New Species: Mystrium maren

 

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Mystrium maren Bihn & Verhaagh 2007

Discoveries of new species on our little-known planet continue apace. The two known specimens of the impressively toothy Mystrium maren were collected in 2001 in Indonesia, and Jochen Bihn and Manfred Verhaagh just published a paper in Zootaxa describing this ant and another new species, M.leonie.

Source: J. H. Bihn & M. Verhaagh, 2007. A review of the genus Mystrium (Hymenoptera: Formicidae) in the Indo-Australian region. Zootaxa 1642: 1-12.

 

*update* Lead author Jochen Bihn writes about the paper on Trophallaxis Blog.