One of the more common ants in eastern North America is, ostensibly, Dolichoderus. I’ve read that, while restricted to particular habitat types, within those bogs and pine forests they are supposed to be abundant. In theory.
Yet in my entire decades-long career as an ant guy, I have never once seen them alive in North America. Anywhere. It got to the point where I was embarassed to admit such a glaring failure.
Anyway. I broke down and finally begged Ant Guru James Trager to send me a few live workers, and James kindly took pity on me. Herewith, at last, photographs of our North American Dolichoderus:
Meet Tetramorium immigrans.
I have never been more pleased to report a taxonomic name change than this one. Long called “Tetramorium caespitum”, then “Tetramorium species E” once it became clear the Eurasian T. caespitum was a complex of cryptic forms, the pavement ant has spread across the world and is now among most common urban ants in North America. After decades of confusion, Herbert Wagner has published a fine monograph on the taxonomy of the species complex. Among Wagner’s many discoveries was that Santschi’s 1927 “immigrans” was valid for this world-traveller. An apt change, and a fine resolution of a long-standing problem.
- Wagner, H.C. et al (2017). Light at the end of the tunnel: Integrative taxonomy delimits cryptic species in the Tetramorium caespitum complex (Hymenoptera: Formicidae)”. Myrmecological News 25: 95-129
Last year, a team of Antweb-affiliated myrmecologists published an evolutionary study concluding, among many results, that a slate of socially parasitic genera had evolved from within their host genera. The names of parasitic genera were subsequently sunk. Inclusion of derived groups in their parent genera has been standard practice for decades as a way to keep names consistent with ancestry.
But a number of myrmecologists do not approve of their favorite ants losing their names, and struck back with a strongly worded opinion in Insectes Sociaux this week:
We contend that banning all paraphyletic groups while simultaneously executing binominal Linnaean nomenclature results in a taxonomy going off the rails.
The dissenting authors make a lengthy argument about information content, evolution, and practicality, but the logic distills to, “the sunk genera look different, and we feel it more useful that the difference is reflected in a unique name.” If this argument looks familiar, it is the same case put forth by Ernst Mayr’s “Evolutionary Taxonomy” school in the 1960s and 70s. This was not a winning argument. Most biologists found disagreements about trait differences subjective compared to the relatively clarity of ancestry, and taxonomists today generally agree that recognizing paraphyletic groups is more confusing than the alternatives.
I have little personal experience with the genera in question. From my perspective as an outsider, I had to look up Epimyrma in Bolton’s catalogue to figure out what kind of an ant it was. Formicine? Myrmicine? Had I known it was basically a parasitic Temnothorax, I’d have been that much ahead of the game. Monophyly is information; paraphyly less so. But utility is a question of perspective and context, I suppose, and I can empathize with those who regularly work with these ants. Treating these distinct species as congeners may be as awkward as attending a party where everyone is named Jayden.
Still, given the volumes of vituperative ink spilled a half-century ago in the cladism wars, and the weight of the pro-monophyly consensus among all biologists, I suspect this renegade group of ant scientists will be fighting an uphill battle.
Disclosure: I eclosed as a myrmecologist from Phil Ward’s lab, so of course I am not without my allegiances.
Sources: Seifert, B. et al 2016. Banning paraphylies and executing Linnaean taxonomy is discordant and reduces the evolutionary and semantic information content of biological nomenclature. Insectes Sociaux doi: 10.1007/s00040-016-0467-1
Ward, P.S. et al 2015. The evolution of myrmicine ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae). Systematic Entomology, 40: 61–81. doi: 10.1111/syen.12090
I am extremely pleased to announce the 2016 BugShot Insect Photo Workshop! The event will be held for the first time in Austin, Texas, and will be instructed by Piotr Naskrecki, John Abbott, and myself. Our 3 1/2 day event will cover basic techniques in macrophotography in the field and in the studio, methods for working with live insects, and advanced techniques in focus-stacking and high-speed flash.
As usual, our location is a site of considerable natural beauty, with rustic lodging and classrooms on site, with nearby hotels for those who prefer more upscale accomodation. We will be at McKinney Roughs Nature Park, a 1,900 acre tract of woodlands, meadows, and canyons. These workshops are a real highlight of my year, not just for the nature and the photo nerdery, but for the community of wonderful people that has coalesced around the BugShot events. If you haven’t been yet, you should try to this year. We’d love to have you!
Last year’s California workshop sold out within a week, so if you’re thinking of attending, you may need to sign up quickly.
***Update (December 19, 2015): BugShot 2016 is sold out. Stay tuned for our next workshop!
And now, an excerpt from my second mid-term exam for the BIO 453L class. Good luck!
8. Australia was able control its infamous bush fly problem by importing several species of:
a. Dung beetle
b. Robber fly
c. Orb-weaving spider
d. Green lacewing
9. In your new job as a forensic entomologist, you receive a sample of insects collected by police from a body discovered in a park. The sample contains mostly beetles in the family Dermestidae and moths in the family Tineidae. It is autumn and the weather has been cool. Would you estimate the PMI (=time of death) to be:
a. Within a day.
b. Within 2-3 days.
c. Between 4 days and 2 weeks.
d. More than 2 weeks.
10. Which insect order is indispensable, as cacao’s required pollinator, to the production of chocolate?
In recognition of the season, I am pleased to announce a Halloween print sale! What does this mean? I have priced 30 images of arachnids, centipedes, and zombie fungi at 70% off, nearly at cost, until November 1. If you’d like to pick up an Arachtober surprise, have a look at the link below:
Looking for a challenge? Here are a few questions from the midterm examination of my current Entomology course.
29. Which of the following animals’ life cycles is most likely to include a puparium?
a. house fly
b. silkworm moth
c. monarch butterfly
d. rove beetle
30. Sclerotization is the process by which:
a. spiracles close to prevent water loss
b. coremata release pheromones as a sexual attractant
c. the exocuticle hardens following ecdysis
d. the wax layer is formed as a barrier to water loss (more…)
You may remember a recent viral video showing an undescribed predatory ant behavior. It turned out that myrmecologists Christian Peeters and Stéphane de Greef had observed these ants in the field, but they’d not assembled enough data to publish, leaving us all in the dark about how the ants coordinated the amazing millipede-hauling chains.
With a bright internet spotlight on the behavior, Christian and Stéphane returned to the project and have just published a detailed description in Insectes Sociaux. The video alone is worth a thousand words:
source: Peeters C, De Greef S. 2015. Predation on large millipedes and self-assembling chains in Leptogenys ants from Cambodia. Insectes Sociaux doi: 10.1007/s00040-015-0426-2