Another Sand Ridge Myrmica Headache

Since James has so cruelly dashed my hopes of having found Myrmica spatulata at Sand Ridge, I have this to say:

How about this ant?


Also photographed at Sand Ridge.

Identifying Myrmica to species involves staring at small shape differences at the base of the antennae. It’s a bit like reading tea leaves.

4 thoughts on “Another Sand Ridge Myrmica Headache”

  1. I’m not a myrmecologist (or entomologist, or taxonomist, or anything along those lines), so forgive me for asking the obvious silly question: if the differences in morphology are so small among the species in this genus, then why (and how) were they separated into individual species from the beginning? Are the species divergent enough on the sequence level to justify the separation of them into species?

    (I do realise I’m walking headlong into the hairy issue of ‘species’, but to be fair, it never ceases to amaze. I’m a student working with yeast at the moment (Schizosaccharomyces fission yeast, to be more precise) and I’m intrigued by how large the genetic (and phenotypic) variation is between strains — and them still being classified as belonging to the same species. If the same degree of divergence was described for metazoans I doubt they’d even be classified in the same genus. But I think it’s a scaling problem and that we need to limit ourselves somewhere when it comes to splitting taxa, and that the line has been drawn at microorganisms — and for good reason.)

    1. An excellent but difficult question, Josephine! Whole books have been written on this topic, so forgive the brief and probably unsatisfying answer.

      Most ant species, like most insects, have never received any sequencing effort. DNA has not had much to do with species delineation in insects. That’s starting to change.

      Inference of species has traditionally resulted from some combination of ecology, morphology, geography, and the philosophy and skill of the taxonomist. Geography is important, because the observation that two or more forms consistently occur in the same places without blending is evidence that the forms are genetically distinct. It might be, for example, that one ant with a particular pattern of hairs usually nests in rotting wood, while an ant in the same forest with slightly different hairs usually nests in soil.

  2. James C. Trager

    You’re going to love this, Alex!

    The triangular-cross-section, irregularly wavy, dorsal mesosomal rugae are not right for M. spatulata or AF-sculpt. To me that looks like the true M. americana Weber, according to Francoeur’s restriction of that taxon. This is a rather northern, true sand ant, according the him and some others that know it (the Ants of New England folks). Most of what we’ve been calling by that name is his species code-named “AF-evani”, more typical of mesic and finer-grain-soil grasslands, and generally not found in sandy sites except occasionally in the southern reaches of its distribution, where the “real thing” does not occur.

    Going on the photo without a good view of a couple of other characters that would help pin this down, but I feel moderately confident about this tentative ID. 😉

    1. Ooooooohhhhhh that’s excellent! Thanks, James. I don’t have other photos of this ant, but I do have the specimen. I’ll point mount it next time I get a chance and take a better look at it.

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