The Bug Geek

Insects. Doing Science. Other awesome, geeky stuff.

“A most variable species,”…

…writes Lindroth (1969) of Pterostichus (Stereocerus) haematopus in his 1200+ page taxonomic key of Canadian/Alaskan ground beetles.

“Black…upper surface as a rule with metallic lustre (bluish, green, brass or coppery)…”

Pterostichus (Stereocerus) haematopus - black/metallic version - dorsal

Black with greeny-metallic lustre – check.

But, lo:

“…elytra sometimes rufinistic [reddish]”.

Well that’s quite different, isn’t it?

Pterostichus (Stereocerus) haematopus - rufinistic version - dorsal

Ok, reddish – check.

These two again from the side:

Pterostichus (Stereocerus) haematopus - black/metallic version - lateral

Pterostichus (Stereocerus) haematopus - rufinistic version - lateral

Believe it or not, these two beetles are the same species. This is a great example of why a well-assembled taxonomic key is critically important to making accurate identifications. I had rough-sorted (i.e., “guesstimated/eyeballed”) these beetles into different groups initially, but the reddish-brownish one (of which there are few) just kept keying out the same as the more prevalent metallic version. I checked in with the experts at the Canadian National Collection to make sure I hadn’t goofed – and I hadn’t.

The key I’m using for my ground beetles was written by Charles H. Lindroth over the course of about eight years, and represents the sum of several “smaller” publications. It is truly a magnum opus in the world of beetles (indeed, of entomology) and is still considered the ultimate reference for this family, even after 35+ years of new research and updated phylogenetic/taxonomic work.

(For Morgan: Taxonomy FTW!)

________________________________

Lindroth, C.H., 1961-1969. The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska. Opusc. Entomol. Suppl. 20,1-200; 24,201-408; 29,409-648; 33, 649-944; 34, 945-1192; 35, I-XLVIII.

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7 responses to ““A most variable species,”…

    • TGIQ December 7, 2011 at 1:55 PM

      That was fast! LOL. Thought you’d like that. 😛

      • Morgan Jackson December 7, 2011 at 2:01 PM

        I sensed a variation in the force, what I can I say!

        This sort of morphological variation can be confusing/maddening, but I’m glad to hear someone has done a good job of sorting it out and made good ID aids available! I look forward to seeing the great ID aids you come up with in the future now that you’ve been bitten by the taxonomy-bug! 😉

  1. ZL 'Kai' Burington December 7, 2011 at 2:52 PM

    This is great! I’m glad you put in how much time it took Lindroth to assemble this piece of work; 8 years is a Darwinian load of taxonomic perseverance.

  2. TGIQ December 7, 2011 at 9:24 PM

    The work is truly impressive, with impeccable attention to detail and marvelous drawings. I cursed it at first (just for the sheer bulk) but now appreciate what an incredible tool it is.

  3. blackflyguy December 8, 2011 at 2:14 PM

    See, you ranted earlier about the preponderance of molecular biology in current entomological research. This provides a perfect example of how these techniques can be applied to “whole organism” questions.

  4. Pingback: A trio of beautiful beetles « The Bug Geek

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