Answer to the Monday Night Mystery

Elaphrus sp. marsh ground beetle (Carabidae)

What were yesterday’s psychedelic speckles?

They were elytral ornaments of the magical mystery Elaphrus, a ground beetle that spends its time lurking about the edges of waterways looking suspiciously like a miniature tiger beetle even though it isn’t.


Eight points to Ben Coulter who guessed the genus almost before I posted the challenge. Two points to B. Boudinot for not overthinking the question and stating that the underlying structure was the elytron.  Plus, one point to Ainsley- who incidentally is the world’s premiere expert on beetle refractive coloration- for providing the mechanical explanation.

There’s been some chatter that I ought to keep the comments hidden until the answer is revealed. I don’t feel strongly one way or the other. Concealed comments would certainly foster greater participation. But I also enjoy the conditional strategies that emerge as people hedge that the earlier guesses might be incorrect.

If we adopt a new Mystery policy, it won’t go into effect until next month. What do you think?

19 thoughts on “Answer to the Monday Night Mystery”

  1. As a super amateur, I really like seeing all of the different attempts and all of the ways people go about trying to ID the mystery. I’d be strongly in favor of either keeping it public or at least releasing it all after it’s been revealed. I actually feel like it really helps me learn.

    What were the objections that people had? Not clear to me what the disadvantage is for the other readers.

    1. The issue is, I think, that timing is more often the determining factor than is knowledge. It isn’t just that some people are constantly online and ready to guess the instant the challenge goes up, it’s that some people are also in the same time zone as me, and some are not. Myrmecos readers in Eurasia, Africa, and Australia are usually not awake when the Mystery goes online.

      That’s an issue, but I’m not sure if it’s enough of an issue to overshadow the benefits of the quick free-for-all that we usually see with the MNM.

  2. I know it wouldn’t make a difference to me. I rarely guess, not knowing the difference between Elaphrus and an elephant, or an elytron and an electron.

  3. I like seeing the to-and-fro in the comments, like Mark. Too dang many “secrets without a clue” in this world as it is.

    It’s an insect/ant blog not a NSA codebreaker project, lol.

  4. Hahaha, aww. EXPERTISE POINT!
    Also, I just noticed the tiny red mite in the corner–I can’t say why exactly, but I think he really makes the photo.

    * <—- that is a mite emoticon

      1. * I am not an mite expert, but all of the mite larvae I have ever seen ALWAYS have 6 legs. *


        1. Correct – for the moment – but who knows how it might change with the application of further genetic analysis

          Phylum: Arthropoda
          Subphylum: Chelicerata
          Class: Arachnida
          Order: Acarina or Acari

          Acarina is a taxon of arachnids that contains mites and ticks. Acarine ontogeny consists of an egg, a prelarval stage (often absent), a larval stage (hexapod except in Eriophyoidea, which have only 2 pairs of legs), and a series of nymphal stages. Larvae (and prelarvae) have a maximum of 3 pairs of legs (legs are often reduced to stubs or absent in prelarvae); legs IV are added at the first nymphal stage.


          “Ontogeny recapitulates phylogeny” Ernst Haeckel
          *– not a bad concept entirely —-*

        2. The two major groups of ‘mites’ do not appear to be that closely related but have either converged on a hexapod larval stage or this is retained from an unknown ancestral marine chelicerate (Ricinulei also have a hexapod larva, so this is a reasonable hypothesis).

          The real question is what is an arachnid? I think it is a grade of evolution – terrestrial chelicerates – and that terrestrialization occurred several times.

          I hope Ainsley S gets a point for the mite emoticon. It’s even about the size of a chigger and in red type is perfect.

        3. Agree with you macromite….

          if Insecta is a class then Acari should be a class as well imo. The “anatomical distance” between the various Arachnida orders seem much greater than those of insect orders, and concluding that Arachnida is entirely monophyletic seems unlikely but I suppose possible.

          Just my opinion based on pretty much nothing at all, lol.

  5. James.C. Trager

    Mite emoticon — Cute!

    and I’m with the keep the comments public group, also enjoying watching the discussion.

  6. Given the habitat, habitus, and colour, could be a larval water mite (some scurry across the surface) or possibly a Johnstonianidae, species of Diplothrombium parasitize semi-aquatic Diptera.

    If you keep comments hidden, you would probably end up giving away a lot more pictures, since more of your readers would have a claim to having got the correct answer without an assist. Also, I’d miss the feeding frenzy.

  7. This is one of the coolest beetles I have seen! Thanks for the full picture.

    I also like the way things are. I benefit a great deal from every one’s guesses and comments, plus the interchange is fun.

  8. Yeah, keep the comments in my oppinion.

    Maybe changing the temporal aspect of the mystery pictures, so that you alternate between say, 3 different points of the day. Is there a way for you to queue blogg posts, so that you dont actually have to actively post them at ungodly hours? Just an idea..

  9. Another thing that occurs to me, is maybe a wagering system, where after there are a couple of ID attempts, subsequent people can get points for picking the person who is correct. Something like this, perhaps:

    – A person makes an ID that, if correct, would be worth some number of points. For purposes of illustration, let’s say 8 points.
    – There is then a pool of 8 additional points, to be spread among the people who agree with them. Maybe the first person to agree gets 4 of the points, the second person gets 2, and persons 3 and 4 get 1 point each. Any points that aren’t picked up by others, then go as a bonus to the person who made the original correct ID. This would give a huge bonus for making an ID that nobody else agrees with, which would encourage wild guesses.
    – There are, of course, no points for agreeing with someone who is wrong. for cruelty, you could even have *negative* points for agreeing with someone who is wrong.
    – Although, maybe there could be one point for being the first person to disagree with wrong IDs, with additional points for good reasoning as to why it is wrong.

    Wow, this would be a bookkeeping nightmare. Something simpler, but still along these lines, would be interesting, though.

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