6 Responses to Discovering Insect Species, week 1: Introduction, and into the field

  1. James C. Bergdahl says:

    As soon as you folks get images of the habiti and median lobes made of the Trepanedoris species made I would love to see them. As you know, there are a number of species in the Washington+British Columbia region and both Hatch (1953) and Lindroth (1961-69) are incomplete.

    I have been going through all my Trepanedoris specimens from the San Juan (WA) and Gulf (BC) islands and adjacent regions. Bembidion fortestriatum are common, but siticum, canadianum, connivens and elizabethae appear to be in some of the many samples too but at much lower numbers. Some of these species are obviously very good fliers, perhaps all of them.

    One interesting characteristic about B. acutifrons that I have noticed after looking through thousands of pointed Trepanedoris specimens over the last week is that the males for some reason often conveniently project their median lobe during the process of being pickled in ethanol. I have noticed that Pterostichus (Pseudoferonina) do the same thing. I wonder why this is? Many carabid species that I regularly collect never seem to do it.

    James Bergdahl
    Conservation Biology Center
    Spokane, WA, USA

  2. James C. Bergdahl says:

    I forgot to mention that B. acutifrons is also fairly widespread in my San Juan & Gulf island samples, and it is found on a wide variety of stillwater wetland types, including brackish seashore marshes with some classic “salty” carabid species (e.g. Bembidion vile, B. indistinctum and Dyschirius integer). It is also regularly encountered on the adjacent mainland. My gesalt, based on habitus and experience with B. acutifrons in the field, suggests your tree based on DNA analysis will place this species as an outlier from the main group of species. Among what are now considered the Trepanedoris (Bousguet 2012) it seems to me this species is the easiest to identitfy, at least in my region of collecting.

    I regularly pray to GOD that state of the art technology for determining phylogenies based on DNA will somehow be reflected in morphological attributes that are reasonably easy to observe on whole specimens with a decent dissecting scope. It is always important to keep in mind that whatever phylotree one builds, no matter what materials and techniques are employed, in the end they are all “just” hypotheses. Thomas Casey provides an good example. He is somewhat infamous among carabidologists for naming new species based on small morphological variation, and presumably a healthy dose of providence. (I keep a file on all the derogatory comments about Casey I come across in the literature.) Casey described many of the “valid” Trepanedoris species recognized today in North America (Bousquet 2012). I predict that the more sophisticated phylotrees based on DNA (barcodes) become, the more species and subspecies Casey described will be considered valid. If this proves to be the case, some very famous and respectable carabidologists, many of which are now dead, will have to “eat their words”. Will DNA tools for building phylogenies eventually re-erected Casey as a visionary/genius, not a crazy splitter? Casey is of course not the only “productive” taxonomist with such great skill for seeing new species and subspecies.

    Note: I am not a “splitter”, and therefore have some reservation about using gene data to do so.

    James Bergdahl
    Conservation Biology Center
    Spokane, WA, USA

    • James,

      Regarding ” It is always important to keep in mind that whatever phylotree one builds, no matter what materials and techniques are employed, in the end they are all “just” hypotheses.”: I wouldn’t have had a successful career if I were naive about this.

      Regarding Casey: I have noted in the past that Casey was correct more often than we had thought. That said, I don’t think he will ever be viewed as a visionary/genius. Even when all is said and done, there will be many of his names that are synonyms. Yes, he did detect valid differences that others failed to detect, but he also oversplit too much too. I think there was a mix there of insight and being correct just by the shotgun approach – if he described enough he would be bound to hit something.

      Using DNA data is independent of being a “splitter” or a “lumper”: DNA data is simply data that provides evidence closer to what we need for species inference. But at least for those of us who are classically trained morphological systematists, we also thoroughly consider morphological data in any of these decisions about species boundaries. As with any scientific study, naive or dogmatic interpretation of limited data can lead to poor inferences; thorough, careful, and skeptical interpretation of more data can lead to better inferences.

  3. Pingback: Discovering Insect Species: hands-on with Trepanedoris | The Subulate Palpomere

  4. Pingback: Discovering Insect Species: Overview in Rearview | The Subulate Palpomere

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