The glass katydid

If you’re a photographer, insect aficionado, or both, you should be checking Harvard biologist Piotr Naskrecki’s website The Smaller Majority.  There you’ll find some of the most amazing animals in the world, all photographed with loving care.

The latest oddity is the glass katydid (Phlugis teres, described in 1773) from the Neotropics. As it ages it changes from completely transparent to green. As Piotr notes:

I coined the name Glasss katydid after seeing for the first time young nymphs of Phlugis teres, a species found in Suriname, who display remarkable, nearly complete transparency of their bodies. These minute insects truly look as if they were made of glass and, peering closely, it is possible to see most of their internal organs, including the entire tracheal system. Unfortunately, these katydids lose most of the transparency as they get older, and eventually acquire pale green coloration, occasionally marked with brown accents.

The nymph sitting on Piotr’s finger (all photos copyright by Naskrecki and used with permission):

phlugis_nymph

It’s not clear (pardon the pun) whether this change in transparency is a direct adaptation or simply a byproduct of something else. I’m not aware of other insects that do this (correct me if I’m wrong), although perhaps in this species the nymphs live in places different from adults.  The green-ness of the adults, pervasive in katydids, probably hides them from both predators and prey.

More on this species from Naskrecki:

Glass katydids are sit-and-wait predators who spend most of the day sitting upside down on the underside of large, thin leaves, usually at the edge of the rainforest or in open, shrubby habitats. They prefer leaves that are fully exposed to the sun so that any insect landing on its upper surface will cast a dark, sharply defined shadow. And that shadow is what Glass katydids are waiting for – it tells them whether the insect is a hard beetle (not good) or a soft fly (excellent), and if the insect looks like a good meal they launch themselves from under the leaf and onto its surface, and capture the victim with their long, very spiny legs in a blink of an eye.

Check out the spines:

phlugis_nymph2

(Naskrecki’s caption): As they age, Glass katydids begin to lose their transparency, and older nymphs and adults acquire pale green coloration.

The species is notable for one other thing: its high-pitched sound:

In addition to being some of the most sophisticated and fastest orthopteran predators, Glass katydids are famous for the sound they produce – their call exceeds the frequency of 55 kHz, which is about three times the frequency a human ear is capable of hearing. A closely related genus Archnoscelis holds the record of producing the highest frequency call among all invertebrates – a whopping 129 kHz, twice the frequency of echolocation of most bats, and about 10 times more than the hearing ability of most adult humans. Another reminder that the ability to look cool and do amazing things seems to be inversely correlated with the body size.

Piotr has discovered a new and yet unnamed species of katydid in Mozambique, which he’ll post about soon.  He gives a photo of another new and unnamed species from Costa Rica:

phlugis_cr

(Piotr’s caption): Their huge eyes are a good indication of Glass katydids’ mode of hunting – they are diurnal sit-and-wait predators of small flies and other soft insects. This newly discovered, yet unnamed species of Phlugis from Costa Rica hunts small flying insects along the edges of mid-elevation rainforest.

Katydids, by the way, are in the order Orthoptera, along with grasshoppers, locusts, and crickets, but, within that group, they’re members of the family Tettigoniidae. It would do you good to look over the orders of insects. Some you’ll know already, but you might pick up a few other names. There will be a pop quiz.

40 Comments

  1. Griff
    Posted November 6, 2013 at 12:36 pm | Permalink

    Transparency provides “Camouflage” perhaps?

  2. Diana MacPherson
    Posted November 6, 2013 at 12:45 pm | Permalink

    Katydids are such beautiful insects. I once raised a robin and used to catch grass hoppers to teach him to hunt. I once caught a katydid but let it go because it was just too pretty to die. 🙂

    I am impressed with macro insect photography as it can be very challenging.

  3. Reginald Selkirk
    Posted November 6, 2013 at 12:55 pm | Permalink

    Here’s an insect article that will annoy you:
    The crazy device that shows fruit flies have free will

  4. Diane G.
    Posted November 6, 2013 at 12:57 pm | Permalink

    “It would do you good to look over the orders of insects. ”

    But maybe not at that site. They misspell Coleoptera* & Plecoptera, give a wrong example for Psocoptera, essentially no example for Strepsiptera…

    *Down in the list; their first usage of Coleoptera is OK.

    • Posted November 7, 2013 at 7:15 am | Permalink

      Not only that, but I find it frustrating when insects are listed in alphabetical order rather than in a cladogram which makes infinitely more sense.

      And I agree: Oleoptera is an unforgivable mistake on a website dedicated to insects.

  5. Posted November 6, 2013 at 12:59 pm | Permalink

    Katydids, by the way, are in the order Orthoptera, along with grasshoppers, locusts, and crickets, but, within that group, they’re members of the family Tettigoniidae.

    So…tasty crunchy wriggly noms for Baihu, yes?

    b&

  6. Posted November 6, 2013 at 1:03 pm | Permalink

    Piotr’s caption says the newly discovered katydid species is from Costa Rica, not Surinam as it says in the text.

    • Posted November 6, 2013 at 1:20 pm | Permalink

      Yes, it’s confusing. First of all, Piotr notes that he found a new species in Mozambique (I got it wrong, it’s not Surinam). I assumed the new species at the bottom was that one, but it’s not; it’s another new species from Costa Rica. I’ve fixed it all now (I think). Thanks.

  7. Howard Neufeld
    Posted November 6, 2013 at 1:22 pm | Permalink

    Beautiful. Does anyone know what compound/pigment katydids use to turn green?

    • Posted November 6, 2013 at 6:15 pm | Permalink

      I knew it had to be a pigment in the blood (and perhaps in the epidermis as well). Here is a bit of the abstract on a paper about the green blood of lepidopterans. I suggest this is similar elsewhere:
      “The green color of the hemolymph of larvae of Pieris rapae, Cacoecia australana, and Amphipyra sanguinipuncta (all Lepidoptera) is due to the presence of yellow and blue chromoproteins. The prosthetic groups of the yellow component are β-carotene and lutein while that of the blue component is probably mesobiliverdin.”

      So their ‘green’ blood is really a combination of yellow and blue pigments! I did not know that.

      • Posted November 6, 2013 at 6:52 pm | Permalink

        It would be especially interesting to pair the spectral distribution of the pigment with the spectral sensitivities of the eyes of various animals in its environment.

        As you point indicate, there are lots of combinations of wavelengths which will appear to our eyes as the same shade of, in this case, green. But it wouldn’t take much in the way of different photoreceptors for an eye to be able to distinguish all those as the different colors they really are.

        Especially interesting would be to compare the blue + yellow of the bug blood with the green of chlorophyll….

        b&

    • Reginald Selkirk
      Posted November 7, 2013 at 7:47 am | Permalink

      It’s not easy being green.

      • Diana
        Posted November 7, 2013 at 8:02 am | Permalink

        😀

  8. Steven Obrebski
    Posted November 6, 2013 at 2:46 pm | Permalink

    What a beautiful insect! If a glassblower were to make a reasonably similar table top size (or larger) model of the one shown on the finger, I would buy it, even if the price were a bit steep.

    The insect segments on this blog are always interesting, fascinating and a major attraction.. Congratulations Jerry6 and Matthew Cobb as well.

  9. Steven Obrebski
    Posted November 6, 2013 at 2:57 pm | Permalink

    From Bookline 4 verses by Oliver Wendell Holmes:

    To An Insect

    I LOVE to hear thine earnest voice,
    Wherever thou art hid,
    Thou testy little dogmatist,
    Thou pretty Katydid
    Thou mindest me of gentlefolks,–
    Old gentlefolks are they,–
    Thou say’st an undisputed thing
    In such a solemn way.

    Thou art a female, Katydid
    I know it by the trill
    That quivers through thy piercing notes,
    So petulant and shrill;
    I think there is a knot of you
    Beneath the hollow tree,–
    A knot of spinster Katydids,—
    Do Katydids drink tea?

    Oh tell me where did Katy live,
    And what did Katy do?
    And was she very fair and young,
    And yet so wicked, too?
    Did Katy love a naughty man,
    Or kiss more cheeks than one?
    I warrant Katy did no more
    Than many a Kate has done.

    Check the site for more.

  10. rose
    Posted November 6, 2013 at 5:02 pm | Permalink

    Animal lover yes,insect lover not so much.Spider on the wall right now really not loving it.

    • Diane G.
      Posted November 6, 2013 at 5:07 pm | Permalink

      Technically, then, you’re more of an animal-subset lover. 😀

  11. JohnnieCanuck
    Posted November 6, 2013 at 5:47 pm | Permalink

    I went to the Smaller Majority link. That was a couple of hours ago.

    I had to stop around page six, if only because there were so many things I really wanted to learn more, much more about that it was making me anxious. In a good way mostly, though depressing in that so many other species are going to be gone before we learn of them.

    • Diana
      Posted November 7, 2013 at 1:36 am | Permalink

      I went there & was happy to see the conehead grasshoppers that I haven’t looked for in years but I know are in the grasses in my yard. They are just as pretty as katydids (they are a similar shade of green) & the females have long ova-positors IIRC. I find it funny that the ones I’m familiar with are named neoconocephalus: new cone head.

      • JohnnieCanuck
        Posted November 7, 2013 at 5:37 pm | Permalink

        Neat.

        Neoconocephalus; it’s almost as if someone was immortalising their own sense of humour.

        • Diane G.
          Posted November 7, 2013 at 6:16 pm | Permalink

          Or anticipating our current political neocons (not only liberals can have pointy heads).

  12. Posted November 6, 2013 at 6:28 pm | Permalink

    I wonder if the transparency is a means of camouflage. It can also help eliminate their own shadow on a leaf. A nice touch.

    Many insects will have a reasonably transparent cuticle, and their color is entirely from their tissues and blood inside. I will never tire from looking at them under a dissecting microscope – used to do that for hours – where I can plainly see the tiniest trachea and even blood cells circulating by.
    but I can not say any were ‘transparent’ in the sense that I could see through them. This katydid is a first for me.

    • Torbjörn Larsson, OM
      Posted November 8, 2013 at 1:45 am | Permalink

      Elimination, and perhaps more generally depending on lighting conditions fuzzying, the shadow sometimes seen through thin leaves was my immediate response as well. The shadow, if any, would likely look like a water drop.

      And with winds, turning blades would expose clear bodies, again a lot like water drops. Which may be either a deterrent or a lure.

  13. Nobody
    Posted November 6, 2013 at 7:25 pm | Permalink

    Fascinating.

    But it brings to mind why it is that marine invertebrates are frequently transparent, but terrestrial arthropods (almost) never, not even underground. I s’pose transparency is only good camouflage in water since the refractory indices of water and transparent arthropod carapace must be more similar than between air and carapace.

    And perhaps transparent carapaces are very reflective of UV? In air transparent arthropods might look, to an insect or certain birds, like a bright, shiny target, whereas underwater that might not be a problem.

    Imagine though if transparency on land were perfectly possible: arthrophobes of all stripes would be even more fearful. Invisible spiders everywhere!

    • Posted November 6, 2013 at 8:11 pm | Permalink

      Now that’s a scary thought…but, I rather suspect that, if that were the case, our visual systems would be different in a way that they wouldn’t be quite so invisible, or we’d use something like echolocation, or in some other way be able to detect and / or fend off the invisible hordes of monsters.

      Or, of course, we’d have gone extinct long before being smart enough to worry about it….

      b&

      • Nobody
        Posted November 6, 2013 at 8:16 pm | Permalink

        Reminds me of that short story by H. P. Lovecraft, where that researcher invents a way to extend human senses outside the norm, and only ends up (predictably) seeing typically Lovecraftian monsters floating around everywhere, and then going insane.

        • Posted November 6, 2013 at 8:38 pm | Permalink

          Yes, that was a good one.

          Of course, the “and then going insane” at the end of a summary of a Lovecraft story is redundant….

          b&

    • Diana
      Posted November 7, 2013 at 1:48 am | Permalink

      I was thinking the same as I remembered the ghost shrimp that I would often put in my aquarium (note: don’t do this in a small tank with a betta as you will turn your back for 30 seconds then find the ghost shrimp gone).

      I came to the same possible conclusion as you did – transparency is a more effective camouflage under water.

      • Posted November 7, 2013 at 5:29 am | Permalink

        That would be true under water, but looks like the ghost shrimp found out differently.

        • Diana
          Posted November 7, 2013 at 7:39 am | Permalink

          Indeed. Sometimes the ghost shrimp wins, sometimes it loses.

  14. MKray
    Posted November 7, 2013 at 3:25 am | Permalink

    Re: “their call exceeds the frequency of 55 kHz, which is about three times the frequency a human ear is capable of hearing.” By the time you get to be a full professor, it’s more likely ten or more times. I went to a talk on sound once when the speaker assured us that by the time we could afford real HiFi it would be wasted on us. Depressing.

    • Diana
      Posted November 7, 2013 at 7:33 am | Permalink

      Sometimes you get lucky. I can still hear the so-called “mosquito” sound that the young hear and I’m 43. In the days of cathode ray tube televisions, if I walked into a TV sales department, I’d feel sick because of that sound they emit (I suppose it is amplified with so many together).

      My eyes however, not so good. I am extremely near sighted at -6.5 each eye. I dread becoming far sighted as well in the near future.

      • Posted November 7, 2013 at 9:21 am | Permalink

        I used to hear that too — room full of old (CGA?) CRT monitors drove me crazy. Newer CRT monitors had a much higher refresh rate. I can’t hear the CRT TV any more, but my daughter knows if it’s on, even if she’s not in the same room. I believe that frequency is 15.7 kHz.

        The vision thing isn’t all bad, when I need to see something up close I just take off my (progressive bifocal, which I’ve needed since I was about your age, sorry) eyeglasses for a high magnification view.

      • Diane G.
        Posted November 7, 2013 at 11:06 am | Permalink

        Well, IME anyway, severe myopia means you get far-sighted later than most…(There was a time when I could lord it over my husband…)

        • Diana
          Posted November 7, 2013 at 5:09 pm | Permalink

          Yeah, my optometrist says that because my myopia started when I was in grade 3 & was fairly bad, the far-sightedness would occur later. He predicts in my late 40s.

  15. Newish Gnu
    Posted November 7, 2013 at 6:00 am | Permalink

    What I hope is a simple set of questions from a non-scientists:

    Are those tiny dots in the eyes pupils?

    If so, are those pupils similar to human pupils in their general function? (expand, contract in reaction to light)

    Finally, assuming those dots are pupils, what is the thinking behind why the rest of the eye (sclera?) is so large relative to the pupil?

    Regarding the question, I could hazard a guess that the insect could have an enormous range of vision but then I wonder how much muscle it would take to move that eyeball. (Thinking here of what I’ve learned about owls on this website: they move their head, not their eyeballs).

    • Torbjörn Larsson, OM
      Posted November 8, 2013 at 1:53 am | Permalink

      – Pseudopupils, a google away:

      “Good fliers such as flies or honey bees, or prey-catching insects such as praying mantis or dragonflies, have specialised zones of ommatidia organised into a fovea area which gives acute vision. In the acute zone the eyes are flattened and the facets larger. The flattening allows more ommatidia to receive light from a spot and therefore higher resolution. The black spot that can be seen on the compound eyes of such insects, which always seems to look directly at the observer, is called a pseudopupil. This occurs because the ommatidia which one observes “head-on” (along their optical axes) absorb the incident light, while those to one side reflect it.[30]”

      [ http://en.wikipedia.org/wiki/Eye ]

      – I assume the eye of arthropods are fixed vs the exoskeleton. Moving eyes would then be found on those arthropods who has eye stalks.

      • Newish Gnu
        Posted November 8, 2013 at 9:12 pm | Permalink

        Thank you.

  16. Posted November 7, 2013 at 7:40 am | Permalink

    I ask out of ignorance. Since the blood must be close to colourless, what’s the oxygen carrier?

    • Posted November 7, 2013 at 11:34 am | Permalink

      A good question – in insects the respiratory system is separate from their circulatory system i.e., their blood (known as hemolymph) does not carry oxygen and is not red. Oxygen is delivered to organs and individual cells through a complex system of tracheal tubes.


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