The amazing Glass katydid

A young nymph of Glass katydid (Phlugis teres) from Suriname sitting on the tip of my finger.

A young nymph of Glass katydid (Phlugis teres) from Suriname sitting on the tip of my finger.

Once again things have been slow on my blog as I am trying to finish a million little things before my upcoming departure for Mozambique. I will be arriving there at the beginning of the rainy season, which means tons of insects and other invertebrates, a multitude of frogs, and hopefully some great new stories for this blog.

One of the animals that I hope to see there is a pretty, yet unnamed katydid from Mt. Gorongosa, which I first found last year in the mid-elevation rainforest on the mountain slopes. I am now working on its formal description and will post its photos as soon as the paper is out. In the meantime I thought I would present one of its close relatives, the amazing Glass katydid from Central and South America, a member of the genus Phlugis (Listroscelidinae).

As they age, Glass katydids begin to lose their transparency, and older nymphs and aduls acquire pale green coloration.

As they age, Glass katydids begin to lose their transparency, and older nymphs and aduls acquire pale green coloration.

I coined the name Glass 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.

It would seem that something so seemingly fragile cannot feed on anything other than dew and rose petals, but in fact Glass katydids are agile, powerful predators. Unlike most of neotropical katydids, the genus Phlugis includes many diurnal species that use their excellent vision to find prey, and their hunting technique is very clever. 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.

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.

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 from Costa Rica hunts small flying insects along the edges of mid-elevation rainforest.

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.

11 thoughts on “The amazing Glass katydid

  1. Hi Piotr,
    In recognition of the immense contributions to american
    culture made by the 70′s TV show _Kung_Fu_, I suggest that the
    common name for the insect you presented at the beginning of
    your Nov. 5 entry be “glasshopper”. You may recall that this was
    the nickname that Caine’s kung-fu master used when speaking
    to the young mixed-race Caine. A more transparent yet-to-be-
    described species might receive the taxonomic appellation
    “Phlugis kwaichangensis”.

  2. Loved this post Piotr! The glass katydids are gorgeous little critters! When are you going to post something about your recent BugShot Belize adventure?

  3. Don’t feel guilty for not writing! It might kill the fun of having a blog at all. I love your well written posts (not to mention the stunning pictures) and I’m happy to stop by now and then to see if there’s a new one. If not, I’m assuming you’re off somewhere taking more great shots.

  4. Pingback: Glass katydid | The Smaller Majority by Piotr Naskrecki

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