The mini grasshoppers that outlived dinosaurs: the fascinating world of Tetrigidae

  • Pensoft Editorial Team
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  • September 8, 2021
  • Guest blog post by Josip Skejo

    “(…) pronotum often takes on various extreme modifications,
    giving to the insects a most grotesque or bizarre appearance (…)”


    quote from Hancock, Joseph Lane (1907)
    Orthoptera fam. Acridiidae, subfam Tetriginae.
    Genera Insectorum.

    Have you ever seen a one-centimetre-long jumping critter in a leaflitter or close to a pond or a stream and thought that it is some juvenile insect? Well, I must disappoint you. What you saw was probably an adult pygmy grasshopper, member of the family Tetrigidae. There are more than 2000 described species of those minute jumping insects, and this peculiar family has been around for more than 230 million years, meaninng that pygmies said both ‘hi’ and ‘bye’ to dinosaurs. And yet, we know more about dinosaurs than we do about pygmy grasshoppers.

    Most of the research you can find out there is probably based on genera Tetrix and Paratettix in Europe or Northern America (Adžić et al. 2021). Species of Northern America (Nearctic region, 35 species) and Europe (W Palearctic region, 11 species) are indeed best known from the standpoint of natural history, even though they represent only about 2% of the diversity. Here is the list of 19 species that are most often observed by amateur naturalists on the iNaturalist platform (Table 1) and as you can see 12 out of 19 species are indeed from Europe and Northern America. Because of that, let us focus on awesome neglected diversity in the tropics.

    SpeciesGeographic distributionN of observations
    Tetrix subulataHolarctic618
    Tettigidea lateralisNearctic505
    Tetrix undulataW Palearctic267
    Tetrix tenuicornisPalearctic225
    Criotettix bispinosusIndochina and islands of SE Asia225
    Paratettix meridionalisW Palearctic: Mediterranean145
    Paratettix mexicanusNearctic111
    Tetrix depressaW Palearctic90
    Tetrix arenosaNearctic82
    Tetrix bipunctataW Palearctic77
    Tetrix japonicaE Palearctic73
    Paratettix aztecusS Nearctic to N Neotropics54
    Paraselina brunneriE Australia54
    Nomotettix cristatusNearctic53
    Tetrix ceperoiW Palearctic51
    Hyperyboella orphaniaNew Caledonia49
    Scelimena productaJava, Sumatra, Bali31
    Eurymorphopus bolivariensisNew Caledonia30
    Discotettix belzebuthBorneo26
    Table 1. Well-known Tetrigidae species. Pygmy grasshoppers with more than 25 Research-Grade observations in iNaturalist, together with their distribution briefly explained.

    Why do I mention the iNaturalist platform? Because I think it is the future of zoology, especially of faunistics. Never before have we been able to simultaneously gather so much data from so many different places. I started using Flickr some time ago to search for photos of unidentified rare pygmy grasshoppers. I did find many rare species, and what is even crazier, species that were not known to science. I’ll try to present you with a glimpse of the diversity I found online, so maybe some new students or amateurs will contribute, as they did with Paraselina brunneri, after the study was published in ZooKeys.

    The Angled Australian barkhopper, Paraselina brunneri (= P. multifora). A, B, D a female from Upper Orara, photos by Nick Lambert. C a female from Lansdowne forest, photo by Reiner Richter. E a male from Mt. Glorious, photo by Griffin Chong. F individual from Mt. Mellum, photo by Ian McMaster.

    It seems that “rare” species from Australia are not so rare after all

    Many new records of Paraselina brunneri and Selivinga tribulata can now be found online, thanks to a study published with ZooKeys.

    The Tribulation helmed groundhopper, Selivinga tribulata, living specimens in natural habitat. A Female from Kuranda, photo by David Rentz. B male from Kuranda, photo by David Rentz. C male from Tully Range, photo by Matthew Connors. D nymph from Redlynch, photo by Matthew Connors. E, G a male from Kingfisher park, photo by Nick Monaghan. F female from Speewah, photo by Matthew Connors.

    Enjoy some selected awesome places and selected amazing taxa that inhabit those places. Emphasis is given on the extremely rare and weird-looking, or as Hancock called them, bizarre and grotesque species. Those with leaf-like morphology, spines, warts, undulations, or horns. Enjoy a short voyage from the rainforests of Madagascar through the humid forests of Australia, New Guinea, Borneo, and finally the Atlantic Forest of Brazil.

    Madagascar is home to some of the largest and most colourful species of Tetrigidae in whole world

    Very peculiar are the species of the genera Holocerus and Notocerus, both of which were discussed in studies published in ZooKeys. Finally, one can find photographs of these beauties identified to species level.

    Variability of Holocerus lucifer. A living specimen in Marojejy NP, photo by R. Becky. B–E variability of pronotal projection morphology (B holotype of Holocerus lucifer C Maroantsentra, Antongil Bay D holotype of H. taurus E Tamatave.

    Interesting fact about those large pygmy grasshoppers: When I visited the rainforests of Madagascar, I observed one Holocerus devriesei and took photos of it. The insect then took flight far away in the rainforest. Who could think that an animal with such a large back spines could be such a skilful flier! The same is maybe true for Notocerus.

    Holocerus devriesei in natural habitat. A Nymph from Andasibe, photo by P. Bertner. B nymph from Vohimana, photo by F. Vassen. C adult ♀ from Andasibe in c in dorsal view and D in dorsal view, photos by P. Bertner.
    Holocerus devriesei and its habitat. A ♂ from Ranomafana in natural habitat, photos by M. Hoffmann. B–E adult ♂ from Analamazaotra, photos by J. Skejo. F–G natural habitat in Analamazaotra G Ravenala madagascariensis, the Traveler’s Palm, photos by J. Skejo.
    Live female of the Formidable Pygmy Grasshopper, Notocerus formidabilis, in lateral view. Photo by Éric Mathieu.
    Live female of the Formidable Pygmy Grasshopper, Notocerus formidabilis, in dorsal view. Photo by Éric Mathieu.

    Not all pygmy grasshoppers are large and colourful

    Some species, like the Pymgy unicorns of Southern America are small but still interesting. Metopomystrum muriciense was described with ZooKeys from the Atlantic rainforests of Murici, Brazil, in 2017.

    Metopomystrum muriciense: A Male holotype, head and portion of sternum, frontal view B head and portion of pronotum, dorsal view C head and portion of pronotum, lateral view (* sternomentum). Scale bars: 2.0 mm.

    Some pygmy grasshoppers are weird

    Giraffehoppers from New Guinea are among the most unique pygmy grasshoppers. Many species can be differentiated by the antennal shape, and maybe by face coloration. Those are very visual animals, and antennae and colours might be used for courtship (Tumbrinck & Skejo 2017).

    A field photographic record of a living Ophiotettix pulcherrima mating pair from Yapen Island, Cenderawasih Bay, W New Guinea, lateral view. Photo by D. Price
    Field photographic records of living Ophiotettix.

    For young entomologists: How did I decide to study pygmy grasshoppers?

    No true biology student knows what she or he wants to study and which direction to take. With me, it was pretty much the same thing. Systematics caught my attention during primary and high school, and I always had a tendency to systematically compare data. My first idea was to study snakes, as I was amazed by shield-tailed snakes (Uropeltidae) and blind snakes (Scolecophidia), about whom I have read a lot. Unfortunately, I never saw representatives of those snake groups, but fortunately, there were a lot of animals that I had seen, and with whom I was more familiar in the field. Among them, there were grasshoppers and crickets (order Orthoptera). Together with Fran Rebrina, my friend and fellow student, I started the first systematic research of Orthoptera of Croatia and the Balkans. Our study on two Croatian endemic species, Rhacocleis buchichii and Barbitistes kaltenbachi, was published with ZooKeys last year.

    In the first years of our Orthoptera studies (2011-2012),  I never saw a single pygmy grasshopper in Croatia. I remember it as if it was yesterday when Fran and I asked our senior colleague, Ivan Budinski (BIOM, Sinj), where we could find Tetrigidae, and he confidently said that they are to be found around water. Peruća lake near the city of Vrlika was he place where I saw pygmy grasshoppers, namely Tetrix depressa and Tetrix ceperoi, for the first time ever. I could not believe that there were grasshoppers whose lifecycle is water dependent in any way, so I kept researching them, contacting leading European orthopterists familiar with them (Hendrik Devriese, Axel Hochkirch, Josef Tumbrinck), and checking all the museum collections where I could enter. The encounter on the shores of Peruća was the moment that determined my career as an entomologist. After I discovered specimens of the extremely rare Tetrix transsylvanica in Croatian Natural History Museum (HPM – Hrvatski Prirodoslovni Muzej, Zagreb) in 2013 (Skejo et al. 2014), and after a serendipitous discovery of a new Arulenus species (Skejo & Caballero 2016), I just decided that maybe this interesting group was understudied and required systematic research, and here I am in 2021, regularly publishing on this very group.

    References

    Adžić K, Deranja M, Pavlović M, Tumbrinck J, Skejo J (2021). Endangered Pygmy Grasshoppers (Tetrigidae). Imperiled – Enyclopaedia of Conservation,. Elsevier, https://doi.org/10.1016/B978-0-12-821139-7.00046-5

    Mathieu É, Pavlović M, Skejo J (2021) The true colours of the Formidable Pygmy Grasshopper (Notocerus formidabilis Günther, 1974) from the Sava region (Madagascar). ZooKeys 1042: 41-50. https://doi.org/10.3897/zookeys.1042.66381

    Silva DSM, Josip Skejo, Pereira MR, De Domenico FC, Sperber CF (2017) Comments on the recent changes in taxonomy of pygmy unicorns, with description of a new species of Metopomystrum from Brazil (Insecta, Tetrigidae, Cleostratini, Miriatrini). ZooKeys 702: 1-18. https://doi.org/10.3897/zookeys.702.13981

    Skejo J, Connors M, Hendriksen M, Lambert N, Chong G, McMaster I, Monaghan N, Rentz D, Richter R, Rose K, Franjević D (2020) Online social media tells a story of Anaselina, Paraselina, and Selivinga (Orthoptera, Tetrigidae), rare Australian pygmy grasshoppers. ZooKeys 948: 107-119. https://doi.org/10.3897/zookeys.948.52910

    Skejo J, Medak K, Pavlović M, Kitonić D, Miko RJC, Franjević D (2020) The story of the Malagasy devils (Orthoptera, Tetrigidae): Holocerus lucifer in the north and H. devriesei sp. nov. in the south? ZooKeys 957: 1-15. https://doi.org/10.3897/zookeys.957.52565

    Tumbrinck, J & Skejo, J. (2027) Taxonomic and biogeographic revision of the New Guinean genus Ophiotettix Walker, 1871 (Tetrigidae: Metrodorinae: Ophiotettigini trib. nov.), with the descriptions of 33 new species. In Telnov D, Barclay MVL, Pauwels OS (Eds) Biodiversity, biogeography and nature conservation in Wallacea and New Guinea (Volume III). The Entomological Society of Latvia, Riga, Latvia, 525-580.

    2 thoughts on “The mini grasshoppers that outlived dinosaurs: the fascinating world of Tetrigidae

    1. It is interesting to see the various forms of largest and most colourful species of Tetrigidae in Madagascar. I am very much encouraged to see the nature’s creations.

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