Dinarippiger discoidalis (Fieber, 1853) Skejo & Kasalo & Fontana & Ivković & Tvrtković & Rebrina & Adžić & Buzzetti & Ćato & Deranja & Gomboc & Scherini & Škorput & Veenvliet & Vuković & Lemonnier-Darcemont & Darcemont & Heller, 2023

Skejo, Josip, Kasalo, Niko, Fontana, Paolo, Ivković, Slobodan, Tvrtković, Nikola, Rebrina, Fran, Adžić, Karmela, Buzzetti, Filippo Maria, Ćato, Sebastian, Deranja, Maks, Gomboc, Stanislav, Scherini, Roberto, Škorput, Jadranka, Veenvliet, Paul, Vuković, Marijana, Lemonnier-Darcemont, Michèle, Darcemont, Christian & Heller, Klaus-Gerhard, 2023, Dinarippiger gen. nov. (Tettigoniidae: Bradyporinae: Ephippigerini), a new saddle bush-cricket genus for Ephippiger discoidalis Fieber, 1853 from the Dinaric karst, Zootaxa 5271 (1), pp. 49-90 : 67-69

Dinarippiger discoidalis comb. nov. —past and future research

Our study establishes the basis for future research on the genus Dinarippiger gen. nov. by presenting a comprehensive overview of the D. discoidalis comb. nov. occurrence in the Dinaric Alps. Special attention was given to the syntopic occurrence of D. discoidalis comb. nov. and Ephippiger species. At the present moment, we know that in several localities in Slovenia, Croatia, and Bosnia & Herzegovina the species co-occurs with E. ephippiger , a central European and Balkan species. In another part of its distribution, i.e., in Istria and Primorska region of Slovenia, D. discoidalis comb. nov. occurs syntopically either with another species of the genus

Ephippiger, Alpine E. persicarius , or with a hybrid population of E. ephippiger x E. persicarius . This could be an interesting biogeographical case that requires further attention, as E. ephippiger and E. persicarius could be two subspecies of a single species, which would provide further confirmation that Ephippiger is an Apennine genus whose representatives spread to Eastern Europe relatively recently across the Western Balkans or along the northern banks of the Sava River. The area between Slovenia and Croatia is a well-known glacial micro-refugium ( Taberlet et al. 1998, Joger et al. 2007, Jablonski et al. 2017, Wang et al. 2022) due to its contact with the Alps, the Dinaric Alps, the Pannonian basin, the Adriatic coast, and the Po region, harbouring ice-free habitats during the last glaciation. In many groups of plants and animals, these areas represent either the center of dispersal or the secondary contact regions ( Surget-Groba et al. 2002, Brus 2010, Dufresnes et al. 2020, García et al. 2020). Dinarippiger discoidalis comb. nov. does not hybridize with any of the Ephippiger species in the areas of sympatric occurrence.

Another interesting biogeographical and phylogenetic question is the presence of a single, highly variable species within the newly established Dinarippiger gen. nov. or several distinct species with more restricted distributions and currently undefined diagnostic traits. Many authors have tried to assess the intraspecific variability of D. discoidalis comb. nov., but have failed in reaching a definite conclusion (e.g., Fieber 1854, Krauss 1879). Previous authors have focused mostly on body size ( Fieber 1853, Krauss 187), the number of inner and outer spines on the hind tibiae ( Werner 1920), or calling song traits ( Gomboc & Šegula 2014). Werner (1920) did not manage to find any consistent differences among D. discoidalis comb. nov. populations and noted that the substantial overlaps in trait variability could be the evidence of a single highly variable species. However, in the same study, Werner (1920) noted the presence of a northern smaller race and a southern larger race, but apart from body size no clear differences between the two were found. Geographical variation in body size is, for example, present in Italian Ephippiger cavannai Targioni Tozzetti, 1881 , a species characterized by smaller individuals in montane locations and larger ones in the coastal areas ( Massa et al., 2012). Galvagni (1956) initially described a separate taxon, E. perforatus tamaninii , which later turned out to be a montane population of E. cavannai .

Without a systematic comparison of the individuals from distant and isolated populations, variability within D. discoidalis comb. nov. remains an open question. This issue is illustrated by a photograph of a peculiar male ( Fig. 13 ) from Vremščica Mt. ( Slovenia), serving as a reminder that future studies have to include a phylogeographical survey, detailed morphometric analyses, as well as comparative morphological and bioacoustic approach.

Figures

FIGURE 13. Dinarippiger discoidalis comb. nov., a remarkably small green male from Vremščica Mt. (Slovenia) with uncharacteristically bright wings, photo Stanislav Gomboc.