The grasshoppers and crickets (Orthoptera) of the Socotra Archipelago (Yemen): a comprehensive overview and a description of a new Oecanthus Tree Cricket (Oecanthidae)

This paper presents all available information on the Orthoptera of the Socotra Archipelago, an area well-known for its endemic flora and fauna. General information is provided about the climate and geology of the Socotra Archipelago. The various habitats where grasshoppers have been found are described and illustrated, followed by a concise history of Orthoptera research on Socotra. Besides an identification key to the species, additional information about the material examined, taxonomy, diagnostic notes, distribution and occurrence, including maps, habitat, biology and bioacoustics, is provided for each species. In total, 65 Orthoptera species are reported here from Socotra, Abd el Kuri, Samha and Darsa, including Oecanthus castaneus Felix & Bouwman, sp. nov. and two unknown species assigned to Ectatoderus . Of these 65 species, 30 (46%) are endemic to the Socotra Archipelago. Re-descriptive notes on Acrotylus innotatus Uvarov, 1933 and Glomeremus capitatus Uvarov, 1957 are provided, including the description of the female of the latter species and the male of Oxytruxalis ensis (Burr, 1899). Acrotylus innotatus Uvarov, 1933, Dictyophorus griseus (Reiche & Fairmaire, 1850), Eumodicogryllus chivensis (Tarbinsky, 1930), Ochrilidia geniculata (Bolívar, 1913), Sphingonotus rubescens (Walker, 1870) and S. balteatus (Serville, 1838) are recorded for the first time from the Archipelago. Bioacoustics are presented for: Ochrilidia socotrae Massa, 2009, Stenohippus socotranus (Popov, 1957), Sphingonotus ganglbaueri Krauss, 1907, S. insularis (Popov, 1957), Acheta rufopictus Uvarov, 1957, Eumodicogryllus chivensis (Tarbinsky, 1930), Ectatoderus guichardi Gorochov, 1993 as well as two other species assigned to Ectatoderus , Oecanthus castaneus Felix & Bouwman, sp. nov. , Ruspolia aff. R. basiguttata (Bolívar, 1906) and Pachysmopoda abbreviata (Taschenberg, 1883). Red List Assessments for 29 endemic species have been prepared including Oxytruxalis ensis (Burr, 1899) (Critically Endangered, CR), Cataloipus brunneri (Kirby, 1910) (Endangered, EN) and Glomeremus capitatus Uvarov, 1957, Phaneroptila insularis Uvarov, 1957, Phaulotypus granti Burr, 1899, Socotracris kleukersi Felix & Desutter-Grandcolas, 2012, Socotrella monstrosa Popov, 1957 and Xenephias socotranus Kevan, 1973 (all Vulnerable, VU).