Island mysteries in the spotlight: Barbitistes kaltenbachi and Rhacocleis buchichii, the only bush-cricket species endemic to Croatia (Orthoptera, Tettigoniidae)

Hvar Saw Bush-cricket Barbitistes kaltenbachi Harz, 1965 (Phaneropterinae: Barbitistini) and Lesina Bush-cricket Rhacocleis buchichii Brunner von Wattenwyl in Herman 1874 (Tettigoniinae: Platycleidini) are flightless orthopterans restricted to a narrow area in the Mediterranean part of Croatia, both originally described from Hvar Island. In this study, all available information on these two interesting species is presented: data on morphology, bioacoustics, distribution, habitat, and a key to identification of the species belonging to genera Barbitistes and Rhacocleis in Croatia. The songs of both B. kaltenbachi and R. buchichii are described here for the first time, with the former one being the second known example of a synchronising and presumably duetting species. Both species were reassessed according to the IUCN Red List criteria, where B. kaltenbachi should be considered an endangered species, while R. buchichii is suggested to be downgraded to a less threatened category. Biogeography and evolution of the species are briefly discussed.