Habitat requirements of the endangered heath bush-cricket Gampsocleis glabra (Orthoptera, Tettigoniidae) in an isolated population

Steppes and xerothermic grasslands are hotspots of biodiversity, but are threatened by habitat destruction and fragmentation. The heath bush-cricket, Gampsocleis glabra, is considered to be a specialist of xerothermic habitats and appears in national red lists as a threatened species in several European countries. The goal of the current research was to determine the habitat requirements of G. glabra in an isolated habitat patch in Poland, at the northern edge of its range. By comparing the composition of plant species and vegetation architecture of vacant and occupied sites in the summers of 2018 and 2019, it was found that this population of G. glabra still maintained a strict specialisation for the xerothermofilous Festuco-Brometea plant community. On the contrary to previous studies, however, Stipa-type grasses were not essential for the occurrence of the species and the majority of occupied areas were based on the plant Brachypodium pinnatum. The physiognomy of plant communities was crucial for the abundance of stridulating males, which showed a preference for dense grasses at 10 cm high. The habitat characteristics of patches occupied by males and females did not differ significantly. The study of habitat requirements of this endangered Orthoptera species in an isolated habitat patch could serve as a prelude to the restoration of similar locations before it becomes extinct. This study may also underpin the development of a global conservation strategy for G. glabra.