Tymphrestos Greek Bush-cricket (Parnassiana tymphrestos) is endemic to Greece and is found on Mount Tymphrestos and Mount Oiti in Central Greece. This species is assessed as Endangered. It has a restricted geographic range: the extent of occurrence (EOO) is 260 km², the area of occupancy (AOO) is 60 km², and it occurs at only two locations. The population is severely fragmented, and there is a continuing decline in the number of mature individuals and the extent and quality of its habitat due to livestock grazing (lately including cattle), skiing activities and forthcoming wind power station infrastructures. Our knowledge of the species' ecology has recently increased, but further research is needed on this species, particularly regarding its distribution pattern, population size and trend, ecology and threats.

Tymphrestos Greek Bush-cricket is endemic to Greece. Its distribution is restricted to Mount Tymphrestos and Mount Oiti in Central Greece (Willemse 1980, Willemse et al. 2018, Kati 2022). A recent study delineated its distribution: 46 km² in Oiti Mountain (out of which 54% falls within the National Park of Oiti -GR2440004) and <1 km² in Tymphrestos Mountain (GR2430001) (Kati et al. 2022, Stefanidis unpublished data: ongoing PhD thesis). The estimated species' extent of occurrence (EOO) is between 260 km² and 300 km² and the estimated area of occupancy (AOO) is between 60 and 100 km².

The two subpopulations of the species are isolated with no or little genetic exchange between them; this population is therefore considered severely fragmented. The population status was satisfactory in Oiti Mountain (species recorded in 38% of sampling sites), and in several localities, the population density was 11 individuals/100 m². The population status in Tymphrestos mountain was unfavourable, as the population density was low, and the species was rarely found (16% of sampling localities). This species has a decreasing population size caused by the ongoing deterioration of its habitat due to grazing and infrastructure expansion for tourism and renewable energy sources.

The Tymphrestos Greek Bush-cricket inhabits open, more or less rocky slopes covered with herbs, grasses and small spiny bushes above 1,400 m (Willemse et al. 2018). The species was recorded in the mountainous grasslands (4090 habitat type), in Abies forest clearings (951B habitat type) and in Nardus communities that are a priority habitat (6230) of the Habitats' Directive (92/43/EC). It selects microhabitats with high grass and herb cover (>50%), with a substantial cover of short thorny bushes, particularly of Astragalus sp. where it hides, and some cover of stones and rocks. It favours microhabitats with a vegetation height between 17–20 cm; dominant plant species in its habitat include Astragalus angustifolius Hyparrhenia hirta, Drypis spinsa, Festuca jeanphertii, and Stipa bromoides (Kati et al. 2022, Stefanidis (unpub. data: PhD ongoing study).

Ski infrastructures in Mt Tymphristos have restricted its habitat in the past. New plans for wind power stations within its distribution area will restrict its habitat extent in Oiti Mountain (RAE 2023). Ηabitat loss is expected, derived from artificial land expansion from tourist and renewable energy investments. Unsustainable grazing in the summer is a constant pressure degrading habitat quality, particularly in recent years when mild sheep/goat grazing has been replaced by cattle grazing. Considering the extent of the effects of the threats and the distribution of this species, it is considered to occur at only two locations.

The species is not utilized.

No conservation measures are in place for this species, but most of its known localities occur within protected areas of the Natura 2000 network (GR2430001, GR2440004). A study was funded by the Management Unit responsible for the two Natura 2000 sites in Oiti and Tymphrestos mountains (NECCA-Natural Environment & Climate Change Agency). A PhD study is also ongoing (A. Stefanidis), and a small project was funded in 2023 to support further fieldwork on the species. The following conservation measures for enhancing the conservation status of Tymphrestos Greek Bush-cricket are suggested (Kati et al. 2022): (a) banning artificial land generation through touristic, renewable energy sources or other infrastructures within the distribution area of the species, (b) initiating and implementing a grazing management plan, including mapping and assessment of the current grazing pressure in the species habitats, adjusting grazing regimes to maintain the habitat quality of the species (great cover and adequate height of grass/herbs) and maintaining forest openings through grazing in fir forests, (c) initiating a monitoring scheme for the species distribution and population trend, (d) expansion of the Natura 2000 site GR2440004 to the south in Mt Oiti to include the species distribution that is currently outside the network. Further research is needed for the distribution pattern, population size and trend, ecology and threats of the species.