Overall, 25.7% and 28% of Orthoptera species are assessed as threatened at the European and EU 28 levels, respectively. However, the exact proportion of threatened species is uncertain, as there are 107 (10%) Data Deficient (DD) species in Europe and 84 DD species (8.5%) in the EU 28. Estimating that a similar relative proportion of the DD assessments are likely to be threatened, the best estimate of the threatened share of Orthoptera species is thus 28.5% in Europe and 30.6% in the EU 28. Further research on DD species to clarify their status is therefore critical. A further 13.9% (149 species) and 13% (128 species) are considered Near Threatened in Europe and in the EU 28, respectively.
By comparison, the best estimate of threatened species of those other groups that have been assessed comprehensively in Europe is 58% of freshwater molluscs, 40% of freshwater fishes, 23% of amphibians, 20% of reptiles, 17% of mammals, 16% of dragonflies, 13% of birds, 9% of butterflies and bees, 8% of aquatic plants and marine fishes and 2% of medicinal plants. Additional European Red Lists assessing a selection of species showed that 22% of terrestrial molluscs, 16% of crop wild relatives and 15% of saproxylic beetles are also threatened. No other groups have yet been assessed at the European level.
Looking at the population trends of European Orthoptera species, 30.2% (325 species) have declining populations, 7.6% (82 species) are believed to be more or less stable and 3.2% (34 species) are increasing. However, the population trends for the majority of species (59%, 634 species) remain unknown.
Out of the 739 species that are endemic to Europe (i.e., they are found nowhere else in the world), 231 (31.3%) are threatened, highlighting the responsibility that European countries have to protect the global populations of these species.
Overall, the European areas with the highest diversity of species are found in southern Europe, especially in the Mediterranean region and the Balkans. Hotspots of endemic species are found in the Iberian, the Italian and the Balkan Peninsulas, and in some large mountain areas (the Alps, Pyrenees, Carpathians and Appenines). The greatest concentration of threatened species is found along some Mediterranean coasts and Mediterranean mountain blocks. Finally, the number of Data Deficient species reflects the general distribution of Orthoptera species, being highest in the Mediterranean and the Lower Volga region in southern European Russia.
The main threat to European Orthoptera is the loss, degradation and fragmentation of their habitats as a consequence of agricultural land use intensification. This includes direct destruction by transformation of permanent grassland or shrubland habitats into cropland, degradation of habitat quality caused by overgrazing, abandonment, use of fertilisers or heavy machinery and direct mortality from frequent mowing or the use of pesticides. Other important threats to Orthoptera are the increasing frequency of wildfires, touristic development and urbanisation, climate change, afforestation and intensive forest management, drainage and river regulations, recreational activities, deforestation, limestone quarrying and sand excavations and invasive species.