Global and European regional assessment: Endangered (EN)
EU 27 regional assessment: Endangered (EN)

This species is endemic to Europe where it occurs with a broad but very localised distribution from northeastern Spain through Central Europe to Ukraine. It is assessed as Endangered, both globally and in the EU 27 region, under criterion B2ab(i,ii,iii,iv,v) as it is very rare throughout its range with only a few localities and an area of occupancy of less than 500 km² (84 km² actually confirmed). The subpopulations are severely fragmented, remote and undergoing continuing decline in the number of mature individuals and in habitat quality and extent, as a result of forest exploitation and management, including the removal of veteran trees and dead wood. This species is a highly specialised predator of rare prey (mostly the rare Lucanidae Asealus spp. and Ceruchus spp.) that can be affected by the decline of its prey species.

This species is present but extremely localised, from northeastern Spain through Central Europe to the forest-steppes in Ukraine (Laibner 2000). It is only reported from very few localities in each country of occurrence.

• In France, the species is recorded from the eastern Pyrenees in France (INPN 2024). A locality record from Colmar (Haut-Rhin department) is very old and was not confirmed recently (Brustel and Van Meer 1999).
• In Spain, only one locality is reported, in the eastern Pyrénées, in continuity with French localities (Viñolas et al. 2012).
• In Ukraine, it occurs in the Carpathians and in the south of the forest-steppe zone.
• In Hungary, it is sporadic and was rediscovered during the late 1990s and early 2000s, in three regions of the southern Transdanubia (Zselic, Mecsek Mts and Villány Hills) (Sár et al. 2003, O. Merkl pers. comm. 2009).
• In Germany (not mapped) it is considered Extinct.
• In Poland, only one old citation from 1929 is reported, in Silesia (Nowotny and Polentz 1933, https://baza.biomap.pl). The species might have disappeared from this country.
• In Switzerland (not mapped), the species' presence is based on a doubtful record (possibly from Mount Pilatus near Lucerne) from the 19^th century and must be confirmed (Chittaro and Blanc 2012).
• In Romania, only old records are available (pre-1912) (Zaharia 2006).
• In Italy (not mapped), the species is indicated from the extreme south (Francavilla Fontana (BR): Policoro), based on specimens in Angelini's collection (Stoch 2005). However, the complete inventory of this collection was published in 2021 (www.sma.unifi.it). The sole Ampedus quadrisignatus present is from Slovakia. Therefore, the actual species' presence in Italy is to be investigated.
• The species is recorded from Croatia (not mapped), but without detailed locality details.

This is a very rare species in Europe, with severely fragmented subpopulations and declines reported.

In Ukraine it is a very rare species; with only one specimen known from the Kirovograd region in central Ukraine. In Czechia there is only one recent record. In Slovakia it is known from five localities and it is considered rare (Laibner 2000). In Hungary all known extant subpopulations are restricted to limited areas and the subpopulations are small (O. Merkl pers. comm. 2009). In France the confirmed localities are grouped in the easternmost part of the Pyrénées; it is considered a relict species (Leseigneur 1972); One old locality (1847) near Colmar (Alsace) has never been confirmed.

This is an obligate saproxylic species. The larvae develop in red-rotten heartwood of chestnut Castanea, oak Quercus and other broad-leaved tree species like Alnus (Brustel and Van Meer 1999); generally with lucanid beetle larvae (Aesalus and Ceruchus). It is a predator of Aesalus scarabaeoides which is itself very rare and localised, but it does not feed exclusively on this species. Pupation occurs in the autumn but the adults remain in the pupal cells in the decaying wood through the winter months. In Hungary, the preferred micro-habitats are red-rotten logs of bird cherry Prunus, beech Fagus, hornbeam Carpinus, and sometimes oak, always with Aesalus scarabaeoides (O. Merkl pers. comm. 2009). In France, the larvae develop in red-rotten wood of Quercus together with Lucanid larvae (Aesalus and Dorcus parallelepipedus) (Leseigneur 1972). In Spain, it has been found in rotten wood of Sorbus (Viñolas et al. 2012).

It is often in remnants of oaks, always inside forests; the preferred habitats are beech-oak woods of lowlands and foothills (Laibner 2000). It prefers dark, shady stands; old growth forest and trees with a large diameter. In Hungary, nearly all records are from closed, dark stands deep inside the forests, mainly in ravines (O. Merkl pers. comm. 2009).

Forest exploitation is one of the main threats, including the removal of dead wood. It is dependent on certain prey species that are locally declining and with very fragmented distribution. In Hungary, the removal of old logs and especially illegal over-collecting of the wintering adults are serious threats; the latter results in the destruction of the red-rotten logs (O. Merkl pers. comm. 2009).

All subpopulations are small, remote and highly fragmented in Europe which is a very significant threat, in relation to the effects inherent in the isolation of small subpopulations (inbreeding and genetic depletion).

Saproxylic Coleoptera tend to be popular with beetle collectors although trade is rarely an issue, the only exceptions being a few larger species of more dramatic form or colour.

The preservation of veteran trees and dead wood in forests is essential. The species is present in protected areas; however in Hungary the protection is not always effective (O. Merkl pers. comm. 2009). The species is legally protected in Hungary. It is nationally classed as Critically Endangered in some European countries e.g. Italy (2014). It is considered Extinct in Germany.