The current IUCN European Red List provides an assessment for 693 species of saproxylic beetles. In 2008, following a two-year project, a total of 436 species were assessed. In 2017, an additional 257 species were assessed.
The species selection includes obligate or presumably obligate saproxylic beetles listed in the annexes of the Habitats Directive, and full coverage of selected families and/or subfamilies. All the assessments were made following the IUCN Red List Categories and Criteria, which is the global standard for measuring extinction risk, and the Guidelines for Application of IUCN Red List Criteria at Regional and National Levels.
Overall, 17.9% and 21.7% of species are considered threatened in Europe and in the EU 27/28, respectively. These values assume that a similar relative proportion of the Data Deficient (DD) species are likely to be threatened, and provides the best estimation of the proportion of threatened species.
For almost one quarter of the species in Europe (168 species – 24.4%), there was not enough scientific information to evaluate their risk of extinction and they were assessed as DD. In the EU 27/28, 133 species (20.4%) were also assessed as DD. When more data become available, it is possible that many of these species may also prove to be threatened.
In Europe, 0.7% of species have been assessed as Critically Endangered, 7.4% as Endangered and 5.4% as Vulnerable. A further 12.9% (89 species) are considered Near Threatened. There is a higher proportion of threatened species in the EU 27/28 (1.1% Critically Endangered, 9.3% Endangered and 6.9% Vulnerable), with 13.5% Near Threatened.
In Europe, 12.9% (89 species) of saproxylic beetle populations are thought to be in decline, while 33.3% are considered stable (229 species), and 3.6% (25 species) are increasing. For half the species (345 species), the population trend is unknown, and 14.8% of these (51 species) are threatened.
The intermediate latitudes of central Europe clearly stand out as areas of high species richness. Biodiversity hotspots seem to be located in mountainous areas such as the Pyrenees, Alps and Carpathians.
Logging, tree loss and wood harvesting are by far the greatest threats to both threatened and non-threatened saproxylic beetles, affecting more than half the species (54.5%, 375 species), including 76 threatened species. This highlights the importance of European forests and other landscapes with trees for the continued survival of these deadwood-dependent species.
: The families and subfamilies comprehensively assessed were the Alleculinae, Boridae, Bostrichidae, Cerambycidae, Cerophytidae, Cetoniidae, Cucujidae, Diaperinae, Elateridae, Erotylidae, Eucnemidae, Euchiridae, Lucanidae, Mycetophagidae, Oedemeridae, Phrenapatinae. Prostomidae, Pythidae, Rhysodidae, Stenochiinae and Trogossitidae.