Hermit beetle  (Osmoderma eremita)

The loss of trees with suitable hollows is the greatest threat to this Vulnerable beetle. In managed forests, trees are cut down before any hollows are formed. Therefore, most sites where hermit beetles live today are situated in agricultural and even urban landscapes. Even in these habitats, hollow trees are cut down because they are no longer used (for example, pollarded trees and in plantations of fruit trees or chestnut trees), or to protect humans from accidents (2) (4). In addition, many hollow trees found on pasture woodlands, where gazing has now ceased, suffer from increased competition from younger trees. In many areas, the formation of new suitable trees occurs at a much slower rate than the deterioration of suitable trees, and there is often a great distance between the new trees and dispersal sources, resulting in fragmented hermit beetle populations that are more vulnerable to local extinctions (4).

Whilst this beetle is a priority species of the Habitats Directive, protection is poorly enforced. Removal permission is generally granted without a hermit beetle search, and only trees that are known to have hermit beetles living in them are protected. Since hermit beetles are rarely obvious on the outside of the tree, populations are often not found until the tree has been felled (2).

Conservation measures need to include the preservation of remaining natural forest, to preserve and restore habitats connected with historic agricultural landscapes, and to preserve any remaining suitable habitat in urban areas (4). The hermit beetle serves as an ‘umbrella' species for other hollow-dwelling species since it is better known, and protecting it will result in overall protection for this important habitat type (2).