Churchyard beetle, Cellar beetle

The churchyard beetle or cellar beetle (Blaps mucronata) is a species of large flightless darkling beetle in the family Tenebrionidae, order Coleoptera. Adults are robust, black-bodied beetles reaching twenty to thirty millimeters in length, with fused elytra that render them incapable of flight, a characteristic that restricts dispersal and makes local populations vulnerable to habitat loss. B. mucronata inhabits dark, cool, and humid environments such as cellars, crypts, cave entrances, stables, and the bases of old stone walls — the latter association explaining the common name churchyard beetle, as ancient stone churches with undisturbed subterranean spaces provide ideal habitat. The species is nocturnal and slow-moving, feeding on decaying organic matter, fungi, and plant debris. Its range historically extended across much of western Europe, including Belgium, Denmark, France, Ireland, and the Netherlands, but populations have declined significantly across this range due to habitat loss associated with modernization of buildings, renovation of historic structures, and reduction of traditional agricultural environments with earthen floors and organic refuse. B. mucronata is currently listed as Endangered on the IUCN Red List, reflecting its sensitivity to habitat degradation and limited dispersal capacity. Conservation efforts in several European countries focus on maintaining undisturbed cellars and crypts as microhabitat refuges. The species produces chemical secretions from abdominal glands as a defense against predators.