Habitat use of Bolitophagus reticulatus (L.) (Coleoptera: Tenebrionidae), living in the basidiocarps of Fomes fomentarius (L.) Kickx, was investigated in three forest areas in south-eastern Norway: (1) a continuous, coniferous forest, (2) an agricultural area with mostly deciduous forest islands in a matrix of cultivated land and (3) a homogeneous, old deciduous forest stand. B. reticulatus was almost exclusively found inside dead basidiocarps. The size of the basidiocarp was the most important variable for predicting the probability of B. reticulatus presence in the basidiocarps from all three study areas. Drier basidiocarps had a higher probability of beetle presence than the wetter ones. Basidiocarps situated above the ground level had a higher probability of beetle presence than those close to or on the ground level. In the first study area, the presence of Cisidae was found to reduce the probability of B. reticulatus presence perhaps as a result of competition. The disappearance of beetles from previously inhabited basidiocarps seemed to be due to depletion of resources.