Habitat requirements of the endangered beetle Boros schneideri (Panzer, 1796) (Coleoptera: Boridae)

.  1. To further knowledge regarding habitat requirements of the threatened species Boros schneideri , a total of 1522 dead standing Scots pine ( Pinus sylvestris ) were checked for the presence of B. schneideri larvae. For the 245 trees inhabited by larvae (16% of all examined trees), tree characteristics and occupancy patterns were measured. 2. As most of the investigated forests were 40–80 years old and were dominated by comparatively thin dead trees (5–20 cm diameter at breast height), B. schneideri larvae were mainly found under the bark of trees with a diameter in the range of 10–20 cm. However, the probability of a tree being inhabited by B. schneideri increased progressively with tree diameter and forest age. 3. Most of the trees with B. schneideri (79%) were in medium‐dense and sparse‐growth pine forests where the canopy cover was 60–80%. The presence of Norway spruce ( Picea abies ) in Scots pine forests was an important factor affecting the probability of trees being inhabited by B. schneideri . Only 6% of trees inhabited by B. schneideri were found in mixed Scots pine‐Norway spruce forests, where the shadowing was higher than 80%. 4. All dead trees inhabited by B. schneideri had loose and at least slightly fragmented bark. A bark area of 0.08 m 2 was found to be sufficient for the survival of B. schneideri . The critical bark thickness for B. schneideri larvae was 5 mm. 5. The data obtained are important for the optimisation of conservation measures implemented during forest management operations.