Renter: Existing cavities; Dead Wood nester. Nests mainly in beetle emergence holes in dead wood, but also in hollow stems, ranches, tree trunks and wooden buildings. The nests are constructed linearly. Cell partitions and nest plug made of mud. Small pebbles, sand grains and other particles which are embedded in the outer plug surface. Inside these narrow cavities, one to several brood cells are arranged in a linear series. Cell partitions and nest plug are made of mud mixed with nectar and probably also saliva (Westrich, 1989). Nectar is added to the mud for the construction of partitions and plug. (Benoist, 1929a; Bonelli, 1967b; Brechtel, 1986; Käpylä, 1978; Ruszkowski et al., 1995; Stoeckhert, 1933; Westrich, 1989; Stanisavljević, 2000).