Renter: Existing cavities. In May 2011, G. Pisanty observed several females of Osmia (Hoplosmia) distinguenda nesting in small rock cavities in Israel (see species account for details). While Hoplosmia species of the spinulosa and the pinguis group all seem to exclusively nest in empty snail shells, the species of the bidentata group also use other nesting sites, such as hollow stems, insect borings in dead wood or rock cavities as now observed for O. distinguenda. (Müller, A., 2012).
Observations from both Israel and southern Greece show that the brood cells are built singly or in small groups within small cavities of rocks and stones (G. Pisanty and H. Wiesbauer personal communication; A. Müller unpublished data; all cited in Müller, 2018).
Nesting material: The brood cells are constructed of leaf mastic with the rock surface usually forming part of the cell walls. The nest cavity is closed by a wall made of leaf pulp (Müller, 2018)