Renter: Existing cavities. The females construct the nests in cavities between stones and in crevices. The nest is linear, and the cells are made with cut petal fragments of Geranium and Ranunculus which are glued together with varying amounts of mud.
Müller writes: Nesting sites: Preexisting cavities: fissures and holes in rocks, stones and cinder; between stones; in abandoned nests of Megachile parietina; between pieces of bark. Nesting material: The cells, which are built singly or in small groups, are entirely constructed from several layers of petals (Geranium, Helianthemum, Hieracium, Meconopsis, Rosa, Ranunculus, Papaver) cemented together with sand or mud in varying quantities; the extremes are pure petal cells on the one hand and mud cells with petals only on the outside on the other hand. (Banaszak and Romasenko, 2001; Benoist, 1931; Ducke, 1900; Friese, 1893, 1895, 1923; Müller et al., 1997; Petit, 1970; Stoeckhert, 1933; Westrich, 1989)