Renter: Existing Cavities; abandoned cells in exposed nests of other aculeates (e.g. Sceliphron, Chalicodoma); insect burrows in the ground (e.g. of Anthophora); empty snail shells (e.g. Sphincterophila) with 1 cell per shell.
Nesting material: Cell partitions are made of resin. (Benoist, 1931; Giraud, 1871; Moreno-Rueda et al., 2008; Popov, 1961; J. Ortiz-Sanchez (personal communication).