Renter: Snail shells. Females of this species commonly use empty snail shells for their nests, e.g. Helix aspersa, Helix pomatia, Cepaea hortensis, Cepaea nemoralis, Helicella itale; R.C.L. Perkins (1891b) additionally cites “whelk” shells on the Devon coast. In a locality on the Hampshire coast, females have been observed inspecting empty Crepidula fornicata shells (pers. obs.). The bee has very occasionally been reported as excavating nesting burrows in sandy soil (e.g. E. Saunders, 1896). F. Smith (1844) reports a female excavating a burrow in an old post; a female, probably of this species, was seen inspecting a burrow in a wooden post on the Isle of Wight (pers. obs.). A nest built in a Rubus stem has been figured by Fabre (1906).
Nesting materials: In empty snail shells, the felt-like cell partitions and closing plug are constructed from chewed leaves, including those of Fragaria (Friese, 1898), Glaucium flavum, Ononis repens and Salix repens (all O’Toole & Raw, 1991) and Helianthemum and Sanguisorba. The number of cells per nest varies, according to shell volume (normally three in Cepaea nemoralis and C. hortensis, and up to ten in Helix pomatia (Friese, 1898)). In large shells, the cells are sometimes arranged side by side with the cell walls partially consisting of leaf pulp. Westrich (1989) suggests the female makes up to 12 cells in larger shells, 1-4 in smaller ones.
LeGoff (pers comm.) reports nesting in shells of Helix aspersa and Cepaea sylvatica in France
Maréchal (1926) provides an exhaustive account of the biology of this species in Belgium, including descriptions and figures of the nest, larva, pupa and cocoon. Westrich (1989) illustrates provisioned cells and describes the nesting biology of this species. An opened nest has also also been illustrated by Bellmann (1995).
The cell partitions are constructed of leaf mastic (Banaszak & Romasenko,1989). The shell surface is plastered with patches of leaf pulp. After nest closure, the shell is neither turned nor moved. (Banaszak and Romasenko, 2001; Bellmann, 1981; Benoist, 1931; Bonelli, 1971; Ferton, 1892; Friese, 1923; Maréchal, 1926; Müller et al., 1997; O’Toole and Raw, 1991; Saunders, 1896; Smith, 1844; Stoeckhert, 1933; Westrich, 1989; G. Else, unpublished manuscript; G. Le Goff, personal observation). Legoff (pers. comm.) reports leaf mastic from Sanguisorba (Rosaceae) is used to close nests in France.
Matache & Ban (2006) additionally state that the species will nest in empty dry stems and in rock cracks.