Renter: Snail shells. Nests are constructed in empty snail shells, including Pomatias elegans, Cornuella virgata, Cepaea nemoralis and Cepaea hortensis. Müller (2018) adds small to medium size snails (e.g. Fruticicola, Helicella, Xerolenta, Zebrina, small shells of Helix). C. O’Toole (pers.comm.) has reared this bee from a series of cells which superseded a snail shell nest of Osmia aurulenta collected at Kenfig Burrows, West Glamorgan (Else & Edwards, 2018)
LeGoff (pers.comm) reports nesting in shells of Candidula unifasciata in Seine Maritime (FR)
Nesting material: The cell lining has been reported as being prepared from sheep and, perhaps hare dung (Gehrs, 1902), and cow dung (Richards (1977). However, it has been conclusively shown by Müller (1990) that the female uses leaf mastic (e.g. from Potentilla, Sanguisorba) for cell linings and partitions; the mastic is bright green when first applied but later assumes a brownish appearance. Müller describes nest construction and provisioning in detail and illustrates opened snail shells to show the H. spinulosa cells and their contents. An opened nest is also illustrated by Else et al. (1979). The shell surface is not plastered with patches of leaf pulp. (Banaszak and Romasenko, 2001; Friese, 1893; Gehrs, 1902; Grandi, 1961; Müller, 1994; Müller et al., 1997; O’Toole and Raw, 1991; Romasenko, 1980; Smith, 1844; Stoeckhert, 1933; Westrich, 1989)