Diagrams of nest structures of nests of Hoplitis fertoni (right) and Osmia ferruginea (left). The nests are identified by locality snail codes (Cern – Cernuella sp., Ever – Eobania vermiculata, Iber – Iberellus sp., Olac – Otala lactea, Scan – Sphincterochila candidissima, Tpis – Theba pisana. Each box represents one brood cell, starting with the innermost cell on the left. Colours represent the various species recorded. White boxes represent intercalary cells.