Probably the bee highlight of the year
The males of this species are among the first of the solitary bees to appear in the spring, with one exceptional record as early as late February. They are shortly followed by the distinctive females.
Status (in Britain only)
Classified as a Nationally Notable (Nb) species by Falk (1991).
Generally calcareous grassland and open deciduous woodland on chalk and limestone soils.
Univoltine; April to early July. The males are very short-lived in comparison with the females.
Females establish their nests in empty snail shells, including those of Helix pomatia, Cepaea nemoralis, C. hortensis and Monacha cantiana. Nests contain about four or five cells, depending on the size of shell used. Cell partitions and the closing plug consist of leaf mastic (i.e. masticated portions of green leaf). The space between the last cell partition and the closing plug is filled with a rubble containing very small snail shells and pieces of chalk, or soil. When the nest is completed the female covers the shell with a mound of dead grass stems, beech scales or leaf fragments (Perkins, 1884, 1891; G R Else, pers. obs.). The reason for this behaviour is not known, but it may camouflage the nest from possible parasites and predators at a time when it may be vulnerable to such attack….BWARS