This is perhaps our only truly native mason bee, but it is arguably the most attractive and has a fascinating life cycle. The females are a medium-sized species (around 10mm) with a rather bulbous head, brick-red thoracic hairs and a dull brown abdomen with orange-gold hairs fringing the tergite edges. The males are slightly smaller and duller. In Ireland all but one population are coastal, where they feed primarily on Bird’s-foot Trefoil and nest in empty snail shells; a unique trait among Irish bee species. The sole inland population, located in Co. Tipperary nests in peaty soils at the base of heather tussocks. It is listed as Near Threatened in Ireland.
Distribution in Ireland: It occurs in many sandy beaches along the east and south coasts, from Baltray in Co. Louth to Creggane in Co. Cork. An isolated inland population exists near Thurles, Co. Tipperary.
Flight Period: April-August, typically peaking between May and July.
Habitat: Almost exclusively coastal dunes.
Flowers visited: Bird’s-foot Trefoil is favoured, but also various vetches, Bugle, Spiny Restharrow, Black Medick, thistles and Red Dead Nettle.
Personal Records: I have seen this species in sand dune systems along the east coast, such as Baltray Dunes in Co. Louth, Buckroney Dunes in Co. Wicklow and The Raven and Ballyteigue Burrow (both Co. Wexford). Females are best searched for along south, east or west-facing, partially vegetated sandy slopes, where they nest in empty snail shells. Both sexes can also be seen nearby visiting yellow fabaceae such as Bird’s-foot Trefoil or Kidney Vetch. The males will seek out empty snail shells and will territorially defend them against other males. Population densities vary between sites and it can be difficult to find at some of the more northerly sites.