This is a tiny (6-7mm), jet black bee which could very easily be missed in the field. Identification is impossible without close inspection with an eyeglass or microscope, as the densely-punctured tergites and thorax and roundish head of the female cannot be seen otherwise. Males possess conspicuous tufts of white hair on their sternites (underside of the abdomen), although a microscope will once again be required to view this feature clearly. It is one of the rarer Lasioglossum although doubtless it is once again an under-recorded species. It is classed as Vulnerable in Ireland.

Distribution in Ireland: Virtually all records are southeast of the line that can be drawn from Belfast Lough to the Shannon Estuary. It is local and primarily coastal.

Flight Period: Females fly from April-September, whilst the males emerge in June and persist until August.

Habitat: Primarily a species of light soils and consequently, it tends to frequent coastal sites. Dry heath, coastal grassland, soft-rock cliffs and sandy brownfield sites may all be used.

Flowers visited: Hawkweeds, thistles, speedwells, daisies, umbellifers, yellow brassicas and others. Yellow composites and Sea Radish are particularly important at some Irish sites.

Personal Records: This is a species which I have encountered at several sites, all but one of which are coastal; Killard Point and Kilkeel Cliffs (Co. Down), Armagh City (Co. Armagh), Portrane Beach (Co. Dublin), Brittas Bay (Co. Wicklow), Knocknasillogue Beach (Co. Wexford) and Long Strand (Co. Cork). I have observed it nesting in loose aggregations in both glacial till/soft rock cliffs and consolidated sand banks. Lekking males often fly tirelessly around the nesting sites, only stopping occasionally to bask on bare soil or to visit flowers such as Ragwort or other yellow composite flowers. It can be rather abundant at some of these sites listed above, particularly during July when the males are at their peak. Sphecodes geoffrellus is a probable kleptoparasite of this species in Ireland. Nomada shepperdana (should it occur in Ireland) likely uses this species as a host.