This is the scarcer of the two Halictus species in Ireland, although it can be locally common in certain sites. It is noticeably smaller than Halictus rubicundus and in terms of size, it rather-more resembles Lasioglossum species such as Lasioglossum albipes. It does however have a variable bronze-green sheen across the head and thorax and a white-banded abdomen. It has reportedly declined by around 50% in recent decades and is consequently listed as Near Threatened.

Distribution in Ireland: Widespread but local, mostly in the south and east of the island. It hasn’t been recorded north of a line drawn from Westport to Dundalk.

Flight period: Females may be seen from early April-September. Males appear in mid-June and are active until August.

Habitat: Brownfield sites, old quarries, soft-rock cliffs, dry heathland, woodland clearings, parks and flower-rich grassland.

Flowers visited: Fond of composite flowers such as Ox-eye Daisy, dandelions, hawkweeds, Devil’s-bit Scabious, Hogweed, and Yarrow, but broadly polylectic and will visit many others.

Personal records: I have recorded it at Bru na Boinne (Co. Meath), Clongownagh (Co. Kildare), Finnamore Lakes (Co. Offaly), Powerscourt (Co. Wicklow) and in the Skerries Ballast Pit in Co. Dublin. Here it nests in aggregations in light soils on south and west-facing slopes, sometimes shared with H. rubicundus and various Lasioglossum species. Here I observed females of the blood bee Sphecodes geoffrellus active around the aggregations, as well as the Western Bee-fly Bombylius canescens. It is reportedly a host species of both Sphecodes ephippius and S. geoffrellus.