The largest Sphecodes species in Ireland and one of the few which can be determined in the field without microscopic examination. Both sexes had a rather wide (but not deep) head and generally have a slender body shape. Females have smokey wings and numerous punctures at the back of the head. Males are very large for Sphecodes and this alone usually enough for successful identification, but the widened head with punctures around the back of the eyes and ocelli will confirm this species. It is a rare species which is currently listed as Critically Endangered.

Distribution in Ireland: Widespread but scarce, with only 16 records collectively from Antrim, Dublin, Wicklow, Carlow, Wexford and Clare.

Flight period: Females emerge in April, whilst new females and males emerge in June and can be seen until early September.

Habitat: The paucity of Irish record makes assessing its preferred habitat difficult, but it has been recorded from brownfield sites, coastal dunes, woodland and heathland margins.

Flowers visited: A variety of open-structured flowers, including Ragwort, Ox-eye Daisy and Wild Carrot.

Personal records: I have only recorded this species on a single occasion, which was male found in the Skerries Ballast Pit in Co. Dublin. It was flying along a south-facing clay bank where Halictus rubicundus (its host) was nesting. It is puzzling that this species is so scarce in Ireland, given that its host is widespread and common. It does appear that this species, Sphecodes ephippius and Sphecodes monillicornis all use H. rubicundus as a host, so perhaps it is a less successful competitor when pitted against the other two species.