A unique and attractive mining bee which flies in two morphologically different broods and is exceedingly rare in Ireland. Males and females of the spring brood have a broad blood-red band on the abdomen, rendering them pretty distinctive. Individuals of the summer generation are much darker and have this red band much reduced or absent, although there is usually some reddish coloration on the sides or underside of the abdomen. Both sexes are similar to Andrena trimmerana, but the female has shorter and sparser body hair, whilst the males possess all-black hind tibia and have differently shaped mandibles. Its general size and appearance otherwise is similar to Andrena scotica. It is classed as Regionally Extinct in Ireland as it had not been recorded since 1977, however this status will need to be revised.

Distribution in Ireland: Both its historical and current distribution are confined to Co. Carlow, although it may occur in neighbouring counties as it appears to be somewhat elusive. So far, it appears to be restricted to the catchment area of the river Barrow and all known sites are adjacent to rivers.

Flight period: Flies in two generations per year, the first from late March until late May, the second from mid-July until early September.

Habitat: Owing to its scarcity, the habitat requirements and associations are poorly known in Ireland. Recent specimens have been found in and around woodland edges over clay soil. There appears to be an association with deciduously-wooded glens and river valleys with plentiful willows and Blackthorn in spring and Angelica in summer, although this may be speculative.

Flowers visited: The spring generation relies heavily on Blackthorn and willows, particularly Eared Willow in Ireland.  Hawthorn appears to be used when willows and Blackthorn have finished flowering. The summer brood relies heavily on Angelica, with the possibility of Hogweed, Wild Carrot and brambles also being used.

Personal records: I have been very fortunate to find this species near the village of St. Mullin’s in Co. Carlow. I observed a sole female, entering her nest on a southwest-facing slope in an area of pasture bordered by scrub and woodland. The nest was inconspicuously placed under the cover of several herbaceous plants and appeared to be solitary. I have also observed females around the village of Borris (also Co. Carlow) in spring and summer, where they were visiting Hawthorn blossom in spring and Angelica flowers in summer. It may act as a host to Nomada marshamella, but there was no evidence of this at either site.