This is a fairly large spring-flying mining bee with a strong association with willows. Females measure around 13-15mm and have a rich brick-red thoracic pile, black face and abdomen and prominent orange hindlegs. The thoracic pile can fade rather quickly to a buffish-brown colour. It is similar to Andrena bicolor but its appreciably larger size is a reliable way to positively identify this species.  The abdominal hairs are also completely black, whilst those of A. bicolor tend to be a mixture of black and brown. Males are smaller and slimmer with pale grey and buff hairs on the face, thorax and abdomen. They are one of the first solitary species to emerge each year.

Distribution in Ireland: Widely distributed across the island and fairly common, although probably under-recorded due to its arboreal foraging habits and early flight period.

Flight Period: Late March-early June, peaking in April with the blossoming of willow catkins. It is unusual to see this species later than the middle of May.

Habitat: Deciduous and mixed woodlands, parks, scrub, brownfield sites, heathland margins, coastal dunes with willows.

Flowers visited: Pollen is obtained entirely from willow species, particularly Sallow. Other spring flowers may occasionally be visited for nectar.

Personal records: I have recorded females of this species at several sites around Belfast and Hillsborough (Co. Antrim and Down respectively) , in Murlough NNR (Co. Down), at Peatlands Park, Seagahan Dam, Benburb Priory, The Argory, Carnagh Forest, Milford Cutting and Armagh City (all Co. Armagh), Drumcairne Forest (Co. Tyrone) and near Ardara and Dunfanaghy (Co. Donegal). Females can best be observed foraging on willow catkins, but may also be seen nesting in clay banks, consolidated sand banks and at the base of trees, usually singly but sometimes in loose aggregations. Males can be seen investigating bare soil banks or basking on sunny rocks and tree trunks.  It is the host of Nomada leucophthalma.