Colletes cunicularius

In Belgium it is described as a fairly massive bee, 13 to 17 mm long, compared with other members of its genus in the region.

It is considered the largest of the nine Colletes species found in Britain.

In Britain it is confined to a number of extensive coastal sand dune systems in north-west England and in Wales.

In 2011 several inland populations were recorded in Britain, in Shropshire, Nottinghamshire and Worcestershire.

It is the only British Colletes that flies in spring, from early April to the end of May.

It is a solitary bee that specialises on a narrow range of pollen plants, yet nests in aggregations.

Its British habitat is large, mature coastal sand dunes wherever creeping willow grows.

Nesting aggregations of up to 18,000 nests have been recorded.

Females dig their nest burrows up to 1 metre deep in sandy soil.

Females forage preferentially on willow catkins.

Males emerge before the females and patrol along the nest entrances looking for a mate.

A female emerging from her nest triggers a scramble among large numbers of competing males.

In the Mediterranean region, males pollinate several Ophrys orchids, whose flowers mimic the scent of female bees.

In Britain it is listed as Rare (RDB3) in the national Red Data Book reviews of 1987 and 1991.