Identifying Bees of the UK - Ashy Mining Bee

Identifying Bees of the UK

Ashy Mining Bee Andrena cineraria

Callum Brooks

Above: Ashy Mining Bee ©Henrik Larsson/Shutterstock

If you were to ask any nature enthusiast to describe a bee, then it’s more than likely that they’ll describe a bumblebee. Therefore, it may come to the surprise of many to find out that in fact bumblebees only make up a small proportion of British bees and the rest belong to a group known as solitary bees. Within the UK, there are approximately 267 species of bee and just under 250 of these are solitary bees, which differ from bumblebees, as they tend not to live in colonies. One of the most distinctive species of solitary bee is the Ashy Mining Bee (Andrena cineraria) and it can be commonly found across much of England and Wales. This non-aggressive solitary bee has shown remarkable adaptability and since the end of the 20th century it’s enjoyed an increase in abundance throughout its range, with habitats such as gardens, parks and calcareous grasslands being ideal places to spot this species.

Luckily, identification is made easier for solitary bees, as unlike bumblebees, they only have males and females. When trying to identify an Ashy Mining Bee, the first thing you should look out for is its distinctive black and grey markings. This species is also roughly the size of a European Honeybee (Apis mellifera), which provides a useful comparison for identification purposes. The female Ashy Mining Bee is rather striking in comparison to the male, with its glossy black abdomen (which can look blueish in a certain light) and two distinct bands of grey hair across the top and bottom of the thorax. The males, do have similar markings to the females, but the thorax is less densely clothed with grey hairs and they’re slightly smaller.

The Ashy Mining Bee is univoltine, meaning that they only produce one generation per year and they can typically be seen on the wing from March to July of each year, with numbers peaking in April and May. Interestingly, in recent years this species has been seen foraging into September and October on Ivy (Hedera) flowers, which suggests that climate change may be having an impact on their flight period. This species is polylectic and it visits a wide range of flowers to collect nectar and pollen, which include buttercups (Ranunculus spp.), roses (Rosa spp.), brambles (Rubus spp.), Silverweed (Potentilla temulum) and Thrift (Armeria maritima).

Although most solitary bees nest alone, in suitable sites they will form aggregations of nests and the Ashy Mining Bee is no exemption to this. This species is capable of forming extensive nesting aggregations, which typically occur along footpaths, south-facing slopes and sheep-grazed hillsides with extensive soil creep or rabbit activity. The entrances to these nests are surrounded with excavated soil and this produces a mound that resembles a tiny volcano. These ‘volcanoes’ are in fact the entrance to a females nest cavity and this species will seal the entrance to the nest when they’ve finished foraging for the day or when it’s raining outside, which shows remarkable intelligence for such a small creature! These colonies also support numerous parasites and cuckoos including Lathbury’s Nomad Bee (Nomada lathburiana), which is a cleptoparasite of the Ashy Mining Bee. The nests can also be attacked by two species of spring-flying bee-fly, the Dark-edged Bee-fly (Bombylius major) and the Dotted Bee-fly (Bombylius discolour) and it’s no surprise that all of these associated parasites/cuckoos have increased in abundance in line with the recent increase in of numbers of Ashy Mining Bee.

Callum Brooks. August 2021.