On a sunny day just over a month ago, I was watching the solitary bees (Andrena flavipes) in a soil bank by the edge of one of the town centre car parks. It was a mid-April Sunday, the car park almost empty, so I wandered along the bank to check for any other bees living there. I had looked before and found nothing but this time I was surprised to find freshly disturbed friable soil and some bees about the same size as honeybees but with prominent black and white hairs. I took as many photos as their behaviour would allow and when I looked at various bee resources I reckoned these were most likely Andrena cineraria, the Ashy Mining Bee. The name refers to the colour of the hairs on the thorax of the bees and cineraria comes from the Latin for ashes.
The Ashy Mining Bee is a very pretty solitary bee, particularly the female with her distinctive black and white hairs; the males are not so clearly marked although they do have white facial hairs. My photos don’t allow me to identify males or females with any certainty although I did see two bees that were either fighting or mating. I have not seen any females with pollen and I don’t think this is a large accumulation of nests but it does show that there are two species of solitary bee living in this unassuming soil bank in a town centre car park adjacent to the Leechwell Garden.
While I was watching these bees, another large insect about the size of a medium bumblebee appeared and patrolled the nest area. With its smart coat of russet hairs and its long proboscis clearly visible, this was a bee fly, most likely Bombylius major. These are parasites of A. cineraria and flick their eggs in to the soil nests where they develop and take over.
Later, I also noticed a smaller insect with a prominent yellow banded abdomen. In the photograph it is digging in the soil upside down. This is probably a nomad bee but, from this photo, I cannot say which species. A few days later I saw two Nomada flying about; these could be Nomada lathburiana known to parasitise nests of A. cineraria by laying eggs which develop and kill the bee egg or early larva.