Mining Bee (genus: Andrena)
Another of those insect grooups that has too many visually similar species to be confident about species level identity. Having said that, this could be Wilkes Mining Bee (Andrena wilkella) which is yet another European invasive arriving here decades ago by ship. There are 1300 species in this genus, so you will forgive my lack of certainty.
Body length commonly ranges between 8 and 17 mm with males smaller and more slender than females, which often show a black triangle (the “pygidial plate”) at the abdominal apex. In temperate areas, Andrena bees (both males and females) emerge from the underground cells where their prepupae spend the winter, when the temperature ranges from about 20 °C to 30 °C. They mate, and the females then seek sites for their nest burrows, where they construct small cells containing a ball of pollen mixed with nectar, upon which an egg is laid, before each cell is sealed. Andrena usually prefer sandy soils for a nesting substrate, near or under shrubs to be protected from heat and frost.
The blossom it is on is sour cherry.