Nomad Bee
Nomada species
Description
There are 34 species of Nomada bees on the British List, many of which are very similar. I have not been able to identify this one. Nomada bees are cleptoparasites of solitary bees, mostly Andrena bees, and often species particular. They lay an egg in the cell wall of the host's nest from which the larvae hatches, kills the host egg and helps itself to the stored food.