Chelostoma campanularum – Harebell Carpenter-bee
I saw plenty of these tiny bees last year but had misidentified them… they are a tiny black bee associated with the flowers of various bellflowers (Campanula species). Seeing thaat I love campanulas and have them all over the garden I shopuld really have twigged!
They are common and widespread in much of England, but absent from Wales, Scotland and Ireland. They are commonly found in town gardens, and nests in old beetle holes or the exposed ends of thatch. They tend to be seen between June and early August.
This one on an osteospernum flower shows how small they are!
This shows more detail…
and this muchn enlarged photo gives some detail.