Small Nomad Bee (Nomada flavoguttata)

Also called the Little Nomad bee, it lives up to its name and can measure as little as 5mm.

Not only is it diminutive, is flies very low on partially vegetated ground lookming for the nests of its host species which can be one of several of the Mini-miners (Micrandrena) bees.

It has a predominantly black head and thorax with a reddish abdomen, usually with small flecks of yellow on the side, with the females having more extensive red markings on the head.

Although widespread, it's only locally common and understandably very easy to overlook.

Given its constant movement, size and habit of disappearing for long periods under vegetation, I was relieved when this photo at least enabled an ID.