Close inspection of the first and second images shows what appear to be small white-coloured mites congregated around the connection of the bee’s thorax to its abdomen. Views from different perspectives show there to be at least six of these mites. The mites are recorded in following sighting 4698735.
Great image, Tim. I think it is L. erythurum, but it might also be L. hemichalceum - they are hard to separate. The thorax can vary from black to bright metallic green. The lighter abdomen suggests L. erythurum, but the dark patch on T1 and the darker legs suggest L. hemichalceum. I see the mites now you point them out!