Situation vacant - entomologist needed

Although they’re not around at the moment because the temperatures have fallen back and it’s too cold for them, one of my highlights of the year so far has been the appearance of bee flies in my garden. This is interesting because you can’t have bee flies without the solitary bees that they prey on. Bee flies are unmistakable, even for a taxonomic numpty like me – bees less so. I’ve been trying to figure to what solitary bees are around – see this. I think they’re mostly Andrena bicolor, but I’m not sure and so far I haven’t tempted any entomologists to venture an opinion. Any takers?

Nikon D5200 Tokina 100mm +68mm f22 1/180 ISO 200
http://wp.me/pieTR-dq