Thanks to Bill Petty, the mushroom guy micologist, naturalist and Master Gardener, for identifying the flying insect visiting the wild foxglove that I thought looked like a tiny bee of some sort. Here's what Bill said in a comment on my Facebook page. . .
"I agree with Dr. Parker's identification. Those are beautiful pix! I especially like that you caught the hover fly in mid-visit."
I learned that Hoverfly is a mostly unknown alternative rock band, a public relations company in Washington, D.C. and (ta da) an insect also known as a flower flly or a syrphid fly. Adults feed on nectar and pollen, while their little maggots are a gardener's friend, since they prey upon aphids and thrips. Read more here.