Found: glittery native bee and friends at Willowbrook Reach.
I think this is an Osmia lignaria which is a common kind of mason bee. Some people call them orchard bees. I saw quite a few of them buzzing around the last of the redbuds still in bloom. When a mason bee is ready to lay her eggs she looks for a hollow reed or hole in a tree. She will lay an egg and then build a tiny wall from clay or mud so that the egg sits safely in a little cell. Mind image: The Cask of Amontillado.
These bees only fly around in early spring for about about one month and then they will die. Any eggs laid now will take a year to fully develop.
You can encourage their presence by building bee hotels. I love this elaborate version but bees don’t mind simpler accommodations.
Orchard bees are a bright blue or green. They could be mistaken for blowflies because of the iridescent color but if you look closely you can see some big differences — especially in the head and eye area.
Blowflies may have icky beginnings (corpse maggots!) but the adults are pollinators. The native fruit tree Asimina triloba (paw paw) relies on blow fly presence. The flowers smell like rotten meat but they will eventually form huge fruit that tastes a bit like bananas or melons. The blowfly & paw paw partnership is another example of how even the ugly bits of the web of life have a purpose.
Now if only that were also true of internet trolls on the world wide web ….