Polleniidae
Cluster Flies (Pollenia sp.)
There are six species of cluster flies in North America, some or all are European in origin. Their larvae are earthworm parasitoids, but they also have been found in caterpillars and bees.
They are one of the first insects to be seen in the spring. I saw some in the garden on 3 Mar 2021.
The species are hard to ID from photos.