Identificaciones de rodrigodios

I'm always surprised at how tiny, boring (to me) white flowers can whip the pollinators into a frenzy. My deciduous holly is blooming and it is seething with all sorts of little bees, strange flies, exotic wasps, and the occasional small butterfly.

One or two of these large (small bumble-bee sized) black and yellow flies zipped in and out of the holly bushes. They liked to feed on flower clusters hidden down in the leaves and never stayed still for long.