Am I in the right place? ("I" being the fly, of course) I wasn't originally even sure of this beast's family; I originally thought Bombyliid but the mouthparts were wrong, more syrphid-like. Descriptions with other BugGuide entries of this species mention mimicking Carpenter Bees, which this one sure does, and breeding in cactus, which we definitely have around here; and the species name fits too, we're definitely near Mexico. The one thing that worries me is that other photos here all show big white patches around the wing bases (halteres?), which mine doesn't seem to have.