Tiger bee fly

I've seen these insects before, but I've never bothered to identify them. Actually, I bothered to misidentify them, dismissing them, on the basis of their pictured wings, as some kind of a blood-letting deer fly. I assumed they might not mind taking some of my blood, so I gave them a wide-berth. That turned out to be silly, since, when I actually sat down to examine one of these rather beautiful flies—I'd stilled it by putting it overnight in the refrigerator—i quickly learned that what I saw as a flesh-sawing mouthpart was something else entirely. After considerable study, I discovered that what I had in front of my was yet another variety of Bee Fly, which are among my favorite insects. This one is the well-known Tiger Bee Fly, and it's harmful only to Carpenter Bees, whose larvae its larvae parasitize. I'm assuming that when my temporary-guest member of the Xenox tigrinus clan warmed up and departed, it was intending to resume its species-continuing mission.