It’s not often that I see an insect that completely stumps me, especially on my regular morning walk in my own neighborhood. However, this morning I noticed a large(ish) brown insect lumbering across the road, and my first reaction was “What the heck is that?!” Initially I thought it was some kind of beetle, but when I bent down and got a closer look at it, I saw that it was actually some kind of fly. But what kind – I’d never seen anything like it before.

It took a little sleuthing, but eventually I determined its identity as Coenomyia ferruginea—the so-called “stink fly” in the family Xylophagidae. I’d never heard of this family before, probably because they formerly were considered a subfamily of the family Rhagionidae (snipe flies), which together are thought to be a sister group to the family Tabanidae (horse and deer flies) and it’s relatives. Like those other groups, xylophagid larvae are thought to be scavengers or predators, some of them doing so in dead and decaying wood as predators of wood-boring larvae (the name “Xylophagidae” means “eats wood”).

Sadly, the fly’s slow and clumsy movements lulled me into a sense of complacency—I had picked it up to bring back home and put in my collection, but such thoughts quickly evaporated when it suddenly took flight and drifted slowly up and into the canopy before disappearing from sight.

©️ Ted C. MacRae 2023