These large moths were pretty plentiful back in June (as in, I saw about a dozen of them this year). This particular one was attracted by the light from our back door at the time. The blue on their body is actually very iridescent (an effect that I have a hard time capturing on camera).

This is a Ctenucha virginica, a type of large “wasp moth”. For size reference, it is resting on a playing card [1]. There are a couple of things about the name that are a problem. First, how the heck are you supposed to pronounce “Ctenucha”?[2] Second, the name “virginica” leads one to believe that they are a southern species, with Virginia being somewhere in the middle of their range. This is a lie. It turns out that they are a northern species, common in the northern US and Canada (and here, of course), and Virginia is the extreme southern portion of their range.

There is a similar species, the “Yellow-Collared Scape Moth[3]” (Cisseps fulvicollis) that can be mistaken for this one, except that Cisseps fulvicollis has a larger orange patch that runs straight across the thorax, while Ctenucha virginica has a smaller orange patch that kind of “drapes around the shoulders”

Based on the size of the antennae, I expect that this one is a male (since male moths tend to have larger, featherier antennae so that they can track down the scent of the females). I’ve seen them flying around in broad daylight, and this one was drawn to a light during the night, so they evidently don’t much care about what time of day they are out hunting for food (the adults drink nectar from flowers). They are pretty strikingly visible during the day, so they must have some defense against getting eaten, but I don’t know what it is[4].

Anyway, according to BugGuide, the larvae “feed on monocots: grasses, sedges, iris”, which seems to me to be a weird list. Why iris? And will they eat any grass (keeping in mind that things like corn can be considered grasses), or just the sorts of species that people use for lawns?

Edit: Much later, I found and photographed the caterpillar, which I posted about here. The caterpillar is pretty distinctive, too.

——————
[1] I mainly used the card because it was hard to get good contrast of a black moth against any sort of dark background. It was the Ace of Diamonds from a “bicycle” deck, if anyone wants to get the scale by measuring the visible diamond symbol. It was big enough that I couldn’t easily use the high-magnification “macro” lens, because it wouldn’t all fit into the picture.

[2] If this were in Esperanto, then I would pronounce the “C” as if it were a “Ts” sound, but it isn’t in Esperanto. So, I don’t know if it is pronounced “ts”, “k”, “s”, “ch”, or, for all I know, “xyzzy”

[3] Whoever came up with the common name for this evidently had the same color naming convention as my father. We had one of those orange “outdoor” extension cords, that he consistently referred to as the “yellow extension cord”. And now, when somebody calls something “yellow” that is clearly orange, I don’t even register that they called it the wrong color.

[4] One possibility, given that they are referred to as a type of “wasp moth”, is that they look enough like a wasp that predators don’t want to tangle with them. I kind of doubt this, though, because they don’t look *that* much like a wasp.