Butterflies, Moths, and...?

Fall semester starts Tuesday, and hawkwatch starts Saturday, so it's about time I put something up. Here's a little selection of moths from this month:

This is a Primrose Moth (Schinia florida):

This one's a Bleeding Flower Moth (Schinia sanguinea):

And this one's a Polymorphic Pondweed Moth (Parapoynx maculalis):

These guys might well make one ask "Why are these moths and not butterflies?" Which might well lead to the question "What IS a moth, anyways?" and "What is a butterfly?" The first version of the answer is, they're all insects in the order Lepidoptera. Wonder of wonders, they're also all of the Lepidoptera; everything in this order is called either a butterfly or a moth. (Well, sort of... more on that in a moment.)

One of the older butterfly guides had an intro where the author tried to answer the question "What is a butterfly?" by saying, roughly, that a butterfly was brightly colored and flew in the daytime. But of course, some things we call moths fit this very nicely. He then pointed out that he's seen crepuscular butterflies in the tropics, so it's not an easy question at all. And if we're using color as a criterion, then what do we make of this guy?


This is a Hackberry Emperor (Asterocampa celtis).

And this is a Common Checkered Skipper (Pyrgis communis):

This last one is the sort of... And that gets us into the heart of the issue. The skippers have been considered a separate suborder, and currently are listed as a superfamily within the Rhopalocera, along with the butterflies (also a superfamily). Most sources do call them butterflies, in any case. The Rhopalocera, though, is listed as one suborder within the Macrolepidoptera, which includes 4 other superfamilies. Although the Macroleps include 60% of the species in the Lepidoptera, they actually include a minority of the superfamilies (and families, not coincidentally). All of those other superfamilies are called moths!

So, what's a butterfly? It's something in the Rhopalocera, possibly excluding the skippers. What's a moth? Any lepidopteran that isn't a butterfly! (Or a skipper....)

Things were often much simpler before we started doing proper phylogenetic analyses, but I'd rather deal with the complications if it means a better understanding of where things came from.