I have the hardest time differentiating between the three: Scaphytopius, Polyamia, and Scaphoideus. I know they are all in different tribes, but somehow they confuse me to no end. Any suggestions?

At least from what I've seen:

Most Scaphytopius species have a very fine-grained pattern in which the individual forewing cells and venation aren't readily apparent, and the forewings appear pretty uniformly dark, even up close. Exceptions include the distinctive S. elegans.

In most Polyamia, the forewing pattern consists of fairly solid-colored cells bordered by bold pale veins, making the cells and venation very easy to see. Exceptions include the distinctive P. apicata.

Scaphoideus have a toothlike marking pointing forward on top of the head, and they have more-twisty veins near the apex of the forewings.

Polyamia tends to have a really different coloration pattern, more spotted, and is smaller. Scaphytopius has a longer, more pointed head than Scaphoideus, which is usually larger.

Thanks for the insights-- I will keep those descriptions jotted down in my notes, for sure. Super appreciate it, Kyle and John!