I could see it both ways. Crustaceans are arthropods and this resembles a true bug about as much as a spider does, but I’ll give you that crustaceans are probably not top on people’s list of “looks like a bug.”

I lean towards using it for most kinds of “small invertebrate pest,” because those are the factors about bugs that I care about. Even a tiny, annoying hummingbird would only seem like a bug to me until I looked at it, but something with chitin almost always feels like it counts

Also called a pillbug. Okay, I'll defer to you - maybe sowbug lol a little flatter.

Bug is a taxonomic term? Fucking taxonomists. Taxonomy is a garbage pseudoscience that takes our living natural language and turns it into a dead, useless thing like their pinned up butterflies.