The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
I have never seen this name used in the scientific literature or in books for anglers, but apparently—at least for kids—the common name "periwinkle" is sometimes used to refer to cased caddisfly larvae.
This common name refers to only one order. Click its scientific name to learn more.