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.
This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
Radius: The radius (denoted R) is the third major longitudinal wing vein in insects. In caddisflies, its principal branch R1 runs nearly parallel to the front wing edge for most of its length and may be very close to the subcosta.
These other words reference the same concept: radial, first radial vein, vein R1, R1 vein, R1, R, vein R, R vein.
