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 specimen keys pretty easily to Onocosmoecus, and it closely resembles a specimen from Alaska which caddis expert Dave Ruiter recognized as this genus. As with that specimen, the only species in the genus documented in this area is Onocosmoecus unicolor, but Dave suggested for that specimen that there might be multiple not-yet-distinguished species under the unicolor umbrella and it would be best to stick with the genus-level ID. I'm doing the same for this one.
Anal cell: The anal cell (denoted ac) is a cell formed by crossveins closing the space between anal veins, including sometimes at their bases, creating of a loop from which the veins appear to arise. Some sources may refer to the two cells basal of the one labeled in the forewing illustration as the first and second anal cells.
These other words reference the same concept: anal cells, first anal cell, first anal cell, second anal cell, second anal cell.
