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.
Radial sector: The radial sector (denoted Rs) is a group of longitudinal wing veins that normally branch posteriorly off the radius, but in mayflies usually appears detached at the base, looking like a separate vein rather than a branch. In some mayflies, especially in hind wings, it may even branch off of vein MA instead. It may have up to four branches (denoted R2 through R5) reaching the wingtip, with intercalaries in between. Vein Rs and all its attached branches are furrow veins (–), but their intercalaries can be ridge veins.
These other words reference the same concept: vein Rs, Rs vein, Rs.
