Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
Media: The media (denoted M) is the fourth major longitudinal wing vein in insects, located behind the radial sector. It can split into up to four branches denoted M1 through M4 from front to back. Smaller number of branches may be numbered as combinations of these potential branches, such as M3+4.
These other words reference the same concept: vein M, M vein, M, M1, M2, M3, M4, M1+2, M3+4, vein M1, vein M2, vein M3, vein M4, vein M1+2, vein M3+4, M1 vein, M2 vein, M3 vein, M4 vein, M1+2 vein, M3+4 vein.