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.
Third radial vein: The third radial vein (denoted R3) is the middle branch of the radial sector. It is sometimes unattached to the base of rs, making it difficult to distinguish from intercalaries except by looking at the fluting. It is a furrow vein (–).
These other words reference the same concept: vein R3, R3 vein, R3.
