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.
This is the first of it's family I've seen, collected from a tiny, fishless stream in the Cascades. The three species of this genus all live in the Northwest and are predators that primarily eat stonefly nymphs Merritt R.W., Cummins, K.W., and Berg, M.B. (2019).
Anal vein: The anal veins (denoted 1A through 5A in caddisflies) are longitudinal veinsposterior to the cubitus. Caddisfly forewings have 3 anal veins, which typically coalesce into a single vein reaching the wing margin, forming a characteristic forked shape. Caddisfly hind wings have 1 to 5 anal veins, which all reach the wing margin.
These other words reference the same concept: anal veins, vein 1A, 1A vein, 1A, vein 2A, 2A vein, 2A, vein 3A, 3A vein, A3, vein 4A, 4A vein, A4, vein 5A, 5A vein, A5.