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.
Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.
Source: Variation In The Epiproct Of Arsapnia Decepta Banks, 1897 (Plecoptera: Capniidae), With Comments On Arsapnia Coyote (Nelson & Baumann 1987)
Tergal process (n = 2). Bearing a slight to moderate notch of posteromedian margin (Figs. 67 - 70). Dorsolateral lobes bearing patches of small conical tubercles. Width of process across anterior margin 200 - 280 µm.