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.
A dark reddish brown species with amber wings.
Head and thorax blackish. Fore legs deep blackish brown, the tarsi somewhat paler. Femora of middle and hind legs brown; tibiae somewhat paler, more golden brown. Wings unicolorous deep amber; cross veins very numerous. About 14 costal cross veins before the bulla, and 23 or more beyond it; many of the latter are anastomosed.
Abdomen deep reddish brown, the last sternite and the forceps base blackish. Forceps paler brown. Penes united only at the extreme base, long and slender and bent outwards slightly at the tip; appear distinctly U-shaped (see fig. 135). Tails pale smoky brown.