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.
This is another brown and white species with all appendages white. It is a little smaller than P. mollis (now a synonym of Neoleptophlebia mollis) and emerges a little later in the season. It differs from that species in having the abdominal spiracles marked with brown dots. The penes are appressed (thus eliminating an intervening cleft), and the thin, lateral lobes at the apex are broader and more extensively up-reared, with the sharp external points wider apart (see fig. 133).