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.
Time of year : May-July, often best in June.
Preferred waters: Perhaps most common in mountain streams, but especially good in some alkaline spring creeks.
In 16 records from GBIF, adults of this species have been collected during June (31%), July (25%), May (13%), October (13%), April (6%), September (6%), and February (6%).
In 2 records from GBIF, this species has been collected at elevations of 200 and 341 ft.
Time of day: Near dusk
Habitat: Riffles are preferred, but on spring creeks without riffles any broken water will do.
Current speed: Some in riffles and runs, but best in slower stream sections and pools.
Substrate: Gravel, sand, vegetation
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 small very pale species, of the Ephemerella invaria group; the second joint of the forceps enlarged distally; 12-14 spines on the penes.
Eyes of male bright red. Thorax and legs pale yellowish. Wings hyaline, iridescent, the venation wholly pale. Abdomen pale yellowish. Tails white, without dark markings. Genitalia yellowish, the second joint of the forceps enlarged distally. Spines on the penes number from 12 to 14, and are usually ventral and lateral in position (see fig. 152).
The small yellowish brown nymph is speckled with pale dots. The lateral extensions of the abdomen are poorly developed, the postero-lateral spines short except on segments 8 and 9. There are no dorsal spines on the abdomen. Claws are strongly curved; each bears 8-9 denticles. Tails pale, rather darker at the tips; may be faintly banded.