The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
In 8 records from GBIF, adults of this species have been collected during June (63%), July (25%), and April (13%).
Environmental tolerance: Tolerant of warm water
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 reddish brown species with the thorax blackish above. Fore legs reddish brown except the tarsi which are paler, as also are middle and hind legs. Wings hyaline with the longitudinal veins a little tinged with brown as are also the cross veins of the stigmatic area. The latter are irregular, somewhat branching, twelve to sixteen in number.
Abdomen brownish with darker lines across the joinings of the middle abdominal segments. Tails dingy whitish, becoming ferruginous basally. The long joint of the forceps is conical at base and parallel sided for half its length, then slowly tapering to the apex. The third joint is about half as long as the second. The broadly U-shaped notch between the penes is almost closed by a pair of hyaline, oblong, broad, flat, obliquely converging lobes that extend most of their length beyond the chitinized tip. They thus give the cleft a flask-shaped outline (see fig. 133). External to these the apex is obliquely truncate, the shorter external angle ending in a sharp backwardly-directed tooth. The reflexed spur is hyaline, semi-elliptical with a straightish external and a convex internal margin and rather acute apex. It is a little longer than the middle cleft is deep. The lobes of the divided tenth sternite are very broadly triangular and rounded on the ends.
Described as P. invalida
Body length 6-7 mm, wing length 7 mm
This is an all brown species, with faintly-ringed abdomen. Thorax shining brown above and beneath a little paler on the sides before the wing roots and about the leg bases. Legs nearly uniform, paler brown only a little darker on the fore femora and knee joints. Wings hyaline, the membrane iridescent, the three long veins of the front brown, the others nearly colorless, as are all the cross veins except those of the stigmatic area. These are about ten in number, simple and oblique.
Abdomen brown, only a little paler below, and narrowly on the joinings of the middle segments. Segments 7 to 10, darker; forceps and penes paler. The cleft between the penes is linear U-shaped. The pale end lobe and the external end tooth are minute, and the reflexed spur is short, with an outcurving acute point (see fig. 135). Tails very pale brown, with very faint indication of darker joinings on basal segments.