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.
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: Revision of the genus Culoptila (Trichoptera: Glossosomatidae)
Adult. Length of forewing: male 2.8 – 3.2 mm; female 3.2 – 3.8 mm. Color yellowish-brown in alcohol, appendages paler; wing uniformly colored, without evidence of cross bar. Mesothorax of male narrow and greatly acute anteromesally; mesoscutal wart elongate, narrowed, sharply angulate anteromesally; mesoscutal setae long. Mesothoracic tegulae of male rounded, greatly enlarged; tegular setae long; tegular gland elongate, pleated, concertina-like. Male genitalia. Sternum VI process short, subtruncate. Tergum IX ventral margin rounded, tapered from anterolateral margin, slightly produced posteroventrally. Inferior appendages short, subtruncate apically. Tergum X short, about as long as wide, apex in ventral view truncate to subtruncate; ventrolateral processes with apices incurved, nearly planar in caudal view, mesal margin acute; apices not or scarcely posteriorly bent. Phallobase large, rounded anteriorly, with dorsal and ventral margins subparallel, apicodorsal projection short, with slight upward inflection at base, apex subacute. Phallic apparatus with 2 phallic spines, subequal in length, about 1 / 2 length of phallobase, strongly sinuously curved.