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Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

Ventral view of a Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Larva from the Yakima River in Washington
With a bit of help from the microscope, this specimen keys clearly and unsurprisingly to Hydropsyche.
27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
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Mayfly Species Anthopotamus distinctus (Golden Drakes)

Where & when

Time of year : Late June through August

Though present in the Midwest, this species is most important in the East, where it constitutes the Golden Drake hatch on the freestone streams of the Catskills and the mountain ranges of Pennsylvania.

It typically peaks in Pennsylvania in late June and early July, and in the Catskills a couple weeks later. There dates for this hatch can be unusually variable.

In 8 records from GBIF, adults of this species have been collected during July (50%), June (38%), and May (13%).

Species Range

Physical description

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.

Male Spinner

Described in Needham et al (1935) as Potamanthus distinctus
Body length: 11 mm
Wing length: 11 mm

Eyes of male moderately large; cross veins of both wings black; vertex, middle of pronotum, fore femur and tibia reddish; a continuous wide lateral purplish red abdominal stripe.

Vertex of head red, except a narrow yellow strip next to eye; bases of antennae reddish, filament pale. Ocelli pale greyish flushed with pink; dark-ringed at base. Eyes black, moderately large, separated by a space slightly greater than one diameter of eye. Pronotum yellowish, with wide red median dorsal stripe. Mesonotum yellowish red, scutellum paler. Pleura and sternum yellowish, somewhat flushed with pink. Metanotum yellowish white. Fore femur quite deep red, extreme base yellowish; tibia reddish, deeper in basal half, tinged with yellow apically, purplish black at tip; short basal tarsal joint purplish black, other joints yellow faintly tinged with reddish, claws and joinings blackish brown. Middle and hind legs yellow, claws tinged with fuscous. Wings hyaline; main longitudinal veins of costal margin yellow, other longitudinals pale yellowish white. Cross veins of both wings, except outer margin of hind wing and anal region of both wings, black.

Abdomen pale yellowish. A wide continuous purplish red stripe occupies lateral areas of abdominal tergites; posterior margins narrowly darker, within this stripe. Sternites unmarked. Genitalia yellowish. Tails yellowish, joinings distinctly reddish brown.

Female Spinner

Described in Needham et al (1935) as Potamanthus distinctus
Body length: 11 mm
Wing length: 11 mm

Female very similar to male. Wings faintly amber-tinged; cross veins black, in both wings. All markings as in male.

Start a Discussion of Anthopotamus distinctus


Mayfly Species Anthopotamus distinctus (Golden Drakes)

Species Range
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