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

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

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 Procloeon simplex (Tiny Sulphur Duns)

Where & when

Time of year : Midsummer

In 8 records from GBIF, adults of this species have been collected during June (50%), August (38%), and July (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 Cloeon simplex
Body length: 4.5 mm
Wing length: 5 mm

Abdominal tergites 2-6 of male imago pale whitish hyaline; traces of a black spiracular hair-line.

Turbinate eyes light green in living insect, pale orange-yellow in dried specimen, base deep brown. Head and thoracic notum dark blackish brown; posterior margin of pronotum creamy with a ruddy brown dot; antero-lateral margins of mesonotum paler brown, its posterior margin, the scutellum, and a small patch anterior to it, creamy. Anterior margin of metanotum creamy; pleura largely creamy, with tinges of ruddy brown. Prosternum whitish; mesosterna and metasterna largely brown, the central and lateral areas with creamy shading. Legs wholly pale whitish. Wings hyaline, venation pale; 6 to 7 cross veins in the stigmatic area, no granulations between them. Intercalaries of the 1st and 2nd interspaces wanting. First cross vein between radius and radial sector in a line with the following one.

Abdominal segments 2-6 pale hyaline whitish, with traces of a black hair-line along the spiracular area. Tergites 7-10 opaque, bright chestnut brown, with creamy lateral shading; posterior portion of 10 also creamy. Sternites wholly pale creamy. Tails and forceps white.

The paler eyes, pale thoracic markings and lack of red dots on the abdominal tergites distinguish this species from C. rubropictum (now a synonym of Procloeon rubropictum). The wholly pale legs separate it from C. vicinum (now a synonym of Procloeon vicinum), in which the bases of the fore legs are fulvous.


Start a Discussion of Procloeon simplex

References

Mayfly Species Procloeon simplex (Tiny Sulphur Duns)

Taxonomy
Species Range
Common Name
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