Header image
Enter a name
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.

Dorsal view of a Kogotus (Perlodidae) Stonefly Nymph from Mystery Creek #199 in Washington
This one pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.
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.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

Alderfly Genus Sialis

Alderflies are typically mistaken for small hellgrammites as larvae and large caddisflies as adults. They turn up often enough in nymph samples that it's nice to know what they look like. There are rumors of their occasional importance to trout, but the average anglers is not likely to encounter it.

Where & when

Time of year : Early season

In 294 records from GBIF, adults of this genus have mostly been collected during April (35%), May (27%), June (25%), and July (8%).

In 85 records from GBIF, this genus has been collected at elevations ranging from 495 to 11526 ft, with an average (median) of 3182 ft.

Genus Range

Hatching behavior

Time of day : Evening

Pupae burrow into the ground near to, but not in, the stream. Because the emergence takes place on land it is unimportant to trout.

Egg-Laying behavior

Time of day: Daytime

The mating adults gather over the water in good numbers but do not usually fall into the water unless wind knocks them off course.

They lay their eggs on dry objects near the water. Ernest Schwiebert describes their egg placement in Matching the Hatch:

The egg masses are deposited on rocks, limbs, leaves and bridges where they are over running water and in the sunlight. They are placed so that the hatching larvae fall into the stream.

Larva & pupa biology

Current speed: Slow

Substrate: Silt

The larvae are burrowers like the Ephemeridae mayfly nymphs, digging down into the silt.

Specimens of the Alderfly Genus Sialis

1 Male Adult
4 Larvae

Start a Discussion of Sialis

References

  • Brigham, W.U., A.K. Brigham, and A. Gnilke. 1982. Aquatic Insects and Oligochaetes of North and South Carolina. Midwest Aquatic Entomologist.
  • Schwiebert, Ernest G. 1955. Matching the Hatch. MacMillan Publishing Company.

Alderfly Genus Sialis

Taxonomy
Species in Sialis
Sialis hamata
1
2
Species in Sialis: Sialis hamata
23 species (Sialis aequalis, Sialis americana, Sialis arvalis, Sialis bilobata, Sialis californica, Sialis concava, Sialis contigua, Sialis cornuta, Sialis dreisbachi, Sialis glabella, Sialis hasta, Sialis infumata, Sialis iola, Sialis itasca, Sialis joppa, Sialis mohri, Sialis nevadensis, Sialis nina, Sialis occidens, Sialis rotunda, Sialis spangleri, Sialis vagans, and Sialis velata) aren't included.
Genus Range
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy