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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.

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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Caddisfly Genus Pycnopsyche (Great Autumn Brown Sedges)

Where & when

In 350 records from GBIF, adults of this genus have mostly been collected during September (35%), August (29%), October (18%), and July (12%).

In 119 records from GBIF, this genus has been collected at elevations ranging from 7 to 12631 ft, with an average (median) of 1513 ft.

Genus Range

Hatching behavior

Time of day : Nighttime; sometimes dusk or early morning

The pupae emerge by crawling out onto shore.

Egg-Laying behavior

Time of day: Nighttime; sometimes dusk or early morning

The females land on shoreline objects and crawl underwater to lay their eggs.

Larva & pupa biology

Diet: Decaying leaves

Shelter type: Twigs arranged lengthwise

This genus is remarkably specific in its adaptation to its sole source of food, fallen leaves. Gary LaFontaine describes its relationship very well in Caddisflies:

Their life cycle is completely synchronized with this food source -- the eggs hatch in the fall, just as the deciduous trees are shedding their foliage; the larvae feed and grow throughout the winter and spring, until early summer when the high water flushes away the accumulations of decaying leaves; the larvae enter diapause, a quiescent period, sealing off their cases, once their food source is diminished; they remain in this inactive state until they pupate in late summer; emergence, mating, and egg laying occurs in early fall, producing a new generation in time for the next input of leaves.

Specimens of the Caddisfly Genus Pycnopsyche

3 Larvae

Discussions of Pycnopsyche

Great Autumn Brown Sedges on Potomac River
3 replies
Posted by BrettB on Oct 2, 2008
Last reply on Oct 3, 2008 by GONZO
Came in to work today and noted several large Autumn sedges on doors facing river(18mm wing-to-head and 34mm total w/ antennae). Though more brownish-rusty than I remember them being, I'm relatively certain it is a Pycnopsyche due to the size, timing and dark markings near the rear mid-wing (sort of looks like a yin-yang symbol). Does anyone know of a good emerger fly for this hatch? I'm assuming it emerges in the evening through early morning. I may tie up some size 8 rusty elk hair caddis for adult imitations. Big bugs!

Start a Discussion of Pycnopsyche


Caddisfly Genus Pycnopsyche (Great Autumn Brown Sedges)

14 species (Pycnopsyche aglonus, Pycnopsyche antica, Pycnopsyche circularis, Pycnopsyche conspersa, Pycnopsyche divergens, Pycnopsyche flavata, Pycnopsyche gentilis, Pycnopsyche indiana, Pycnopsyche limbatus, Pycnopsyche luculentus, Pycnopsyche rossi, Pycnopsyche sonso, Pycnopsyche subfasciata, and Pycnopsyche virginica) aren't included.
Genus Range
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