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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.

Case view of a Pycnopsyche guttifera (Limnephilidae) (Great Autumn Brown Sedge) Caddisfly Larva from the Yakima River in Washington
It's only barely visible in one of my pictures, but I confirmed under the microscope that this one has a prosternal horn and the antennae are mid-way between the eyes and front of the head capsule.

I'm calling this one Pycnopsyche, but it's a bit perplexing. It seems to key definitively to at least Couplet 8 of the Key to Genera of Limnephilidae Larvae. That narrows it down to three genera, and the case seems wrong for the other two. The case looks right for Pycnopsyche, and it fits one of the key characteristics: "Abdominal sternum II without chloride epithelium and abdominal segment IX with only single seta on each side of dorsal sclerite." However, the characteristic "metanotal sa1 sclerites not fused, although often contiguous" does not seem to fit well. Those sclerites sure look fused to me, although I can make out a thin groove in the touching halves in the anterior half under the microscope. Perhaps this is a regional variation.

The only species of Pycnopsyche documented in Washington state is Pycnopsyche guttifera, and the colors and markings around the head of this specimen seem to match very well a specimen of that species from Massachusetts on Bugguide. So I am placing it in that species for now.

Whatever species this is, I photographed another specimen of seemingly the same species from the same spot a couple months later.
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 Leptophlebia nebulosa (Black Quills)

Where & when

Time of year : Early May through mid-June in Michigan; unknown elsewhere

This widely distributed but uncommon species generally hatches earlier than Leptophlebia cupida and is even more attracted to slow water.

In 39 records from GBIF, adults of this species have mostly been collected during April (28%), June (23%), May (23%), and July (23%).

In 9 records from GBIF, this species has been collected at elevations ranging from 3 to 3701 ft, with an average (median) of 660 ft.

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 Blasturus nebulosus
Body length: 10-12 mm
Wing length: 10-11 mm

This is a brownish black species with ringed abdomen and a pale brown cloud covering the tip of the fore wing. Face brown including antennae.

Thorax shining brown above and below, with somewhat paler sides, that area traversed by pale sutures. Fore legs reddish brown. Middle and hind legs yellowish. Wings hyaline with brown veins, and with a brownish cloud covering the apical third of the fore wing. Its straight inner margin lies one or two cells beyond the posterior fork of the radial sector. Costal cross veins faint except in the stigmatic area where they are crowded and irregular and slightly anastomosing. Hind wings wholly hyaline.

Abdomen brown, paler beneath, a little darker on segments 1 and 2 and again on 8 and 9; 10 a little paler than 9. Middle pale line very fine and partly interrupted. Oblique marks crescentic and isolated. Joinings of the middle segments whitish, giving the abdomen an obscurely ringed appearance. Tails pale brown, ringed with dark brown on the joinings. Middle tail one-fourth as long as the others.

Genitalia yellowish amber. Penes separated by a goblet-shaped cleft. Reflexed spur strongly bent and its dilated tip extending below the level of the cleft between the penes. Lobes of the forceps base separated by a sharply V-shaped cleft and subtruncate on their apices (see fig. 135).

This species seems to differ from cupidus (now a synonym of Leptophlebia cupida) by the apical brown cloud on the fore wings and by the more nearly uniform coloration of the abdominal segments. The alternating darker and lighter rings on the tails are very pronounced. The depth of color of the apical cloud of the fore wing varies markedly in different specimens.

Discussions of Leptophlebia nebulosa

Posted by Steamntrout on Jun 14, 2017
Last reply on Jun 14, 2017 by Steamntrout
Looking at Purdue's May Fly Central it shows nebulosa being found in Canada's Far North, North East and North West as well as USA's North East, South East & Far West.

Start a Discussion of Leptophlebia nebulosa


Mayfly Species Leptophlebia nebulosa (Black Quills)

Species Range
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