Salmonflies
Pteronarcys californica
The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
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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.
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.
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Speckled Duns
This common name refers to only one genus. Click its scientific name to learn more.
Mayfly Genus Callibaetis
These are pretty much always called Speckled Duns.
The speckle winged Callibaetis genus contains on average the largest species in the Baetidae family with hatches ranging in size from 20 to 12 (6mm to 12mm). However, most can be matched with 14 and 16 imitations. They reside only in very slow weedy sections of rivers or lakes and ponds.
The most important are the sub-species Callibaetis ferrugineus ferrugineus in the East and Midwest and Callibaetis ferrugineus hageni in the West. It is in the West however, where this genus achieves its densest populations and most significant hatches. Other important western species also happen to be at both sides of the size scale. The outsized Callibaetis californicus can produce excellent hatches. The diminutive Callibaetis pictus can also be locally prolific, especially at higher elevations.
The duns are easily recognized by their speckled bodies and distinctive wings usually featuring a dark background overlaid with white veins. Female spinners are also easy to recognize with their clear wing's leading edges marked with dark blotches -- see the pictures.
The most important are the sub-species Callibaetis ferrugineus ferrugineus in the East and Midwest and Callibaetis ferrugineus hageni in the West. It is in the West however, where this genus achieves its densest populations and most significant hatches. Other important western species also happen to be at both sides of the size scale. The outsized Callibaetis californicus can produce excellent hatches. The diminutive Callibaetis pictus can also be locally prolific, especially at higher elevations.
The duns are easily recognized by their speckled bodies and distinctive wings usually featuring a dark background overlaid with white veins. Female spinners are also easy to recognize with their clear wing's leading edges marked with dark blotches -- see the pictures.
These adults are probably C. ferrugineus.
This nymph was one of a horde I could see cruising the still shallows of a cold tailwater, mixed in with an intense emergence of duns. It's one of four specimens I photographed together from the same hatch, also including a male dun, a female dun, and a male spinner.
This nymph keys to either Callibaetis ferrugineous or Callibaetis pallidus. The lack of a darkened preapical band on the femora would suggest pallidus, but I can't definitively make out the "single seta" on the outer, ventral apex of any of the tarsi, the length of which is supposedly a more reliable characteristic to tell the species spart. I can maybe make something out on one of the legs at the highest magnification, and its dimensions would suggest ferrugineous.
This nymph keys to either Callibaetis ferrugineous or Callibaetis pallidus. The lack of a darkened preapical band on the femora would suggest pallidus, but I can't definitively make out the "single seta" on the outer, ventral apex of any of the tarsi, the length of which is supposedly a more reliable characteristic to tell the species spart. I can maybe make something out on one of the legs at the highest magnification, and its dimensions would suggest ferrugineous.
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