Hex Mayflies
Hexagenia limbata
The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
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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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Caddisfly Genus Cheumatopsyche (Little Sister Sedges)
To generalize broadly, Cheumatopsyche is found lower in the watershed than the similar genera Hydropsyche and Ceratopsyche. It is also smaller, but there is wide variation in size and color between the species. See the family Hydropsychidae page for life cycle details common to these genera.
The most important trout stream species are Cheumatopsyche campyla and Cheumatopsyche pettiti.
The most important trout stream species are Cheumatopsyche campyla and Cheumatopsyche pettiti.
Where & when
In 1233 records from GBIF, adults of this genus have mostly been collected during June (28%), July (22%), May (17%), August (15%), April (7%), and September (7%).
In 444 records from GBIF, this genus has been collected at elevations ranging from 10 to 9186 ft, with an average (median) of 2690 ft.
Genus Range
Specimens of the Caddisfly Genus Cheumatopsyche
1 Male Adult
I didn't identify this one directly, but I eventually identified one of several I collected from the same swarms that appeared to be of the same species. (I lost track of which specimen was which in storage.) The microscope pictures come from one of these specimen, not necessarily the same specimen as the DSLR pictures. They key to Cheumatopsyche, and the hind wing venation that separates them from Hydropsyche is pretty clear in the attached picture as well as another specimen I checked under the scope.
This specimen was one of tens of thousands we saw on a July 1st evening on the Madison, beginning with big swarms around every vehicle and tree at the Eight Mile Ford access point and continuing all up and down the river bank. We somehow didn't catch any trout, perhaps because they were stuffed with pupae from when these things emerged. Or maybe we just weren't fishing well. Either way, this one represents a major hatch there.
I somehow forgot to photograph this important specimen against the hooks size chart, but fortunately I preserved a few. The body length is about 6 mm, and total length from head to wingtip is 9 mm.
This specimen was one of tens of thousands we saw on a July 1st evening on the Madison, beginning with big swarms around every vehicle and tree at the Eight Mile Ford access point and continuing all up and down the river bank. We somehow didn't catch any trout, perhaps because they were stuffed with pupae from when these things emerged. Or maybe we just weren't fishing well. Either way, this one represents a major hatch there.
I somehow forgot to photograph this important specimen against the hooks size chart, but fortunately I preserved a few. The body length is about 6 mm, and total length from head to wingtip is 9 mm.
2 Female Adults
This one has a body a little bit over 6 mm long.
1 Adult
3 Pupae
This is the first fully formed caddis pupa (technically, a pharate adult) that I've collected and photographed alive and healthy. I'll put a video of this specimen online soon, too.
I photographed this one recently dead. It's hard to keep caddis pupae alive for very long in a collection container.
I was surprised how bright green this pupa is. It's chartreuse. After collecting it, I experimented with melting down chartreuse jigs and making little translucent rubber caddis abdomens on my flies. They looked good, and the trout liked them, but they weren't very durable at all. This specimen is recently deceased in the photographs.
Start a Discussion of Cheumatopsyche
References
- LaFontaine, Gary. 1981. Caddisflies. The Lyons Press.
- Swisher, Doug and Carl Richards. 2000. Selective Trout. The Lyons Press.
Caddisfly Genus Cheumatopsyche (Little Sister Sedges)
Taxonomy
Species in Cheumatopsyche
Cheumatopsyche campyla
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Cheumatopsyche etrona
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Cheumatopsyche gracilis
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Cheumatopsyche harwoodi
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Cheumatopsyche lasia
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Cheumatopsyche pasella
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Cheumatopsyche pettitiCaddisflies
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Cheumatopsyche sordida
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Cheumatopsyche speciosa
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Species in Cheumatopsyche: Cheumatopsyche campyla, Cheumatopsyche etrona, Cheumatopsyche gracilis, Cheumatopsyche harwoodi, Cheumatopsyche lasia, Cheumatopsyche pasella, Cheumatopsyche pettiti, Cheumatopsyche sordida, Cheumatopsyche speciosa
35 species (Cheumatopsyche analis, Cheumatopsyche aphanta, Cheumatopsyche arizonensis, Cheumatopsyche bibbensis, Cheumatopsyche burksi, Cheumatopsyche cahaba, Cheumatopsyche comis, Cheumatopsyche edista, Cheumatopsyche ela, Cheumatopsyche enonis, Cheumatopsyche flinti, Cheumatopsyche gelita, Cheumatopsyche geora, Cheumatopsyche gordonae, Cheumatopsyche gyra, Cheumatopsyche halima, Cheumatopsyche helma, Cheumatopsyche kinlockensis, Cheumatopsyche logani, Cheumatopsyche mickeli, Cheumatopsyche minuscula, Cheumatopsyche mollala, Cheumatopsyche morsei, Cheumatopsyche oxa, Cheumatopsyche parentum, Cheumatopsyche petersi, Cheumatopsyche pinaca, Cheumatopsyche pinula, Cheumatopsyche richardsoni, Cheumatopsyche rossi, Cheumatopsyche smithi, Cheumatopsyche vannotei, Cheumatopsyche virginica, Cheumatopsyche wabasha, and Cheumatopsyche wrighti) aren't included.