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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This is a striking caddis larva with an interesting color pattern on the head. Here are some characteristics I was able to see under the microscope, but could not easily expose for a picture:
- The prosternal horn is present.
- The mandible is clearly toothed, not formed into a uniform scraper blade.
- The seems to be only 2 major setae on the ventral edge of the hind femur.
- Chloride epithelia seem to be absent from the dorsal side of any abdominal segments.
Based on these characteristics and the ones more easily visible from the pictures, this seems to be Grammotaulius. The key's description of the case is spot-on: "Case cylindrical, made of longitudinally arranged sedge or similar leaves," as is the description of the markings on the head, "Dorsum of head light brownish yellow with numerous discrete, small, dark spots." The spot pattern on the head is a very good match to figure 19.312 of Merritt R.W., Cummins, K.W., and Berg, M.B. (2019). The species ID is based on Grammotaulius betteni being the only species of this genus known in Washington state.
- The prosternal horn is present.
- The mandible is clearly toothed, not formed into a uniform scraper blade.
- The seems to be only 2 major setae on the ventral edge of the hind femur.
- Chloride epithelia seem to be absent from the dorsal side of any abdominal segments.
Based on these characteristics and the ones more easily visible from the pictures, this seems to be Grammotaulius. The key's description of the case is spot-on: "Case cylindrical, made of longitudinally arranged sedge or similar leaves," as is the description of the markings on the head, "Dorsum of head light brownish yellow with numerous discrete, small, dark spots." The spot pattern on the head is a very good match to figure 19.312 of Merritt R.W., Cummins, K.W., and Berg, M.B. (2019). The species ID is based on Grammotaulius betteni being the only species of this genus known in Washington state.
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Caddisfly Genus Hesperophylax (Silver Striped Sedges)
These are very large caddisflies, up to 1.3 inches long as adults.
Where & when
Time of year : Emergence in summer, egg-laying in fall
In 248 records from GBIF, adults of this genus have mostly been collected during July (23%), August (21%), June (18%), September (13%), May (12%), and October (6%).
In 139 records from GBIF, this genus has been collected at elevations ranging from 3 to 31496 ft, with an average (median) of 6289 ft.
Genus Range
Hesperophylax Fly Fishing Tips
LaFontaine notes in Caddisflies that the adults are worth imitating, and they make a good searching pattern, but he does not give specifics about their behavior.Specimens of the Caddisfly Genus Hesperophylax
1 Female Adult
1 Larva
Based on both range maps and key characteristics, this larva is either Hesperophylax designatus, Hesperophylax alaskensis, or Hesperophylax occidentalis. However, the species key in Parker & Wiggins (1985) cannot separate these species as larvae.
Start a Discussion of Hesperophylax
References
- LaFontaine, Gary. 1981. Caddisflies. The Lyons Press.
- Merritt R.W., Cummins, K.W., and Berg, M.B. 2019. An Introduction to the Aquatic Insects of North America (Fifth Edition). Kendall/Hunt Publishing Company.
- Parker, C. R., Wiggins, G. B. 1985. The Nearctic Caddisfly Genus Hesperophylax Banks (trichoptera: Limnephilidae). Canadian Journal of Zoology 63(10): 2443-2472.
- Swisher, Doug and Carl Richards. 2000. Selective Trout. The Lyons Press.
Caddisfly Genus Hesperophylax (Silver Striped Sedges)
Taxonomy
Species in Hesperophylax
Hesperophylax designatus
1
1
Species in Hesperophylax: Hesperophylax designatus
5 species (Hesperophylax alaskensis, Hesperophylax consimilis, Hesperophylax magnus, Hesperophylax minutus, and Hesperophylax occidentalis) aren't included.