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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives
Baetis

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

Dorsal view of a Grammotaulius betteni (Limnephilidae) (Northern Caddisfly) Caddisfly Larva from the Yakima River in Washington
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.
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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Hesperophylax (Silver Striped Sedge) Caddisfly Larva Pictures

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.

Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Case view of a Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Ruler view of a Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington The smallest ruler marks are 1 mm.
Dorsal view of a Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Ventral view of a Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington
Hesperophylax (Limnephilidae) (Silver Striped Sedge) Caddisfly Larva from the South Fork Snoqualmie River in Washington

This caddisfly was collected from the South Fork Snoqualmie River in Washington on June 13th, 2019 and added to Troutnut.com by Troutnut on June 15th, 2019.


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Hesperophylax (Silver Striped Sedge) Caddisfly Larva Pictures

Collection details
Location: South Fork Snoqualmie River, Washington
Date: June 13th, 2019
Added to site: June 15th, 2019
Author: Troutnut
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