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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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Dorsal view of a Limnephilidae (Giant Sedges) Caddisfly Larva from unknown in Wisconsin
GONZO
Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on Oct 14, 2006October 14th, 2006, 8:34 am EDT
Jason-

I just can't convince myself that either of the larvae pictured in this section are Brachycentridae. The cases don't conform to any I know (usually tapered four-sided "log cabin" cases for most Brachycentrus or smaller tapered round cases for Micrasema and Amiocentrus).
Troutnut
Troutnut's profile picture
Administrator
Bellevue, WA

Posts: 2758
Troutnut on Oct 14, 2006October 14th, 2006, 9:44 am EDT
You're probably right. These larvae were from the old site and I mostly had identifications based on various helpful emails I've since lost track of. So I don't remember what the rationale was.

That's why the new site has this comment system on the specimens: to keep a public record of the identification talk.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
GONZO
Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on May 22, 2008May 22nd, 2008, 11:01 am EDT
This is another specimen that has bothered me for some time. The fourth picture in the sequence seems to show a dorsal hump. I'm guessing that this is another limnephilid. Creno, help me out here!
Creno
Grants Pass, OR

Posts: 302
Creno on May 22, 2008May 22nd, 2008, 1:25 pm EDT
Gonzo - Sorry I cannot help much other than agree with you it is not a brachycentrid. Looks like a limnephilid to me. I can't get a good enough view of gills or legs to get any closer.

dave
GONZO
Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on May 22, 2008May 22nd, 2008, 2:14 pm EDT
Fair enough. Thanks, Dave.

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