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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

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.

Lateral view of a Male Baetidae (Blue-Winged Olive) Mayfly Dun from Mystery Creek #308 in Washington
This dun emerged from a mature nymph on my desk. Unfortunately its wings didn't perfectly dry out.
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.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

Posts: 8
PeterO on Jun 6, 2007June 6th, 2007, 3:58 am EDT

This is actually a specimen of Acroneuria abnormis. Paragnetina species have a complete set of spinules/setae on the occiput, which this guy is lacking. On a semi-related subject, could you forward me the collection data for the Arcynopteryx paralella you got from the Catskills? Thanks a bunch.
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"Bear Swamp," PA

Posts: 1681
GONZO on Jun 6, 2007June 6th, 2007, 4:15 am EDT
Thanks, Peter. The ID mistake was mine, not Jason's. When he collected this specimen, I took a quick glance at it and assumed it was P. immarginata (which is one of the more common of the highly marked "golden stones" in the Poconos). When I returned to see his close-up pictures, I noticed the difference in the dorsal markings and realized I had made a hasty judgment.
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Bellevue, WA

Posts: 2758
Troutnut on Jun 6, 2007June 6th, 2007, 4:28 am EDT
Thanks for the correction, Peter. I'll get you that Arcynopteryx info.

Gonzo, I guess I can forgive you... ;) Really, thanks for showing me to that collecting spot! I got the first Cinygmula nymph I've collected, so it was worth it for that, among other things.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
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"Bear Swamp," PA

Posts: 1681
GONZO on Jun 6, 2007June 6th, 2007, 4:59 am EDT

The forgiveness is appreciated, although it also means that we failed to collect a P. immarginata specimen for your site. But, the Cinygmula was a revelation to me as well. And I'm still trying to figure out why we found mature D. lata (cornuta) nymphs two weeks before they normally emerge in that stretch. That little stream was abnormally low and warm, but I'm not sure that accounts for the difference.
Williamsburg, VA

Posts: 1
Huckleberry on Oct 1, 2010October 1st, 2010, 4:02 am EDT
Hey guys,

I don't see a cercal fringe, even in the closeups. As you know, this is a key characteristic of Acroneuria, sp. Could it be blending in with the white background?

I'm not all that familiar with abnormis. Clue me in.

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"Bear Swamp," PA

Posts: 1681
GONZO on Oct 1, 2010October 1st, 2010, 8:21 am EDT
Could it be blending in with the white background?

Yes. If you click on the full size view of photo #9, you can make out a fine faint fringe of long hairs along the inside edges of the cerci. In photo #5, the (whitish) fringe along the inside of the right cercus partially obscures part of the hook.

In general appearance, A. abnormis nymphs lack anal gill tufts and tend to have broadly concolorous (dark) tergites and femora instead of the narrower dark abdominal banding and leg bands often found in sympatric species like lycorias or carolinensis. The pale band across the back of the head also tends to be more narrowly linear.

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