This one pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.
This large Perlodidae stonefly was a strikingly bright yellow color, more so than any other insect I've seen. I didn't enhance it much. See the discussion threads to follow how we identified this specimen, which was listed incorrectly for several years.
Troutnut on Jul 7, 2006July 7th, 2006, 3:46 am EDT
This stonefly comes from a fertile, cold small stream in the Catskills. I tried to ID it using the key to genera in Merritt & Cummins but I ended up with a fairly confident identification that can't be correct: Arcynopteryx, a western mountain genus. So I'm stuck at couplet 89 in the M&C key.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Guess I posted this response in the wrong place, as it didn't show up here. I realize you've already acknowledged the information somewhere else, but I'm re-posting it here for others to see.
Not to despair; this is what American Stoneflies: A Photographic Guide to the Plecoptera by Bill P. Stark, Stanley W. Szezytko, and C. Ridley Nelson has to say about genus Arcynopteryx:
"This genus is represented in North America by A. compacta (McLachlan). This species ranges from Alaska to Maine and has been reported as far south as Colorado. Males usually have shortened wings and are easily recognized by the long, lash-like epiproct tip. Females and nymphs are quite similar to Skwala. A. compacta has been collected around alpine lakes in the northern Rocky Mountains. No photographs are available for this group."
Also, Arcynopteryx compacta is listed by Stark/Baumann as residing in New York.
Dsc1 on Oct 14, 2008October 14th, 2008, 9:49 am EDT
Jason:
Not Arcynopteryx - they look quite different. It DOES look like Cultus verticalis, but you would have to have gone a different direction in interpreting the mesosternal sulci to get to Cultus. Found occasionally in cold, northern streams in New Hampshire (Arcynopteryx here also, but only one specimen so far). Another species or two of Cultus could possibly be candidates, but larvae in this group are not characterized for the species, with verticalis being the best candidate based on distribution.
Sheinz on Feb 10, 2009February 10th, 2009, 4:40 am EST
For Troutnut:
Is the color true on the pictures?
These bugs look similar in shape to what I've found on branches and rocks all over Maine, but the photos you have posted look much yellower, and I've yet to see one 2.5 inches long. Based on other photos, it seems like the colors tend to be lighter than you'd observe stream side, I assume due to the artificial light you need to use to get decent depth of field and sharpness.
Most of the stone fly nymphs up here are more cream colored underneath with a darker back and might go 2 inches.
I'm trying to improve the version I tie. Are these pictures likely the same bug?
Troutnut on Feb 10, 2009February 10th, 2009, 2:28 pm EST
Sheinz,
Your bugs are probably different species of stonefly in the same family, Perlodidae. This specimen really was strikingly yellow. The bright light helps, but this one would certainly stand out in a bucket anyway.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Sheinz on Feb 12, 2009February 12th, 2009, 3:56 am EST
Dear Mr. Nut,
Thanks for the response.
Based on your reply, then would I be well advised try to imitate his shape and tie away? I'm liking moose mane for tails, tan antron yarn for the body, brown swiss straw (raffia) for the wing case, and plastic key chain eyes.
Troutnut on Feb 12, 2009February 12th, 2009, 7:13 am EST
Now that I re-read your description, that does seem more likely. Only you know what you saw... just find the Perlid or Perlodid that looks the most like it here, and tie from that. :)
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist