Ohanapecosh River bug id?

Discussion in 'Fly Fishing Entomology' started by Gary Knowels, Sep 10, 2012.

  1. Gary Knowels Active Member

    Posts: 1,075
    Ratings: +394 / 0
    Hey guys,

    I found dozens of these guys, about 1.5-2" long, crawling on rocks around the Ohanapecosh this past weekend. I wasn't sure what it was, thought it might be megaloptera (alderfly)? They were pretty poor flyers as I threw a couple into the river to see if the trout might like to eat them (they did) and they plopped down onto the water instead of flying. The kinda swam/scurried across the top of the water toward shore.

    I didn't have anything in my box that matched them, but had some skwala patterns that I had some success on by skating them across the surface, one fish launching about 3 feet out of the water it was so aggressive on the (missed) take. 20120908_160214.jpg
  2. Preston Active Member

    Posts: 2,459
    Ratings: +434 / 0
    The alderfly carries its wings tented, like a caddis. I would say that the picture is almost certainly that of a stonefly based on the way the wings are folded flat over the back.
  3. Taxon Moderator

    Posts: 952
    Ratings: +111 / 0
    Hi Gary-

    Preston is certainly correct about it being a stonefly. I believe it to be of family Perlidae, and based on the elevation, suspect it may be Doroneuria baumanni. Is its color in the photo the way it actually looked, or simply an anomaly of the photo lighting?
  4. Gary Knowels Active Member

    Posts: 1,075
    Ratings: +394 / 0
    The image turned out a bit on the silver/gray side. As I recall, the bug was a light tan/sandy side. I was shocked to see something that large. I looked around for shucks but the only ones I could find where considerably above water level and a couple of sizes smaller than this but definitely stoneflies.
  5. Taxon Moderator

    Posts: 952
    Ratings: +111 / 0
    Hi Gary-

    The discarded nymphal exoskeletons would be shorter, as the wings of the adult extend well beyond the end of the abdomen.
  6. Gary Knowels Active Member

    Posts: 1,075
    Ratings: +394 / 0
    Thanks Roger. Do members of doroneuria have a common name?
  7. Taxon Moderator

    Posts: 952
    Ratings: +111 / 0
    Hi Gary-

    Yes they do. Some years ago, all of the (then known) N. American stoneflies were also assigned common names. Doroneuria baumanni was assigned a common name of Cascades Stone. However, if you were to go into a fly shop and start talking about a Cascades Stone, I suspect you'd just receive a blank look. Because they are mostly found at higher elevations, most folks have probably never heard of them.
  8. Gary Knowels Active Member

    Posts: 1,075
    Ratings: +394 / 0
    Thanks Roger, I wish I had a better imitation in my box as it could've tempted the larger fish in the river to come out and play, I know the one I threw in did.
  9. Travis Bille Active Member

    Posts: 651
    Ratings: +360 / 0
    Taxon, could you point me in the direction of a book or link that contains the common names of these stoneflies? It sounds like it would be interesting to read
  10. Taxon Moderator

    Posts: 952
    Ratings: +111 / 0
    Hi Travis-

    Although I'm not aware of a book which lists the common names which were assigned to all of the N. American stonefly species, they are comprehensively listed by scientific name within family on Northern Prairie Wildlife Research Center's Stoneflies of the United States page.

    And of course, either common name or scientific name can be queried by clicking the Names link on my website. Just key Skwala into the Scientific name entry box, and click the Submit Query button to see how this works.
  11. Travis Bille Active Member

    Posts: 651
    Ratings: +360 / 0
    Thank you very much!