Stonefly ID

Discussion in 'Fly Fishing Entomology' started by Gary Knowels, May 27, 2014.

  1. Gary Knowels Active Member

    Posts: 1,078
    Ratings: +398 / 0
    Sorry for the poor pictures, I got a new camera and am still figuring it out. Western WA, about 230 ft elev, last Wednesday, early afternoon.
    DSCF1197.JPG DSCF1198.JPG

    And another. NE WA mid March, ~2400 ft elev
    DSCF1115[1].JPG
    View attachment 42580 DSCF1113[1].JPG
  2. Teenage Entomologist Gotta love the pteronarcys.

    Posts: 641
    Ratings: +208 / 0
    Looks like an Isoperla(Yellow Sally). Looks like a male. Fish a red butt Stimi and you should always be able to catch fish during its hatch.
  3. Gary Knowels Active Member

    Posts: 1,078
    Ratings: +398 / 0
    I've run into yellow sallys a number of times and I don't think this is it at all. The body is medium-dark brown and this was larger and much earlier in the year than I've found them before. I could be wrong, but this didn't look the same.
  4. Teenage Entomologist Gotta love the pteronarcys.

    Posts: 641
    Ratings: +208 / 0
    I've seen a stonefly that looks exactly like the one above. A small species of Golden Stone was originally what is was going to say.
  5. Taxon Moderator

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

    The adults seem to closely resemble Osobenus.
    Gary Knowels likes this.
  6. Gary Knowels Active Member

    Posts: 1,078
    Ratings: +398 / 0
    Thanks Roger! That would fit the description, size, and hatch timing. There were quite a few fluttering about and clinging to streamside vegetation. Any pattern suggestion for matching them? I can't find much info on them via google.

    Also saw a bunch of, what I believed to be, brown duns in size 8-10.
  7. Taxon Moderator

    Posts: 952
    Ratings: +111 / 0
    Hi Gary-
    Sure. I would suggest an adult stonefly imitation of the appropriate size with a dark brown abdomen/thorax, the same as in your photo:

    [IMG]
    Gary Knowels likes this.
  8. GAT Active Member

    Posts: 4,013
    Ratings: +2,593 / 0
    Gary, considering the smallish size, you can probably get away with using a size 8-12 brown Elk Hair Caddis... or fluttering style caddis pattern in brown.
    Gary Knowels likes this.
  9. Gary Knowels Active Member

    Posts: 1,078
    Ratings: +398 / 0
    Any guess on the nymph?
  10. GAT Active Member

    Posts: 4,013
    Ratings: +2,593 / 0
    As far as the nymph goes, I'd probably try a Brown Forked Tail (AKA: Prince Nymph) with a bead head in the size of the nymph. Or, a color matching GRHE also with a bead head. Stonefly nymphs normally have large, blunt heads so I like to add a bead to my stonefly nymph patterns.
    Gary Knowels likes this.
  11. Gary Knowels Active Member

    Posts: 1,078
    Ratings: +398 / 0
    Yeah I have a few patterns for that guy, biot tails, tan dubbing with dark brown back and dark wire rib, partridge hackle legs, beadhead. I'm a little curious what the genus is though.

    I was unsure about imitating adult stones as that isn't something I have much experience with being relatively new to fly fishing and most of the small waters I fish, the trout happily take generic dry patterns. The case wasn't much different, but the only pattern they seemed to want was a Montana Bucktail dry in the riffles.

    Thinking I might try to do some of these up in various sizes and colors: http://washingtonflyfishing.com/forum/index.php?threads/damiens-suv-stonefly-sbs.98996/
  12. Taxon Moderator

    Posts: 952
    Ratings: +111 / 0
    Hi Gary-
    Yes, I had a guess, but chose not to express it before being confirmed by a professional aquatic entomologist for whom I have high regard. And, here is what he replied:
    Gary Knowels likes this.