The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
This is the first of it's family I've seen, collected from a tiny, fishless stream in the Cascades. The three species of this genus all live in the Northwest and are predators that primarily eat stonefly nymphs Merritt R.W., Cummins, K.W., and Berg, M.B. (2019).
This species, the primary "Sulphur" hatch, stirs many feelings in the angler. There is nostalgia for days when everything clicked and large, selective trout were brought to hand. There is the bewildering memory of towering clouds of spinners which promise great fishing and then vanish back into the aspens as night falls. There is frustration from the maddening selectivity with which trout approach the emerging duns--a vexing challenge that, for some of us, is the source of our excitement when Sulphur time rolls around.
Ephemerella invaria is one of the two species frequently known as Sulphurs (the other is Ephemerella dorothea). There used to be a third, Ephemerella rotunda, but entomologists recently discovered that invaria and rotunda are a single species with an incredible range of individual variation. This variation and the similarity to the also variable dorothea make telling them apart exceptionally tricky.
As the combination of two already prolific species, this has become the most abundant of all mayfly species in Eastern and Midwestern trout streams.
Martinlf on May 19, 2009May 19th, 2009, 2:54 pm EDT
OK, this is going to seem like a major duh experience for some of you, but the other night I found a sulphur spinner on the door of a bathhouse in a campground I was staying at. Looking for other bugs I then saw a pale nymph shuck on the door. I was totally confused. A nymph this far from the stream? Was this some alien bug? Looking closer I noticed that the shape was too slender for a nymph and that the wing pads were more like little protruding pockets--and it hit me. Spinner shuck. I knew that mayflies molted to produce a spinner, but I had thought the shuck would be more insubstantial--something that would be flimsy and lack form. This was so cool, and at the same time I felt so silly for thinking it could somehow have been a nymph shuck. It's the first spinner shuck I've seen, but I assume that I'll start seeing them everywhere now, like a new word you learn. Anybody else have a spinner shuck story?
"He spread them a yard and a half. 'And every one that got away is this big.'"
Shawnny3 on May 20, 2009May 20th, 2009, 12:36 pm EDT
You calling Louis a "dun shuck", John? This forum has an interesting way of getting people riled up.
Regardless of how the term was intended, I think it should become a new fishing expletive. I know I'm going to say it loudly to myself the next time I flip my leader into a tall tree.
Troutnut on May 20, 2009May 20th, 2009, 9:23 pm EDT
I can see the hit movie now! A passenger jet flies through a massive Hex hatch, and it's up to Samuel L. Jackson to save the passengers and the engines from millions of mayflies. Near the end of the movie he finally gets really angry and proclaims, I have had it with these dunner-shucking drakes on this dunner-shucking plane!
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Oh boy, that is funny.
I can't wait to add this new expletive to my fishing. My friends already shake their heads at "frelling," "fracking," and "gorram."