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Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

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.

Lateral view of a Psychodidae True Fly Larva from Mystery Creek #308 in Washington
This wild-looking little thing completely puzzled me. At first I was thinking beetle or month larva, until I got a look at the pictures on the computer screen. I made a couple of incorrect guesses before entomologist Greg Courtney pointed me in the right direction with Psychodidae. He suggested a possible genus of Thornburghiella, but could not rule out some other members of the tribe Pericomini.
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.

This topic is about the Caddisfly Genus Mystacides

Example specimens

Troutnut
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Bellevue, WA

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Troutnut on Sep 24, 2006September 24th, 2006, 8:51 am EDT
I've been extremely frustrated several times by trout feeding on Black Dancers, especially on the Brule in Wisconsin. The flies gather in little swarms beneath overhanging alders along the bank, usually within a foot or two of the surface, and "dance" around. A trout or two, usually small, will appear below them and rise steadily.

This is one of the most reliable insect activities on that river in the summer. It's quite unlike any other hatch, since it never affects most of the stream. Instead, there are just little pockets of activity here and there along the bank. It would be interesting to see if some of the trout are Mystacides "specialists" who are conditioned to cruise the banks looking for this food source.

At any rate, I've never had much luck catching these trout. I've tried most often on the Brule but I've run across similar situations on Finger Lakes and Catskill rivers in New York, too. Has anyone cracked the code?
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Taxon
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Plano, TX

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Taxon on Sep 24, 2006September 24th, 2006, 1:38 pm EDT
Jason-

What you're describing is a mating swarm. The only time Mystacides adults are really available to trout is when the female dives underwater to deposit eggs, as the pupae crawl out of the water to emerge, and the adult female doesn't dip her abdomen in the water to oviposit. I would expect the egg-laying dive to be a (more or less) singular (as opposed to a large group) activity that would probably be best imitated with a wet fly. Not sure whether or not this takes place immediately below the mating swarm, but that would tend to explain your observation.
Best regards,
Roger Rohrbeck
www.FlyfishingEntomology.com
Troutnut
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Bellevue, WA

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Troutnut on Sep 24, 2006September 24th, 2006, 2:30 pm EDT
Yes, that's one thing I've considered, although I never seem to see them diving underwater... not that I would necessarily notice.

I know mating swarms don't necessarily indicate flies on the water. Yet there's often a rise or two below the little clouds. They swarm so low to the water that it seems quite plausible that they occasionally hit the water by accident and that's when the trout take them. I've also seen trout jump under the swarms.

They're probably just zealously taking something on or near the surface, but maybe some of them can actually snatch the low-flying insects from the air. I think that's unlikely, but it would be neat if they do it. If only I had a high-resolution high-speed video camera with a long zoom lens...
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
GONZO
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"Bear Swamp," PA

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GONZO on Sep 24, 2006September 24th, 2006, 4:48 pm EDT
I've had success with Mystacides, but results are very mixed. Jason, you are fortunate to have witnessed actual rises; in my experience nearly all of the efforts to feed on the mating swarms are aerial. Sometimes the leaping is quite frenzied and frustrating (I suspect for both me and the trout). It sure doesn't seem like an efficient way to feed, but the swarm seems to drive the fish crazy.

The traditional tactic for leaping fish is to "hit-'em-on-the-head" with the fly immediately after the leap, and I have had that work occasionally. I've had more success by repeatedly presenting and withdrawing the fly about a foot or two upstream of a leaper, then allowing the fly to float down to the fish. It works better, but still no sure thing. From my observations, the flies in the swarm never touch the water, but the teasing tactic is still the most successful one I've found.

There's a famous old story (by Robert Traver, I believe) where he talks about solving the problem by connecting his leader to a partner's. They would stand on opposite sides of the pond and dangle the fly over the fish with a tight line between them. When a fish took, they would take turns reeling it in. I suspect that the story is apocryphal, but admit to having considered it as a tactic. Unfortunately, the positioning of the black dancer swarms has never lent itself to two-man fishing. As an alternative, I have considered dangling the fly from a 15' Spey rod, but I have no such rod and the leapers are usually rather small.

Success with a wet imitation of the diving females has also been rather modest. Roger is probably right that the concentrations of diving females never match the concentration of the males in the mating swarms. It could also be a bit of a timing/location issue; perhaps the wet could be used to better effect later on or in a slightly different location. I doubt that the females dive to lay eggs directly beneath the swarms of males. (If they did, the wet would surely be more successful).

This leaves the emergence of the pupae. I'm told that they emerge early in the morning, but I've never been able to intercept them. Pupae that crawl out to emerge are always easy to miss. I'm sure that if the emergence sites could be located, it would be much like fishing to a Chimarra emergence--and I have had very good luck with that.

All-in-all, this is an extremely frustrating bug most of the time. Even figuring out why the trout bother with it is frustrating. Trout are known to be stimulated and attracted by the feeding activity of other trout, and the concentration of fish under a mating swarm does seem unusually dense at times. My best theory is that one overanxious little idiot attracts the others and gets them excited. I seriously doubt that they get enough food value to make up for the energy expended by leaping, but they do it anyway. Maybe someone should explain this to the fish! :)
PaulRoberts
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Colorado

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PaulRoberts on Dec 24, 2006December 24th, 2006, 12:49 am EST
There was always a good number of blcak dancers on the East Branch Owego. Small trout were willing to leap at them at least, and would take a small black dry caddis. But I can't say I've ever seen major trout activity surrounding them.
Reify
Easton, Pennsylvania

Posts: 8
Reify on Jul 7, 2007July 7th, 2007, 3:41 am EDT
We call these simply black caddis - and yes, they'll frustrate the heck out of you. We have good success with emerger patterns fished mid to late afternoon before the mating swarm. I have it from a great book called The Riverkeeper that the swarm is comprised of all males and that the females dart into the swarm - 2 or 2 ata a time, get "picked up" by a male and they ascend together (he "carrying" her) then head to the bank to mate. After about 20 minutes, the male returns to the swarm/dance and the female eventually heads back and oviposits onto the stream surface. The males may mate with more than one female and the females, after ovipositing, head to the woods, fields, whatever and die there.

The author's suggestion is that occasionally, the coupled male and female don't execute their escape quite correctly and crash onto the surface where they struggle to uncouple - AND - according to the author, they are a prime target for hungry trout. He says he's had good sucess with this but fails to give any patterns.

As I mention in another recent post, Mating of the black caddis - the matter is now, trying to tie an imitation of the fallen, struggling couple; and I don't know what body orientations, if any apply.

Reify
Spillerdave
Posts: 1
Spillerdave on May 19, 2009May 19th, 2009, 3:18 pm EDT
I have had similar problems on our local lakes. Lots of black caddis looking insects and no luck. Then one of the insects landed on my boat and I had miss identified them. They were actually Alder Flies!!

Both look basically like black caddis from a distance, but the adult alder fly has extra segment between the wing and eyes. They also can not land on the water because they lack the hair like structures that allow insects to float. Alder flies lay eggs on vegitation over hanging the water. When the larva hatch they simply fall in the water.

The night dancers have long antennae and a slightly shorer wing profile. As discribed by others, the aldult caddis has limited access to the fish, mostly as a wet fly.

Both the caddis (night dancer) and alder flies hatch at about the same time of the year localy. I have had limited success fishing wet flies very slowly near the shore of my local lakes. I'm not sure if they take it as a drowned Alder or Caddis fly.

If I see caddis along the shore, I'll try pupa at various times and some times have great days fishing the pupa. I rarely have many in exact imitationsl, but allways have multipurpose soft hackles. I have not noticed much difference on my lakes. Basically if the pupa are available the fish tend not to be very selective (between soft hackles and more exact imitations).

Generally, I ignore the alder fly. The nymph, emergence, and adult are not available to the fish on a regular enough basis. Even the drowned adults are available on a much less percentage than other food sources.

The only problem I tend to have is seeing the insects from a distance and not being able to identify if they are caddis or alder flies.
Entoman
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Northern CA & ID

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Entoman on Jan 13, 2011January 13th, 2011, 8:23 pm EST
My experience is pretty extensive with this hatch because they are fairly abundant in some of the waters I fish regularly out here in California. Usually they swarm in the midmorning, sometimes in the evening during hot weather. Frustrated me like hell until I identified them and did a little research some years back. Their habit of crawling out of the water to hatch and crawling back under water to lay their eggs is the reason why your dry fly fishing or drifting pupa (if you tried that as well) proved useless. Also, the reason you only find them in certain spots is because that is where the current, depth, and bottom structure are optimal for their benthic habits. Rule 1. Don't waste your time during the early part of the swarm. The females are in the air not the water. Mark the spots and return to fish them as the swarms start to dissipate or even well after they are over. Evidence suggests that the females may not oviposit until well after their arial dance. All you accomplish is giving them a "good study" of your fly for later rejection if you start too soon. Rule 2. Use a wet fly. For lakes, I tie mine on a dry fly hook (skims along the bottom better) with a short dubbed black antron body, no tail, no wing, and a long thick throat of black hen hackle splayed along the bottom just past the hook bend. Finish with a couple of strands of clear antron to simulate air bubbles and you're done. Why no wing? So the fly will fish upside down (more snag proof). The beard becomes the wing. Rule 3. Use a line and leader combination tailored to the water you are fishing: Lakes- clear slow sinker w/a 9 ft fluor. 5X leader. NO FLOATING LINE OR STRIKE INDICATOR IN LAKES. The fly must inch across the bottom horizontally not hanging from a tippet vertically and bobbing like a jig. Fish under the swarm location. Cast as close to the shore as you can with a side arm cast underneath the overhang, let sink to the bottom and retrieve with a very slow hand twist. The hot spot is usually under the outside edge where the swarm was. Rivers - Surprisingly large fish will hold downstream to pick up spent females drifting along the bottom, so fish down as far as 50 yd. below with your imitation. Use any method you feel comfortable with for presenting a deep dead drift, but I've also had good results swinging the fly if the water type fits. I prefer a standard hair wing black gnat (tailless) sexed up with a little antron on a heavy wire hook. Finally, I'm convinced that they are rarely available to the trout in sufficient numbers to cause hyper-selectivity. The large swarms trick us into believing that a lot of them will be available because we think in terms of mayflies. That swarm doesn't represent a days hatch, it represents a weeks worth! Unlike mayflies, only a certain percentage of what we see in the air ever ends up in the water on the same day, let alone hour. I'm hazarding a liberal guess of less than a tenth? Even at that, they may just trickle back over a period of hours. This species has developed behaviors optimized at avoiding predation: Larva in cases hidden in the detritus; pupa that crawl out of the water to hatch; only adult females going back to the water; entering by crawling back in from shore; and finally, ovipositing is probably spread out over several hours. The only collective behavior they clearly exhibit is swarming, but even that is done under or near overhanging brush for protection from birds! Amazing critters... Hope this helps!
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
JAD
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Alexandria Pa

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JAD on Jan 14, 2011January 14th, 2011, 3:09 am EST
Very nice reply , thanks for taking the time to post .Welcome to the forum.

Best

JAD

They fasten red (crimson red) wool around a hook, and fix onto the wool two feathers which grow under a cock’s wattles, and which in colour are like wax.
Radcliffe's Fishing from the Earliest Times,
PaulRoberts
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Colorado

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PaulRoberts on Jan 14, 2011January 14th, 2011, 4:18 am EST
Ento,
Thank you for taking the time to clue us in. Very much appreciated. Love this kind of detail. Makes our time on the water so much more interesting.

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