Header image
Enter a name
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.

Dorsal view of a Pycnopsyche guttifera (Limnephilidae) (Great Autumn Brown Sedge) Caddisfly Larva from the Yakima River in Washington
This specimen appears to be of the same species as this one collected in the same spot two months earlier. The identification of both is tentative. This one suffered some physical damage before being photographed, too, so the colors aren't totally natural. I was mostly photographing it to test out some new camera setting idea, which worked really well for a couple of closeups.
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.

Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Aug 14, 2012August 14th, 2012, 6:56 pm EDT
Jere -

Please straighten me out. I have never seen a big PMD. Early in the Summer they might be a #14, but more than likely a #16. and the next generations are quite small, like now...an #18 at the biggest. Maybe we are talking about a different bug.

PMD as a name is perhaps second only to Blue -winged Olive when it comes to a common name causing confusion for western anglers. Unfortunately, while some of the confusion can be resolved, some can't. What can be reasonably assumed accurate at this point is the following:

1. The common name "Pale Morning Dun" originally referred to quite a few pale western ephemerellids that have since been combined, "distilled" if you will, down to two species - E. dorothea infrequens (prev. E. infrequens and others) and E. excrucians (prev. E. inermis and others)
2. The two are virtually impossible for anglers to tell apart taxonomically. Neither size or certain nymphal characters are as dependable as once thought.
3. They do not have "broods" as do the baetids. They coexist as disparate species and populations with some strains smaller and later than others.
4. Both species can be as large as size 12 and at least excrucians can be as small as size 18, though size 14 and 16 are the most common. I have fished over size 12 PMD's many times in the Sierra's (particularly one lake with a nice feeder coming into it where they come off in early June)

What can't be resolved at this time but assumed to be probable (in other words, the jury is still out):

1. Where both are found together, the largest and earliest of the two for a given watershed is E. d. infrequens. It is also thought to be the shortest in duration.

2. The smaller, later, and longer lasting of the two is E. excrucians.

3. Alleged sightings of "PMD's" size 20 and smaller are probably false. The sizes may be exaggerated, anglers may be referring to the smaller sized flies that are often more effective, or they could be confusing them with the tiny sulfur baetids Centroptilum and Procloeon that hatch in the Summer from similar habitat.

The "flies in the ointment" for the above assumptions are populations of large excrucians have been documented as well as possibly populations of small d. infrequens. There are populations of "PMD's" hard to place with either species (over a variety of characters). Also, while not currently reported to be so tiny, there is documentation of other ephemerellids being as small as size 20, so who knows? Bottom line is there's a lot left to learn about these pale western ephemerellids.

Hope this helps.

Westco - What's not clear to me is whether you were at the river or not at the times that Dubbin reported. Besides having to be there more than 30 days ago, you had to be there pretty early as well if I read him right. I've never heard of them coming off at the crack of dawn before, usually running into them either during the day or right at dark on the blue-bird hot days at the end of their cycle. But, perhaps that's why I've missed them so many times.:) Regardless, I agree with Sayfu that Drakes are spotty as hell.
"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
Sayfu
Posts: 560
Sayfu on Aug 15, 2012August 15th, 2012, 8:03 am EDT

Entomen..Looks to me like that high altitude in the Sierra's got to you, and the #12 PMD's you saw were actually my big yellow critters, Epeorus Albertae! The ones my fly shop wants to group into the PMD catagory! :) Thanks for the clarification. What I do find happening on my technical water as the Summer moves on, and 2nd generation of excrucians as they now are being called emerge, you had better have your PMD's tied up as small as your BWO's. Those #14's in the box won't work very well.
Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Aug 15, 2012August 15th, 2012, 2:02 pm EDT
Ha!:) High altitude in the Sierras has gotten to me many times (a lovely euphoria), but these critters are found at mid-elevation. Trust me, they're Pale Morning Duns (that ironically hatch in the evening). Unless of course Sierra Epeorus have sprouted a third tail and changed habitat requirements.:)
"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
Sayfu
Posts: 560
Sayfu on Aug 15, 2012August 15th, 2012, 2:38 pm EDT

EntoMAN!..I would trust you far more than I would trust myself! I got up last nite from bed having to go to the bathroom, looked down at my foot, and saw what I thought was a spider on my foot. I had put some colored medication on a blister my sandals had caused me, and the band aid had come off I smashed the thing with my other foot! You are way over my head when it comes to the bugs.
Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Aug 15, 2012August 15th, 2012, 2:41 pm EDT
:)
"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
WestCO
WestCO's profile picture
Palisade, CO

Posts: 65
WestCO on Aug 15, 2012August 15th, 2012, 5:37 pm EDT
Entoman, while I've acknowledged that this season has shown some somewhat unpredictable behavior, such as the questionable hatch period of the drakes, I can't ever remember seeing morning drakes on the Pan. The pan in July and early August is known for mid day hatches of PMD's and Drakes. I'd say the later hatches are no later than 6-7. In my experience that time is usually either really quiet, or you get caddis hatches. Its usually the calm before the storm before the ridiculous spinner falls at 8. The PMD's are pretty big this summer and I could certainly see some of those that I see rising being close to 14's. All I was saying was that its entirely possible that people confused them for Drakes. Its also entirely possible that I've picked the wrong 4 days a week if the drakes are only showing 3. I really didn't mean to come across as anyone being wrong or right, I just wanted to know if anyone had any definitive information because a lot of the reports this summer from fly shops out of the valley have been inaccurate in other areas. This was the hottest summer I've ever seen in Colorado and while I don't know exactly what leads to the hatches, everything from the fruit to the fires occurred 2 weeks to a month earlier than usual, so it wouldn't surprise me if the bugs weren't right there. Hell I had good hopper action on the pan in mid July and I've never seen that either.
...but fishermen I have noticed, they don't care if I'm rich or poor, wearing robes or waders, all they care about is the fish, the river, and the game we play. For fishermen, the only virtues are patience, tolerance, and humility. I like this.
Sayfu
Posts: 560
Sayfu on Aug 15, 2012August 15th, 2012, 6:35 pm EDT
And WestCo..Please don't take me as someone that can deem you right, or wrong. I'm a local yokul that only knows my local water's insects, and not all that well at that.
Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Aug 15, 2012August 15th, 2012, 7:59 pm EDT
Westco - Your experience matches mine as well. I wouldn't have guessed first light emergence. I'm a little curious as to how Dubbin came by his info as I don't know too many guys that would think to be on the water at first light to look for them. Perhaps Trico hunters were surprised by them? But they're usually found on different types of water in my experience.

After a lot of planning and chasing over quite a few years, I've missed drake hatches and salmonfly hatches more than I care to remember.:) Many times I've been on the water when few were seen only to hear they were thick as "flies" either the day before or the day after. As far as fly shop reports, I take them all with a grain of salt.:) In fact, I'm usually more interested in where they are telling everybody to go... So I can avoid those locations!:) For example, when you see them reporting salmonfly activity along a certain stretch, start fishing well upstream from there as a general rule...

The really valuable information comes from good guides and competent anglers that are on their home waters all the time, and they usually hold their info dear.
"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
DUBBN
DUBBN's profile picture
Colorado

Posts: 47
DUBBN on Aug 16, 2012August 16th, 2012, 2:42 am EDT
Westco - Your experience matches mine as well. I wouldn't have guessed first light emergence. I'm a little curious as to how Dubbin came by his info as I don't know too many guys that would think to be on the water at first light to look for them.


I have to agree about the bugs hatching early this year. I would agree that most hatches have occured a couple weeks early. Perhaps this is due to warm temperatures, and lower than normal water levels in the river. Perhaps this allowed the water to warm a few weeks earlier than the norm.

How I came by my info is, I float the Roaring Fork river year round. I am on the water at first light. I have taken a few weeks off this summer, but by and large I float the river 2 to 3 times per month, year round. Weather and ice permitting.

The Drakes I see are the left over (stragglers) from the night before. The majority of the Drakes on the Roaring Fork, Colorado, White, and Gunnison rivers hatch after the sun goes down.

A stop by any gas station in the Roaring Fork Valley,at night with Green Drakes in the near vicinity, will reveal how active they are after the sun goes down. Head lights, and wind shields are covered in their goop.

All I have to know is that the Drakes are emerging in the vicnity. Knowing this will usually bring out a Green Drake pattern and usually get great results. I dont have to see big numbers of insects. The fly shops are not a bad source of information if all you want is greneral vicinity. Most of the info can be gleaned from their web sites if they have one.

Westco, I saw the Drakes, in the early Morning, about one mile below West Bank. I checked my journals (7/14/12) and I was on the water by 6:30 AM. The guides and clients usually start their day at around 8:00 to 9:00 AM. This gives me close to a two hour head start on the Float Parade.

I rarely chase the Drakes with a dry. A size 12 or 10 Soft Hackle with an Olive Body, and Green Hen Hackle usually turns the trick for me. I am pretty sure it resembles and drowned emerger/cripple.

So, perhaps a misundersatnading has occured. If so, I hope this helps clarify what I saw, where I saw it, and when I saw it.

I do not "chase" hatches. I never have in 35 years of fly fishing my local Western Colorado rivers. Theres fish to be had before and after the hatch. That being said, it does not hurt me to know what to do if I find myself in the middle of a hatch. More important, it helps to know what the true bug that the fish are hitting during over lapping hatches.

These are opinions that I have formulated. I do not have one shred of evidence or documentation to prove them right. That being said, I do not know alot of fly fishers that mistake a caddis for a Green Drake. They are probably out there, but must not run in the same circles as I.
It's OK to disagree with me. I can not force you to be right.
Sayfu
Posts: 560
Sayfu on Aug 16, 2012August 16th, 2012, 5:54 am EDT
Entomen.."The really valuable information comes from good guides and competent anglers that are on their home waters all the time, and they usually hold their info dear." That thought brings me much regret. And I live in one of the best, freshwater river systems in the lower 48. Maybe in select, flat-water stretches of the Henry's Fork, but little else. ON my tailwater, the SF of the Snake, most guides drag a bobber and a nymph around covering 15 miles of river in a day. They know the timing of major hatches, but are not very bug wise ID folks. The fly shops don't want to confuse the matter with technical jargon. It seems that the industry wants to dumb-down to expand their marketing. They are now promoting Tankera (sp?) rods as a way to get anglers interested in fly fishing. Are you familiar with them? Even the good doctor, (has two Dr. degrees) and is the bug expert in these parts, appears to me to be south of myself when it comes to aquatic insect ID'ing) in many ways. The feeling is we have made it too lofty, to technical for the average angler. And I could be wrong.
PaulRoberts
PaulRoberts's profile picture
Colorado

Posts: 1776
PaulRoberts on Aug 16, 2012August 16th, 2012, 8:09 am EDT
Well I have to pipe in to say that yes, a lot of the entomology requires too much time investment for most anglers. Most just want to get away and fish, not make a big study of it. Entomology, or other sciences, can also confuse things beyond what's necessary to "get away and catch some fish". The quip -"Too much info can be a dangerous thing"-comes to mind. Entomology, for one, IS technical, and being revised constantly. It's a HUGE world out there.

This doesn't mean that there aren't anglers out there that have done some homework and field work, and become knowledgeable. If you look around (in the right circles I suppose) you'll find them. No one covers all the bases though. We all learn from each other.
Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Aug 16, 2012August 16th, 2012, 10:23 am EDT
Great comments all! Thanks for taking the time to expand on your experiences, Dubbin. The apparent contradiction between yours and WestCo's observations is now cleared up. I agree with you that "chasing hatches" is not a way to describe fishing the same water as much as you do. However, I do plead guilty to this often futile activity when planning trips!:)
"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
WestCO
WestCO's profile picture
Palisade, CO

Posts: 65
WestCO on Aug 16, 2012August 16th, 2012, 9:01 pm EDT
Dubbin, do you have any thoughts on the different hatch patterns between the Pan and the Fork because I know exactly what you're talking about. Late evening green drake hatches are intense on the Fork, but I've never seen them like that on the pan. And I wasn't trying to label you as the one who couldn't tell the difference between a drake and a caddis. I was speaking generally about "sources" and responding to several posters. But as to the first part of my post, do you see the same thing, and do you have any potential explanation as to why Drakes hatch midday on the Pan and in the evening on the Fork?
...but fishermen I have noticed, they don't care if I'm rich or poor, wearing robes or waders, all they care about is the fish, the river, and the game we play. For fishermen, the only virtues are patience, tolerance, and humility. I like this.
Sayfu
Posts: 560
Sayfu on Aug 17, 2012August 17th, 2012, 6:04 am EDT

Paul, Good Post, and a good reminder perspective that I knew was true just lost perspective now that I'm trying to elevate my bug ID game. I just hope for local excitement from anglers jumping at the chance to enter the discussion, and it often tends to move the other way.
PaulRoberts
PaulRoberts's profile picture
Colorado

Posts: 1776
PaulRoberts on Aug 17, 2012August 17th, 2012, 7:33 am EDT
I just hope for local excitement from anglers jumping at the chance to enter the discussion, and it often tends to move the other way.

Gotta go easy. Anglers are easy to spook. :) Speak a little latin or rattle off some seemingly arcane (even though you know it isn't -or at least it's REALLY cool!) info and you'll have a chunk of river to yourself pronto. Which can be a good thing I suppose. :) That's in large part why we're chatting here. And I suppose why this site has so many lurkers and so few regular posters.

Lesseee...to the topic:

Possible reasons I can think of for differences in emergence patterns:
-different, but similar looking, species.
-elevation (similar to latitude)
-diff water sources/local weather/canopy cover creating diff temperature regimes
-energy productivity/food availability

The last two pertain to the fact that insects need to go through a certain number of instars during maturation each requiring a certain amount of growth. Extra food, heat can cause quicker growth and influence maturation. Less can delay maturation and seasonal timing and/or affect final size of adults. Following, I wonder if larger adults can retain more body moisture and heat, which might possibly affect daily activity.

Daily emergence patterns (the specific question) can be affected by daily temperature, humidity, and light levels. With Colorado's extreme variation in elevation and aspect (North exposed vs South exposed) one might expect variation in activity. It's hard to completely separate a critter from the land it lives on.

Kurt, GONZO, and others may be able to offer more and better info.
Sayfu
Posts: 560
Sayfu on Aug 17, 2012August 17th, 2012, 9:30 am EDT
Here is a thought on emergers, and the difficulty you can encounter. I think one of my guru's brought up this possibility, and as I remember it related to PMD's, the Ephemerella ones. When trout can become picky after angler after angler wades the riffles, trout can turn off on the dry flies, and focus on what appears to be a motion trigger that takes place during the emergence. That motion can be virtually impossible to duplicate.(ie) a twitch, sparkle, something that causes them to eat. Oh, the guy was Neal Streeks I do believe. Somewhat older now, Neil spent many a day on the rivers of Montana guiding.
PaulRoberts
PaulRoberts's profile picture
Colorado

Posts: 1776
PaulRoberts on Aug 17, 2012August 17th, 2012, 10:18 am EDT
It may not just be angling pressure, but something particular about E dorothea. Maybe it was hatch density? But in some relatively unfished eastern creeks I frequented, the fishing could be darn difficult during heavy dorothea emergences, although the water was boiling with feeding trout! They were seeing something I wasn't.
Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Aug 17, 2012August 17th, 2012, 11:02 am EDT
The only thing I can add to Paul's excellent summary are the effect of flows and weather from year to year. One of my local rivers has been subject to wild swings the last 30 years or so. In years of drought and heavy siltation, T. hecuba does very well to the detriment of D. grandis while the reverse is true during normal years (if there is such a thing). Floods are a disaster for both, and we've had several in the last 10 - 20 years.

Mostly, I'd have to say the only consistent hatches of mayfly are PMD's and Baetis. In certain locales, Tricos, Hexes, March Browns, and a variety of Summer heptageniids are also consistent, but the big ephemerellid drakes are not in this category. The nymphs usually sample very well, but the adults are pretty scarce either because the trickle off or emerge at night. In CA, inclement weather seems to heighten their activity and has always presented the best opportunities for me. I remember one particular day on Fall River. The weather was what I would categorize as good steelhead weather. One of those dark days when the air bit and the sky spit at you from time to time, but not too windy. The drakes were on big... While I contented myself with trying to fool selective "shoulders" throwing all varieties of extended bodies and emergers, a friend I had with me in the boat couldn't deal with it. I remember him asking if a nymph he selected would work. I also remember a quick glance back to see him tying a giant peacock monstrosity to the end of his severely shortened leader (due to tangles trimmed out). I responded, "Sure, just don't cast that thing anywhere near the water I'm working." So, he flipped it out as best he could and just left it dangling a short distance behind the boat. Within seconds he hooked and hauled in a 20 incher. The fish didn't stand a chance with that hay hook of a nymph and leader of at least 12 lb test. Over the next several hours he proceeded to hook and land more big fish dangling that sausage off the back of the boat than I've seen on the river before or since - and we're talking one of the toughest spring creeks in the nation! Go figure...

Though common all over the West Coast, I've only had what I would consider really good dry fly fishing involving them on a handful of rivers. The Truckee, Fall River and Hat Creek come to mind in CA . The Metolius in OR, and of course the HF in ID have also fished well. But this is largely past glory as drake populations have been on the decline at these locations for many years now. Though I'm fishing some new locations that show promise, my suspicion is this is true across their range.
"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
DUBBN
DUBBN's profile picture
Colorado

Posts: 47
DUBBN on Aug 17, 2012August 17th, 2012, 1:35 pm EDT
WestCo, I can only guess that with the Frying Pan being a relatively short (13 miles) Tailwater, and the Roaring Fork being a Freestone. The answer lays somewhere in there.
In 35 years of fishing those rivers I wish I would have added water temperatures to my journals.
In any case, enjoy. They are both great places to fish.
It's OK to disagree with me. I can not force you to be right.
WestCO
WestCO's profile picture
Palisade, CO

Posts: 65
WestCO on Aug 18, 2012August 18th, 2012, 5:56 pm EDT
I also wonder if the Pan not having a real blowout in June added to the changing of the timing. Usually flows are in the 500-600 range during "runoff," and this year they never rose much above 200.
...but fishermen I have noticed, they don't care if I'm rich or poor, wearing robes or waders, all they care about is the fish, the river, and the game we play. For fishermen, the only virtues are patience, tolerance, and humility. I like this.

Quick Reply

Related Discussions

Topic
Replies
Last Reply
12
Aug 14, 2012
by Sayfu
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy