Simply put, it is one of the most iconic pieces of trout water on Earth. The very mention of the storied Railroad Ranch section of the Henry’s Fork conjures images of expansive flats with large rainbow trout sipping away on the surface. Anglers who frequent this water tend to abide by a largely unwritten code of conduct, and generally hunt those heads patiently, often waiting on the banks or walking and hunting until a rise is spotted. A careful and well thought out approach greatly increases the chances of success on this very technical piece of water. Tackle is well thought out as well, leaders are prepared with great care, and the most trusty of flies are often fastened to a well tended tippet while in wait. This process is part of the joy of fishing The Ranch, and gives the angler plenty of time to admire the day’s tackle selection from his or her quiver of available arms. Both failure and success here often result in a thoughtful recapture of the day’s activities and careful consideration to the why’s and how’s of the day’s events.
Though it is the trout that most immediately draw anglers to The Ranch, anglers quickly learn that by timing their efforts with certain hatches or even certain phases of hatches, they are able to increase their opportunities. These hatches become part of the focus of Ranch anglers and exist throughout the summer and fall, usually starting with a bang when the drakes and heavy pmd hatches pop. Next, Ranch insect activity eases into flavs, then to flying ants and other terrestrials, and finally to the mahogany duns and baetis of Autumn. Caddis are present throughout the summer in a variety of species. There are even micro-habitats scattered throughout the 7-mile-long reach that can present fantastic and fascinating hatch matching opportunities when other sections are blank.
Everyone seems to have their favorite times of year here, and as a guide on the Ranch, I have my favorite times to take anglers. As an angler myself, my favorite time to fish The Ranch is whenever I can go. The magic of this piece of water is never lost on me and I consider it a privilege to spend a morning, afternoon, evening, or if I’m lucky, a full day walking its banks in search of a target to try and wrangle. This is usually when I reach for that special rod I’ve been waiting to cast, the one I keep in my truck for just this moment. There are, however, other times that I reach for my highest performing rod and this is determined by what it is that I expect to see.
Rod selection is one of the first things I consider for a day on the Ranch. Fly fishing advertisements often favor a moderate or slow-action rod for this sort of fishing. A rod that exemplifies the feel of a smooth fly cast. Sometimes that is reflected in my selection as well. Other times, the elements/weather or the bugs that I expect to throw push me to select a faster action rod. For example, when fishing a spinner fall, when I know that the water will be littered will millions of spent mayflies, and trout will be eating only 1 out of any possible 50 drifting over them at any point in time, I reach for my SAGE X 590-4 rod. This trustworthy, high performance rod is capable of picking up long amounts of line, 40 plus feet, and makes it easy for me to convert a single back cast into a tight-looped forward cast that delivers the fly right back into the lane it came from. It is this efficiency of many drifts in the same feeding lane that brings success to the spinner-fishing angler. This is harder to accomplish using a softer action rod as the angler may have to make more strips of line in after each drift in order to execute a proper back cast, resulting in more false casts and ultimately into more shooting of line and less accuracy. In this game of inches, I favor the stiffer SAGE X, and I appreciate the bit of touch the rod has in the softer tip (compared to some of SAGE’s other models), which helps get the cast started in just the right way.
When fishing larger flies, either the drakes in the early summer or terrestrials in the heat of summer, I know that fewer presentations will be required as the natural competition on the water will be less than during a thick emergence or spinner fall. In these circumstances, I still favor a rod that I enjoy casting, but one with a softer action that places more emphasis on the pace of the casting stroke. This same softer touch is more efficient at feeding line, a technique that goes hand in hand with larger flies on The Ranch. The trout feeding on them are often moving targets in search of fewer but larger morsels. Less rhythmic feeding is characteristic of these situations, so between presentations I’ll often be bringing my flies to hand to wait for the targeted trout to show himself again before I re-cast. In these situations, I’ll reach for one of my classier rods – a rod that I appreciate for its performance as well as its artistry. My Burkheimer 590-4 Classic, for instance. Burkheimers not only are finished with an artists touch, they also are built with a sense of feel and smoothness not equaled in other rods out there. They are capable of throwing a tight loop on short casts and perform very well up to 60 feet or so. Though there are many that prefer a 4 weight for some of this fishing, I always prefer my 5 weight, for its versatility in windy conditions.
During terrestrial season, an angler is likely to encounter spinner falls in the morning, ants in the late morning, and maybe even sight fishing with nymphs, and targeting grasshopper-searching trout in the afternoon. Often, the Ranch has plenty of aquatic vegetation (which most of us unceremoniously refer to as weeds) at this time of year. In August, large weed banks reach the surface and isolate trout in little channels that funnel bugs and change the river’s currents. In the afternoon, weeds will often cut loose and begin to drift down the river. Having a rod that can maintain lots of pressure on a hooked fish without breaking a fine tippet is a must. A Winston Pure in a 5 weight, nine foot is a great tool for the job. I find that this rod excels at short range casting. Many times the answer to getting a drift in these variable weed bed currents is to sneak up close to your target and make shots from 30 feet or less. On windy afternoons, “Hoppertunities” arise and being able sling a large fly in the wind and stack out lots of slack into a long drift can make the difference between catching nothing or hooking the largest trout of your year. Again, the deep bend in Winston’s Pure lineup does this well, and allows me to put maximum pressure on the line while minimizing the chance of breaking a fine tippet on a large, angry rainbow trout.
If you and I were to discuss historical advancements in fly tackle over beers some evening in Last Chance, we could start with the transition from bamboo to fiberglass and on to graphite, or Red Ball Flyweight waders to Gore Tex. But I would argue that the greatest advancements in the last decade have been made in the area of fly lines. The new breed of fly lines by companies such as Scientific Anglers, RIO, Airflo, and Cortland are leagues ahead of where they were 10 years ago. New finishes allow for easy shooting and feeding slack, as they move through the guides with less friction. Complex tapers offer unprecedented control over energy transfer and leader turnover. Modern lines are stiffer in the bodies of the heads in a wider range of temperatures and can be more supple in the tips, which both helps with casting in the wind and getting drifts in swirling currents. They also have less stretch than older generation lines which increases contact with fish during the fight and for a quicker, more responsive hook set. For fishing on the Ranch, I prefer the Scientific Anglers Amplitude Smooth in an MPX taper for my SAGE X and Burkheimer, and a Scientific Anglers Trout taper for the Winston Pure. The RIO Gold is a great all around line as well and I find it fishes well with all of the rods mentioned.
In this game of stealth, hatch matching, and drag free presentations, a long, fine leader is a must. Tippet you can believe in is critical as well. There is no sense taking all this time to find a target and plan your approach if your tippet is going to break when you finally do hook your Ranch fish. This is a trophy hunt, and every fish is special. You’ll come across anglers that swear by 15+ foot leaders in 6 or 7X, and that seems to work for them. Usually, however, I’ll select a Trouthunter 10’ 3X leader as a base and then modify it with fluorocarbon tippet in a length that favors accuracy versus overall length. I like the Trouthunter mono leaders because they have a longer butt section than most, designed to turn over long leaders in windy situations. I have yet to find a stronger tippet than the Trouthunter Fluorocarbon. It is impressive stuff and is often stronger than the steel of the hook the fly is tied on.
Construction of my own Ranch leader goes as follows: Starting with Trouthunter 10’ 3X leader, I cut about 15 inches off of the fly end. I then attach a 15 to 20 inch long section of 4X Trouthunter Fluorocarbon to the end of the tapered leader using a double surgeon’s knot. This knot is important when joining mono to flouro. Lastly, I add a 2 foot long section of 5X Trouthunter Flurocarbon tippet to the end of the 4X, using a blood knot. The result is a leader with a total length of about 12 feet. If I need to step down further, I might trim the 5X section a little shorter and add another 2 feet of 5.5X or 6X for an overall length of 13 to 14 feet, that is typically my maximum leader length. Having the 3X leader as my base also gives me the flexibility to trim back to a 4X tippet in a pinch and throw a bigger beetle or hopper at an opportunistic target along the way.
The final component of Ranch tackle is the one that makes the magic happen, and probably the one that receives the most attention – the flies. On this subject, I could probably write an entire book, but I’ll try to keep it short and sweet here. One should always start by familiarizing themselves with the bugs they might expect to encounter during your visit. A quick stop or phone call into Big Sky Anglers will give you a heads up to what’s happening out there. Generally speaking, you’ll want to be prepared to match mayfly spinners in a variety of colors and sizes, and the Harrop Paraspinner is a good start. JoJo’s Green Drake, conceived by BSA’s own Joe Moore, is, without fail, the first pattern I put over a trout feeding on these chunky green sailboats. As a bonus, it’s design allows for significant on-stream modification (bring tiny scissors) to adjust the way the fly rides on the water, giving this pattern unprecedented value. Emerger patterns are a must for any of the mayfly hatches you might encounter. These can vary from hair wings like the Challenged Emerger PMD or CDC versions like the Last Chance Cripple PMD. Comparaduns and Sparkle Duns in the appropriate color and size for the hatch are solid choices as well. High-riding duns in thorax ties are great for mahoganies and PMDs. Low profile and spent versions of both olive and tan caddis occupy permanent spots in my Ranch box and can be effective throughout the year. Most Ranch anglers are also never without a few black ants, hoppers, and beetles, and definitely not without a Harrop’s CDC honey ant.
I will conclude with a bit of philosophy. Fly fishing is filled with opinion. It has been my intent in this post to illustrate what has worked for me over the years, and offer some insight to the inquiring angler. I hope this information helps the reader make a decision that leads them to success, whether it be on the Ranch or on another piece of water. One of the joys of fly fishing in general, and certainly for the Ranch angler in particular, is the process of thoughtfully considering the scenarios you might encounter, preparing a selection of flies and your leader for the day’s fishing, and selecting tackle from your quiver that represents what you wish to use. There is no right and wrong here, or it could be said that any choice is both right and wrong, as adapting to changing conditions is usually the name of the game. I hope that every fly angler that comes across this article gets a chance to stand ankle deep in this most special of places and has an opportunity to tango with one of its residents.
In many ways the hopes and dreams of fly fishers rest on the existence of bugs. Sure, you can venture out onto your favorite piece of water on any given day and catch some fish, many times lots of fish, when there is seemingly no bug activity. But, those aren’t the days that get etched into your memory. Those aren’t necessarily the days that inspire you to make life decisions. Like, say, picking a college that is surrounded by the most prolific dry fly fishing on the East Coast, or, perhaps picking a wedding date in late September which, conveniently, doesn’t overlap with any major trout stream hatches…hypothetically speaking, of course.
Streamer fishing has its virtues; “the tug is the drug”. And, nymph fishing most certainly produces more than it’s fair share of memorable days and 3-dimensional challenges. But, nothing in our sport tops the visceral experience that is watching a body of water come to life with an exuberance of bug activity, and the ensuing trout feeding frenzy. In my opinion, nothing illustrates that better than a Callibaetis spinner fall on western stillwaters.
Callibaetis mayflies have a massive distribution across most of North America. It is the western subspecies (Callibaetis ferrugineus hageni), though, that produces inspirational fishing on countless lakes, and several notable rivers, in the Rocky Mountain West.
Callibaetis mayflies live in stillwater environments. They thrive in water that has rich weed growth. And, while the emergences are often inconspicuous, the spinner falls are the stuff of legends.
Callibaetis mayflies, along with their diminutive brethren Tricos and Midges, are responsible for the legendary “Gulper” fishing that happens on Hebgen Lake each summer from late-July to mid-September. The shallow, weedy arms of Hebgen Lake are such ideal habitat for Callibaetis mayflies that they produce an awe inspiring amount of insects. Dense spinner falls occur here, and trout rise to the spent adults with such rhythm and regularity that you can hear the fish rising with an audible gulp that resonates across the glass flat waters.
Warm, calm mornings are ideal conditions for these size #14-16 speckle winged mayflies to form mating flights. It is impossible to miss them when they are around as seemingly billions of adults will dance above the water in a rhythmic undulation. When it is good, and it often is in Big Sky Country, spinners will blanket the water, and everything on the water, including fishermen.
Callibaetis spinners are unmistakable due to the unique speckled blotches present on only the leading edge of their fore wings, and their two long, widely separated tails. Their bodies range in color from brownish-olive to tan to light grey with a majority of spinners displaying a lighter tanish-grey coloration on the bottom of their abdomen and a darker, blotchy charcoal color on the top.
Here are Three Geeky Bug Facts about Callibaetis that will help you catch more fish.
1. Callibaetis are Multi-brooded
When we think about the life cycle and seasonality of mayfly hatches, we generally reference a particular bug with its spot in the seasonal lineup of hatches. Certain bugs, like March Browns, hatch in the early season, and they are followed by summertime hatches of PMDs, and autumn hatches of Mahogany Duns, etc. These hatches occur at roughly the same time every year with the progeny of those hatches growing and developing in the river until the following season when it is their turn to complete the cycle.
There are certain bugs, however, that breed multiple times during the course of the fishing season. Like their cousins the Baetis (Blue Winged Olives), Callibaetis will begin hatching early in the season (June in Big Sky Country), and those early bugs produce the ones that we fish later in the season. Also, like their Baetidae cousins, the size of individuals decreases with each brood of the season. Spring hatches of Callibaetis can have duns as large as size #12, whereas September emergences will produce size #16.
Early hatches of Callibaetis are often available in fishable numbers far earlier than when we begin paying attention to them. Unfortunately, the unsettled early season conditions of June in the Rockies don’t often produce dense mating flights of spinners, or the glass flat lake surfaces required for dry fly fishing.
Most years, those early season emergences go largely unnoticed, and it is their offspring that draw our attention later in the summer when weather conditions are more conducive. The warm, calm mornings of mid-summer in Big Sky Country provide both the perfect environment for massive flights of spinners and the glass flat waters needed to bring hordes of trout to the surface.
While average June conditions are generally not optimal for Callibaetis spinner falls, it’s important to remember that the bugs are still active. Duns will continue to emerge, sometimes trickling off one at a time, randomly throughout the day. On the rare day in June, when conditions are cloudy and calm, emergences can be concentrated, and provide outstanding dry fly fishing with duns. The occasional warm, calm morning in June can also generate a fantastic dry fly session with Callibaetis spinners. More often than not, these early season spinner falls are sparse, providing just enough food on the surface to get fish hunting on top, but not so much that your fly is competing with hundreds of naturals for the attention of gulping trout.
2. Callibaetis Nymphs are Strong Swimmers and Fast Emergers
Callibaetis nymphs are a perfectly evolved product of their weedy, stillwater environment. Their bodies are slim in profile with feathery gills, and pronounced variegation on their tails. Coloration ranges from light olive to tan, or gray.
Callibaetis nymphs are agile swimmers, dashing from one weed tendril to the next with short, powerful bursts of speed. Frequently, nymphs will pause for a brief second between sprints, hanging motionless in the water column with their abdomen hanging down. This choreography is important to imitate when fishing Callibaetis nymph imitations. Short, swift strips of 4-6” with a definite pause between movements is the best retrieve as fish will commonly pounce on the fly at the pause.
Just as they move through the water with speed and momentum, Callibaetis nymphs emerge into duns quickly at the water’s surface. It’s common for the nymphs to make several trips back and forth to the surface in preparation to emerge, but once they commit to the meniscus and break through the surface tension, they make quick work of the act. During these “practice runs” the nymphs are prepared to make their quick escape at the surface with fully formed wings bulging beneath their dark brown thoracic carapace (wing pad).
For more great info about Callibaetis nymphs check out this great Callibaetis Nymph Article from our Blog archive written by our very own fanatic of all things stillwater, Matt Klara.
3. Callibaetis aren’t just found in Lakes
Callibaetis mayflies may be the most infamous stillwater hatch, and Big Sky Country is home to some of the most legendary spinner falls of these speckle winged mayflies.
Hebgen Lake, outside of West Yellowstone, MT, is ground zero for the notorious activity known as Gulper Fishing. Named for the nail biting sound that echoes across the glass flat waters of Hebgen’s weed-laden arms and bays as large trout gulp Callibaetis spinners from the surface, Gulper Fishing is an annual pursuit that rivals the most celebrated spectacles in Fly Fishing.
As epic and addictive as Gulper Fishing is, it’s not the only Callibaetis game in Big Sky Country. The same slow water environments that harbor fantastic populations of Callibaetis on lakes also exists on several of our most legendary rivers. The Henry’s Fork of the Snake River, the Yellowstone River in YNP, and the Missouri River all boast substantial populations of these speckle winged mayflies.
When Callibaetis are found in riverine environments, they aren’t present in the same abundance as stillwaters. Emergences and subsequent spinner falls are generally sparse in comparison to the activity seen on legendary waters like Hebgen or Yellowstone Lakes. What Callibaetis lack in numbers on rivers they more than make up for in the influence they have on feeding fish. When Callibaetis are present on rivers like the Henry’s Fork and Missouri, they are usually the largest bug around at that time, and trout go way out of their way to feed on them.
Now Get Out There and Find Some Callibaetis Mayflies
If you haven’t experienced the thrill and suspense of fishing to cruising gulpers on a warm calm morning in Big Sky Country, do yourself a favor and explore one of the many still waters in our region during Callibaetis time. Remember, Callibaetis will be active as early as June when conditions permit. The bugs will be larger (size #14) in the early season, and later broods will be smaller (size #16). If you fish the nymph imitation, do so with short, brisk strips of 4-6”, and be sure to pause between strips. And, don’t forget to have some Callibaetis dun and spinner imitations when fishing the Henry’s Fork, Missouri and Yellowstone Rivers (in YNP).
Brown Drakes (Ephemera simulans) are to fly fishers what the New Kids on the Block were to teenage girls in 1990. If they made mayfly posters, you would definitely have one of a Brown Drake on the wall in your bedroom. You would do anything in your power to go see their show. And, if you were lucky enough to see them perform, the sheer thrill of the experience could produce tears of joy.
Like their boy band counterparts, Brown Drakes are a national phenomenon. These massive, size #8-12, mayflies are found in many of fly fishing’s most elite venues from the East Coast’s Delaware to the Midwest’s Ausable, and out to the fabled waters of the Henry’s Fork in Big Sky Country.
Here are Three Geeky Bug Facts about Brown Drakes that will help you catch more fish.
1. Brown Drakes aren’t always Night Owls
Brown Drakes are synonymous with evening fishing. Ask most experienced anglers about them, and you’ll hear a tale of big fish rising to big flies as daytime fades into darkness. Many an epic evening has been had on the Railroad Ranch section of the Henry’s Fork during late June and early July when Brown Drakes are hatching. Often times a mating flight will coincide with an emergence providing both duns and spinners for the Fork’s world class rainbows to feast upon. Emergences generally occur in the final hours of daylight, and can last well into darkness. Unsettled weather due to evening thunderstorms is common up in the caldera during this time of year. These storms have been known to produce thick hatches of Brown Drakes both before and immediately following the deluge.
However, these stormy conditions will generally squash the mating flight and subsequent spinner fall. When this happens, it’s possible to see good numbers of Brown Drake spinners flying on the following morning if conditions are appropriate (warm and relatively calm). During periods of stormy weather that last for multiple days, spinners will jump at any opportunity to form a mating flight and finish their life cycle. This can occur in small localized areas of the Ranch where bugs can fly on the leeward side of streambank trees and foliage.
While Brown Drakes are best known for their twilight emergences, don’t forget to keep an eye out for localized mating flights and spinner falls during the morning and early afternoon, especially after periods of stormy weather.
2. Brown Drake Emergers act like Daredevils
If you’re thinking of the red and white striped spoon named Daredevil that you can find in Grandpa’s old tackle box, that’s not the idea. Brown Drake Emergers more closely resemble the shot out of a cannon while wearing a red, white and blue leather jumpsuit style daredevil.
Unlike their drake cousins, the Green Drakes (Drunella grandis), who are awkward, clumsy, vulnerable emergers, the Brown Drake nymph emerges at the surface with speed and skill, making them a difficult target for feeding trout.
Aquatic insect maestro, Jason Neuswanger of troutnut.com, appropriately describes the emergence of a Brown Drake nymph as popping through the surface and into the air like it was shot from a cannon.
It’s common to see large trout feed with a swirling, aggressive rise just below the water’s surface during periods of Brown Drake activity. This is undoubtedly the result of the fish chasing a Brown Drake nymph as it ascends through the water column.
Imitations of crippled Brown Drake emergers will sometimes fool a feeding trout. However, drift sampling during peak emergences generally reveals far fewer crippled emergers compared to the vast numbers of duns, spinners, and nymphs.
Brown Drake nymphs have slender bodies built for burrowing. The nymph’s coloration is similar to the adult’s with a mix of amber, brown, and olive. The slim thorax has definitive mottling, and the abdomen has pronounced, feathery gills. Sizes range from size #8-12.
A Brown Drake nymph is an excellent addition to your quiver, and, rather than an Emerger imitation, may be just the ticket when tricky fish seem to be keyed in to subsurface activity.
3. You won’t find Brown Drakes just anywhere. It has to be the right place at the right time.
Brown Drakes are found in a variety of celebrated trout waters across North America.
In Big Sky Country, the best populations of Brown Drakes are found in the lower Missouri River near Cascade, MT, the upper Gibbon River in Yellowstone Park, and in the Railroad Ranch section of Idaho’s Henry’s Fork. Another renowned Gem State fishery, Silver Creek, has an infamous Brown Drake Hatch as well.
Simply knowing that Brown Drakes are found in a certain watershed is not enough to guarantee your success in witnessing the revered spectacle that these massive mayflies create.
Brown Drakes have very specific and limited habitat requirements. Within a given body of water you will find some reaches that produce massive numbers of Brown Drakes, and others that are devoid.
Knowing the right habitat to look for is critical to finding Brown Drakes. The nymphs are borrowers with distinct tusks for digging u-shaped tunnels into fine gravel and silt substrates. They prefer large areas of quiet water with gentle currents over fast paced riffles and runs.
Fishing the Brown Drake hatch and spinner fall by and large requires playing the waiting game. A large part of the thrill that Brown Drakes create is the suspense that builds while you sit and watch as an early summer evening fades away. The sun drops. The air cools. And, slowly the river comes to life.
If you find yourself sitting on the banks of the Railroad Ranch, or any other water that has a good population of Brown Drakes, at a time when the hatch is happening, and daylight is getting scarce, but you haven’t seen a single dun or spinner, there is a good chance that you have parked yourself on the wrong piece of water. Consider a change of venue, and search for quiet water with a fine gravel or silty substrate.
Now get out and find some Brown Drakes!
Whether you are fishing the Holy Waters in Michigan, the mainstem of the Big D, or the Millionaires Pool on the Railroad Ranch, do everything you can to catch the Brown Drakes. It’s one of the pinnacles in the sport of fly fishing for trout. But, bear in mind, in addition to the storied evening hatches, you could see some great fishing with spinners in the mornings and early afternoons, sometimes a nymph could be your best fly, and like Dr. John said, make sure you’re not in the wrong place at the right time.
Hook: MFC 7000, Barbless MFC 7000KBL, or equivalent. Size 14
Thread: Danville 6/0 Rusty Brown or your choice
Tail/Trailing Shuck: Sparkle Emerger Yarn – Brown
Abdomen: Superfine Dry Fly Dubbing, Olive
Thorax: Olive Goose Biot, tied flat side up
Wing post: Calf tail, white. Try using a synthetic like tan or grey Widows Web as a “cheat” if you are tying these on your own!
Hackle: Grizzly, tied parachute style. Whiting 100 packs are a great way to get the perfect feathers for parachutes.
Notes: My Para-shuck series of dries, tied by MFC, is a variation of the classic parachute style and has worked well for us all over Yellowstone Country. The Flav Para-shuck in particular works great on Hebgen Lake during the Callibaetis hatch, in the NE Corner of the Park for drake mackerel emergers, and on the Madison and Henry’s Fork for its original purpose as a Flav imitation.
Every fall in Yellowstone Country there is a tiny mayfly in the Baetis family that is responsible for some outstanding dry fly fishing. These miniature mayflies range from size 20-26, but what they lack in stature they more than make up for in abundance, and mystique.
Massive emergences of these bugs are commonplace in the fall on legendary rivers like the Henry’s Fork, Madison, Big Horn and Missouri. For generations fly anglers have called this bug Pseudocloeon (Sue-doe-clee-on) or Pseudo for short. However, in recent years the entomology community has re-classified the taxonomy so many times that it is hard for the average angler to keep up; consequently, many anglers have no idea what these little olive mayflies are actually called.
Iswaeonanoka is the current genus and species of the mayfly formerly known as Pseudocloeonedmunsi,Pseudocloeonanoka, Heterocloeonanoka, Baetispunctiventris and Plaudituspunctiventris. As is always the case, fish could care less about taxonomy, and old habits die hard. The name Pseudocloeon is so ingrained in fly fishing culture that it is hard to imagine a day when fly bins have the name “Anoka” on them instead of “Pseudo” or even “BWO”. There’s also no telling how many more times this little bug will be renamed. So, in deference to fly fishing history, and practicality, the mayfly formerly known as Pseudocloeonedmunsi, now known as Iswaeonanoka will be referred to as “Pseudo” for the purposes of this article.
The genus Pseudocloeon was first described by Frantisek Klapalek in 1905 from samplings of mayflies he obtained in mountain streams that drain volcanoes in Java. Similar specimens were found in Argentina, and of course, the American West. The main differentiating feature of these mayflies is the absence of secondary wings. Most mayflies in their dun (subimago) and spinner (imago) stages have large primary wings and small secondary wings. Pseudos are missing these secondary wings all together. Aside from their diminutive size, this is one way to tell them apart from their larger Baetis cousins who are sometimes hatching at the same time in the spring and fall.
Pseudos, like others in the Baetidae family, are multi-brooded. There is a hatch in the spring and one in the fall. Eggs laid in the spring have a shorter gestation period as water temperatures are warmer during the summer, and spawn the fall hatches. Eggs laid in the fall have a longer gestation time as water temps are cold in the winter, and spawn the spring hatches.
Pseudo nymphs are strong swimmers and inhabit a wide range of habitat types from pea gravel to large cobble, and long strands of weeds. These tiny (size 22–26) nymphs have two elongated tails and a body coloration that ranges from light olive to tan with dark brown wing pads. Their aptitude for swimming makes them difficult targets for feeding trout; therefore, nymph imitations fished deep are often unproductive.
As good as Pseudo nymphs are at swimming, they are equally lousy when it comes to emerging. Nymphs ascend quickly from the bottom of the water column then pause just under the surface riding the current for some time before they struggle to break through the water’s surface tension. Small nymph imitations fished in, or just below the surface, although challenging, can be very effective.
The emergence process is a clumsy affair for Pseudo duns too. Many duns have difficulty freeing themselves from their nymphal shuck. Half-emerged duns ride the surface for great distances with their trailing shucks trapped in the water’s surface tension. These vulnerable emergers are an easy meal for feeding trout, and patterns dressed with cdc or deer hair to imitate a partially emerged wing, and synthetic materials for a trailing shuck are a must have for selective fish.
Once emerged, Pseudo duns will display a variety of body coloration depending on location and sex which can range from light olive to a vibrant, chartreuse green. Duns have dusky gray wings with no secondary wing, and two long tails that are a striking, chalky white.
Emergences occur during the afternoon, and unlike other Baetis mayflies, strong hatches do not rely on scuzzy weather. Pseudos are perfectly content emerging in vast quantities on sunny days as well as cool, cloudy ones. Though, on especially warm, sunny fall days emergences might not happen until an hour or two before dark.
Pseudo spinners generally return to the water at dusk, and are often present in the drift with duns and emergers during evening emergences. They too lack a secondary wing, but their primary wings are glassy clear. Body coloration can span the full spectrum of greens, but is many times bright apple-green. Adult female Pseudos lay their eggs under water. After mating the females will routinely land on stream side objects and crawl into the water to deposit eggs.
The mayfly formerly known as Pseudocloeon has undergone massive changes in it’ s taxonomy. Yet, despite several new names and an altogether different genus, it remains the same tiny mayfly that hatches in incredible numbers producing memorable dry fly sessions with trophy trout on many of our favorite rivers in Yellowstone Country.