Mayflies
Written By: Dick Babine
Jason Neuswanger of
troutnut.com and Richard J. Babine of
richard@thebabines.com have generously authorized the use of all macro photographs used in this chapter.
| Kingdom: |
Animalia |
(Animals) |
| Phylum: |
Arthropoda |
(Arthropods) |
| Class: |
Insecta |
(Insects) |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemerellidae, Baetidae, Heptageniidae, Leptophlebidae, Potamanthidae, Ephemeridae, & Leptohyphidae |
| Genus: |
Attenella, Baetis, Callibaetis, Epeorus, Maccaffertium, Paraleptophlebia, Ephemerella, Stenacron, Isonychia, Ephemera, Potamanthus, Hexagenia, & Tricorythodes |
Common Names: Mays, Mayfly, Up-wings, Duns, Dippers & Spinners
If there is one aquatic insect that is always associated with the art of Fly Fishing, then the May Fly is this insect. The Mayfly has been referred to as the very foundation of the sport. Since the year 1496, the Mayfly has been known to have a great influence for the angler. Dame Julianna Burners of England described the dressings for a dozen imitations that are known to catch fish. The journal that contained this information was called Treatys of Fyshing with an Angle. In the 1600s both Issac Walton and Charles Cotton wrote on the subject and started a splurge of writings promoting the use of Mayfly imitations and this insect became the symbol associated with the art of fly-fishing. Whether you are watching a film, video, movie or reading a book, magazine, or article on Fly Fishing, you will be told that the May Fly is the Holy Grail insect. There are 23 Families, 119 different Genera and over 500 North American species of this important insect. The good news is that only a very small portion is of importance to the Maine fly angler.
In Maine there are over 162 species. Maine also has the distinction of having more species of Mayflies than any other state in the union. The reason for this is the state is located perfectly between the two major geographical regions. Maine sits at the northeast corner of the Southern Region and in the southeast corner of the Northern Region. To this add the fact that this state is somewhat free of the type of pollution that greatly affects the quality and numbers of these insects.
All aquatic insects are under a constant attack from insect predators such as; their own kind, diving beetles, salamanders, frogs, back swimmers, birds and of course the fish.
These Mayflies have a technical name of, (Ephemerellidae) which translates into the phase, “lives but a day”. These insects emerge from their underwater world without mouthparts and therefore can’t eat. Now, you know why they were thought to live only but a day. We now know that these insects can live for several days.
There are four basic types of nymphs in the Mayfly Order. There are, starting from the bottom of the streambed, burrowing nymphs, crawling nymphs, clinging nymphs, and last but not least, the free-swimming nymphs. The crawlers are variable in size and generally inhabit areas of medium and slower currents; they consist of the prolific Ephemerellidae family, the weak-legged Leptophlebiidae family and the very small insects of the Tricorythidae and Caenidae families.
The clingers, that hang out in slow to fast riffled areas of the stream, are of the fast-water Heptageniidae family and the very large Baetidae family is made up of fast swimmers, while the burrowing types are of the families Ephemeridae, Potamanthidae and Polymitarcyidae.
The eggs of the insect are deposited on or in water differently depending on the species. In some species the female will skim across the surface of the water in order to dislodge the eggs from her abdomen. Another species will fly across the waters surface and drop yellow or orange egg masses onto the waters surface. Some female mayflies will even use a protruding stem, leaf or other organic structure to crawl into the water in order to safely deposit her eggs at the bottom of the water column and others will actually dive into the waters surface in order to break the surface tension, then release the eggs underwater. Once the egg lying has taken place the exhausted insect will often times fall onto the surface of the water only to be taken by fish that have observed it from below the water’s surface.
After time, which in some species can be as little as a few hours and in others the time can be several months, these eggs will hatch and an immature nymph will then crawl under the stones of a riffle or the medium to large rocks or boulder of a run, burrow into the silt or muddy area of the slower currents of pools or the nymph may cling to the under sides of submerged vegetation or the branches of a fallen tree along the banks or shoreline.
There are even some species that will be free-swimming aquatic insects that will swim around areas of aquatic vegetation and/or any structure that has been created by fallen shoreline or banking debris.
Most of the Mayfly species have three tails but there are some that only have two.
These tails are visible throughout most of the developmental stages. All will have six legs with one sharp claw on each foot. In the adult the tail can be as long as the insect itself. There are generally 10 abdominal segments with moving gills along the sides of the insect.
The Mayfly goes through an incomplete metamorphosis, which simply means that the insect does not go through the larval stage common to most other aquatic insects. This Mayfly Life Cycle starts with adult female depositing eggs in or on the water. The eggs then fall slowly onto the lake or stream bottom and in time will develop into an aquatic creature called an immature nymph. These nymphs are classified into four basic groups: Burrowing, crawling, clinging, and free-swimming. The Burrowing nymphs like areas that have a either slow or very calm current with a soft bottom made up of rich silt, fine sand, decayed organic debris and marl bottoms of pools, eddies and quiet stretches of river and streams, as well as, the firm bottom-muck of cool lakes and ponds. The free-swimming nymphs will inhabit areas where there is plenty of natural structure such as, aquatic vegetation and heavy aggregate bottom areas. Some fast swimming nymphs will also inhabit a riffled area. The Crawling nymphs will inhabit areas of moderate to fast current. Most species have weak legs and are very poor swimmers. They will inhabit the moderate currents among vegetation, gravel and the rubbled bottoms of the water column. Some will even exist in the riffled waters and also the faster current of runs.
The Clinging nymphs love the faster and highly oxygenated waters of the riffles. This nymph has a classic flattened appearance with their heads and bodies designed for the faster currents. Nymphal life cycles can range from between 3-4 weeks to 2.5 years depending on the species of the insect. This process skips the common Larval Stage that most other aquatic insects go through, thus the incomplete life cycle that I mentioned earlier.
These Mayfly Nymphs can spend as little as six (6) months or as much as the next two years (give or take a month or two) Borrowing, Crawling, Clinging, and Swimming around the bottom of the water column.
The period of time spent as a Nymph will depend on the specific species of the Mayfly. For instance the Baetis Mayfly can complete up to three life cycles in a years time. However, the Hexigenia limbata mayfly will require slightly more than two years completing its life cycle.
Nymphs will feed on algae, diatoms, plankton, vegetable or decaying organic matter and microscopic organisms. As the aquatic insect grows, the outer skin, which serves as a skeleton, limits the ability of the nymph to enlarge. In order to continue to grow this insect must from time to time, shed or molt the hard exoskeleton.
Once the hard shell has been removed the insect will secrete a fluid from its epidermal cuticular membrane, which will harden into another exoskeleton in which the nymph can grow.
The period of time between these molts is called an “instar” and many species will molt some 20 to 30 times before emerging into the air-breathing world above. Between the molts and during the instars the nymph is very vulnerable to its principal animal, bird, fish, amphibian and insect predators such as: dragon fly nymphs and adults, diving beetles, frogs, back-swimmers, salamanders, swifts, swallows and phoebes. The mayfly nymph will spend nearly 95% of its entire lifespan below the waters surface.
When the Nymph reaches maturity it will transform into a ‘sub-imago’. The sub-imago is what we see emerge or hatch from the Nymphs. They are not an adult but are fully winged. This insect is called a Dun and must go through one more molt before becoming a sexually mature, “imago”.
Now, the year has gone by and the Mayfly Nymph along with tens of thousands of other Mayfly Nymphs begin to instinctively desire to leave their aquatic environments and rise to the air breathing world above. What really triggers this event can be debated by those much wiser that I. There seem to be two schools of thought allowing us to consider two options. These options are that the processes are either biological or environmental. The biological explanation is that during the last few weeks of the mature Nymphs life stage, gasses will form between the Nymphal Shuck (outer shell) and the immature Mayfly. Over time the gas will greatly affect the insect’s ability to remain below surface and the gas will create positive buoyancy sending the insect to the surface whether it likes it or not.
The other real factor is the water temperature. When an area of water reaches a temperature of 50 degrees and maintains that temperature range for three consecutive days, there will be a Mayfly hatch. You could even include the two by allowing the gases to expand as the water temperature increases. In any event, we all know that in the spring, the fly angler will eagerly await this ritual.
The four stages and length of cycles of a Mayflies life cycle are:
1. Egg (Ovum, 1 to 3 Days to Several Months)
2. Nymph (Nymphal 14 Days to 24 months with 20-36 Instars)
3. Dun (Sub-imago 1 to 4 days)
4. Spinner (Imago 1 to 2days)
This process of aquatic insects rising towards the surface is called an Emergence. Yes, I know that everyone refers to this event as a Hatch but you know the truth and that is that nymphs hatch from eggs and emerge from the water as duns. Every species has its’ own emerging characteristics and time table. As the insects rise toward the surface, they become very vulnerable and fish will feed readily on them. During this emergence, fish will become very selective to the physical size, color, shape and actions of the emerging species.
Once on the surface the newly emerged Mayflies will either remain in the waters current or attach itself to a partially submerged limb or rock in order to then separate themselves from their skins or shucks – or more appropriately called exoskeleton, spread their wings, pump fluid into the veins causing the wing to strengthen in order to support flight. The Mayfly will float on the surface of the water, like little sailboats, with its newly inflated wings acting as sails being dried and blown around by the wind. This surface activity can last for only a few seconds to only a few minutes. Once the wings are dry enough and strong enough the insect will take flight. After taking flight, the sub-imago usually rests on the shoreline vegetation for 1 or 2 hours or 1 or 2 days depending on the species, while gradually going through the last molt and transforming from sub-imago into adult (imago or spinner).
These Mayflies can emerge like this by the thousands and is an experience that will be remembered by any angler encountering it for the first time, because it almost looks like a blizzard. These mass emergent patterns are the Mayflies main defense against its natural predators, among them being fish and birds. They will hatch in such great numbers, condensed in both time and location, that the before mentioned predators are unable to rally their troops for a mass consumption.
This hatching process is natures why of a guaranteed survival rates that will allow the species to thrive. After this transformation, the adult will still take one day to three weeks to become sexually mature. The sexually mature adult male spinner will mass in swarms over the waters surface. The characteristics and timing of the nuptial flight or mating swarm will vary from species to species. Once the selection and the mating activities have occurred the male will shortly die and the female will wait for low light conditions before depositing her eggs, then she too will die and fall to the surface of the water only to be consumed by a waiting fish. The dead or dying adults will then lie on the waters surface with wings spread and, at that point, is referred to as ‘spent’ spinners.
Most Mayflies have one or two generations per year but can range from a couple to weeks to a few years. This whole process completes the lifecycle of egg (ovum), nymphal (larval), dun (sub-imago) and finally the sexually mature adult spinner (imago).
In order to identify this aquatic insect, you start at the upright wings. If you look closely the wing will resemble a stained glass window. Among other characteristics, the wings veins or venations are used to classify these insects. The other real important characteristic of the wing is its appearance. Are the wings clear and shiny or slightly discolored or opaque? The shiny wings will indicate that the insect is getting ready to lay its eggs and the slightly discolored or opaque wings will indicate that the insect has just hatched. This insect will usually lay its eggs during the low light conditions of dusk or a dark overcast day.
Since our quarry will consume nearly 85% of its nutritional needs below the waters surface, then it only seems proper that we should have a working knowledge of this all important food source.
Now, let’s assume that you have decided to dive head first into the more technical aspects of the sport. This subject is called Entomology and to be more specific, Aquatic Entomology. You will quickly find that there is no shortage of reading material or videos covering this subject matter. The study of aquatic insects can drive a person into buying a can of worms.
Imitations, When, What and Where
The basic problem is the trout is a master of survival in an otherwise cool, shallow, fast moving and ultimately hostile environment. The fish’s basic survival is directly attributed to its’ ability to find an area that provides the four necessities of life; comfort, food, proper habitat and shelter. When the fish start to feed on aquatic insects, they will almost always become selective to the most prevalent species. They will intentionally ignore anything that doesn’t imitate the same size, shape, color and action of the most prevalent emerging species. The angler’s observations will dictate the required pattern. During the various emergences, the need for different imitations to duplicate the size, shape, texture, color and required action is demanded in order to be consistently successful.
The advanced or expert angler will also react to the fish’s feeding behaviors that may shift from the sub-surface nymph to the surfaced, struggling dun or to the egg laying or spent spinner. This is the key to the entire problem of what to use and when to use it.
Let’s look at the source of all these imitations that are required for our fly box. Almost all of the Entomology books that I’ve read or seen, concentrate their efforts on insects found in the West and Mid-Western rivers plus the more famous Eastern streams. In fact, they are known for including European species that are not even in this country. There is some mention of Northern New England aquatic mayflies but sadly I found them all too short and many times all too inaccurate. That is not to say that all these mayflies weren’t important, because they certainly are but only to those that frequent those particular waters.
I was eager to learn all about the aquatics of my home waters here in Maine.
I started quite some time ago attempting to solve the riddle of what should the average fly angler carry in his/her fly box that would help during any circumstance occurring on any body of water in our home state. Yes, I know it’s a tall order but like most problems, the answer was considerably easier that the question. If you’ve heard any of my lectures or attended any of my classes then you know that I like to keep things real simple and easy to understand.
I started the process just like everyone else and that was to read everything that I could on the subject, watched endless videos and talked to those who were much wiser than I and wanted to share their precious knowledge. I also utilized information received from professional entomologists, numerous authors, university entomology department heads, professional associations, Iowa State Entomology Index, University of Maine Entomology Department, The Smithsonian Entomology Department, Troutnut.com, The Federation Of Fly Fishers, University of Illinois Department of Entomology, Trout Unlimited and every angler I ever met on any body of water.
At first glance, the problem seemed rather formidable. Just go to the L.L. Bean, the Kittery Trading Post and any local Tackle Shop and check out all the fly cases and see the hundreds and hundreds of patterns that have been tied to imitate your favorite natural. Then take a look at the variety of books dedicated to your favorite aquatic insect and you will find hundreds and hundreds of imitations there too. In fact, the largest percentage of imitations sold and listed in pattern books are actually imitations of insects not even found in our northern New England area let alone our state waters.
Remember that we have over 500 species of Mayfly and that’s impressive, but we only need to know about the species that exist in our home waters and identify those that would be the predominate species at any given time. Thanks to a lot of work done by a lot of other people; I feel very strongly that this number can be safely reduced to a little more than 20 imitations. How this occurred is by the process of elimination.
The key to understanding which fly to use, is solved by your own observations to figure out which food source interests the fish at any given time or place. This can be accomplished in any of four different ways. First, the angler can catch a fish and determine the fish’s diet from the stomach contents, which would be the most prevalent food source just prior to the catch. The second technique would be to catch the very same thing that the fish was catching and try to match that food item with an imitation from your fly box. Third, you could take a seine net and obtain an accurate sample of all the biological drift and determine the most prevalent food source from the samples in the net.
Last but certainly not least, is the ability of the angler to use nature as the guide to understanding the environment and obtain the various clues to determining the best possible choice. This done by careful observations made as you approach the water. Be alert to any insect activity at or high above the water. Check for bird activity that may be a sign of prominent insect activity. Check the streamside vegetation and the rocks on the edge of the water. Take the water temperature and use a seine net or pull some smaller rocks and boulders to see what’s crawling or clinging to there undersides.
Our task is to reduce the numbers of imitations in our fly box but without affecting our ability to match the hatch. In Maine there are really only six out of the 23 Families that are of any real importance to the fly fisher. Yes, I know that all the other mayfly families can catch fish. But you have heard me more than once admitting that I play the odds and like to keep things simple. The state of Maine has about 162 species of mayfly, well I know how to get rid of 142 of them leaving only 20 left, and here is how it’s done.
Many mayfly families simply don’t do well this far north and therefore emerge sparsely and infrequently, resulting in a hatch that seldom becomes the prominent species, so I didn’t consider them at all. A large number of early and mid-season species were not considered because they are simply outclassed by more significant mayfly and caddisfly hatches. Others were not considered simply because they don’t emerge until after dark and most anglers don’t or won’t fish after dusk. I then eliminated several species that emerge only sporadically throughout the day. Some May Flies only emerge for a few days then just disappear. Now, although for those very few days they may be the dominant species, you would have to be very lucky to be there when the hatch occurred, so their importance is very questionable. Other facts that helped reduce the numbers were imitations that can quite easily imitate more than one family, genus and species of mayfly. The last groups to be eliminated were those whose differences were so minimal that only a trained entomologist could tell the difference and even though fish can be very selective during an actual emergence, even the smartest wouldn’t be able to tell the difference.
Now, I know that every fly eliminated will catch fish on any given day with the right circumstances but we still have within our box an imitation that will be just as effective. Always remember that a few minutes spent searching for the most prominent insect emergence will eliminate countless hours of pure angling misery.
So, I concentrated my efforts on the selection of flies that will cover the most prominent hatches and yet still be able to imitate other species the same time. By doing this, the angler can have the ability to reflect the characteristics of several different species and can cover a multitude of selection errors, at the same time.
The end result is a list of 20 flies that should provide a very close match for almost any circumstance that the Maine angler might encounter. These 20 Mayflies are also numbered based on their probable emergence dates and periods of prominence.
Tricaudatus Dun (sub-imago) |
tricaudatus Nymph |
tricaudatus Spinner (imago) |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Baetidae |
(Blue Winged Olives) |
| Genus: |
Baetis |
(Small Blue Winged Olives) |
| Species: |
tricaudatus |
(Small Eastern Blue Winged Olive) |
| Nymphal Type: |
(Fast Swimmer) |
| Nymphal Pattern: |
Wet Hare’s Ear #18 - #20 |
| Emergent Pattern: |
Wet Hare’s Ear #18 - #20 |
| Dun Pattern: |
Olive Adams or BWO #18 - #20 |
| Spinner Pattern: |
BWO Sparkle Winged Spinner #18 - #20 |
Nymphal Activity
This is one of the most prolific Blue Winged Olive species. The Baetis tricaudatus species is multibrooded. This means that there can be as many as three or four generations of the same insect during one fly fishing season.
Nymphal Migrations: April 7 - July 14 - October 14
During the first week of April these nymphs will start to migrate to the quiet side currents in preparation for the first of three emergent periods.
The first emergent period is about the middle of April to the end of the month.
The second generational migration will be around the first week of July and the emergence will be around the middle of July to the last week of the month.
The third generational migration will be around the first week of October and the emergence will be around the middle of the month.
Size is usually everything, but because of their great numbers far outweighs their small size and explains their great importance.
These nymphs are very strong swimmers and can in fact find area riffles and runs quite comfortable as fine waterfront properties in which to establish their homes. They will remain there, feeding and going through their various in-stars until they become mature nymphs. Once the water temperature reaches at least 50 degrees for about three consecutive days, the nymphs will prepare for emergence.
Emergent Activities: Apr 14-May 14 / Jul 14–Aug 14 / Oct 14–Oct 21 @ 10-2pm
This move down-stream to slower currents is to facilitate the difficult emergent activities. Once in the proper emergent location and sometime between 10am to 2pm, these nymphs will attempt to shed their Nymphal shucks and rise towards the waters surface. Once at the surface but still beneath the surface film (Meniscus), the newly hatched duns (sub-imagos) will struggle to break through the surface film and escape their former watery world and enter their new air-breathing worth. Of course all this activity has not gone unnoticed by area fish. This act of emerging places the newly hatched dun in a very vulnerable situation and any nearby fish will take advantage of this feeding opportunity. Once on the surface these very wet immature duns will ride the currents drying their wings, looking very much like little sailboats, blowing around the surface of the water. Once again, the fish will take great pleasure in removing these small insects before they fly away.
Once the insects’ wings are dry enough to support flight, the new dun will fly off to surrounding stream-side vegetation. Once safely off the water and occupying the local vegetation, the insect will go through one more change and that is a final molt into the sexually mature adult spinner (imago).
Spinner Activity: Apr 14 – May 14 / Jul 14 – Aug 14 / Oct 14 – Oct 21
Just a short few hours before dusk the male spinners will form a mating swarm above the riffles. These sexually mature spinners will fly all over the riffle location and occupy the waters entire width. At dusk, the females will arrive from surrounding vegetation and fly into the mating swarm. The insects will mate in mid-air, after which, the exhausted male spinners will fall to the waters surface. Once again, the local fish are more than ready to except nature’s gift.
Once the females now fertilized egg sacs have been squeezed from their lower abdomens, the females will then dive to the waters surface and crawl down the down-stream sides of rocks, aquatic vegetation, and other partially submerged debris. Once at the bottom, the female spinner will deposit a single strand of eggs to the sub-strate. Once the egg laying has been completed, the exhausted female spinner will join her male counterpart as a spent spinner. And you guessed it, the fish have indeed noticed all this activity and will scurry about grabbing as many of these spinners as it possibly can.
Fishing Opportunities
Remember that this species of Mayfly is multi-brooded and we can expect three generations to hatch during a single season.
Around the second week of March the Nymphs will migrate downstream to calmer waters prior to the first generational emergence of late April to the second week of May.
This same sequence will repeat itself come the middle of July and again in late September.
Maine’s #2 Mayfly, The Black Quill
cupida Spinner |
cupida Nymph |
cupida Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Leptophlebiidae |
(Black Quills & Blue Quills) |
| Genus: |
Leptophlebia |
(Black Quills) |
| Species: |
cupida |
(Black Quill) |
| Nymphal Type: |
Feeble Legged Crawler but swims well |
| Nymphal Pattern: |
Pheasant Tail Nymph #20 |
| Emergent Pattern: |
Wet Dark Hare’s Ear Nymph #20 |
| Dun Pattern: |
Dark Blue Winged Olive #20 |
| Spinner Pattern: |
Sparkle Winged Blue Winged Olive #20 |
Nymphal Migration: Apr 21
These medium sized mayfly aquatic insects will not produce and major hatching activity, but their medium size and many peculiar habits, force the educated angler to consider their importance for early season success.
Although these mayfly nymphs are classified as Feeble Legged Crawlers, these cupida nymphs are fairly good swimmers. As with most classified crawlers, this species prefers areas of slower currents.
This makes perfect sense because cupida nymphs feed off decayed leaf matter that settles in the nocks and crannies of rocks, gravel, and other substrate debris in the areas of quieter currents.
Come around the middle of April, and the water has warmed up to 55 degrees, this species of mayfly will demonstrate its’ first very peculiar behavior. As though a message was sent through the entire community, every area nymph will start to migrate downstream en masse to the quieter waters off eddies, back-currents, and small pools. In order to achieve this mass exodus to the calmer waters downstream, sometimes the migration will cover surprisingly great distances.
Needless to say, that all this sudden activity will not go unnoticed by area fish.
Emergence Activity: May 7 - Jul 14 @ 2-4pm
Once these nymphs have reached a suitable emergent location, the next days’ late afternoon sun will display the cupidas’ next peculiar behavior. At about 3 to 4pm and on cue, all these nymphs will make several practice runs to just below the waters’ surface. These pre-emergent activities will cause quite a commotion and no doubt create great interest from local fish.
Once the practice is over, the nymph will rise to and attempt to break through the surface film. This emergent activity and the fact that this particular species has a very difficult time, ridding itself of its nymphal shuck, will once again, cause area fish to investigate all the commotion. The newly hatched dun (sub-imago), will twist from side to side, skitter across the waters surface, and otherwise make quite a commotion, which will once again, result in every nearby fish racing in to take full advantage of natures offering.
Spinner Activity: May 7 - Jul 14
Once the dun gets off the water, it will like most other species, fly into the surrounding stream side vegetation and molt into the sexually mature imago (Spinner). At about 5 or 6pm, the males will begin to create a mating swarm above the rough water. The females will follow an hour or so later and fly into the mating swarm, mate in mid-air with the males. The exhausted males will fall onto the waters surface as Spent Spinners. The female will return to the stream side vegetation. Once the female has squeezed the now fertilized egg mass from her lower abdomen, she will fly over to the rough water and repeatedly dive into or onto the water in order to dislodge the egg mass from her lower abdomen. Once the oviposting (egg depositing) has taken place, the exhausted female will join her male counterpart and fall to the waters surface as a Spent Spinner.
All this activity will create great feeding opportunities for any interested fish in the area.
Maine’s #3 Mayfly, The Speckled Dun
fluctuans Dun |
fluctuans Nymph |
fluctuans Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Baetidae |
(Blue Winged Olives) |
| Genus: |
Callibaetis |
(Speckled Duns) |
| Species: |
fluctuans |
(Speckled Dun) |
| Nymphal Type: |
Darting Swimmer |
| Nymphal Pattern: |
Sawyer’s Pheasant Tail Nymph #16 |
| Emergent Pattern: |
Tan Hornberg or Hare’s Ear #16 |
| Dun Pattern: |
Gray Quill #16 |
| Spinner Pattern: |
Gray Quill Spinner #16 |
| Emergence |
Water Temperature 50
April 21 – October 15
3pm – Dusk |
In some still waters, damselflies provide explosive angling for unusually large trout, and on other waters fish wouldn’t survive but for the presence of midges; but taken as a whole, no bug dominates more waters than the Callibaetis mayfly.
If you have never experienced this prolific emergence, you just can’t imagine the sheer numbers of these insects and the feeding frenzy that they can cause for active fish.
Nymphal Migration: Apr 14 Jul 7 Sep 14
The C. fluctuans are among the largest in the multi-brooded Baetidae family. They will occupy both, slow or still waters. These are highly specialized nymphs that can dart minnow-like in the calmer waters when not perched on the shafts of aquatic vegetation or on the slowly undulating soft foliage of aquatic growth.
Most of the important species range from 7 to 12mm in body length, while those of the Baetis, who prefer riffles and faster water, average between 5 and 8mm.
They are also dissimilar to the B. baetis by their three tails of equal length.
Emergence Activity: May 7 - Jun 14 Jul 14 – Aug 14 Sep 14 - Oct 14 @ 3pm to Dusk
These nymphs are multi-brooded and as many as three generations will hatch in a single season. They can first hatch as early as early April and continue sporadically into late May. They will show their true colors during the early summer by having large emergent activity until late August and then although the hatches will continue, they will become less intense into early September.
This nymph will lose its middle tail during the transformation from nymph to dun. Look for the hatches to be in the quiet waters of eddies, pools and the side currents of runs.
Callibaetis duns emerge on the surface and usually are airborne rather quickly after emergence. These nymphs will make several trips to and from the surface before the actual hatch, which is also common in the Ephemerellidae family. The hatch may last for up to several hours during the cooler overcast days that are preferred by this species. The hatching activity will vary from species to species and the timeliness of emergence will also vary according to whether the conditions are harsh or favorable in each geographical area. This means that on some waters, these insects are important from the middle of April until well into the month of September.
Their uniquely speckled or mottled wings quickly identify the duns of this genus. They also will lose their middle tail in the transition from nymph to the sub imago adult. Of the 28 some species, only three are considered very important to the northeastern fly fisher.
Spinner Activity: May 7 - Jun 14 Jul 14 - Aug 14 Sep 14 - Oct 14
In their sexually mature adult stage (imago), the wings lose most of their colors and appear spotted and splotched and take on the appearance of a delicate lace.
A very interesting characteristic of this genus is that these nymphs hatch from the fertilized eggs almost as soon as they hit the water. In order for this to occur, the females will delay normal oviposting activities for up to five days.
Callibaetis (pronounced cal-uh-BAIT-is) are highly tolerant of ecological extremes and will be found in alkaline desert ponds, roadside ditches, sewage treatment plants, and even tidal marshes. It seems however, that the Callibaetis is best suited for those waters that nurture trout, and every Western weedy lake that holds trout will have its population of Callibaetis.
The Callibaetis nymph is available 365 days of the year and it predictably hatches throughout the entire fishing season. The Callibaetis is a fly fisher’s dream; it acts in predictable ways and trout key in on that predictability. The angler who takes the time to understand the ways of the Callibaetis will cross rods with far more trout than he imagined possible.
The Callibaetis belongs to the Baetidae family of mayflies. The Baetidae are extremely important to the fly fisher because many of its members are multi brooded. That is, the nymphs mature exceedingly fast and several generations will emerge within a single season. Compare this to the average mayfly which hatches only once in a brief annual flurry.
The Callibaetis is the most perfectly proportioned of all the mayfly nymphs. The head is slightly narrower than its shoulders and the slender body tapers to three equal length tails that are about as long as the body. Seven pair of heart shaped gills fringe each flank of the abdomen. The sweeping antennae are over twice as long as the head is wide. The only other stillwater nymph that might be confused with the Callibaetis is the Siphlonurus whose antennae are short and stubby by comparison.
The coloration of the Callibaetis is as variable as the waters in which it dwells and the nymphs can change color quickly to match their environment. Because of the tremendous variation in the color of Callibaetis nymphs, I’ve never known trout to be too picky when it came to the coloration of the artificial. The earth tone hues of the pheasant tail nymph seem to be universally accepted by even the most finicky fish.
The nymphs have neither skin nor bones; they have instead, a semi-rigid exoskeleton that must be periodically instarred. The typical Callibaetis might undergo a twenty or more such instars throughout the winter.
Early in spring, gasses begin filling the void between the exoskeleton and the body within. As the pressure builds, the exoskeleton starts to swell and the nymph becomes unnaturally buoyant. The exoskeleton stretches thin and radiates a shimmering glow as light reflects from the taught skin and interior gasses. Perhaps to lessen the uncomfortable pressure, the nymph starts crawling upwards. This isn’t happening to a lone individual, but to dozens, hundreds, or perhaps thousands of nymphs at the same time. Up the reeds, and up the rocks, up the stumps, and even up the legs of wading anglers these nymphs migrate toward the sun.
When these swelling nymphs lose their footing or try to swim, the buoyancy in the trapped gasses lifts them away from familiar surroundings and they desperately swim back down to the protective cover. Soon they will lose footing again and once more be buoyed towards the surface and once again the nymph will struggle back down to cover.
Just after the sun appears, in the eastern sky, all season long this dance is taking place. The trout grow attuned to the daily rhythm and come to expect the meal that is rightfully theirs. The knowing angler will oblige them.
Gas-filled Callibaetis nymph at surface
Get out on the water around six am. Rig up a floating line with a standard nine foot leader then guestimate the depth of the water you are about to fish. To the end of the leader tie on a 6X tippet one and a half times the depth of the water. In eight feet of water you’ll use a twelve foot tippet. Tie on a pheasant tail nymph of the appropriate size (we’ll get to that in a second). With a series of roll casts work out the line, leader and that hellacious tippet. You will be pleasantly surprised that the tippet isn’t as ghastly as you might have imagined. Lay the line out over the water and be happy as the tippet piles into a big heap.
The nymph will immediately begin to sink, pulling the skinny tippet down with it. Start counting, "one one-thousand, two one-thousand, three one-thousand," etc. As the tippet dives through the film it will create a “V” shaped wake with the point of the “V” facing the angler. When the “V” turns into a circle or dimple, it means the nymph has landed in the weeds and is no longer pulling the leader downward. At this point stop counting and remember the number. For the sake of this article let’s pretend that number was eight.
Retrieve the nymph and pull all the weeds off the hook. Cast it out again, watch that “V” and start counting. At seven, draw in line with the stripping hand and make one very slow, very long strip until the stripping arm and hand are extended behind you. Trap the line against the cork with rod hand and let the nymph fall. Watch that “V”!
By retrieving at seven you stopped the nymph just short of the weeds. The long slow strip does a good job imitating the nymph being buoyed to the surface and the subsequent fall of your pheasant tail mimics the real nymph’s frantic return to cover. This is what the trout expect. When the fish inhales the pheasant tail, the nymph will of course stop sinking and the leader will no longer be making a “V”. It will come to a standstill and the water’s surface will simply dimple around the leader. If the fish starts to swim with the nymph (usually they never stop swimming, they just intercept the nymph and keep on cruising) the “V” will reappear with the point of the “V” pointing the direction of the trout’s travel. Tighten up.
The 6X tippet might seem like a terribly fine connection between you and those lake hogs, but not to worry! Because the tippet is so long it harbors tremendous stretch and will easily control most trout. The skinny tippet is necessary to cut through the water with a minimum of resistance as the nymph falls.
Callibaetis Dun - Note the light veins on the dark background.
As the morning progresses and the gas pressures continue to build within their exoskeletons, the nymphs acquiesce to nature’s demands and rise to the surface to hatch. At the surface they hold just beneath the film with only the hump of the thorax breaking the meniscus. Within moments the thorax splits and the adult emerges. The mayfly pulls its head and then its legs out of the husk of the exoskeleton. It sprawls the legs out across the water and, levering down against the surface tension, draws the wings and abdomen out of the shuck. Only the tail remains in the husk and then it too pulls free leaving the mayfly to drift across the surface of the lake as it hardens its wings.
In the spring the insect is dark sooty gray so that it will quickly absorb the sun’s warmth. As the hatches progress through the season, the Callibaetis are born with increasingly lighter hues to reflect the hot summer sun. In the fall, as temperatures drop, the mayflies once again emerge in the darker colors. The bellies of a Callibaetis are always lighter than the dorsum. No matter the season, all the Callibaetis will have distinctively light colored veins that contrast with the relatively dark wings giving them a speckled effect, hence the common name the speckled dun.
As the majority of the nymphs drift up from the weeds and converge on the surface, so do the trout. Here the feeding is easy, and at times gluttonous. The fish often disregard the nymphs and duns to feast on the hapless emergers. The emergers can neither swim nor fly away and the trout feed at their leisure.
I use two patterns to imitate the emergers: the mayfly cripple, originated by Bob Quigley and the Bivisible Dun. The mayfly cripple hangs at an eighty degree angle in the water so that the marabou on the distal end of the shank dangles in the water like the discarded exoskeleton. A few turns of hackle hold it in the film and a post of elk hair creates the silhouette of the upright wings of the emerging dun. It is a classic, killing pattern, but the Bi-Visible Dun is even more so.
The shuck of most still-water mayflies does not dangle below the emerging dun, but is stuck against the tacky underside of the film and extends out from the emerger. The translucent Zelon hangs just below the film and looks amazingly like the slipped shuck of the real bug.
The Bivisible Dun is a sparkle dun pattern with an upright post of white calf body hair stacked against a post of black calf body hair. The beauty of the bivisible post is that the fly can bob into and out of shadows or glare, and one or the other post colors will be easily seen. I use this pattern for fishing just about any mayfly hatch when visibility is compromised. When hatches are dense, the bivisible post acts as an exclamation point telling the angler exactly which fly is his. Even on heavily fished waters with discriminating trout such as the Henrys Fork and Silver Creek, the fish don’t seem to mind the odd looking wings. The Bivisible Dun also makes a great midge pattern because it can be seen even when fished on size 24 and 26 hooks.
A nice thing about fishing emergers is that size isn’t too important. The nymph might be a size twelve and the dun a size fourteen (remember the dun had to fit inside that nymph), but the emerger can be fished all the way to a size ten because it is imitating a part of the nymph as well as part of the dun.
Once the duns leave the water they’ll retire in the lakeside vegetation to hide from the desiccating rays of the sun. The following morning the duns will begin walking around in circles and shudder and shake and act like they ate something awful. The wings spread and quiver then magically the thorax bulges open and a new mayfly quickly and efficiently emerges from the body of its old self. This new incarnation has translucent wings with only a trace of splotching on the leading edge. Like the dun, the hind wings are shriveled useless stubs. The forelegs are spindly, the eyes unnaturally large, and the twin tails are beautifully long and graceful. This is the sexually mature spinner.
The spinner has no mouth parts and the digestive organs have been replaced by reproductive ones. These are winged sex machines that have but one goal in their short lived existence. About mid morning (sometimes in the evening) droves of males rise from the riparian growth and form clouds of insects that fly high into the air and flutter back towards earth. When they reach the level of the riparian canopy (often nothing more than clumps of sagebrush), they burst heavenward once again then repeat their fall.
During the fall the males are releasing pheromones that waft downwind and attract the goggle eyed females. Thus aroused, the females flutter into the bobbing frenzy of males. From your float tube it is easy to discern the males acting like crazed yo-yo’s while the females execute crisp horizontal patterns through the melee. The insects briefly copulate in flight and the males go off to die.
Just about the time the morning hatch is winding to a close, the spinners arrive to lay their eggs. These are the mayflies one most commonly finds crawling all over his body and car during lunch. The female Callibaetis whisk along the surface of the water and dap their abdomens into the film to release showers of fertile eggs. The eggs hatch almost immediately and the cycle begins anew.
Callibaetis spinners can cause tremendous frustration. The angler is doing great during emergence but suddenly the fish no longer want his fly. The trout are still rising, but the pattern that was so successful twenty minutes earlier is ignored. Anticipate the spinner fall. The burnt out females (spent spinners) have no strength left after laying their eggs and wind up on the water with wings flush to the surface. They can be tough for the angler to see, but to trout they are very visible indeed.
As soon as spinners start landing on your arm or the trout begin to refuse your fly, tie on a spinner imitation, but not just any spinner. Most spinner patterns are junk.
The wings of the spinner had to fit inside the exoskeleton of the dun. To fit, they were folded up nice and neat like Geisha fans. When the wings unfolded, they didn’t unfold all the way, but retained their pleats. When the crystal clear, corrugated wings of the spinner lay flush on the water, they trap air in the folds and bends light rays every which way.
From an underwater vantage below and a few degrees to the side of the spinner, the wings are like windows. Through them the sky, the clouds, and the seagulls are clearly seen. This is in sharp contrast to the water on which the spinner is bound which is reflecting the dark bottom of the lake. From directly beneath the spinner, and those pleated wings now glitter like diamonds and spew rainbows like the micro prisms that they are. Compare that to the artificial burnt chicken wing pattern that looked so cool in the fly shop.
The best spinner patterns are barely there; a little fuzz on the hook and a wispy loop of Zelon to suggest the possibility of wings. Add a couple of strands of sparkle organza to add flash and a prism. Not perfect, but usually good enough. The CDC biot spinner also works well because it too has sparkle organza and the fluted CDC feathers trap air like the real spinner wings.
Maine’s #4 Mayfly, The Trico
stygiatus Nymph |
stygiatus Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Leptohyphidae |
(Tricos) |
| Genus: |
Tricorythodes |
(Tricos) |
| Species: |
stygiatus |
| Nymphal Type: |
Multi-brooded Feeble Legged Crawler |
| Nymphal Pattern: |
Hare’s Ear (Shaped Accordingly) #22 |
| Emergent Pattern: |
Trico CDC Emerger #22 |
| Dun Pattern: |
Hair-winged Trico #22 |
| Spinner Pattern: |
Head to Head Spinner #22 |
| Emergence |
Water temperature 52 -56
July 7 through Sep 14
Males at Night and Females at Dawn
Dawn – 10am |
These very small Mayflies are commonly referred to as the White Winged Curse by most fly fishers because of their size. These Mayflies are tiny and will often emerge in the calmer waters below riffled areas or at the heads of quiet pools. Their surface-wide, reliable and heavy hatches will draw out the larger fish that will rise selectively to these small food morsels.
Nymphal Migration: Jun 21 - Jul 14 - Sep 7
Fishing these Mayflies will place demands on the even the most technical dry-fly angler’s skills. The emergence will take place with the males emerging during the night and the females will become active just after dawn and continue until the sunlight covers the water. As far as, the fly angler is concerned the males are of little importance since their hatching activity is during the hours of darkness. As the days become cooler, this entire process will take place well after sunrise. The nymphs appear to be much smaller versions of the Hendrickson Nymph. The Tricos are also Multibrooded and will be active from the middle to late July with the resultant generations continuing the hatching activity into September.
Emergence Activity: Jun 28 - Jul 21 - Sep 14 @ Female Dawn – 10am : Male Dusk to Dark
This species will certainly test both your skill and patience. The emergence activity tends to be more intense during the heat of July and August. Later in the season, when most other Mayfly species have come and gone, their activity will become sporadically active through most of the morning. Remember also that the emergence will take place both on the surface and just below the meniscus.
Spinner Behavior: Jun 28 - Jul 21 - Sep 14
Once emerged, the tricos will return as spinners, sometimes within only a few minutes or a few short hours. These sexually mature adults will gather in very tight mating swarms rather than roaming the water bank to bank.
After mating, the males will fall as spent spinners and the females will fly towards the banking areas to rest for about an hour. While there the females will squeeze their abdomens and small green egg masses will be ready to be dropped onto the waters surface.
Tactics
Remember that these very small Mayflies are especially susceptible to microdrag. This drag is created by the imitations connection to the tippet and will create a small almost imperceptible motion that is in the fishes eyes, unnatural. Remember that the fish spends its life seeing things drift along the currants naturally, and unnatural movement too subtle for us to detect is very obvious to their specialized senses. To eliminate this problem, use full-hackled imitations. Also, make sure that your patterns have hooks with up-turned eyes, which have a larger gap in the required small sizes.
Maine’s #5 Mayfly, The Quill Gordon
pleuralis Dun |
pleuralis Nymph |
pleuralis Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Heptageniidae |
(March Browns, Cahills, Quill Gordons) |
| Genus: |
Epeorus |
(Little Maryatts & Quill Gordons) |
| Species: |
pleuralis |
(Quill Gordons) |
| Nymphal Type: |
Two Tailed Clinger |
| Nymphal Pattern: |
Dark Olive Brown Hare’s Ear # 16 |
| Emergent Pattern: |
Wet Hare’s Ear or Wet Quill Gordon # 16 |
| Dun Pattern: |
Quill Gordon #14 |
| Spinner Pattern: |
Dark Epeorus Spinner #14 |
| Emergence |
Water Temperature of 50 degrees
May 7 – May 30 @ 1 – 2pm |
Nymphal Migration: Apr 21
The 2-tailed epeorus nymphs require fast, pure water with very little or no pollution. The nymph needs vast amounts of highly oxygenated water, which is supplied by rapids, riffles and swift, gravelly runs. They cling to the bottoms of large gravel, rocks and boulders. Their flat heads, bodies and disc-like gill plates enable them to retain their tough existence in this turbulent environment. A unique activity of these nymphs is that they will migrate to the downstream sides of rocks and boulders where they will congregate a day or so before their emerging activity.
Emergence Activity: May 7 - Jun 14 @ 1-2pm
The best Epeorus hatch in Maine is E. pleuralis, the famous Quill Gordon, the first abundant large mayfly hatch of the year. Epeorus vitreus (Sulphur) will comes a little later and is the second most important hatch of the season.
At nature’s signal, which is a water temperature of 50 degrees or more for several consecutives days, these nymphs will migrate in large groups to the downstream side of the larger stones, rocks, and boulders. Once there, they will escape their nymphal shucks on the streambed and rise to the surface. Once started, this nymph will hatch daily even if the springs unpredictable weather and temperatures can drop back to the forties rather quickly. Once on the waters surface, this dun will float along with the currants for quite sometime before making several failed attempts to air-born.
Spinner Activity: May 7 - Jun 14
Once emergence takes place and the adult spinners will return in 3 or 4 days to hover over the riffles. These mating swarms will usually occur during the warmest part of the day, between noon and 2 P.M. and during the warmest days of late spring heat of 75 to 80 degrees, these spinners will return in the late afternoon or early evening. Female Epeorus spinners oviposit by making repeated trips the water’s surface to deposit eggs, resting periodically before taking of to the streamside vegetation, only to repeat the whole process over again and again until all the eggs have been released from the females abdomen. You should remember that these imagoes mate, oviposit and fall as spent spinners in the white pocket-water or heavy runs.
Tactics: #1
Because of the females repeated trips oviposting, a wet fly that represents an emerging Quill Gordon is one of your best tickets to success, during the hatch.
Fish will lurk in the small eddies and the smaller pools to opportunistically feed of this free lunch. These areas are just downstream from the riffled area where the insect have completed their mating activities and when they fall onto the waters surface where the currents will carry the spent spinners to waiting fish.
Now having said the above, even though these sub imagoes usually emerge in the riffles and pocket-water, pay special attention needs to be given to the downstream heads of pools where the helpless duns are swept along to the quieter waters below.
Tactics: #2
This species is often times hatching along with other species of Mayflies, with dense numbers of larger and more available March Browns, Hendricksons and other Stones, as well as, Caddis. In the spring use a tandem setup of a primary imitation of either a small Black Stonefly Nymph or Caddis Larva and then a secondary Mayfly offering. This gives that necessary advantage to you and not the fish. Imitations should be fished in a way that will effectively simulate the emerging duns. Cast across and downstream and allow the imitation to drift across the feeding lanes and various lies. When the current starts to straighten the tippet, the imitation should be forced from the bottom to simulate the rising (emerging) dun.
When duns are being intercepted near or in the surface film, fly fishers need to cast upstream and allow the fly to float drag free to the feeding fish.
Maine’s #6 Mayfly, The Blue Quill
adoptive Dun |
adoptive Nymph |
adoptive Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Leptophlebiidae |
(Black Quills & Blue Quills) |
| Genus: |
Paraleptophlebia |
(Blue Quills) |
| Species: |
adoptive |
(Blue Quill) |
| Nymphal Type: |
Feeble Legged Crawler |
| Nymphal Pattern: |
Sawyer’s Pheasant Tail Nymph #18 |
| Emergent Pattern: |
Wet Hare’s Ear #18 |
| Dun Pattern: |
Dark Blue Quill #18 |
| Spinner Pattern: |
adoptive Compara-Spinner #18 |
| Emergence |
Water Temperature of 50 -55 degrees
11am – 5pm |
Nymphal Migration: Apr 28
Because these feeble legged crawling nymphs are very poor swimmers, they usually prefer the quieter water such as slow runs, side-currents and pools. As this nymph matures, it will migrate to slightly slower currants. They can also be found in eddies and back-3ddies that have the faster water and moderate, gravelly runs. This nymph can also be found anywhere that detritus has accumulated which serves as an excellent hiding place with a built in food source. P. adoptive nymphs feed on decaying organic debris during the daylight hours and then change their diet to algae covered rocks at night.
The spring species P. adoptive and P. mollis nymph mainly prefer moderate currants then their fall cousins P. debilis whom prefer the quieter waters of slower pools, eddies and backwaters. Once these insects are well into their mature Nymphal stage, they will migrate to calmer currants to hatch.
Emergence Activity: May 7 - Jul 7 @ 3-4pm
During the emergence, the nymphs will attempt to swim towards the surface in a real awkward and clumsy way.
Once they leave their bottom hiding places, they are at the complete mercy of both currents and fish. Once on the waters surface, these duns are quick to get air-borne.
Spinner Activity: May 7 - Jul 7
A few days after the start of hatches, around midday, the spinners will begin their nuptial flights. The males will hover high above the riffles in swarms and the females will fly into the swarm and select a mate. After copulation, the females will repeatedly dip their posteriors into the water time and time again until the eggs have been deposited into the water. Having completed their duties, the male and females will fall as spent spinners onto the waters from whence they came.
Although the sub imagoes usually emerge for a one-week period, the spinners will be busy for a couple of weeks. Spinner flights will occur progressively later in the day as the hatches peak until the best flights will occur during early evening.
Tactics:
Have you noticed the repeated use of Frank Sawyer’s gift to the fly fishing sport. Frank was a river keeper in jolly old England and protected his employer’s rivers and streams from being overly fished and unlawfully attacked by those pesky peasants. His pattern was a result of years studying the nymphal activity of his beloved English rivers and streams. Trout will gorge themselves on these emerging insects, so a nymph pattern can be deadly. Fish this pattern drag free through medium runs, the slower pocket water and side eddies for quick results.
You can also fish the emerger pattern drag free in the surface film to entice the fish that are feeding just below the surface.
When the duns are on the water’s surface, trying desperately to get airborne, switch to a hackled imitation and fish with occasional twitches, to simulate this emerging activity.
Maine’s #7 Mayfly, Large Eastern Blue Winged Olive
lata Dun |
lata Nymph |
lata Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemerellidae |
(Hendricksons, Sulphurs, PMDs & BWOs) |
| Genus: |
Drunella |
(Blue Winged Olives) |
| Species: |
lata |
(Large Eastern Blue Winged Olive) |
| Nymphal Type: |
Fast Water Clinger |
| Nymphal Pattern: |
Dark Hare’s Ear Nymph #12 |
| Emergent Pattern: |
Wet Dark Hare’s Ear Emerger #12 |
| Dun Pattern: |
Blue Winged Olive #12 |
| Spinner Pattern: |
Sparkle Wing Blue Winged Olive |
| Emergence |
Water Temperature: 50 – 60 degrees
May 7 – July 28th
10am – 2pm |
Nymphal Migration: April 28
These nymphs will become very active; during the period just after the water temperature maintains the proper temperature for several consecutive days. The lata nymphs will begin to migrate from the fast riffled waters to the slower currents downstream. Once located in the slower currents, these nymphs will become quite active by splitting their exoskeletons and escaping the bottom of the water column. While rising towards the surface, the insect will shed the nymphal shuck, and then rise to the surface as an immature adult dun.
Emergent Activity: May 7 - July 28 @ 10-2pm
This activity will start around 10am and continue until the middle of the afternoon, between 2 and 4pm. Unlike most of the mayflies, Drunella lata, emerges as an immature adult dun. Once on the waters surface, quite wet and still very weak, this insect will ride the currents until its wings are dried and can support flight. Also directly after emergence, this insect will change color very rapidly. The bright green body will become a muted olive to reddish brown. Once airborne, the insect will fly to surrounding vegetation and go through one more change and that’s to molt into the sexually mature adult spinner.
Spinner Activity: May 7 - July 28
This activity will occur between 7pm and dusk. As with most mayflies, the Drunella lata males will form mating swarms above the riffled waters, as the sun starts to set. When dusk approaches, the females will fly into the mating swarm and mate with the males. The males will fall as spent spinners and the females will wait with patience until the sun has set. At dusk and just before the early dark hours the females will fly high above the riffled waters and jettison her egg sacs into the rough water. The female will then join her male counterpart as a spent spinner.
*Note*
Because of two factors, particular to this species, the spinner activity is not very productive for anglers to try and imitate. One is the fact that most of the spinner activity is close to the dark hours of the evening and two the female oviposting is done high above the riffled area and the eggs are dropped onto the water.
Maine’s # 8 Mayfly, The Pale Morning Dun
excrucians Dun |
excrucians Nymph |
excrucians Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemerellidae |
(Hendricksons, Sulphurs, BWOs, & Pale Morning Duns) |
| Genus: |
Ephemerella |
(Hendricksons, Sulphurs, & Pale Morning Duns) |
| Species: |
excrucians |
(Pale Morning Dun) |
| Nymphal Type: |
Feeble Legged Crawler |
| Nymphal Pattern: |
Dark Hare’s Ear Nymph #18 |
| Emergent Pattern: |
Wet Hare’s Ear #18 |
| Dun Pattern: |
excrucians Compara-Dun #18 |
| Spinner Pattern: |
Sparkle Winged Dark BWO #18 |
| Emergence |
May 7 – July 7 3pm – Dusk
Water Temperature 55 – 60 |
Nymphal Migration: April 28
When the water temperature reaches between 55 and 60 degrees, these nymphs will start to migrate to smooth, calm waters below the riffles and/or medium fast runs. They will particularly look for areas surrounding vegetation. Once there and the low light conditions of either dusk or a cloudy, cool late afternoon, these nymphs will prepare to head for the surface.
Emergence Activity: May 7 - June 28 @ 3pm to Dusk
The excrucians nymphs will rise to beneath the surface and ride the currents for quite some time and then attempt to break through the surface film. Once through the surface film, these nymphs have a difficult time shedding their nymphal shucks. Once rid of their nymphal baggage, the newly hatched dun will float for quite some time before its wings are dried enough to support flight. During the emergence and subsequent fight to break the surface film and shed its shuck, many of the nymphs will be either crippled or stillborn. As you have learned by now, all this activity has not gone unnoticed by area fish.
Spinner Activity: May 7 - June 28
Emerged duns will retreat to the surrounding vegetation and of course molt into the sexually mature spinner (imago). This process can take one or two days and then the males will form the customary mating swarms and yes, the females will come along enter the swarm, and mate with the males.
Unlike other species of mayflies, this mating activity will render both genders exhausted and the males will immediately fall as spent spinners and the female will attempt to jettison her two bright green egg sacs onto the water but more often than not, she will fall to the waters surface with the egg sacs still attached.
Having said all that, this creates problems for both the fish and the angler. The fish will of course selectively feed on the most prevalent activity. We of course have a great difficulty in determining what activity the fish has chosen. Because a selective fish may target a floating dun, an emerging nymph, sub-merged rising nymph, a cripple, spinner, or stillborn insect, this is one of the most puzzling hatches in all of fly fishing. Let’s add to that problem, the fact that because these insects are small, hook size #16 - #18, such small imitations are very prone to microdrag…tight lines.
Maine’s #9 Mayfly, The March Brown
vicarium Dun |
vicarium Nymph |
vicarium Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Heptageniidae |
(March Browns, Cahills, Quill Gordons) |
| Genus: |
Maccaffertium |
(March Browns & Cahills) |
| Species: |
vicarium |
(March Brown) |
| Nymphal Type: |
Clinger |
| Nymphal Pattern: |
vicarium Compara-nymph #14 |
| Emergent Pattern: |
Wet March Brown #14 |
| Dun Pattern: |
American March Brown #14 |
| Emergence |
May 21 – June 21 11am – 7pm
Water Temperature 55 – 60 |
Nymphal Migration: May 14
The Maccaffertium vicarium nymph is the largest and first of these species to emerge in northeast waters. These nymphs are easily identified by their wide angled 3-tails. Each tail is almost 90 degrees to the others. They are one of the most popular mayflies in Maine waters, because these naturals usually emerge sporadically throughout the day, providing an easy day on the stream. Like the other clingers, they have the flattened head and body, including the femoral portion of the legs. This profile allows them to withstand the fast currents of riffles and runs.
Like most other clingers, they are extremely sensitive to environmental pollution and reduced oxygen levels of the water. For that reason, they prefer to hang out on the undersides of rocks and stones in the riffled areas of a stream.
They will feed on algae and detritus by scouring these rocks and other stones by holding on for life with single hooks located at the end of each of its six legs. These nymphs will usually migrate to downstream to the pools, quiet eddies and side currents of runs. The nymphs will often drift along the currents for long distances and thereby offering numerous opportunities to waiting fish.
Emergent Activity: May 14 - July 14 @ 11am – 7pm
These nymphs are no different than other nymphs with respect to migrating downstream to calmer waters just prior to emergence.
After the migration to the slower side- currents and calm eddies, the nymph will wait until the low light conditions of pre-dusk before attempting the rise to the surface.
During the emergence, these clumsy nymphs have a hard time getting off the water. They will flutter and bounce across the surface in their various attempts to achieve flight, creating such a disturbance, which often incites a feeding frenzy.
Spinner Activity: May 14 - July 14
The spinner flights will usually occur just before dusk. Once the mating activity is complete, the female will dip her egg laden posterior into the water time after time to deposit the fertilized eggs. This is another activity that drives fish crazy. Oviposting done, the female will fall spent to the waters surface, joining the male who has preceded her.
Tactic: 1.
A weighted Sawyer’s Pheasant Tail nymph fished on the bottom to imitate the swimming and crawling motions of the active nymphs is deadly.
Tactic: 2.
A unweighted Sawyer’s Pheasant Tail nymph, tied on a dry fly hook. During emergence, nymphs labor strenuously in or just below the surface film to escape their shucks, causing such a commotion that fish find it irresistible. With your unweighted offering, grease your leader from 12 inches above the imitation to the butt section. This will cause the imitation to drift just below the surface thus imitating the insects repeated attempts to enter the air-breathing world.
The duns have great difficulty in getting off the water, so wade to the middle of the stream, and then you can be in position to cast your offerings to the deep side of pools while you rest the shallow edges. The shallow edges will often out-produce the more often fished deeper water. These emerging duns are a large sized treat for any opportunistically feeding fish.
Maine’s #10 Mayfly, The Hendrickson
subvaria Dun |
subvaria Nymph |
subvaria Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemerellidae |
(Hendricksons, Sulphurs, PMDs & BWOs) |
| Genus: |
Ephemerella |
(Hendricksons, Sulphurs & PMDs) |
| Species: |
subvaria |
(Hendrickson) |
| Nymphal Type: |
Fast Water Crawler |
| Nymphal Pattern: |
Prince Nymph #16 |
| Emergent Pattern: |
Deerhair Emerger #16 |
| Dun Pattern: |
Light Hendrickson (Female) #16
Red Quill (Male) #16 |
| Spinner Pattern: |
Rusty Spinner #16 |
| Emergence |
April 14 – June 14 12pm – 6pm
Water Temperature 50 – 60 |
| Spinner Activity |
4- 6pm |
The Ephemerellidae are by far the most important family of Mayflies for the Maine angler. Most of the species within this family are known and called Hendricksons. The Sulphurs of this same family belong to the genus Ephemerella.
Nymphal Migration: April 7
A particular oddity of this family is that the two genders (Males and Females) often will occupy different location in the same stream. The Female Hendrickson prefers the slower currents and the Male Hendrickson prefers the faster currents of the same stream. Also to make matters confusing, the males and females often are different colors and sizes. The male has the appearance of being slender and fragile, and has a mahogany-colored body. The male has large red eyes and smoky bluish wings. This insect is perfectly matched by a classic, Red Quill dry fly invented by Catskill-tier, Art Flick in the 1930s.
The female is the larger of the two, but with much smaller eyes. She has the same smoky bluish-gray wings, but the body and thorax are much lighter colored with a pinkish-yellow hue. The Hendrickson dry fly created in 1915 matches this female.
I mention this to alert you to the fact that you probably will need to match the specific gender, color, and size that is emerging in your stretch of the stream.
Look for the subvaria in the sandy or graveled areas and also on or about the surrounding aquatic vegetation of the slower waters.
These 3-tailed nymphs have a migrating instinct, which causes them to seek out convenient emergence sites adjacent to or within the fast-water currents.
This mayfly hatch is one of the most exciting and the first prolific hatch of the early season.
This species provides excellent dry fly opportunities for the Maine angler.
Emerging Activity: April 14 - June 14 @ 2-4pm
Once emergence activity starts, daily hatching is normally very reliable. Emergence may take place at any time between noon and 6p.m., but peak activity is usually between 2p.m. and 4p.m., when the water temperature is ideal. The Hendrickson is another mayfly that has the unusual habit of making several practice runs toward the waters surface. Another habit of these creatures is that the nymphs will crawl up underwater structures to get closer to the surface. In doing so, the nymph is at the mercy of the fast currents and will get knocked off its perch and become caught up in the biological drift.
Some Hendrickson duns emerge laboriously in the surface film, where emerger and floating patterns give the angler the best opportunities for success. Others shed their nymphal shucks on the bottom of the water column, some during the rise to the surface, or immediately below the surface film. Most of these Hendricksons also present the angler with great wet fly action and the insect can take quite a long time to dry its wings, once reaching the surface.
This emergence is the most prolific and reliable hatch of the season. They wiggle enticingly during their ascent and like others of this genus; usually take several attempts to break through the surface tension. These nymphs are dark brown (almost black) in color, with some highlights of dark amber or dark olive.
Because of their unusual behaviors of being in or on exposed location, making repeated trips towards the surface, unsure footing as it climbs to the higher emergent sites, and getting caught up in the biological drift, the emerging insects of this family are a Maine Anglers favorite hatch.
Spinner Activity: April 14 - June 14
This activity will begin with the males forming the mating swarm. Soon the females arrive and mate leaving the exhausted males to fall to the water as spent spinners. The females will fly upstream to the riffled waters and drop to the water to release two very yellow egg sacs onto or into the water. The females will join the males as spent spinners.
Tactics:
In order to simulate the erratic swimming actions of this nymph, in the slower water, you should twitch the imitation with very short and rapid motion. In the faster waters, a drag-free drift is required with no nymphal movement.
Even though the Hatch Schedule indicates an emergence of late May to late June and the basic time frame should be from midday until 6 P.M. with a peak between 2 and 4 P.M., you need to consider the following conditions that will affect this schedule. The exceptions are during the unusual cold, rain or heat waves that frequent our northern New England weather. Hot weather will delay a hatch until later in the day or in some cases, early evening. During any unusually cooler weather, the emerging activity will be sometime during the warmest part of the day. Also during these cooler hatches, the duns will float along with the currents for extended periods of time, thus making themselves more available to feeding fish.
Remember that inclement weather often provides the best fishing of the season. Accurate, drag free drifts are critical to success.
Tactics:
If you see a fish rising to take offerings in the same area time after time, you can assume that the fish is holding in a lie and will continue to stay there until driven out by a larger fish or spooked by an impatient angler. You can now determine your choice casting position and the proper imitation to lure the fish to your leader.
Now, what happens when the fish seems to be rising in different locations? The problem is that by the time your ready to cast, this same fish may be out of range or your casting position is all wrong for the situation facing you. Fear not, there are things that you can do to counteract this situation.
For one thing, stay clear of the wide, flat areas of the slower water. Instead, pay particular attention to the heads of these same areas or locate yourself in the tail of a pool where these duns and emerging insects are naturally funneled into a more concentrated mass. The big fish will almost always protect these optimum feeding lies and force out the smaller or weaker fish.
Another tactic is to fish the faster pocket water where fish will hold behind rocks, boulders and deadfalls within the white, rough faster waters. For surface feeding fish, use a dun pattern such as a subvaria Compara-dun drag free to the feeding lies or through the feeding lanes of opposing currents.
If you get repeated refusals, switch to a Hackled pattern that will imitate an emerging insect. Also, remember to throw in the intermittent twitching and skittering motions of the dun trying to break through the surface film. These above tactics are also very true of the Hendrickson and Red Quill imitations.
Maine’s #11th Mayfly, Little Yellow Quill
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Heptageniidae |
(March Browns, Cahills, Quill Gordons) |
| Genus: |
Leucrocuta |
(Cahills, Quill Gordons) |
| Species: |
hebe |
(Little Yellow Quill) |
| Nymphal Type: |
Clinger |
| Nymphal Pattern: |
Hare’s Ear (Lt. Tan) #18 |
| Emergent Pattern: |
Hare’s Ear Wet #18 |
| Dun Pattern: |
Deer Hair Emerger #18 |
| Spinner Pattern: |
March Brown Spinner #18 |
| Emergence |
Late May through September
Best time is June |
| Spinner Activity |
Late dusk into darkness |
Now, the genus, Heptageniidae is still an important genus in its own right, but Heptagenia no longer includes many of the key hatches it used to. Several important species have been moved to its sister genera Nixe, Leucrocuta, and Ecdyonurus.
Nymphal Migration: May 28
Heptageniidae contains the "clinger" type mayfly nymphs. They sport flattened profiles and strong legs suitable for life in very fast water. They also sport three tails with distinctive 60 degree flared profile. Some species have branched out from this role and are found in slow, warm, or even dirty streams, but they retain the flat bodies of their kin.
Two-tailed Nymphs
The closely related genera Epeorus and Ironodes are among the only mayflies to have just two tails as nymphs. They include the Eastern super hatch of Epeorus pleuralis, the Gordon Quills.
Emerging Activity: June 7 - September 14 Done & Gone
Many Heptageniidae mayflies emerge from their nymphal shucks on the stream bottom or during their rise to the surface. Others hatch in the surface film. Read about the species you need to match for full details. Heptagenia nymphs emerge very quickly, so emerger patterns are unimportant. The duns may or may not float long enough to get trout excited. Because these emergers leave the water so fast, fishing the Duns is mostly pointless, so fish the nymphs and emergers hard and often. Their hatch is often referred to as, Dun and Gone
Spinner Activity: June 7 - September 14
Because fishing the emerging duns can be damn frustrating, please take advantage of and expect good fishing during cool dark overcast late afternoons and at dusk on normal days, fishing the spinners.
Maine’s #12 Mayfly, The Sulphur Dun
vitreus Dun |
vitreus Nymph |
vitreus Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Heptageniidae |
(March Browns, Cahills, Quill Gordons) |
| Genus: |
Epeorus |
(Little Maryatts & Sulphurs) |
| Species: |
vitreus |
(Sulphur) |
| Nymphal Type: |
Clinger |
| Nymphal Pattern: |
Hare’s Nymph #16 |
| Emergent Pattern: |
Wet Hare’s Ear #16 |
| Dun Pattern: |
Light Cahill #16 |
| Spinner Pattern: |
ithaca Compara-spinner #16 |
| Emergence |
June 7 – July 14 2 – 7p.m.
Water Temperature 55 – 60 |
| Spinner Activity |
Late dusk into darkness |
Northeastern anglers praise this species because their arrival is one of the last predominant mayflies to hatch. This species will emerge from the first week of June through the last week of June. These insects are of more fishing importance of even the most respected hatches of the (E. pleuralis), Quill Gordons.
These insects inhabit a much wider range of water and therefore much more abundant. The E. vitreus emergence takes place after the waters have warmed up and many other Mayfly cousins have come and gone. By now the fish have accustomed themselves to surface feeding and this insect’s bright colors are to the fish, simply irresistible.
Nymphal Migration: May 28
These clingers live most of their lives in the fast wasters of riffles and runs. Some will migrate to the calmer waters of eddies and side-currents a few days prior to emergence. Unlike most Mayflies, this species will shed their nymphal shucks on the streams bottom before emerging to the surface.
During the dog days of summer, you should look for any cooler, overcast or rainy days. This type of weather will promote active hatching of this species during both the mornings and early afternoons. The duns of the vitreus species have the same color as their cousins but are slightly larger in size and the same color, is pale in comparison. The real good news is that if you carry dark brown patterns in three sizes, you can imitate all three species.
Emergent Activity: June 7 - July 14 @ 2-7pm
Once the emergence starts, these nymphs will break free of their nymphal shucks as they rise towards the surface. They will, like their cousins, drift along with the current for an extended period of time, drying their wings for flight.
Spinner Activity: June 7 - July 14
The delicate cream-colored duns will return to the riffles at dusk. These mating swarms will hover high above the rough water. Mating completed, the males will fall as spent spinners and the females will fly low over the water and repeatedly dip her lower abdomen into or on the waters surface to release the eggs. Following the oviposting, the female will then fall to the waters surface as a spent spinner. Once the spinner activity begins, it will only last for 30 to 45 minutes.
Tactic:
Remember that during low water conditions, the fish are quickly spooked. Your attention should switch to the deeper runs and pools. Your leader will also change because the imitations are smaller and may require a smaller diameter tippet and a more accurate presentation. After a catch, always rest the water or go elsewhere. Prior to emergence, fish these nymphs on the bottom with occasional twitches to imitate the crawling motions of the nymph as it instinctively migrates to the quieter waters to await the urge to reach for the air-breathing world above.
During the actual emergence, your patterns should be fished in the surface film and allowed to drift along drag free with the currents. Use fine-wired hooks for the surface work and the heavy-wired hooks for the sub-surface work.
Maine’s #13 Mayfly, Pale Evening Dun
dorothea Dun |
dorothea Nymph |
dorothea Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemerellidae |
(Hendricksons, Sulphurs, PEDs, & BWOs) |
| Genus: |
Ephemerella |
(Hendricksons, Sulphurs, & PEDs) |
| Species: |
dorothea |
(Pale Evening Dun (PED)) |
| Nymphal Type: |
Feeble Legged Crawler |
| Nymphal Pattern: |
Hare’s Ear Nymph #16 |
| Emergent Pattern: |
Little Maryatt Wet #16 |
| Dun Pattern: |
dorothea Compara-dun #16 |
| Spinner Pattern: |
dorothea Compara-spinner #16 |
| Emergence |
June 7 – July 14 7p.m. – Dusk
Water Temperature 60 – 65 |
These nymphs are typical of their subgenera group, having the same robust features but supported by feeble legs. Because of the weaker legs this nymph prefers less turbulent waters that are located downstream from the riffles or in the various side-current of both rough and calmer waters. Their hatch is almost always incorrectly classified as a “Sulphur Hatch”. This also explains the often-used common name of a “Sulphur Dun”. The “Sulphur” activity usually occurs after the first week of May.
Nymphal Migration: May 28
This activity is caused by the invaria and rotunda species and not by dorothea. The E. dorothea hatches are usually later, when the invaria and rotunda activity has diminished to the point of completion. The easily recognized differences between E.dorothea and other members of this sub-generic group are both in size and color. The E. dorothea species are smaller (by 2 hook sizes) and much lighter in color. There are several other differences such as, thoracic markings, dorsal spines and the adult dun size of at least a hook size smaller than either the invaria or the rotunda species. Another important difference is that the hatches in the afternoon are without doubt, those of the invaria and rotunda species whereas the dorothea will hatch much later, just before dusk and of course later on in the season then those of its cousins. The last and real major difference is that the dorothea species prefer the quieter and calmer waters while their cousins the invaria and rotunda species are predominantly fast-water dwellers. I should also remind you that the fast-water cousins can be flushed or drift into the quieter dorothea waters of the heads of pools and side-currents, adding to the “Sulphur Myth”. These small, yellowish mayflies will make their appearance when the early warm days of spring turn into the much warmer temperatures of late spring.
Emergent Activity: June 7 - July 14 @ 7pm to Dusk
Shortly after the first series of hatches, the spinners will make their appearance above the riffles and mate in the usual generic fashion. The female will either jettison a single egg sac above the fast water or like others of her genera; dip her posterior into the water to release the egg sac.
Spinner Activity: June 7 - July 14
After the mating rituals and subsequent egg-laying, the spent-spinners will fall exhausted to the waters surface. These spinners will normally be active at dusk and as the season advances the spinner falls will take place just before dark.
Tactics:
Like the other Crawlers, dorothea emergers can’t swim so their efforts are very clumsy because they will wiggle enticingly in an effort to reach the surface and emerge as a dun. Bottoms bump your nymph pattern along the bottom, or fish your emerger pattern on the surface and don’t forget to add some action. Because it is possible for the early dorothea species to hatch overlap the late invaria and rotunda hatches, you must take care and observe whether the fish are taking dorothea or the larger invaria and rotunda species. During the start of the spinner fall, pick up a natural and carefully match the size, shape and color.
Maine’s #14 Mayfly, The Green Drake
guttulata Dun |
guttulata Nymph |
guttulata Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemeridae |
(Hexes & Big Drakes) |
| Genus: |
Ephemera |
(Big Drakes) |
| Species: |
guttulata |
(Green Drake) |
| Nymphal Type: |
Burrowing |
| Nymphal Pattern: |
guttulata Compara-Nymph #10 |
| Emergent Pattern: |
guttulata Deerhair Emerger #8 |
| Drake Pattern: |
guttulata Compara-Dun #8 |
| Spinner Pattern: |
guttulata Compara-Spinner #6 |
| Emergence |
May 21 – July 14 11a.m. – 4p.m.
Water Temperature 60 -68 |
These Mayflies are among the largest insects to emerge from the depths of our Northern, New England streams. Their hatching characteristics are notorious as well as, overpowering to both the fish and the angler. There are basically only three species of any importance to the Maine angler, E. guttulata, E. simulans and E. varia. The green (E. guttulata) and brown (E. simulans are each almost legendary for their short-lived but heavy, blizzard-like hatching characteristics.
The third species, yellow drakes (E. varia), have a slow but sporadic emerging characteristic, and therefore provide only a somewhat low-key importance. This is due to the short cycle of sporadic hatching activity of only a couple of weeks in duration. This makes them have a low degree of importance to the Maine fisherman.
So, the drakes of choice are the Green Drake (E. guttulata) and the Brown Drake (E. simulans). These Great Drakes, size, emerging numbers and hatching characteristics, have made them Maine’s favorite dusk and evening fly fishing action.
Two of our sports most famous writers, Al Caucci and Bob Nastasi described these drakes in great detail in their best selling book, Hatches ll.
“Too many afflicted Eastern fisherman, the “Green Drake Hatch is as irresistible and habit-forming as blackjack, whiskey or easy women.”
Nymphal Activity:
These E. guttulata nymphs have plumage-like gills arranged dorsally in two rows on their abdomen and their heads are adorned with fearsome tusks. They are also long and slender, looking more like a swimmer than a burrower. Remember that these large insects take more than one season to mature to the point of emergence. Although they burrow into silt beds, detritus and mud bankings as do those of E. simulans and E. varia, they can also be equally abundant in the faster runs and riffles where sand, silt and organic debris is collected between the rocks and boulders.
The cream-colored duns are erroneously referred to as the Yellow Drake and Yellow Dun. Oddly enough, the yellowish P. distinctus mayflies are commonly called Cream Duns and Cream Variants. This is why advanced anglers always use the less confusing scientific names to promote better and much more accurate communication.
Emergence Activity: May 14 - July 14 @ 11am – 4pm
These drake hatches will almost always, lure the largest fish into devouring these insects at the water’s surface, when their normal survival instincts would call for these larger fish to remain on the streams bottom, waiting for low light conditions before the rise to enjoy one of natures greatest food offerings.
Often, these great insects will emerge during periods of extended warm temperatures of the late spring afternoons.
The fishing can be challenging, since these large bugs are easy for the fish to observe, inspect and contemplate before consuming, thus the fish will feed very selectively during this rare day-light emerging activity and always well into the last period of the hatch.
During emergence, the E. guttulata nymphs wiggle temptingly towards the surface. Once there, the newly emerged dun will struggle by several attempts to get air-borne. At this time, you should utilize as much imagination as possible when manipulating your imitation. The best emergence takes place on days that have both low humidity and a water temperature of less than 70 degrees.
Spinner Activity: May 14 - July 14
Unlike the E. guttulata spinners that appear high at treetop level in swarms prior to ovipositing, the E. varia imagoes appear sporadically and are first sighted at shoulder height. The males will often appear prematurely and therefore must rest from time to time on the waters surface. During a good spinner-fall, many male spinners will rest intermittently on the surface film.
Once the females arrive and the mating activities are in full swing, the wise angler will select the best casting positions prior to the resultant spinner-fall. The first activity is when the female flies to the waters surface and rests on the surface trying to extrude her eggs. This in combination with the males falling spent on the waters surface plus the spent females is a real natures picnic for any fish around.
Maine’s #15 Mayfly, The Light Cahill
Interpunctatum Dun |
interpunctatum Nymph |
interpunctatum Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Heptageniidae |
(March Browns, Cahills, & Quill Gordons) |
| Genus: |
Stenacron |
(March Browns & Cahills) |
| Species: |
interpunctatum |
(Cahill) |
| Nymphal Type: |
Clinger |
| Nymphal Pattern: |
fuscum Compara-Nymph #14 |
| Emergent Pattern: |
fuscum Deerhair Emerger #14 |
| Dun Pattern: |
Gray Fox #12 |
| Spinner Pattern: |
fuscum Compara-Spinner #12 |
| Emergence |
June 14 – August 14 2p.m. – 7p.m
Water Temperature 55 to 65 |
This is the second major Stenonema hatch to emerge and usually follows the S. vicarium by a week or so. The name Light Cahill is usually associated with this species. While the name, Ginger Quill, is associated with the spinner of this same species. Although these hatches tend to be early evening activities, remember that in cooler overcast or rainy days, these hatches will be in the afternoon or in the rain.
Nymphal Migration: June 7
These are fast water clingers, so you know that they will be found in riffles and runs. The Light Cahill is a little smaller then the S. vicarium. Both species have the same migratory and emergent habits. During this emergence, the nymphs will abandon their bottom hiding places between the heavy gravel, rock and deadfall areas and crawl or clumsily in a swimming attempt, struggle towards the surface.
Emergence Activity: June 14 - August 14 @ 2 – 7pm
Once on the underside of the surface film, the newly hatched dun will make several vain attempts to break through the surface tension. Trout will feed eagerly on these drifting duns and a properly presented imitation is deadly. Just like the S. vicarium, most of your beginning hatches will be in the shallows of both eddies and pools. Remember that the weak, dead and crippled naturals will drift downstream to funnel towards waiting fish.
Tactics: When you locate a feeding fish, cast upstream and allow a drag free drift to the fish’s location. If the fish ignores your offering but takes another insect instead, change your presentation. Try the same cast but add a little motion to you imitation by twitching and skittering the fly. Chances are that the fish will now want your offering rather than taking a motionless natural. Keep in mind that the shallow, quiet waters below you can also provide excellent fishing.
Spinner Activity: June 14 - August 14
The fuscum spinner activities and falls will occur over the rough waters of riffles and white pocket-water.
Before the females arrive, the males will congregate high above the stream in mating swarms. Once this activity is sighted, you should take the time to tie on the appropriate spinner pattern and wade into the stream for a proper casting position. The casting position should give the casting angler the ability to cast from the rough, white water into the calmer pockets and side eddies on the streams edge.
This very impressive sight is your signal to prepare yourself for the soon to come, spinner falls. Usually within 30 minutes or so, the females will arrive; the mating rituals take place above the rough waters. Now, the fun begins because the female will fly to the waters surface and repeatedly dips her posterior into the waters surface to release the newly fertilized eggs. Their instinctive responsibilities complete, both the male and female mayflies will fall to the waters surface and waiting fish.
Maine’s # 16 Mayfly, The Leadwing Coachman
bicolor Dun |
bicolor Nymph |
bicolor Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemeridae |
(Hexes & Large Drakes) |
| Genus: |
Isonychia |
(Slate Drakes) |
| Species: |
bicolor |
(Leadwing Coachman) |
| Nymphal Type: |
Feeble Legged Crawler |
| Nymphal Pattern: |
bicolor Compara-Nymph #10 3x |
| Emergent Pattern: |
bicolor Deerhair Emerger #10 3x |
| Dun Pattern: |
bicolor Compara-Dun #6 4xl |
| Spinner Pattern: |
White Gloved Howdy # 6 |
| Emergence |
June 14 –October 7 7p.m – Dusk
Water Temperature 65 – 68 |
This mayfly is one of the largest and quite possibly most spectacular in the northeast. Its size is only surpassed by the mighty Hexagenia limbata. The hatch is considered to be one of the most thrilling of the season and many believe it to be the climax hatch of the northeast fly-fishing. Large fish that would usually be sitting on the streams bottom until dusk will often willingly rise with reckless abandon in the bright of day to grab these large tasty treats.
Nymphal Migration: June 7
These bicolor nymphs are among the best swimming insects in the mayfly world. They can dart around the fast watered riffle section with ease. Although their main food source is plankton, these nymphs are among the few mayfly predators and will also feed on midge larvae, caddisfly larvae and even smaller mayfly nymphs.
Emergence Activity: June 14 - October 7 @ 7pm to Dusk
Some of these bicolor nymphs will emerge by crawling out of the water onto the shore. Others will climb up rocks, boulders and other partially submerged objects. Of course, this activity pretty much negates any angler’s ability to take advantage of these emerging insects.
Spinner Activity: June 14 - October 7
When the new Dun completes the last molt, the insect becomes a sexually mature imago adult Spinner. The insect now has front legs of brown and feet of white. This gives you the origin and name bicolor. Another twist of names is the fact that this insect will stand on its middle and hind legs, with the front bicolored leg extended outwards. This gesture in combination with the two different colored front legs looks as if the insect is reaching out to greet you, thus the Spinner name of White Gloved Howdy.
Around three days after the first emergent activity is observed, the spinners will make their appearance. Emergence usually takes place sporadically all day with a peak around 7 to 8 P.M. Fish will take the easy offerings of the awkward, struggling duns and spinners. An hour or so before dusk, the male imagoes can be observed high above the waters. They will descend lower and lower, with the sky so thick with them, it will look like a snowstorm in July.
Just before the arrival of the females, the males will be seen hovering erratically just above the waters surface, awaiting the arrival of the females.
Every now and then, some of the males will land on the waters surface to rest, causing the premature rise of smaller, unknowing fish.
At this point, I would like to mention a most peculiar trait of this mayfly. On the cloudy or overcast and sometimes rainy days, you already know that the emergence activities are different in that the activity will be much earlier in the day. This will result in the male making his appearance a few hours early. The resultant premature mating flight will exhaust the impatient male forcing him to fall the surface of the water frequently to rest.
While somewhat rested, the male will attempt to get airborne but still somewhat weak will struggle to get off the water. These impatient male will even attack newly hatched females in their frustration to instinctively mate. It is not unusual to observe two or three males clumsily clasp to an uncooperative female dun. This impatience just causes the group to fall onto the waters surface providing yet another opportunity to waiting fish not to mention the anxious angler.
Once the females finally show, the nuptial flights commence, followed by the males falling to the waters surface as spent-spinners. Eggs fertilized, the female will begin to fly high above the riffled areas and drop her egg sacs onto water and then join her male counterpart and fall to the waters surface as a spent spinner.
Maine’s #17 Mayfly, The Great Leadwinged Drake
limbata Dun |
limbata Nymph |
limbata Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemeridae |
(Hexes & Large Drakes) |
| Genus: |
Hexagenia |
(Large Drakes) |
| Species: |
limbata |
(Leadwinged Drake) |
| Nymphal Type: |
Burrower |
| Nymphal Pattern: |
limbata Compara-Nymph or Maple Syrup #6 |
| Emergent Pattern: |
limbata Deerhair Emerger #6 |
| Hex Pattern: |
Nelm’s Caddis or limbata Compara-Dun #6 |
| Spinner Pattern: |
limbata Compara-Spinner #6 |
| Emergence |
June 21 – September 21 7p.m. – Dusk
Water Temperature 60 – 70 |
Nymphal Activity
The nymph of the genus Hexagenia and Litobrancha recurvata are the largest mayflies in North America. These burrowing nymphs thrive on marl-rich, siltaceous bottoms laden with detritus. In these slow moving waters, the nymph gets its oxygen by undulating its body and plumage-like gills.
These areas can exist in lakes and ponds as well as areas between rocks, boulders, deadfalls and other submerged structures in rivers and streams.
These large nymphs can take as much as two years to mature enough to emerge as duns. They will molt every 24 days or so and can go through some 30 molts before their emergence.
Emergence Activity: June 21 - September 21 @ 7pm to Dusk
During the emergence, the nymphs evacuate their burrows and ascend towards the surface reasonably fast considering their rather poor swimming capabilities. Once in the surface film, the newly hatched duns have great difficulty shedding their nymphal shucks. This problem will require them to remain on the waters surface for up to 10 or 15 minutes. You can imagine the commotion made and how it would create easy opportunities for the fish, let alone a number of birds eager to participate in nature’s banquet.
Spinner Activity
The mating swarms, nuptial flights and resultant spinner-falls all occur sometime after 9 P.M. Most anglers don’t bother because of the lateness but to those of you that feel adventurous, here’s the schedule. In some rivers and streams, the hatch and or spinner fall happens usually between 10 PM and 4 AM. , and can be as little as a 20 – 30 minute event. This large nymph spends some eighteen months burrowed in the mud and silt, so as it ascends toward the surface, fast and agile, wiggling, sometimes taking over two minutes to get airborne. The final molt will take place usually within 72 hours after emergence. The male imagos are then ready to create the cloud-like mating swarm. When the females arrive and enter the swarm, nuptial flights are developed and mating takes place. The female will then usually fly to a riffled area and land on the water, where she attempts to extrude twin egg sacs containing some 8000 eggs. Having completed their duties the male and female spinners will fall to the waters surface as spent-spinners.
These mayflies are a yellowish olive to golden olive in sizes 6 – 8.
Tactic:
Artificials should be cast and allowed to drift drag-free over the feeding fish. In the case where the fish seem to be taking only the duns that are struggling, imitations must be twitched and moved to look like the natural.
Because these duns appear at night, one casting tip is to pick your casting position during the late dusk and make your various casts. Once you’ve determined the correct distance, place a piece of tape at the point just beyond the reel. This way during the late night when visibility is very restricted, you can feel the tape and know that you haven’t cast beyond the safety zone so you won’t cast into problems after dark.
Fish the nymph with a lot of movement, and the dry, across, dead drift and then back up with short twitches.
Maine’s #18 Mayfly, The Yellow Drake
distinctus Dun |
distinctus Nymph |
distinctus Spinner |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemeridae |
(Hexes & Big Drakes) |
| Genus: |
Ephemera |
(Big Drakes) |
| Species: |
varia |
(Yellow Drake) |
| Nymphal Type: |
Feeble Legged Crawler |
| Nymphal Pattern: |
varia Compara-Nymph #12 3x |
| Emergent Pattern: |
varia Deerhair Emerger # 12 3x |
| Drake Pattern: |
varia Compara-Dun #8 |
| Emergence |
June 21 – August 15 6p.m. to Dusk
Water Temperature 60 – 68 |
Nymphal Migration: June 7
The large mayflies of the P. distinctus species, along with the cream colored duns of the E. varia, constitute some of the best evening fly-fishing of the season for every angler in the northeast.
The nymphs are very distinct and easy to identify from the other mayfly genera. Their most notable feature is the obvious gills, which extend laterally from the body in pairs on abdominal segments 2 through 7. Another easily recognized feature is the large pincer-like tusks. The obvious amber body is mottled with brown body markings that are arranged dorsally along its entire length.
An interesting fact is that over the years this Potamanthus species was mistakenly classified as a burrower. It was probably due to this species originally classified as a member of the Ephemeridae family. They have been since placed in their own family, Potamanthidae.
The reason being that these nymphs are not burrowers at all, they are most definitely crawlers and slower swimming types of the Polymitarcyidae family which inhabit the quiet stretches and medium runs as well as the eddies of faster pocket water. These nymphs are quite similar to the E. varia species in size, color, so many tiers will tie imitations that are a compromise between the two species. This nymph shares the same habitat as the Hexagenia and Ephemera genera.
Emergence Activity: June 14 - July 28 @ 6pm to Dusk
Hatching is usually best on pleasant summer evenings of low humidity and a water temperature of less than 70 degrees. Prior to emergence, the nymphs will move about nervously on the bottom. The emergence starts off rather sporadically a few hours before dusk. The much heavier emergence will take place at dusk. Just about dusk, they will make a quick ascent to the surface, lingering momentarily as they transform into the delicate duns and struggle to get air-borne. If the weather is hot and humid these same hatches won’t take place until after dusk. These duns will emerge in slow-to-medium currents.
Spinner Activity: June 14 - July 28
Like the E. varia species, the mating activity begins at or just before twilight and is at shoulder height rather than, like most other mayfly species, high above the waters surface. Oviposting occurs around dusk and into the dark evenings. Like the E. varia, the P. distinctus females will fly to the waters surface to extrude her eggs into the water. Then both the males and females will fall spent to the waiting fish.
Tactic:
One of the best imitations that you can use is the Light Cahill pattern. This is a time-tested design that has not been improved upon since William Chandler tweaked Theodore Gordon’s original pattern.
The reason for its success is not too surprising because the barred Wood-duck wing and light ginger hackle blended over the cream body of the classic pattern is very impressionistic of the S. ithaca, E. guttulata, E. varia and P. distinctus nymphs. All you do is add some motion to create a deadly combination. If you’re fishing the surface or just below it with your distinctus Deerhair Emerger, be sure to manipulate to simulate the various movements of the dun.
Maine’s #19 Mayfly, The Brown Drake
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Ephemeridae |
(Hexes & Large Drakes) |
| Genus: |
Hexagenia |
(Large Drakes) |
| Species: |
simulans |
(Brown Drake) |
| Nymphal Type: |
Burrowing |
| Nymphal Pattern: |
simulans Compara-Nymph #10 3x |
| Emergent Pattern: |
simulans Deerhair Emerger #10 3x |
| Drake Pattern: |
simulans Compara-Dun #8 |
| Spinner Pattern: |
simulans Compara-Spinner #8 |
| Emergence |
May 14 – June 28 8p.m. – Dusk
Water Temperature 60 |
Nymphal Activity
These nymphs are very fast emergers. Their emergence has been described as popping through the surface film and into the air as if shot from a cannon. The start of early hatching can occur in late May and peak between July and August. Isolated small local hatches can continue into early October.
This means that the best technique for fishing the emergence is to imitate the nymphs and leave the duns to the birds and bats.
Brown drake nymphs can take two years to mature to the point of emergence. They prefer sand and fine gravel over the firm silt of their relatives the Hexagenia limbata.
Emergence Activity: May 14 - June 28 @ 8pm to Dusk
These nymphs are very fast emergers that will pop through the meniscus and into the air as if launched from an underwater submarine. In other words, they leave the water’s surface “almost instantly.”
This reduces your fishing them as nymphs and not dries. This very fast and violent emergence is proceeded by trout chasing nymphs to the surface rather than taking duns.
There are some accounts of fish feeding on the duns, but they are regarded as the least important stage of this species. Full-hackled imitations are common and successful, imitating the fluttering commotion of duns trying to quickly depart from the water.
Spinner Activity: May 14 - June 28
After the Drake molts into the sexually mature imago spinners they will appear at treetop heights up to an hour or two before dark. The females will enter the Mating Swarm and both the males and females will descend with the males and females falling as spent Spinners.
Maine’s #20 Mayfly, The White Fly
Ephoron leukon Duns |
Ephoron leukon Nymph |
| Order: |
Ephemeroptera |
(Mayflies) |
| Family: |
Polymitarcyidae |
(White Flies) |
| Genus: |
Ephoron |
(White Flies) |
| Species: |
leukon |
(White Fly) |
| Nymphal Type: |
Burrower |
| Nymphal Pattern: |
Ephoron Compara-nymph #12 |
| Emergent Pattern: |
Ephoron Deerhair Emerger #12 |
| Dun Pattern: |
Ephoron Compara-dun #12 |
| Spinner Pattern: |
Polywing Spinner #12 |
| Emergence |
August 14 – September 14
8p.m. – Dark
Water temperature 65 -70 |
On some rivers and streams, Ephoron mayflies can cause “Blizzard-like hatches”, because their large white bodies give the appearance of a true snowstorm in late summer. This can be the most intense aquatic insect hatch of the late season, and sometimes the true flies are so thick that the fish will have a difficult time finding your imitation among the carpet of real white flies on the waters surface.
Nymphal Activity:
These leukon nymphs will leave their nymphal burrows and become very active two hours before sun set. They will begin the process of splitting the nymph exoskeleton at the wingcase and attempt to shed the shuck as it rises towards the surface. While rising, the insect will get caught up in the biological drift and become exposed to area fish.
Emergence Activity: August 14 - September 14 @ 8pm to Dark
Hatching activity is much the same as Ephemera simulans (Brown Drake) and things happen so fast and furious that most anglers will concentrate on the Spinner activities rather than chuck and duck the nymph.
Spinner Activities:
The hatching activity is so fast and furious that the following explanation will paint a picture that is truly worth a thousand words.
At about an hour before dark and of course well after sunset the males will emerge from the water as if shot from cannon. Once airborne, they very quickly molt into true spinners. Some 30 minutes later the females will emerge and unlike their male counterparts will not molt into a true spinner but be sexually mature enough to have her eggs fertilized by the male.
The males are so eager to mate that often times attempt the act before the female has had a chance to leave the water.
These insects will hatch, molt, mate, ovipost, and fall spent within just a couple of hours.
This tremendous commotion caused by their emerging antics will create great feeding opportunities for surrounding fish.
To mimic this activity with your imitation, just impart a little twitching and skittering to your offering and you will have tight lines the rest of the night.
Here are your best subsurface imitations (in three colors and sizes)
Pheasant Tail Nymph
This pattern will imitate the dark Ephemerella (Hendrickson, Red Quill, Pale Evening Dun, Cream Variant and Green Drake), Isonychia (Mahogany Dun), Paraleptophlebia (Blue Quill) and Epeorus (Quill Gordon) nymphs and of course the first important early spring mayfly, the Ephemerella cornuta and attenuata & Baetis vegans (Blue Winged Olive). Use this style for your emerging and sub-surface applications
Bead Head Pheasant Tail Nymph
When you need to be down and quick, this is the trick. Use this fly for all your bottom presentations.
Gold Ribbed Hare’s Ear Nymph
These flies will imitate the light Ephemerella (Hendrickson, Red Quill, Pale Evening Dun, Cream Variant and Green Drake), Baetis (Dark Blue Winged Olive) and Stenonema (March Brown, Grey Fox and Light Cahill) nymphs. Fish these patterns in the surface tension or just below the surface.
Bead Head Hare’s Ear Nymph
Use your bead heads when you absolutely need to be deep and bouncing across the bottom.
Zug Bug
This pattern will imitate the Isonychia (Leadwing Coachman) nymphs.
Bead Head Zug Bug
I’ll let you figure it out for yourself.
Wooly Bugger
This fly is one of the best all round searching patterns as it can represent many different aquatic creatures. Tied in Black or Olive this fly can imitate baitfish, leeches, hellgramites and stonefly nymphs.
White Marabou
Add this to any pattern and the very fine barbules will give the imitation a much more lively action which can result in consistent strikes. Purchase the select grades as they have the extra long barbules required for good streamer patterns.
Maple Syrup
This is the pattern that represents the large, golden drake, known as Hexagenia limbata and rolled across the substrate, it becomes a Crane Fly Larvae.
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