The Mayflies

by Bill Luscombe

Mayflies are the age-old staples of fly-fishing. There are, by far, more dry mayfly patterns than any other dry fly. Let’s have a look at the lifecycle of the mayfly and at the imitations created to resemble them.

The mayflies undergo incomplete metamorphosis. They have no pupal stage. Mayflies start out as eggs in the mud of the river or lake, regardless of the species. The eggs hatch out into larva that we, the fly-fishers, call nymphs. These nymphs are quite tiny at first, but grow over the winter and progress through what is called larval instars. These instars are simply progressively larger stages of the nymph. The larvae are similar to an ant, where the little creature wears its skeleton on the outside of its body, like a suit of armour. This is called an exoskeleton. The exoskeleton does not increase in size, so as the larva grows it must shed the exoskeleton in favour of a larger one. That is what occurs and that is what the instars are, simply the nymphs shedding the smaller exoskeleton for a larger one.

There are three kinds of mayfly nymphs, depending upon which species we are talking about. There are clinger, crawler, and swimmer nymphs. The clingers cling tightly to the rocks on the bottom and are almost never available to the trout until the hatch. The crawlers crawl along the rocks and often get washed off and swept downstream. The swimmers are always moving about and they too are swept around by the current. Both the crawlers and swimmers are available to the trout all winter and spring.

Patterns to imitate the mayfly nymphs are plentiful, but their general shape remains fairly constant. One of the best, and best known, mayfly nymph imitations is the Gold Ribbed Hare’s Ear. This pattern has been a standard for decades and continues to produce. Below are the instructions on how to tie the pattern:

Gold Ribbed Hare's Ear:

Fly Tying Instructions:

1. Attach the thread to the hook shank and tie in the guard hairs from a hare’s ear to form the tail.
2. Tie in the gold wire.
3. Form a dubbing loop with the thread.
4. Wax the thread and dub the hare’s fur, including the guard hairs, onto the loop.
5. Spin the loop to form a tight thread and wrap on the hook to form a tapered abdomen.Stop at the shank’s mid-point.
6. Wrap the gold wire forward to form the rib.
7. Tie off and cut.
8. Tie in the turkey fibres on the spine and then dub on more fur and wrap to form a large thorax.
9. Pull the turkey over the back to form a wing case.
10. Tie off and cut off excess.
11. Whip finish and cement.

A second good mayfly nymph pattern is the March Brown nymph. It can be tied in any colour pattern to match any nymph, but the standards tie is described below:

March Brown Nymph:

Fly Tying Instructions:

1. Attach the thread to the hook shank and tie in, at the butt, a few strands of dark moose mane.
2. Tie in a length of black monocord thread and then two to four strands of chocolate brown floss.
3. Wrap the floss to the mid-point of the hook shank forming a tapered abdomen, fatter towards the eye, tie off and cut.
4. Wrap the monocord forward as a rib and tie off and cut.
5. Tie in the pheasant tail on the spine of the hook, then the furnace hackle and then the herl.
6. Form the thorax by wrapping the herl to the eye of the hook ensuring to leave enough space to tie off and form the head.
7. Tie off and cut.
8. Palmer the furnace hackle over the herl and tie off and cut.
9. Pull the pheasant tail over the back and tie off to form the wing case.
10. Cut off excess.
11. Whip finish and cement.

Once the nymph is ready to mature (about April – May) it swims as best it can to the surface and breaks its way out of the nymphal case. This is called the emerger stage and lasts only a few seconds to a minute. It is not uncommon to find trout feeding upon the emerger almost exclusively and at these times a good emerger pattern is essential to being successful. Below is a good pattern you can tie to represent the emerger.

Mayfly Emerger:

Fly Tying Instructions:

1. Attach the thread to the hook shank and tie in, at the butt, a few strands of brown hackle fibres.
2. Form a dubbing loop and dub on an abdomen of olive brown antron, or any colour that matches your hatch.
3. Tie off half way up the shank of the hook. Do not cut.
4. Tie in the wingcase hackle and then continue dubbing on the thorax. Leave room for the head to be tied off.
5. Pull the wingcase fibres over the back, tie off and trim excess.
6. Tie in the legs on each side of the thorax about 2/3rds shank length so that they sweep back along the sides.
7. Whip finish and cement.

Once the emerger extricates itself from the nymphal shuck it pulls its wings upright like a sailboat and sits on the surface drying its new-formed wings. This is the sexually immature adult, or "dun". The duns can be easily recognised by their opaque/greyish wings and long slender two or three filament tail. While the duns ride along on the surface they hardly ever move until they are ready to fly off. This provides the trout with ample opportunity to feed on them.

There are innumerable dry mayfly patterns. All colours and sizes are represented. To pick one out as best would be impossible, so instead I will give you a pattern that I tie that works exceptionally well during the dry mayfly hatch and you can simply change the colour of the various parts to match your local hatches. The colour pattern described here is for the Western March Brown Mayfly:

Western March Brown Mayfly:

This pattern is an "all hackle" pattern; it contains no "wing" as such. The steps to tying it are as follows

Fly Tying Instructions:

1. Tie in the thread and then the horse mane hairs.
2. Cut the tail fibre off at about twice the hook shank length (mayfly tails are very long).
3. Dub a loop of light brown or tan antron and wrap to a point mid-way between the hook point and the eye of the hook.
4. Tie it off and cut.
5. Tie in the hackles tip first, first the short furnace and then the long ginger.
6. Wrap the long hackle quite thick and heavy.
7. Tie off and cut the excess. Trim off the bottom side of the ginger hackles you just wrapped so that only the top 1/3 of the hackles remains.
8. Wrap the furnace hackle forward to standard density to form the legs and thorax.
9. Tie off and trim the excess.
10. Whip finish and cement.

Some of you may not know what a "variant" is. The standard dry fly hackle length is determined by the gap between the hook shank and the hook point. In a standard dry fly the feather barbules (hackle fibres) are just barely longer than that distance. In a variant, the barbules are about ½ again as long. Thus, the ginger hackle in this pattern sits about ½ again as high as the furnace hackle, thus forming the illusion of a wing.

Once the duns’ wings are dry they fly into nearby bushes and rest there while they continue to mature. In a few hours they will once again break out of their present shuck and emerge as the sexually mature "spinner". You can recognise the spinners by their bright, glossy, translucent wings. They then fly back to the water where the males swarm and hover. The females fly into the swarm, mate, fall to the water and lay their eggs, and then they die. When they die their wings fall to the side and they look like little aeroplanes. This is called the "spent spinner" stage. Trout can key in on this stage as well, and a spent spinner pattern is needed to catch fish.

Below is a fairly standard spent spinner pattern.

March Brown Dry:

The steps to this pattern are the same as for the March Brown dry above, except that you "X" in an aeroplane wing of elk hair or hackle fibres instead of the wrapped hackle wings and legs.

There is only one lake dwelling mayfly, the Callibaetis, or speckled mayfly. Most of BC’s lakes contain this mayfly and you should tie up some patterns to match this insect in all its stages. The body is a very light blue/grey and you can substitute this colour for the appropriate body parts in the above-described patterns. The wings for the dry can be tied with one variant length blue dun hackle and one standard length grizzly hackle.

The mayflies are the first of the major hatch to come off the streams and rivers in the spring. In BC this occurs between late March and early May, depending upon the weather and water temperatures. Be sure you tie up some of the representations that imitate your local species and be ready for their appearance.

Bill Luscombe has been hunting and fishing for most of his 42 years. He has been flyfishing for 20 years. He instructs flyfishing, and has done so for the past 12 years. He also instructs the federal FSET firearms course and the BC CORE hunter training course. He is an award-winning outdoor writer and has been writing freelance since 1987. He has been published in BC Sport Fishing Magazine, Outdoor Edge, BC Outdoors, Western Sportsman, Island Fish Finder, and the BC Hunting Guide.

Bill Luscombe was born an army brat and raised in Ladner (Delta, BC) where he was raised hunting waterfowl and pheasants. He presently resides in North Cowichan on southern Vancouver Island where he has lived and worked full time as a professional forester since 1982.

He presently works in Nanaimo for the BC Forest Service and continue to write the fly-fishing column for BC Sport Fishing Magazine as well as contributing articles freelance to various outdoor magazines in western Canada. Bill Luscombe is also a BC Director of the Northwest Outdoor Writers Association.

"Catching fish is not hard. You simply need to understand what makes them tick. If you think like a fish, you will catch fish. It’s as simple as that."- Bill Luscombe