Matching the Hatch


Matching the hatch is one of those phrases that permeates fly fishing culture the world over. It is something that is so fundamental to what we do as fly fishers, that regardless of whether we are familiar with the phrase or not, we all do it to some degree. Made popular by Ernest Schwiebert in his book of the same name, it has become the catch cry of the thinking angler, and the mere mention of it, is a short-cut to acceptance among your angling peers.

“He spoke of matching the hatch – he must know his stuff”.

So what is it?

Matching the hatch refers to the practice of determining exactly what a particular fish is eating and then selecting an appropriate fly pattern to match. It is that simple.

When a trout sees a large number of a particular insect over and over, it can ‘lock onto’ that particular bug, to the exclusion of all other food items on the water. This is what is known as selective feeding and often the reason for those occasions when a fish will not look at any fly pattern you present, much less eat it. At such times, fly fishers who are unable to ‘break the code’ of what is going on, will often end their day with few fish caught, yet having exceeded their ‘bag limit’ of frustration.

Not wanting to appear condescending, like I have all the answers, I have to say that sometimes working out what is going on, is not always so simple. Even as a guide who is on the Goulburn every single day of the season, there are times and moments of utter frustration and despair. Times when you’ve made all your best guesses and still come up short.

But learning to match the hatch will ensure that the number of times you experience this flailing, failing situation, will be greatly reduced.


Why are there times when you cannot work it out?

Well for starters, there are situations when there might be a ‘complex’ hatch of several species of insects in various stages of emergence, all happening simultaneously. One session that is still fresh in the memory occurred down in the Breakaway section of the Goulburn River. It was late spring and we experienced a a situation where there were several species of caddis, both emerging pupa, as well egg laying adults; plus three species of mayfly at various stages of their life cycle. That’s pupa, nymphs, emergers, cripples, adult caddis, duns and spent spinners. And in a number of sizes and colours.

In other words a smorgasbord of options for the trout and a situation where that Russian Roulette scene in The Deer Hunter doesn’t look like bad odds at all.

When this happens it’s up to you to work it all out, knowing that you are racing the clock as the light fades quickly from the sky.

Firstly you must determine which stage of the hatch the fish are feeding on. Are they slashing from the top? Or leaping clear of the water? Are they gently rising with their snouts breaking the surface and leaving behind and air bubble? Or is it a push/swirl rise just beneath the surface where the back and and maybe tail break the surface, but not the snout? This is the first thing to determine when working out what it is they are feeding on.

Slashing from the top indicates the fish are chasing something that can get away, on or above the surface, often a caddis skittering to safety after hatching. Leaping denotes a fish which is taking insects in flight which is often a sign that spinners hovering just above the water or egg laying, are on the menu. Gently rising with snouts/beaks breaking the surface will quite often mean that small insects floating on the surface are being taken. And finally a bump or swirl just beneath the surface could indicate emergers are the go.

In the instance I’m referring to above, it was a gentle rise with the fish breaking the surface with just the tip of their snouts, that gave away the fact that insects on the surface were being taken. This is despite a multitude of insects being on the water. And it was simple. The fish were just keyed into the insect they were seeing  the most of.

We could immediately dismiss the skittering caddis and emerging caddis as options. There was no aggressive take indicating the former and no tail/back breaking the surface, as per if the latter were on the menu.  A quick seining of the bubble line immediately revealed three types of duns; a March Brown size 12, a Rusty size 16-18 and a Grey size 14. As it was hard to see exactly which insect was being taken two flies were chosen; a #12 March Brown pattern and a #14 Grey pattern. The fish soon showed their approval by taking the #14 grey in preference to the March Brown with not a single trout taking the larger fly. And we all changed out to the correct pattern and did quite well.

This simple application of the rules of matching the hatch, allowed us to select the correct pattern without too much fuss or wasted time. This is something that we can all do, with the benefits being immediately obvious.

So why were the fish taking the Grey dun over the others. Well we know that fish will most often lock onto the food item that is most prevalent and most easily attained. The immediate success of that pattern, told us that although a lot of insects were hatching and visible on the water, the #14 Grey pattern was probably the most prolific of them. A case could be made that a spent spinner is more easily captured by the fish, or an emerger stuck beneath the mensicus; but on this occasion the sheer number of #14 grey duns must have been such, that the fish were not interested in anything else.

In this instance, most inexperienced fly fishers would have tied on the biggest fly. The logic being that the bigger the fly the bigger the fish. While most experienced fly fishers, would have tied on the smallest fly, and with good reason I might add. As down-sizing is always a good idea when fishing to picky, rising fish. But in situations such as these, I do not hesitate to tie on two of the most likely flies and then see which, if any are eaten. If you are fishing with a mate, you can quickly test out multiple flies and quickly ascertain what is going on.

One thing that I would mention is to not be fooled by the size of the insects. Often we are deceived into tying on the larger pattern because we attribute our own logic to the fish, that is a larger meal must be more attractive and therefore likely to bring success. This is not the case. The insect that makes up the greater mass will be the food item sought by the fish. While the bigger insects may be easier to see there is often a much larger number of smaller bugs hatching at the same time, despite our brain’s tendency to focus on the bigger item. This situation is often referred to by experienced fly fishers as a ‘masking hatch’ i.e. the presence of a few larger/brighter colored insects masks the presence of more numerous but smaller/duller colored insects.

The Four Rules

The most important thing you can take from this brief outline of ‘Matching the Hatch’ are the Four Rules as we teach them. They are 1.Size, 2.Shape or Profile, 3.Colour and 4.Presentation.


Size is by far the most important of the rules and when you get this right in combination with presentation, this is usually enough to achieve success, even if shape and colour are wrong. When trying to match the hatch, grab a sample of the insect and measure it off against your imitations. We often refer to patterns in sizes e.g.. #12, #14, # 16 etc and this is a universal system. All this does is allow us to gauge the insect’s approximate size against a hook size, allowing for an accurately chosen imitation. Remember, while there may not be a big difference between a #14 and a # 16 to us, to a trout it can represent a nearly 50% increase in size. A fish locked into a prolific food item in #16, will pay scant attention to a #14 floated across his bows. A # 12 will get the proverbial single FINger salute from the fish and nary a look.

You must be reasonably close when choosing your fly size. I cannot recall how many times an incorrect pattern, in the correct size, has been eaten, while the right fly pattern,in the wrong size, is refused. Get the size right and you are in with a shot.

Shape is second on the list of rules and by this we mean the profile that the fly has. For instance, if it is a mayfly dun you must have a low riding body, prominent wing, slim abdomen and thorax. If it is a beetle you should try and mimic the round, stocky shape of the natural as well as getting it to sit in the film like the real thing. An egg-laying spinner should sit on its hackle points and tail causing it to ride high like a hovering natural and an emerging caddis pupa must hang in the resting ‘tuck’ position just like the hatching pupa.

Hook selection is important when it comes to shape. A scud or midge pupa requires the use of a curved hook to give the correct shape, a short shank will often assist when tying beetles and a larger one when representing grasshoppers and crickets. Choose hooks carefully with the desired effect in mind. The gauge of the hook is also critical when tying ultra small, dry flies that have little in the way of hackle or dressing. Think about what it is you are trying to achieve, even when you are at the vise creating your specialist ‘match the hatch’ flies.

Also important when it comes to the second rule, are ‘triggers’ that the fish are likely to key in on when targeting various insects. Duns have a definite trigger in the upright wing, something which is so obvious to anyone who has watched them drifting like so many yachts on the water. This wing dominates their profile, and hence parachute ties that mimic this feature, while still allowing a decent imprint of the body in the water’s surface, now dominate our fly boxes at mayfly time.

Caddis pupa collect air bubbles on their body during emergence, something well imitated by using sparkle yarn in the construction of pupa patterns; a very definite trigger. Rubber legs on grasshoppers, wiggling tails on damselfly nymphs, a flashback on a nymph pattern. The list goes on. Try and work out what triggers are present and imitate these in your flies.

One last point when talking of shape must be made. Although it’s arguably a part of presentation. That is, how fly behaves or sits on the water. As previously mentioned, a mayfly spinner should sit high on the water, a dun low in the film and an emerger hanging beneath the surface. Knowing how to imitate the various stages of the insects takes a little time to come to terms with fully. Reading the rise form and then knowing whether the bugs being eaten are below, in, or on the water’s surface, is most important. While too complex to be explored in this short piece, it is something to always consider.

Don’t be afraid to modify flies on the spot. A small pair of scissors allows you a lot of latitude to alter patterns to suit the situation. Something I do regularly when fishing to ant feeders and when converting duns to emergers/cripples.

The importance of colour is being constantly being debated by all fly fishers and it is perhaps only among our guiding crew that some sort of consensus has been achieved. And then, only after decades vigorous back and forth, both in the field and in the bar! While both sides have their ambassadors, each with their supporting arguments, we feel pretty safe to relegate colour to being the least important factor. Most of the time.

Just how important colour is remains to be seen (pun intended) and hopefully this will always be the case. There has to be some mystique if fly fishing is to retain all of its charm as time goes by. More often than not, getting the other three right, size, shape and presentation, will achieve the desired result.

At times though, changing colour will be the key to success. Grasshoppers are one of the insects for which colour of the pattern plays a critical role. In December the hoppers are immature and their olive/green colour is very different to later on in summertime when they are brown, tan and yelllow. We see this a lot early in the summer and switching to the exact same pattern as late summer but a hook size smaller and using olive chenille and deer, will bring success. Also with Blue Winged Olives in Autumn you will find that getting the size and shape right will often not interest the fish without the correct olive/grey dubbing for the body.

And don’t get me started on PMD’s in the Montana and Idaho. Those fish can be bitches and hey. What is it with pink? Hello trout!

While not always the case we would recommend that you try and get the colour, or at least the tone, as close as possible to the natural. If the mayfly you are attempting to imitate is a slightly different shade of grey when compared with your pattern, do not despair. To try and get it perfect would drive you insane and unless you live on the river and have access to a multitude of different materials and a ridiculous amount of spare time, you will never precisely imitate any of these insects. Be content to approximately match the colour of the insect.

Interestingly, some guides in the USA have found a novel way of approaching this problem. They tie their patterns in white and colour the wing and body in with permanent markers at the point of fishing them. A clever and inexpensive way to ensure that they’re ready for everything, but a very boring fly box to look at!

I’d go mad tying all white flies all the time!

Last, but definitely not least, we come to presentation. While this is made up of several distinct parts, in the end it can be seen as the way a fly arrives at the fish.

First of all, you must not spook the fish while casting. To us this means dull colored lines, laying the line an leader away from the fish i.e. casting from behind and to the side, and generally being careful when presenting the fly. Minismising false casts. Not casting over the fish. Shooting the last 10-15 feet to avoid leader flash scaring the trout.

Depending on the situation you may need to cast from downstream of the fish, upstream, the side even from directly above. The trick is to be aware of just what the fish can see and to present the fly without the line, or your body movement spooking it.

So, can you cast sufficiently well to get the fly to the fish without spooking it? If not, get out and practice. If you cannot get to the river due to time constraints, take your rod to work or to the local park. Twenty minutes a day for a month, on the roof at work, or in the alley, car park or local sport’s field, and you’ll be ready for anything. Set up targets at 20-50 feet away and practice from all angles and distances. With the wind at your back, front and side.

When you can lay a 12 foot leader out accurately into a 1×1 metre area, you are ready to take on our toughest fish.

So that’s the mechanical part of presentation, as in the delivery of the fly to the target. But what about how are the naturals behaving? If there are egg laying caddis, the insect will be seen dipping and crashing to the surface, and so should your imitation. Fishing from above the trout and carefully skittering a dry fly down to it will work, as will an upstream presentation with a twitch at the appropriate moment. A mayfly dun presents a different kind of challenge, as most will be found drifting with the natural flow of the current, something that your natural must also do. A long leader and fine tippet are needed here to allow the fly to drift free of any drag, and successfully imitate the naturals. If you were to take the aforementioned caddis technique and swing the mayfly dun down to the fish, you would most likely never hook a fish; just as dead drifting a caddis over a fish chasing the egg laying adults will also likely fail.

So to effectively and successfully present the fly, you need to both get the fly to the fish without spooking it, as well as accurately imitate what the naturals are doing. Most of the time a dead-drift will work better than movement. But with some caddis, grannoms, cicadas, hoppers, stoneflies etc the right amount movement at the right time can make the world of difference.

While this seems rather difficult and complicated; it really isn’t.

First things first

You need a fold-up seine net. These are indispensable and can be found here or you can make your own using some dowel rods and screen material from the hardware store.

Once on the river, all you need do is get into the bubble line in the tail of the pool you are going to fish, directly downstream of the rising fish you wish to target, and take a quick sample. A fold up net that takes in the surface drift and down to about a foot below is great and portable enough to carry with you at all times.

Then take a look at what you’ve caught. Compare your evidence with the rise forms you are seeing, and then make an educated choice.

Choose the correct size, get the shape and approximate colour right and then present it well, and you will catch more fish than you miss. Armed with this knowledge, it can sometimes seem like things are too easy, with every fish you present to, taking the fly, making you think you are invincible. Then, without warning, the hatch will change, perhaps the duns are less numerous, while more  spinners start falling to the water, leaving you wondering why the fish have stopped taking the fly that you’re using.

The key to it all is simple observation, be aware that the fish will swap over to other bugs or stages of the life cycle if the hatch changes. If you suddenly stop getting takes, take a few moments to watch and work it out, rather than casting the same fly out of hope.


Matching the hatch has become synonymous with fly fishing over the past few decades, and with good reason.  You wouldn’t think that something so simple could be seen as revolutionary. But the efforts of many meticulous anglers to better understand trout and their behavior, and to build a logical framework for choosing which fly to use, most definitely was seen as radical at the time. But this methodology is one that has withstood the test of time on many of the most technically difficult waters. From Idaho’s Henry’s Fork to New Zealand’s Mataura to  Armstrong’s Spring Creek in Montana.

Matching the hatch has become the starting point for every fly fisher targeting selectively feeding trout and it should be the first thing that a new fly fisher learns, after the basics of casting. This common sense approach to the sport will hold all who follow its principles in good stead.

So the next time you are fishing a hatch and cannot get a take, watch the riseforms carefully and jump in the water to catch some bugs, before choosing a fly. A little time spent doing this investigative work before making a cast, will pay big dividends.