Eye of the Guide


Tom Travis - Februrary 7, 2011

In 1981, Gary LaFontaine published his masterpiece entitled Caddisflies. This body of work brought to the attention of the fly fishing community the importance of caddisflies as related to the feeding habits of trout. Fly fishers the world over woke to a new set of challenges in dealing with creating effective imitations and fishing the various forms of the caddis.

All of the well-known spring creeks and tail waters that I have fished across the United States have caddis. In their 1997 release of Caddis--Super Hatches, Carl Richards and Bob Braendle chronicle the distribution of the major caddis hatches across the country. A study of their work will show you that somewhere between the months of April and November there are caddis hatches which are important to both the trout and the angler. For those who wish to peruse species identification, Carl and Bob's book has some excellent keys which will assist you in accomplishing the task.

To become a more efficient angler one must understand the caddis, the different stages of its life cycle, and how the trout feed on the various stages. Some might think that this means dealing only with time periods surrounding the major caddis hatches. Yes, dealing with the caddis hatches is important, however, there are also time periods when the cased caddis and free-swimming caddis larvae are very important to the trout's diet months before the caddis hatch takes place.

The Life cycle of the Caddis Fly

Caddisflies belong to the order of Trichoptera which means "Hair Wing". Trichoptera are one of the largest groups of aquatic insects, with approximately 1,200 species found in North America. The caddis have a complete life cycle (Metamorphosis), going through egg, larvae, pupae and adult.  Caddis eggs are of no importance to the angler/tyer. However all the rest of the stages of the life cycle are important to both the angler/tyer and the trout. 


There are two basic types of caddis larvae which the angler/tyer must be aware of. First are the free-living forms. These caddis larvae are the net-makers who build nets to trap their food, which is plant material such as algae, diatoms and decaying plant matter. This type of larvae is only marginally available to the trout. However, there are free swimming caddis larvae that are mainly predaceous. These types are constantly moving about in search of prey and thus are available to the trout.

The second type of caddis larvae is the case-makers, which comprise many of the most popular species that the fly fishers are familiar with, such as Brachycentridae. These larvae construct portable cases of various shapes and with various materials and move from place to place while seeking food. This makes them very available to the trout. Sizes and color variations will depend on the area. The best method is for the angler/tyer to become familiar with the caddis larvae forms found in the home waters.

The caddisfly spends the majority of its time as an aquatic insect. There are a few species which produce two generations per year and some that even take two years to mature, however most species have one generation per year. Therefore, due to the distribution of the various species and their emergence cycles there are always caddis larvae available to the trout, often months before the actual hatch. Let me provide an example.

During November, the main hatches on DePuy Spring Creek in Montana are Baetis and Midge. However almost every stomach sample obtained (using a stomach pump) will contain several cased-caddis larvae. As a matter a fact, this is an excellent searching pattern for the spring creeks during the winter months.


The actual pupal stage will last from two to three weeks. The larvae will attach itself to something solid and build a sack, or cocoon if free-living, or seal off both ends of the case. During this time period the caddis really isn't very available to the trout as it is not moving around. However, when the metamorphosis is completed and as the time to emerge draws near, the active adult inside the pupal cuticle leaves the pupal case and swims to the surface. During this time period they are very available to the trout.

Much has been written about the speed of the emerging caddis pupa. Some believe that the caddis pupa blasts loose from the bottom and takes off like a missile. Nothing could be further from the truth!! My own observation and studies have shown me that caddis pupa do not rise off the bottom like a missile. This observation is reinforced by the findings of Gary LaFontaine and others. As the caddis pupa begins its journey to the surface, it will swim up and drop back several times before it finally reaches the surface. The trip to the surface may start as much as an hour prior to the actual emergence. This fact, coupled with the fact that not all of the insects emerge at one time, gives the fly fisher a two or three hour period where emerging caddis pupa are available to the trout. Remember, the trout's survival is based on energy spent vs. energy ingested.  When you sit back and think about it, the caddis pupa missile theory is indeed very funny!


As the main emergence period draws closer, the observant angler/tyer will notice an increase in the numbers of emerging caddis and an increase in the numbers of trout visibly feeding on them. Generally, the adult caddis will not ride on the top of the water for long periods of time after hatching, unless the air temperature has dropped and/or the day is damp. However, the emerging pupa will normally ride a considerable distance in or just below the surface film while struggling to escape the pupal shuck. At this time the caddis is half on top and half just under the film and is very vulnerable. During this time period trout will prey on the caddis with wild abandon. Often flush imitations or flies that imitate a struggling half hatched caddis can be deadly. Adults of most species are quiet during the day; however they are very active during the evening and night hours or on overcast days. 

Adult caddisflies live approximately one month. For over twenty years I have used a stomach pump on trout and I can state beyond a doubt that 95% of the contents during a caddis emergence is made up of pupal and emerging adults.

The next time that both the trout and the angler/tyer will see the caddis is during the egg laying process. There are three methods that the caddisflies use to lay their eggs, the first being fluttering over the water and dipping the abdomen. This method is where the term "the traveling sedge" comes from. The second method is diving into the water and swimming to the bottom of the stream to lay the eggs. Once the eggs are deposited they try to return to the surface, most never make it!  The final method is at rest, or spent, on the surface of the water.   

Here again, there is no simple answer for the angler/tyer. Various dry flies can be very effective, however so can some of the wet diving patterns.


The keys to improving your skills as a caddis angler are observation and knowledge. Knowledge of the hatch dates and of the species that will be hatching. Understanding how the trout feed during the hatches, understanding the life cycle and what forms of the caddis will be available to the trout during non-hatch periods. The knowledge of what imitations and presentation methods that will allow you to maximize your fishing. Finally, the fly fisher needs to be observant to what is taking place on the water.



Note:    This pattern can also be tied without a bead, then just weight the hook shank as desired. This style of imitation was developed during the late 1970's by George Anderson and has proven to be very effective.  This is a great searching pattern. I also tie this imitation with an olive or cream thorax.


This style of imitation can be tied in many different color variations to match the naturals. This imitation may be fished with an indicator or behind a dry fly, which is my favorite method.


Once again this pattern can be tied in many color variations. I fish this pattern like a wet fly or soft hackle and allow it to swing. Often I will fish this two feet behind a dry. This pattern is simple, fast to tie and effective!


This pattern floats very well and can be fished with movement to imitate the struggling adult that is stuck in the shuck. Once again you can tie this in many different color variations to match the natural on the waters you fish.

There are many other fine patterns which you can use, but first you must be observant. Last October I spent a couple of days fishing the Henry's Fork with Rene' Harrop. The main hatches were midges in the morning and Baetis later in the day. However, late in the evening there were a few large caddis coming off. The Autumn or October caddis is a large insect and believe me, the trout would definitely key on this large food form. However the stomach sample showed that the emerging pupa was the overwhelming favorite. The point being is that the fly fisher should always have a box of caddis imitations along. For me they are like the American Express Card, I never leave home without them. Enjoy & Good Fishin'.

Editor’s Note:
This was written several years ago but the information is still correct and useful.

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