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Tying and Fishing Chironomid Larva


Bloodworm patterns are excellent choices during the fall.
After slowly cruising the shoreline areas of the lake I finally found a spot that appeared promising.  My chosen spot was a small shoal extending approximately 50 feet from shore.  I chose to anchor myself parallel to the steep drop off in about 18 feet of water.  Due to the gin clear water the fish would not be on the shoal but cruising rather leisurely along the drop off making the odd foray into the shallows.  Experience had taught these fish that prolonged exposure on these shoals was a dangerous proposal.  Ospreys, Eagles and Loons had all taken their fair share of fish.  I tied on one my favorite patterns for early spring, prepared my dry line and leader and made my first cast of the day.  I glanced at my watch, observing the position of the sweep second hand.  I had roughly one minute I figured, so I busied myself readying the boat further for the days fishing.  Picking up my rod I removed any slack in the line and began a very slow hand twist retrieve.  About twenty seconds into the retrieve I felt a very subtle take.  Instinctively I raised my rod.  My line erupted, the loose coils from the boat floor raced through the guides, disappearing into the blue green depths of the lake.  After a number of spectacular jumps and two runs into my backing the 4lb Kamloops Rainbow slid quietly into my waiting net.  I removed the barbless fly from her mouth, and she returned back to her watery world.  A fish on my first, cast what a way to start the day.  I quickly recast my line quartering it slightly towards the deeper water and let the slight drift of the wind swing my fly back around the boat.  This time I did not even get a chance to retrieve the fly.  My line just started to peel off of my reel.  Once again after a spirited battle I returned the rested fish to the lake.  The fly pattern I caught these magnificent fish on was not a Woolly Bugger, leech or dragon fly nymph pattern but rather a simple chironomid larva pattern, commonly referred to as a bloodworm in western Canada.


In most of North America they known as midges, in the United Kingdom they are buzzers but in Western Canada we usually call them Chironomids. There are over 3,500 known species of chironomids.  They are the number one item on the menu of trout in productive stillwaters.  Chironomids belong to the order Diptera and these two winged insects are the most important insect for the stillwater fly fisher to imitate.  From my own records the pupa and larva of these insects account for over 50% of the total food intake of trout in the nutrient rich lakes of south central British Columbia.  Similarly productive lakes also exist throughout the western United States.  Chironomids are tolerant of a wide range of water conditions and it is safe to say that any productive lake or pond will contain good numbers of these insects.  Yet for most they are difficult to imitate as the patience required to fish them often undermines the confidence of the angler.  There is fishing information available upon the adult and pupal stages of the chironomid but little or no information available on larval techniques.  Yet this is an important stage  to imitate as it is certainly one the trout does not pass up.  Some have said that the larval stage is not worth imitating, and for those people they are missing out on some great fishing. At certain times of the year only chironomid larva patterns will consistently catch fish.  The lowly chironomid larva does not seem to get the credit it deserves.


Life Cycle


Many larvae are a distinct blood red color, hence their 'bloodworm' nickname.
The chironomid life cycle is typical of a complete metamorphosis.  Beginning life as an egg the chironomid then progresses to the larval, pupal and adult stages to complete the cycle.  The larval stage of the chironomid in many ways mimics that of the better known caddis fly.  Some species are free living, spending their time amongst beds of weeds and other bottom debris.  Other species of chironomids actually construct cases much like the case builders of the caddis family. The majority of species, especially the larger sizes live in tubes they construct in the mud water interface at the bottom of the lake.  However some of the tube dwelling species spend their first instars as free swimming larva, settling down to a tube home existence later in their development.  Chironomid larvae seem to prefer mud bottoms but are quite at home in marl or other bottom substrates.  In these tubes the worm like larva usually feed upon passing algae and detritus although a few species are carnivorous, feeding upon zoo plankton and other small creatures. Some species feed using a net system coupled with a rhythmic pumping action causing a current that drifts their food towards them, others emerge from their tube homes to forage.  Trout feed readily on these exposed larvae.  The larvae also emerge from their tube homes when they out grow them or during seasonal migrations.  Migrations usually occur in the spring as the larvae move from the deeper waters to the shallows in preparation for emergence, and again in the fall to avoid the effects of winter, specifically ice up.  These are prime times to fish chironomid larva imitations.  The larval stage usually lasts less than a year, progressing through as many as 6 molts or instars.  In some parts of the world such as British Columbia and England some species can take up to 2 years to progress to the pupal stage.  This is due in part to the specific species and the amount of time a lake remains frozen over during the cold winter months.  The average size of the chironomid larva ranges from 3/8” to 3/4”, although I have seen some species that attain sizes of over 1” in length.  These particular species are large morsels for the trout and are definitely worth imitating.  The worm-like body usually has any where from 8 to 10 segments and prolegs are visible on the front and rear sections of the larger species.  The larvae vary in color.  Common colors include; tan, green, red, maroon and combinations of red and green.  Probably the most common colors are green, maroon and “blood” red  Fue to the larva’s unique ability to produce hemoglobin that enables them to store oxygen.  Hemoglobin enables the larva to survive in oxygen poor waters and at depths as deep as 200 ft, although depths of 3’ to 20’ are usually more common.  This red coloration is the reason for their common nickname of “bloodworms” and usually applies to all chironomid larva regardless of their color, however, the larger the “bloodworm” the more prominent the red coloration.  In addition the clearer the lake the brighter red the larvae seem to be.  Muddy bottomed lakes tend to have darker maroon colored larvae.  This is simply a result of their detritus diet.  The hardy nature of the larva enables them to live in a variety of environments from clear mountain lakes to sewage treatment ponds.  In sewage ponds the larvae consume huge amounts of algae assisting the treatment process.  The larvae are feeble swimmers moving about in an exaggerated head to tail lashing motion mixed with an extended resting position.  Heavy winds can lift vast numbers of larvae off the bottom and circulate them throughout the water column, making them an easy target for cruising trout.  The observant angler can experience some exciting fishing during this phenomenon. 


Equipment and Tactics


The equipment requirements for successful chironomid larvae fishing are fairly universal to all types of stillwater fly fishing.  I prefer a soft action rod between 9 and 10 feet in length.  Rods such as Sage’s SLT allow the angler the sensitivity to detect the subtle takes and the forgiveness when striking the fish.  I use 5 or 6 weight rods for the majority of my lake fishing, 7 weights are an option when wind conditions demand it.


Perhaps one of the most important ingredients to success when stillwater fly fishing is the ability to consistently place your fly in the feeding zone of the trout.  Usually when fishing chironomid larvae imitations, your pattern is on or near the bottom of the lake.  Fortunately there are now a wide range of fly lines to assist the angler consistently reach the right depth.  Some of the more popular types include Intermediates, Type 1 slow sinking lines, and the new Stillwater lines.  Intermediate lines are especially helpful when windy conditions don’t allow the effective use of a dry line.  I will have to admit however that the majority of my larvae fishing is with a floating line and long leaders.  Long leaders usually begin at 12 feet, and leaders of 20 feet or greater are not unusual.  The simplest way to reach these lengths is to begin with a standard tapered leader of 9-12 feet in length tapered down to 4X. One simply adds tippet to reach the desired length.  Some points to remember include keeping your tippet diameter as thin as possible without breaking off or causing un-due stress to the fish.  A thin diameter tippet enables your offering to sink quickly, much the same as nymph fishing in rivers or streams.  Secondly keep your leader the same length as the depth of water you plan to be fishing.  This will enable to retrieve the pattern slow enough so that you are not constantly hanging up. 


There are some other items of equipment that should help with your success rates when fishing larval imitations.  Non-toxic split shot can be useful if you do not tie your own patterns or if wind becomes a problem.  On a lake there are often subtle currents that increase with the velocity of the wind.  At times these currents can effectively lift your pattern out of the specific zone you are trying to fish.  This is similar to how current flow in rivers and streams affect nymph patterns.  Adding weight to your leader can help you cope successfully with this situation.  Strike indicators can also be off assistance to the beginning or struggling chironomid fly fisher.  Strike indicators enable the angler to accurately control the depth they are fishing and provide a visible indication that a fish has accepted your offering.  Once the angler finds the right depth he can be into consistently good fishing all day.  Depending upon whom you talk to however strike indicators can elicit some varied responses.  Some do not consider strike indicators to be part of fly fishing.  I am not suggesting they are vital to success but they are a tool available to the angler and can save the day at times.  I tend to fish without an indicator preferring to feel the strikes but I use them from time to time with good success.  You be the judge. 


Once you meet your tackle requirements the next item you need is an anchor.  Boat or float tube control is vital to success.  If your boat or tube is not under control then it is difficult if not impossible to control your fly.  Consequently you will be missing takes.  When fishing from a boat you must anchor firmly.  This means anchoring from the stern and bow of the boat.  If you are using a float tube double anchoring is almost impossible, so a single anchor will do.  I usually anchor the bow first, allowing enough rope out to obtain a good purchase.  Then let the wind swing the boat into position with help from the oars and securely anchor the stern.  The majority of the time you will be fishing out of the stern of the boat.  Depth is critical to success yet this is not always easy to determine.  Unfortunately there are no signs showing you the depths around a lake.  Thankfully the solution is fairly simple.  Take your anchor ropes and mark them at 5 foot intervals with a black magic marker.  When lowering your anchor simply count the number of black marks, multiply by 5 and presto you can accurately determine the depth.  An important point to remember is to know the depth of the water you will be fishing as opposed to the spot you anchored in.  In some situations you could anchor in water that is of a different depth than you are fishing.  You could be having a tough day simply because your offering is not getting near the fish..  Another useful tool is a stomach pump.  Used correctly you can accurately determine the size and color of the larvae the fish may be feeding on.  The stomach pump samples those food items in the esophagus of the trout.  The majority of samples you get will still be alive!  Stomach pumps can also help determine the depth at which the trout are feeding.  If your sample contains adult insects and emerging pupa, chances are the fish are at or near the surface. If the sample contains larvae and bottom dwelling nymphs, the fish are most likely feeding at or near the bottom.  Remember with a stomach pump do not to use them on fish under 12”.  Fish under 12” can be seriously injured by incorrect or rough use of a stomach pump.  Other helpful tools include aquarium nets and a watch with a sweep second hand.  The aquarium net is useful for sampling the weeds and shallows for the prevalent size and color of the chironomid larvae you are trying to imitate.  It is amazing the sheer number of organisms that are prevalent in some lakes and ponds.  The watch is helpful in accurately counting down the fly to the right depth.  It can be distracting at times trying to mentally count down a pattern.  When I use watch I can accurately time the pattern to the right depth.


Now armed with the equipment to successfully fish larvae, there are some helpful tactics you can use.  The vast expanse of some lakes can be especially intimidating.  There is however some key areas of a lake that can usually provide a starting point.  One of the primary defensive reactions of a trout is the sanctuary of deep water.  Areas such as drop offs adjacent to shoals and sunken islands are two of my favorite areas.  Try to anchor parallel to the drop off.  That way your fly is always working productive water.  This is much better than crossing through the strike zone if one where to retrieve perpendicular to the drop.  Points of land also contain deep water near by and fish can use them as turning points in their ritualistic cruising patterns.  Finally weed beds are especially productive as they provide oxygen through the process of photosynthesis and a smorgasbord of food for the trout.  Weed beds can harbor significant populations of chironomid larvae.


Once you have settled upon your location you can begin to fish.  Prior to your first cast you should straighten out your line and leader.  Any coils left in your line and leader can translate into missed strikes.  A fish will gently inhale chironomid larva much like tropical fish eat fish food.  So the takes are quite subtle.  A straight line and leader assist greatly in detecting these soft strikes.  The simplest way to stretch you line and leader is to pull it firmly between your hands.  On cooler days you may wish to repeat this at different times during the day.  When casting you want your line to lie out as straight as possible.  Don’t be concerned with terribly long casts either as the more line you have out the more difficult it can be to control and react to takes.  Wind can assist in fishing the pattern.  I try to quarter my cast, and allow the wind to gently drift the fly behind my boat or float tube.  Be wary when wind drifting as strikes can come at any time during the swing.  Techniques such as mending help to keep the contact between yourself and your fly and ultimately control your cast.  Once you complete a cast, you will have to patiently wait for your offering to sink to the right level.  Typically you will fish your patterns on or near the bottom.  When you feel you have waited long enough for your pattern to sink you can begin the retrieve.  The typical retrieve consists of a very, very slow hand twist or figure 8 retrieve.  You want to retrieve slowly enough to just keep the tension in your fly line.  A typical cast can take 5 minutes or longer to retrieve!  When retrieving it is important to keep you rod tip low or even slightly beneath the water's surface.  A trout will exploit any slack in your line to its fullest potential.  The typical strike will be soft.  Often just a slight tightening of the line or a slight “pluck” is all one feels.  One even develops a type of sixth sense that something doesn’t feel quite right, strike at anything by simply lifting your rod.  Aggressive strikes are not necessary and will usually result in break offs and angler frustration. 


Larval patterns such as the Frostbite Bloodworm are slender and simple.
While you can use larval imitations any time there are some specific opportunities to increase your chances of success.  Early spring can be a prime time as the larvae migrate from deeper water to shallow in preparation for emergence.  Also due to low weed growth at this time of the year trout can easily spot exposed larvae.  Spring can also bring on windy, unsettled days that can circulate water currents and sweep the larvae off the bottom, distributing the larvae throughout the water column.  This phenomenon can provide some exciting fishing.  In the fall larvae can once again become active migrating back to the deeper regions of the lake in anticipation of winter.  Various types of water fowl such as Coots can disturb the shallows with their feeding.  A well-placed casting amongst these birds can bring excellent results.  Over the years I have noticed fish showing a preference for larvae at certain times of the day.  Chironomid larvae appear to be light sensitive and are most active in the morning and during other low light conditions.  I have recorded numerous stomach samples showing predominant feeding on chironomid larvae at this time.  A larval imitation is one of my favorite ways to begin fishing when I am not quite sure what specific insect the fish will be taking.  Remember the feeding habits of fish are always changing, as they are the ultimate opportunist.


Thoughts on Fly Patterns


Some might argue that understanding and fishing chironomid larvae imitations can be frustrating.  Fly patterns are not.  The patterns are quite simple in nature, so presentation is the key to success.  One has to keep the following points in mind:


  • The larvae are of uniform diameter from front to rear so keep the patterns as thin as possible.
  • Consider long shank hooks ranging from #8 2xl to #16 Std.  A #12 2xl hook is good standard.
  • Chironomid larvae have a shiny translucent body. Use materials such as Flashabou, Crystal Hair and Frostbite to imitate this characteristic.  Other materials such as Tapestry wool,  Flexi-Floss and V-Rib also create effective imitations.
  • If you look a chironomid larva closely you can see the contrasting digestive tract running through the middle of the insect. Shiny translucent materials allow you to simulate this with contrasting colors of thread such as black and maroon.
  •  Use wire ribbing to add durability, flash and most importantly,
  • segmentation.  Favorite colors are usually gold and copper.  Wire also serves to weight the pattern.  I weight nearly all of my larval imitations with wire or thin diameter lead substitutes.  Usually .010” diameter or less.  Remember the slim profile you need to achieve.
  •  Finally, consider a sparse hackle of pheasant rump, grouse or partridge hackle to simulate movement.  The larvae are feeble swimmers and swim in a head to tail wiggling motion.  While the hackle obviously does not imitate the wiggling as such it does offer some suggestion of life. 

Learning to understand and effectively fish Chironomid larvae imitations leads to some rewarding fishing while others around you wonder what magic pattern you are using.  Remember the specific times of the year and the day larval imitations can be especially effective.  Select a style of fly pattern you like and will fish confidently with.  Vary the sizes and colors.  When fishing seems slow avoid the temptation to go with larger patterns and fish faster.  Try going smaller and slowing down the presentation speed.  With some practice and patience you will enjoy some great fishing and add an additional weapon in your arsenal of lake tactics.

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