CHIRONOMIDS

The following is reprinted from Philip Rowley,s website: Fly Craft Angling with his permission.

Pupa

If scuds are an infestation then chironomids are an epidemic. Chironomid pupae are a year round food source and a regular feature on the trout's menu making them the number one food source in stillwaters. Imitating the slender pupae has eclipsed into a science. The silvery glow of the trapped air and gases the pupae use to elevate to the surface makes fly patterns incorporating materials such as Frost Bite, Flashabou and Krystal Flash mandatory for selective fish. The hovering pupa takes up to 4 days to ascend so trout have ample time to gorge themselves silly. Figuring out what depth the trout are feeding at is the key to chironomid fishing. For years anglers have used floating lines in conjunction with leader 15 feet or longer depending upon the depth. Using a leader about 3 to 4 feet longer than the water is deep is a good basis point. Don't be adverse to adding weight under windy conditions, as sub surface circulation currents will carry the pattern away from feeding trout. Make a straight line cast and count the pattern down systematically then begin a painstakingly slow retrieve. Five-minute retrieves are not unheard off. For precise depth control attach a strike indicator to the leader. Begin by placing the fly about 1 foot from the bottom. Adjust the indicator until feeding trout are found. The strike or perhaps more appropriately depth indicator tethers the fly in the feeding zone throughout the retrieve. If fishing slows try a slow 1-foot strip to raise the fly followed by a long pause. Takes often occur immediately after the strip. The floating line presentation reaches its limits in about 20 feet of water. When chironomids are emerging in water over 20 feet switch to a full sinking line of at least Type 2 density. Firmly anchored pull off a length of sinking line equal to the waters depth. Make a cast and allow the line to sink until it is hanging directly below the rod tip then begin a slow handtwist retrieve. Be prepared for rough takes as the trout follow the pattern to the surface taking the fly in a vicious downward motion.



Trout also key on size and color under selective conditions. Chironomid pupae tend to be larger than the hatching adults. Use pupal imitations one size greater than the observed adults. Under intense hatch conditions try larger pupa pattern so it stands out amongst the crowd of ascending pupae. Recently emerged adults tend to be brighter in color than the rising pupa so choose patterns a shade darker. The largest species of chironomids (often nicknamed bombers) favor muddy bottomed lakes while clear marl lakes tend to house smaller species. In the early part of the day smaller sized pupa tend to predominate with the larger pupa become more prevalent as the day progresses. Sizes also vary throughout the year. Pupa will be largest in the spring tapering down in size as the season progresses through August into October. For British Columbia lakes a selection of patterns from size 8 through 16 will cover most hatch situations.



 Larva

Perhaps it is their slim nature, perceived small sizes or the fact that majority of species live out their larval existence burrowing and writhing about in the bottom ooze. Whatever the reason few stillwater fly fishers realize the importance of chironomid larvae. Trout on the other hand are acutely aware of the intrinsic food value of chironomid larva.


The worm-like larva are a year round food source or staple as important as the more famous staple entourage that includes scuds, dragon nymphs, damselfly nymphs and leeches. In the absence of a hatch imitating a stillwater staple of some sort is the way to go. In the early morning hours many food sources are active, foraging under the relative security of the low light conditions. Chironomid larvae venture out of the protective tubes many species construct in the mud water interface. Feeble swimmers chironomid larva writhe and wriggle about at the mercy of the elements, foraging upon detritus and decaying vegetation. Opportunistic trout cruise above tipping head down to vacuum chironomid larva from their mud tubes and those left wandering too far from home. During intense windstorms many larvae are swept from their homes and dashed amongst the weeds. Using the ambient wind to sweep or wind-drift a larval imitation on a floating line and long leader (15 feet plus) can be lethal. Any time an angler sees chironomid larva adrift in the water column try sweeping a larval imitation using this wind-drifting tactic. Wind drifting is an excellent tactic to cover water with a near static presentation.


As with many insect larva and nymphs in stillwaters bloodworms migrate on a seasonal basis. In the spring larva migrate into the shallower reaches and reestablish their tubular homes. During the late fall those larvae not mature for their transition to the pupal stage travel to deeper climes to escape the harsh temperatures and ice of winter. Matching presentation techniques to simulate the natural travel of aquatic invertebrates is a sound plan.


Chironomid larvae are present in a wide array of colors. The most popular schemes include brown, medium green, olive, maroon and red, the red larvae have been christened by many as "bloodworms." The distinct red coloration is a result of hemoglobin that many species use to survive in oxygen poor waters. A certain times of the year such as the middle of summer oxygen levels in lakes drop as a result of increasing water temperature. Like humans, larva use iron molecules in their red blood cells (hemoglobin) to bind and carry oxygen. Later in the season as the oxygen levels return to comfortable levels the larvae return to their natural green and olive colorations. During this transition period it is not uncommon to see unique candy cane colored larvae of red and green. Keep a few barber poled imposters in the fly box to take advantage of these occasions.


Typical size range for most stillwater larva or bloodworm patterns ranges from size 8 2xl down through size 16 standard. Materials such as Frostbite, Superfloss, acetate floss, Flashabou and V-Rib are amongst the most popular. Don't forget the strategic addition of a glass or metal bead for added appeal.


The stillwater fly fisher should use the same presentation techniques that have been refined for the pupal phase of the chironomid life cycle. The key is keeping the offering near the bottom, within one to two feet. Strike indicators are of great assistance to novice fly fishers struggling with the confidence to fish a pattern that reassembles a tiny red stick in the vast expanse of a lake.

"Because you never stop learning"

 

© 2008 Fly Craft Angling