The Chironomid
Peter MacPherson

Chironomid..............awkward to say, hard to spell and an intimidating hatch to some fly fishers. Once you can say, spell and fish chironomids correctly, the name will produce thoughts of anticipation, not intimidation. The chironomid provides a mainstay in the trout's diet. They are available year round but are most heavily feed upon when the larvae leave the security of the bottom or especially when they pupate and leave the safety of the bottom to emerge into the flying adult.

There are often comments made regarding chironomid fishing as to it being slow, boring and often unproductive. At times this is true but on average, if chironomid activity is happening, the trout will be feeding on them. For most of May and June the most significant insect activity will be the chironomid. Personally I find a good chironomid hatch comparable only to the most perfectly timed sedge hatch.

In the early season it is best to fish either the surface or bottom couple of feet. This is mostly determined by the water depth at which most oxygen is present. Seldom after ice-off is it necessary to fish deeper than 20’ and often water depths less than 10’ will be the most productive. After "turnover" the lake will proceed on its yearly pattern. June will be the most predictable month, hatches will occur daily depending on the weather.....sunny, cloudy......hot or cold.

The chironomid larvae are somewhat confined to the bottom where they will burrow in the mud to avoid predation. Some actually bore into aquatic plant stalks. Trout feeding on larvae will scour the bottom plucking the unsuspecting larvae as they wiggle and undulate on the bottom or amongst vegetation. The larvae will vary in color from bright red, purple, brown, grey, white, yellow, green and olive. The most popular larvae imitation is the "bloodworm". As the name implies, "bloodworm" patterns are bright red, blood red and purplish red. These colors indicate the presence of hemoglobin in the larvae and seem to be the most effectively fished colors. When fishing larvae patterns it is most important to ensure your fly is very close to the bottom where trout expect to find them. With a floating fly line, the use of an indicator on your leader will allow you to specifically dictate the maximum depth your sunken fly can attain. Keep your retrieve as slow as possible, the wave action (if present) will usually impart plenty of movement to your fly. The takes will be very soft as trout feeding on the larvae are in no panic as they feed.

When the larvae reach maturity they begin their transformation into the chironomid pupae in the safety of their mud burrows. Once the process is complete they will be ready to begin their journey to the surface. Hatches will usually be triggered by favorable water temperatures in the late morning and afternoon. Although the pupae seen to be fairly active in their effort to "swim" to the surface there is little gained for their labor. The gases trapped in the pupal case provide buoyancy allowing the pupae to basically "float" to the surface. The pupae are most vulnerable as they begin their departure from the bottom and again at the surface film where they will pause from several minutes to a couple hours before starting their emergence. For the most part, chironomid pupae are most effectively fished near the bottom or near the surface. At times it may be more comfortable for the trout to feed at depths having more favorable temperatures or oxygen levels. Chironomid pupae vary in color with olive, brown and black being the most common. Observing the adults as they emerge will be the best indicator of the pupae coloration. Size is also one of the keys to success, try to match size and color as close as possible. If adult chironomids are apparent on the surface yet little surface feeding by trout is present, fish your pupae sub surface.

Fishing a floating fly line with an indicator on your leader is always the most efficient way to accurately determine the depth your pupae is fished at. The use of a small lead weight on your leader will ensure your fly achieves the desired depth. Allow for enough leader length between fly and indicator to get your fly near the bottom. If you wish to fish at a depth between the surface and bottom simply adjust your indicator position accordingly. Shallow depths to about 6’ are easily fished without an indicator and additional weights are seldom necessary unless under windy conditions. Your retrieve should be as slow as manageable paying close attention to your indicator or floating line for any pause, tug or resistance. The "take" of a trout must be quickly responded to by raising the rod tip. Be ready to either retrieve line quickly or allow for line to be drawn out. Surprised trout, fooled by your chironomid pupae often respond by bolting in one direction......sometimes towards you, sometimes away.

Once the chironomid pupae reach the surface film they begin the final stage of their transformation into the adult. They must exit their pupal case by crawling out of the split thorax and separating themselves from the shuck. Within a few seconds of separation they will be ready to fly away. This process is referred to as "emergence" and will take from a few minutes to an hour to be completed. The calmer the water conditions the longer this process takes. Under very calm conditions it may take the pupae over an hour to break through the surface film, yet in windy conditions this only takes a minute or so.
Trout feeding on emergent pupae will show themselves by "sipping" the emergers at the surface. This action often produces only small ringlets often interpreted as small fish rising. Keep in mind that large trout expend as little energy as possible and are relaxed at feeding knowing that the emergent pupae are totally helpless until the process is complete. The chironomid pupae can be fished with a floating line and long (12’) leader coated with floatant right up to within an inch or two of the fly. This technique represents the pupae as it pauses to break the surface film. An emerger pattern can be fished in the same manner representing the adult in its final stage of emergence just prior to separating from its pupal husk. "Sipping" or "nose-up" rises indicate to fish a pupae at the surface film. More aggressive, "spitting" rises usually indicate an emerger pattern would be more appropriate. Aggressive "swirling" rises tend to indicate a fish is taking adults prior to gaining their complete flight abilities. Using a long leader, fine tippet and an adult imitation such as a Midge, Bivisible or Griffith’s Gnat will produce well when gently "skated" across the surface.

The most prominent chironomid hatches of the season are ahead. Once "turn-over" is complete and insect and trout activity stabilizes the chironomid hatch will provide daily opportunities. Be observant and patient with your chironomid fishing techniques and the pay-off will be worthwhile.

Respect the fish, the resource and your fellow fisherman,
Good Luck and Good Fishing! Peter Mac Pherson

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