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Column: How to choose from among hundreds of chironomid patterns

Great Outdoors by James Murray
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It’s in the air, you can feel it; spring is coming.

Which means it won’t be long before the ice will be off the lakes and they’ll be starting to turn over. It won’t be long, therefore, before the first chironomid hatches will start coming off. A smart fly fisher will have already started to tie up a good supply of chironomid patterns so they will be ready for the start of the new fishing season.

Ah yes, chironomids, those tiny little members of the two-winged order Diptera.

I read somewhere that there are about 2,500 species of chironomids in North America, and at least 200 different species in the B.C.’s Interior. That’s quite a few possible fly patterns.

Chironomids, which begin hatching immediately after ice-off, undergo a complete metamorphosis. Their life cycle begins when eggs are deposited on the surface of a lake and settle on the bottom. The eggs develop into larvae which are thin, worm-like creatures, half an inch to one inch in length, with a rather pronounced segmentation along the full length of their body. They are usually bright red in colour due to a hemoglobin substance in their bodies which allows them to live in relatively oxygen-poor waters in the winter months.

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The majority of chironomid hatches take place in waters no more than 10 to 20 feet deep, and although individual chironomids are often tiny in size, one only has to look at the tremendous number of empty chironomid pupae cases floating on the water to realize just how large many are hatching at any given time. The pupae stage can be anywhere from less than a quarter of an inch to as large as three quarters of an inch. In shades of pale green to brown, wine and black, chironomid pupae are easily identified by their pronounced segmentation along the abdomen, and the presence of white feather-like gills on the head and sometimes on the tip of the abdomen. The pupae emerge from protective tubes in the lake bottom to begin their ascent to the surface by trapping gases under the skin of their abdomen and thorax. As the pupae make their way towards the surface, they often take on a silvery mirror-like appearance due to the trapped gases. Immediately upon reaching the surface, a split forms along the back of the thorax, the winged adult emerges and the mature insect flies off to mate and begin the cycle all over again.

It is during their ascent to the surface that chironomid pupae become easy prey for opportunistic trout which will often feed almost exclusively on the emerging pupae.

Most anglers fish chironomid patterns with a floating line and a long sinking leader. An integral part of fishing with chironomid patterns is having enough patience to wait for such a tiny fly to sink to the required depth. Strikes are often subtle and hard to recognize. It can take three to five minutes for a fly to sink 20 feet in the water. A slow retrieve is also essential – a couple of inches, pause, a couple more inches, then a longer pause. Too fast a retrieve and your presentation looks too unnatural.

The key to successful chironomid fishing is to remember size matters. You want your imitation to blend in with all the other little chironomids trying to emerge, so you need to select a pattern that is very close in both size and colour to the naturals that are emerging at the time.

Spring has been a long time coming, but it won’t be much longer before you’ll be making that first, long awaited, cast of the new fishing season.

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