A chironomid is a midge. Same order (Diptera), same family (Chironomidae), same larva-pupa-adult life cycle. It gets its own page because the lake version of this insect is a different fishery from the river version in almost every way that matters. In a tailwater you fish midges in size 22 on 6X under a pinch of yarn in two feet of moving water. On Crowley Lake the local pattern is a size 12 black and red chironomid, and you hang it eighteen feet down under a slip indicator from a float tube and wait. This page is the lake version. River midging is covered on the midge fishing page.
Bloodworm, pupa, adult: the lake life cycle
Chironomid larvae live in the soft bottom of a lake, from the shallows out to surprising depths. Many are bright red from hemoglobin, which lets them survive in low-oxygen mud, and that is the bloodworm. They are bigger than their river cousins: the lake fly lists here run from size 18 up to size 10, and Henry's Lake lists a Vertically Suspended Bloodworm in 10-12, a pattern you would never tie on in a river.
The pupa is the stage the whole sport is built on. When it is ready to emerge, it leaves the mud and rises slowly through the entire water column. Gas trapped under the pupal skin gives it a silver sheen, and it often stalls partway up, hanging vertically, before finishing the trip. Trout cruise at whatever depth the pupae are staging and eat them one after another, which is why a pupa fished dead still at the right depth outfishes anything that moves. The rising pupa is where the numbers are.
Indicator fishing: the standard method
The setup is a floating line, a leader long enough to reach near the bottom, a slip indicator that lets you set depth anywhere from four feet to twenty-five, and one or two chironomid pupae with a small split shot or a tungsten bead. The fly hangs straight below the indicator, and the presentation is no presentation: anchor, cast, let it settle, and leave it. A very slow hand-twist retrieve imitates the rising pupa when fish want movement, but most days still is better.
Depth is the only variable that matters. Start with the fly a foot off the bottom. If nothing happens in twenty minutes, come up two feet, and keep coming up until you find the fish. Trout are usually near the bottom early in the hatch and higher as it builds. Takes are soft; the indicator dips an inch, drifts sideways, or just stops. Set on anything.
The naked line and the deep rig
When the water is deeper than an indicator can handle, or fish are spooking off it on a flat calm day, fish "naked": floating line, a very long leader, and a fly you count down and creep back while watching the line tip for a twitch. On deep lakes like Flaming Gorge or Lake Chelan, a sinking line fished vertically under an anchored boat does the same job. The Strawberry Reservoir page lists its Zebra Midge as "suspended," a good one-word description of the whole approach.
Colors and patterns from the lake pages
All 31 lakes on this site list chironomids, and the fly lists converge on a small set of patterns:
- Black Chironomid #12-16 and Red Chironomid #12-16: the two colors on nearly every lake page. Black with a silver or red rib is the default; red when bloodworms are the food.
- Zebra Midge #14-18: the river fly tied larger. Listed on Strawberry, Blue Mesa, Spinney Mountain, and a dozen others.
- Mercury Chironomid #14-16: a glass bead at the head for the gas bubble. Listed on Georgetown, Hebgen, Pass Lake, and Crowley.
- Local ties: the Crowley Chironomid #12-14, the Bear Lake Chironomid #14-18 in tan and olive, the Henry's Lake Chironomid #10-14. When a lake page names a pattern after the lake, buy that one first.
Sizes run bigger on rich, shallow lakes (Crowley, Henry's, Crane Prairie, all listing 10 through 14) and smaller on cold, high lakes (Yellowstone Lake lists 16 through 20).
When each lake peaks
Chironomids hatch from ice-out until the lake warms and again in fall, and the peak months sort cleanly by elevation and climate:
| Lake | Ice-out | Peak chironomid months |
|---|---|---|
| Pyramid Lake, NV and Walker Lake, NV | Do not freeze | Nearly all year (Pyramid pauses Jul-Aug) |
| Pass Lake, WA; Strawberry, UT; Blue Mesa, CO; Flathead, MT; Pend Oreille, ID; Lake Chelan, WA | Varies | March through October |
| Crowley, CA; Bear Lake, UT/ID; Diamond, OR; Almanor, CA; Eleven Mile, CO; Spinney Mountain, CO | March to early May | April through October |
| Georgetown, MT; Hebgen, MT; Scofield, UT; Heron, NM; Eagle Nest, NM; Odell, OR | April to May | May through September or October |
| Henry's Lake, ID; Fish Lake, UT; Jackson Lake, WY | Late May | June through September |
| Convict, CA; Fremont, WY; Redfish, ID; Yellowstone Lake, WY | Late May to June | July through September |
| Eagle Lake, CA | March to April | March-April and October-November (summer is too warm) |
Flaming Gorge is the outlier: it peaks March through May and again in September and October, because the fish go deep when the surface warms.
Reading a chironomid day on the water
Look for the shucks. Empty pupal skins in the wind lane or against the downwind shore tell you a hatch is on and roughly what size to fish. Swallows working low mean adults are coming off. "Porpoising" trout that show back and tail without a splash are taking pupae just under the surface; shorten the indicator to a few feet and fish to them. Flat calm mornings put fish higher in the column. A chop puts them down and makes the deep rig the better choice.
Gear notes for a first chironomid trip
- A 9 or 10 foot rod in 5 or 6 weight, for lifting a long leader and setting at distance.
- A floating line, plus an intermediate or type III sinker for the deep lakes.
- A slip indicator with a release, so a twenty-foot leader can be reeled to the net.
- 4X or 5X fluorocarbon. Fish are not leader-shy at depth.
- An anchor, front and back in a boat, so the rig hangs vertically.
Several of these waters have tribal, park, or state rules (Pyramid Lake is on Paiute tribal land, Yellowstone Lake is in the park), so check the managing agency before you launch.