Tiny chironomid pupae, big trout bite

Chironomids don’t seem to have the same impact in a fishermen’s fly box that they do in nature, at least on the Kenai Peninsula.


Although they are the most abundant insect in any aquatic environment and are found in every aquatic habitat that one could name, some area fly fishermen are simply unaware of the pattern’s effectiveness for snaring trout.

When area fishermen think about trout, they often think about patterns that relate to the salmon runs and the massive amount of food they bring into a river or stream, said Dr. David Wartinbee, Kenai Peninsula College professor of biology.

But the small and simple chironomid or black fly pupae pattern can be another effective tool in the angler’s arsenal, especially on lakes or in the river when the salmon food source isn’t available.

“They’re overshadowed,” Wartinbee said of the pattern.

The simple fly — a small, size 10 or 12 hook wrapped in clear plastic ribbon — can represent a wide variety of potential insects, Wartinbee said. There are thousands of species of chironomids in Alaska — 88 in the Kenai River alone and many more than that in area lakes — in addition to the eight or 10 black fly species that call the Peninsula home.

By tying a length of various colored plastic wrap onto the body of a small hook and sometimes adding a brassy bead head, Wartinbee can successfully imitate the emerging pupa of either the chironomid or black fly.

“What we are doing is fishing with their most vulnerable stage. This transition from an aquatic pupa to an aerial adult is when they get preyed-upon most often. During the pupa stage, and as a larva, they are hidden in the substrate where they are feeding or resting,” he said. “That transition to an adult is their vulnerable period.”

The optional brassy head of the fly adds a little weight and also serves to imitate a piece of the black fly’s natural life cycle, Wartinbee said.

“The way they emerge is they come up to the surface and it has a little bubble of air that it has created to open up the shell and when he hits the surface, he flies away,” he said. “That brass mimics that.”

The majority of the area’s chironomids emerge and complete their lifecycles in the central portions of the summer, with some bookending the seasons in spring or fall. While there are some large species in the Kenai River, most of the larger chironomid species live in the lake environment and emerge all summer long.

In the spring, Wartinbee said the first of the chironomids to emerge from the Kenai River are colored dark brown and gold. But as the weather warms, the species turns to more red, green, yellow and grey colors. In the lakes, the larger red and golden brown colored pupae are predominant throughout most of the summer, he said.

Wartinbee said he often fishes the pupae patterns in open waters along the edge of lakes. Although chironomids can be fished on, or just below the surface, Wartinbee said he sometimes adds just a bit of weight to send them deep.

“The fish tend to be at the bottom and if all you are doing is playing with stuff on the surface, you are only going to get a few of them cruising up high,” he said. “If you can draw them up from the bottom, you can have more fish see your fly.”

When fishing with chironomids, Wartinbee said he uses a floating line with an eight-foot leader. He lets the pattern sink down, rest for a while and pulls it slowly back to the surface.

“That movement is exactly what the fish are looking for,” Wartinbee said. “... The fish kind of realize that when pupae hit the top of the water the adult will fly away in a few seconds. Sometimes fish will chase pupae to the surface, but I’m most successful when I fish them deeper like a nymph.”

Wartinbee said he has had great success with those two patterns — chironomid pupae and the brassy or bead-headed nymph black fly patterns — in addition to an adult dry mosquito/midge pattern.

“All I can tell you is that I have caught hundreds of grayling with those three patterns alone,” he said. “Once you are out there catching fish, if they ain’t broke don’t fix it.”


Brian Smith can be reached at brian.smith@peninsulaclarion.com.


An Outdoor View: Fishing tips

Fishing is a lot like life. Consider these tips:

Read more

Memorial Day weekend promises sun, Lower Peninsula fishing

Memorial Day weekend will likely bring a wash of fishermen down to the Kenai Peninsula with school out, predicted temperatures in the 60s and the... Read more