By Bruce Ajari ·
Little Yellow Stonefly ·
The Little Yellow Stonefly (isoperla) is an insect that typically emerges from around mid-May through July in the Truckee River. The timing of any of these hatches can be earlier or later depending on how much snow pack is in the hills and the corresponding runoff.
The Little Yellow Stonefly, or Yellow Sallies as they are sometimes called, is what I consider a big fish fly. A big fish fly is one that the larger fish in a system will take on the surface (dry fly-fishing) with great frequency.
The emergence occurs for a much greater time than many of the other so called big fish flies. As a result, anglers can take advantage of this hatch for a longer time.
They can typically be imitated with flies as simple as a yellow elk hair caddis in a size #14 to #16 for those fishing dry flies. While there are more realistic patterns out there, the elk hair caddis provides a good imitation.
Little Yellow Stoneflies are like all other Stoneflies. They need highly oxygenated water, so look for areas with good flows. The best hatches will occur there and that is where you will find large fish feeding on them.
Each year, we begin the season with Carpenter Ants and Green Drake Mayflies. Both of these insects are considered big fish hatches. Both are rather short lived compared to the stonefly though, only lasting a matter of weeks. Mixed in around the Drake emergence is the stonefly hatch.
We have caught large fish even during the Drake hatch that key on the stonefly. It is probably just a function of the sheer numbers of insects that hatch during the stonefly emergence. When they emerge in large numbers, the large fish turn attention to them because, while smaller, they are more numerous.
Fish have to take in more calories than they expend. It takes less energy for fish to eat a smaller, abundant food source than to go after the less frequent, larger insect. Thus, the stonefly becomes the fly of choice during a good emergence.
Some of the largest fish that we have caught in the Truckee River is during the stonefly hatch. We dead drift our fly on the surface to a rising fish and wait for the bite.
Over the years, we have experimented with a lot of different fly patterns to imitate the adult stonefly. The best two that we have used were developed in the 80s and another in the 90s.
The first fly we have not used much since developing the second one. The first one was just a simple elk hair caddis, but tied with a body of yellow crystal flash. The second one is tied like an elk hair caddis with pale yellow dubbing, dark barred ginger hackle and a white CDC wing. We put a spot of red dubbing at the rear to represent the egg-laying female that the fish sometimes key on.
This second fly fishes great because of the CDC wing helps it float well. The white CDC also is visible and makes fishing this fly great when the light is failing and the stonefly hatch is in full swing.
We have had some stellar times fishing the stonefly dries during the day and evenings. It is probably one of the most consistent big fly hatches on the Truckee River.
FISHING REPORT (See Sightseeing for water levels.)
Boca | Inflow is at 65 cfs and the outflow is 224 cfs. Try powerbait or nightcrawlers. Throwing lures from shore has been working. Fly-fishers have been catching some fish near the inlet, mostly nymphing and with streamers.
Donner Lake | Fishing has been good. Nightcrawlers and Powerbait seem to be the bait of choice. Mackinaw and Kokanee fishing has been fair. Fly-fishermen are catching some fish with streamers.
Lake Tahoe | The Lake within 300 feet of a tributary is closed. Tributaries are only open July 1 to Sept. 30. Fishing has been fair to good for mackinaw. A guide is highly recommended if you are fishing for mackinaw for the first time. Toplining and shore fishing is fair. Most shore fishermen use inflated nightcrawlers.
Little Truckee River | Flow is now at a 65 cfs. Fishing has been fair to good. Keep an eye on the flows here. Try a dry dropper rig here. PMDs have been the top producer of late.
Martis Lake | Zero kill. Catch and Release only with barbless artificial lures or flies. Some small cutthroats and an occasional large brown or rainbow can still be caught here. Smallmouth bass have been introduced in this water. It is probably too warm for fishing now; wait until fall.
Prosser | The lake is fishing fair to good. Powerbait and nightcrawlers are the best bait. Lure and fly-fishermen are taking some fish from shore and near the inlets. Smallmouth Bass fishing is fair to good.
Stampede | Stampede continues to drop. Fishing has been fair to good from shore. Kokanee and Mackinaw fishing have been good. Smallmouth bass fishing is fair to good.
Truckee River | Flowing out of the lake at 199 cfs. The flow through Truckee is at 209 cfs as of July 20. Fishing has been good. Keep an eye on the flows. Fish have been caught on nymphs, emergers, dries and streamers. The water flows seem to be stabilizing. Caddisflies and Little Yellow Stones are the main insects. Grasshoppers are starting to show. Nymphing, dries and streamer fishing have all been good.
Other Waters | Davis and Frenchman have been fair to good. The damsel hatch is slowing down. Carry some adult damsels with you now. Fish are being caught on blood midge patterns and Callibaetis imitations. Streamers fished deep can be productive.
Bruce is a long-time area fly-fisherman and past president of Tahoe Truckee Fly Fishers.
