Little Yellow Stonefly

NYMPH SIZE: 7-16 mm

NYMPH COLOR: Mottled tan/brown/light yellow.

ADULT SIZE: 7-16 mm

ADULT COLOR: Yellow to light brown body, head; yellows can be very bright, almost fluorescent. Wings light tan to yellow.

OTHER CHARACTERISTICS: Nymphs have no external gill filaments. Adults have well-developed tails.

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About Little Yellow Stoneflies

Some rivers have significant populations of little yellow stoneflies. Nymphs live in riffles and rocky runs with moderate to fast flows. They are often knocked loose and drift in the current, so a nymph imitation can be productive when dead-drifted through riffles and runs.

At maturity, nymphs migrate to slower water, then crawl onto shore. Migration times are another nymph-fishing opportunity, especially near dusk because that is the major "drive time" for the nymphs.

Adults emerge on out-of-the-water objects such as rocks and tree trunks. Adults are active in the warm part of the day. Some end up on the water, so it is worthwhile to cast a dry fly near bankside vegetation. Odds are, a trout will be close at hand waiting for errant little yellow stoneflies to stumble onto the water and drift to them.

Females return to the water to lay their eggs by dipping their abdomen in the riffles. Many are taken by trout at this time, and others end up spent on the water and drift into collecting areas, such as backeddies. This creates more dry fly fishing--one in the riffles with a heavily-hackled fly, and one in the quieter water where less hackle is needed.

While most little yellow stonefly adults hatch out on land, there is a species that emerges in the water like a mayfly.

STAGE

PATTERN

SIZE/
COLOR

PRESENTATION

WHERE

Nymph

A. P. Nymph, Hares Ear

8-14/Pale yellow, brown

Indicator, Tight line

Riffles, runs; just below these

Adult

Stimulator, Elk Hair Caddis, Clarks Stonefly, Parachute Hares Ear

10-16/Yellow, brown, yellow-brown

Standard dry fly

Bankwater near foilage

Egg-layer

Stimulator

10-16/Yellow, brown, yellow-brown

Standard dry fly

Riffles, moderate-fast runs, backeddies, current seam

Egg-layer

Elk Hair Caddis, Clarks Stonefly, Parachute Hares Ear

10-16/Yellow, brown, yellow-brown

Standard dry fly

Riffles, moderate-fast runs, backeddies, current seams