Little Yellow Stonefly

Other Common Names: Yellow sally, early orange stonefly, western yellow stonefly
Scientific Names: family Perlodidae, especially the genus Isoperla

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.

 

How to Match a Yellow sally

Hatches are matched from Westfly's database of "standard" fly patterns.

Nymph
Size 12 Hares Ear. Yellow, brown, yellow-brown
Bankwater near foilage: indicator, tight line
Adult
Size 12 Clarks Stonefly, Stimulator, Chubby Chernobyl. Yellow, brown, yellow-brown
Riffles, moderate-fast runs, backeddies, current seams: standard dry fly
Egg-layer
Size 12 Clarks Stonefly. Yellow, brown, yellow-brown
Riffles, moderate-fast runs, backeddies, current seam: standard dry fly
Egg-layer
Size 12 Stimulator. Yellow, brown, yellow-brown
Riffles, moderate-fast runs, backeddies, current seams: standard dry fly
Egg-layer
Size 12 Chubby Chernobyl. Yellow, brown, yellow-brown
Riffles, moderate-fast runs, backeddies, current seams: standard dry fly

 

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Characteristics

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: Nymph--no external gill filaments. Adult--well-developed tails.

 

More About Yellow Sallies