(Isoperla, alloperla)
Characteristics
Most species have a pale yellow to bright green body. For that reason these stoneflies are commonly referred to as Yellow Sallies. Females commonly have red egg masses on the tips of their abdomens. They commonly emerge on most rivers during mid-summer. Most of these little stoneflies become active between late afternoon and early morning hours. On some waters the dry fly fishing can be spectular when adults land on the water during egg-laying.
Timing of Hatches
Henry’s Fork – May 25 through June 30
Madison River – June 25 through July 20
South Fork – June 25 through July 20
Habitat
Medium to fast, oxygen rich water with rocks and boulders
Comments
Look for these small stoneflies to become active during the late afternoon and evening hours. Large swarms of females often cloud the air. The females stop flying at a height of 10 to 15 feet and glide down to the surface to lay their eggs. They can repeat the process several times. Trout can become very selective on these small, slender stoneflies.
Patterns
Henry’s Fork Yellow Sally, Head Light Yellow Sally, Yellow PMX
Hook Sizes
12, 14 & 16