(Ephemerella inermis)
Characteristics
Three tails. Light gray wings. The body is bright yellow olive to light tan or pink. Body colors vary widely according to stream.
Timing of Hatches
Early June through August. Related species can emerge well through September. Duns emerge mid-mornings and can extend throughout the day. Spinners fall in the morning and late evenings.
Habitat
Medium to fast water with gravel or rocky bottom. Very common throughout the region including all sections of the Henry’s Fork, South Fork, Madison, Firehole, and other waters of Yellowstone Park.
Comments
Pale Morning Duns or PMDs provide some of the finest dry fly action of the summer. They are classified as crawler nymphs. Nymphs, emergers, cripples, duns, and spinners are very important to catch the most selective trout. Spinners vary according to sex. Male spinners have a rusty body while the body color of the females is yellow olive.
Patterns
Cocktail Nymph, Barr Beadhead Emerger, Halfback Emerger, CDC Biot Emerger, PMD Thorax, PMD Captive Dun, PMD Nohackle
Hook Sizes
16, 18 & 20