(Drunella grandis)
Characteristics
Three tails. Dark gray wings with bright olive green body. The body quickly darkens to dark reddish or olive brown after emergence. Duns normally emerge during the late mornings. Spinners fall early in the morning. Best activity occurs on cloudy humid days.
Timing of Hatches
June into early July. The Green Drake hatch often takes place during cool spring afternoons. It can be challenging because the large flies are easy for trout to inspect in the daylight and they feed very selectively especially late in the hatch.
Habitat
Medium to fast water sections of the Henry’s Fork, South Fork of the Snake, Yellowstone, and other surrounding waters. Especially common on the Last Chance section of the Henry’s Fork and the tailwater section between Ashton and Saint Anthony.
Comments
Due to the wide distribution of the species, color variations exist from stream to stream. They are classified as crawler nymphs. The body color of the duns is considerably darker on the South Fork of the Snake. A related species, Timpanoga hecuba is common on the Lamar River and tributary streams including Slough Creek and Soda Butte Creek as well as the Upper Snake System near Jackson, Wyoming. The emergence period of this species occurs in late August, September, and early October.
Patterns
Green Drake Nymph, Hare’s Ear Nymph, Green Drake Emerger, Green Drake Cripple, CDC Emerger, Green Paradrake, Mike’s Green Drake, Green Drake Spinner, Rusty Spinner
Hook Sizes
10 & 12