Western March Brown Soft-Hackle Emerger

March Brown Emerger tied by Steven Bird

     If you fish a freestone stream west of the Rockies, the western march brown mayfly is an important insect to imitate this time of year. March brown (Rithrogena morrisoni) is the first large mayfly of the year, appearing as early as February in warmer regions, & into June in colder climes, though most Northwest streams will host emergence March-May, & into June.

March brown nymphs inhabit rubble bottom in moderate to fast flows; muscular clingers, they are seldom loose in the drift until emergence. Prior to emergence, the wing pads turn black & the wings begin to unravel while the nymph still clings to the bottom. When the wings have opened enough, the nymph lets go of the bottom to ‘sail’ upward on the current while completing emergence -- probably the reason winged versions of this mayfly work well.

Though some streams host heavy hatches of march browns, on many streams they are a more obscure presence, though still a presence, so the imitation is useful throughout the hatch season, as trout know they are around & will take them when the opportunity presents.

March Brown Emerger

Hook: #12-#16 (Can be tied on a standard wetfly hook, weighted or not; or a standard dryfly hook to fish higher in the water column & on top as a cripple.) 

Thread: Camel

Tails: Three hen pheasant tail fibers – equal to body length

Rib: Single flat, yellow strand taken from a length of cheapo poly cord, 5 to seven turns, wound as a rib over the abdomen

Abdomen: 50/50 blend of medium olive & golden-brown rabbit dubbing (This is a generic color dressing; naturals will vary according to location, ranging from light golden brown, olive-brown, to dark olive & dark brown.)

                 

Thorax: Olive-brown rabbit dubbing

Wingcase: A Pinch of black rabbit (original choice), CDC, marabou, or poly (Tie in ahead of the thorax, spread over the top half, & extending to about the center of the hook shank; (optional) tie in three or four strands of olive midge flash on top. I use WAPSI olive/pearl midge flash, which reflects olive & copper highlights.)

Hackle: One turn of brahma hen, brown partridge or grouse -- the one in the foto is tied with Welsummer hen, a very useful Dutch chicken: see fotos below

Head: Olive-brown rabbit dubbing - build at least as thick as the thorax – & finish.

Flyfish the Upper Columbia/NE Washington with Steven Bird: http://ucflyfishing.blogspot.com   

 

Welsummer Hen Cape