Isonychia mayflies go by many names—Mahogany Dun, Slate Drake, and Leadwing Coachman, among others—and they are among the more important sporadically hatching bugs in the East and Midwest. These insects rarely provide the blanket hatches that make sulfurs and caddisflies so exciting, but Isonychia emerge in light numbers almost every evening for much of the season, long after the “sexier” hatches are over. Although these bugs are generally not as important in the West, there are localized populations.
In this great video from Tightline Productions, Matt Grobert, an author and blogger, offers his simple method for creating this useful pattern. The ways that Matt creates the post and uses the moose body hair to make both wing and rear of the body are very cool, but it’s especially ingenious the way he finishes the fly. Even if you live in a region where Isonychia is not important, the tricks on display here will help you tie better Parachute patterns of any kind.
Hook: 1X-long dry-fly hook (e.g. Dai-Riki #300), sizes 10-14.
Thread: Olive, 6/0.
Post: White calf-body hair, cleaned and stacked.
Tail: Moose body hair.
Abdomen: Burgundy, black, and gray rabbit fur, mixed.
Hackle: Medium dun neck hackle.
Thorax/head: Burgundy, black, and gray rabbit fur, mixed.