Lipton's Black Flag:
Hook: Umpqua U401 (O'Shaugnessy Stainless) Size 6
Thread: UNI Thread, 6/0 Black
Tail: Moose Mane
Body: Roughfisher's custom dub, Black Gold
Underwing: Krystal Flash, Black/Peacock
Legs: India Hen, natural
Thorax: 3.2 mm tungsten bead; Roughfisher's custom dub, Black Gold
Eyes: #3 (2.4 mm) ball chain, black
This fly is patterned after the black quill mayfly, Leptophlebia Cupida, prevalent in northern Minnesota in early Summer. Most nymphs range in the 9-11 mm size range with adults measuring around 15 mm. While not prolific enough to generate superhatches, their medium to large size and their propensity to school up and migrate upstream like minnows are enough to make this species of mayfly relevant to anglers. As a result, I would not hesitate to fish this fly as a streamer in riffle sections or in pocket water adjacent to the slack water they are known to reside in much of the year. Due to the dark coloration and size of this pattern, these would also fish well as a larger mayfly, or stonefly or skwala nymph pattern.
Notes: I like to tie on heavy, short-shanked hooks, so even though this particular pattern is tied on a size 6 O'Shaugnessy hook, the body of the fly is probably sized closer to a traditional sized 10 or 12 nymph hook. I colored the hook black with a marker to keep hook glare down and give the fly a dark, subdued look. Like most mayfly nymphs, I tie mine heavy; there is a tungsten bead tied in underneath the body just behind the bead chain eyes. This will help keep your fly in the zone when fish riffles or deep runs.