Old Blue Dun

James Leisenring notes that an optional starling wing can be added to this dressing, though the Old Blue Dun he pictures in The Art of Tying the Wet Fly and Fishing the Flymph (1941) is dressed as above, without it. 

Hook:		12-16
Thread:		Primrose
Tail:		Two or three rusty-dun hackle fibers
Rib:		One strand of silk buttonhole twist – Coats and Clark’s 72-A primrose, size D; or full twist, tightly twisted
Body:		Muskrat dubbed on primrose Pearsall’s Gossamer Silk, wrapped so that some silk shows through the dubbing at the tail end
Hackle:		Blue-dun hen
		James Leisenring included the Old Blue Dun in The Art of Tying the Wet Fly and Fishing the Flymph (1941). He dressed it: “HOOK  12, 13, 14. SILK  Primrose yellow. HACKLE  Blue-dun hen hackle of good quality. TAIL  Two or three glassy fibers from a rusty-blue-dun cock’s hackle. RIB  One strand of yellow buttonhole twist BODY  Mustrat underfur spun on primrose-yellow silk, a little of the silk showing through dubbing at the tail. WINGS  Starling optional.” Leisenring’s name for the fly does not appear in older angling literature, but the word “old” suggests it should. Since many patterns utilize combinations of dun colored furs on yellow silk bodies coupled with hackles in varying shades of dun and, quite often, with smoky dun-colored wings, the most distinguishing feature of Leisenring’s dressing is the addition of a primrose rib. In the third edition of the Modern Fly Dressing (1950), Roger Woolley lists various dressings of the Blue Dun as the Early Olive Dun. Blue Dun is a relatively common name, and shows up alongside other dressings that utilize blue fur bodies, but they usually omit the rib. Like Leisenring's Old Blue Dun, Woolley's dressings, particularly those under the heading of "Hackled Wet Patterns for Midland and Welsh Waters," often include bodies of various blue furs and a rib that is yellow (on in a few cases, of silver wire). William Blacker gives an almost identical dressing in his Art of Angling (1843), although it neither stipulates the color of the tying thread nor makes the starling wing optional. He calls it the Whirling Dun, No. 29, and he argues it is best suited for June and July fishing. Richard Bowlker, too, includes a Little Pale Blue in his Art of Angling (1758) that neglects tail fibers and uses “the lightest blue feathers of a sea-swallow” for the wing. Perhaps the oldest direct precedent for Leisenring’s Old Blue Dun is the “whirling Dun” that Charles Cotton listed for April in his additions to the Compleat Angler (1676). He notes that “About the twelfth of this Month comes in the Flie call’d the whirling Dun, which is taken every day about the mid time of the day all this Month through, and by fits from thence to the end of June, and is commonly made of the down of a Fox Cub, which is of an Ash colour at the roots, next to the skin, and ribb’d about with yellow silk, the wings of the pale grey feather of a Mallard.” The lineage of Leisenring's Old Blue Dun has much in common with the lineage of the prevalent Waterhen Bloa, though most of the latter's dressings are not ribbed.