No. 13. The Yellow Dun.
This beautiful ephemera is one of our very best flies. There are several varieties, and some of them are an inch in length. It changes to a spinner, very similar to the metamorphosis of the blue dun (No. 2), only lighter and yellower, and should be so tied.
Imitation.
Body.—Yellow mohair spun very thinly on pale blue silk.
Wings.—From the lightest part of the feather of a robin’s wing.
Legs.—A pale yellow dun hackle.
This fly must not be finished off at the head with the blue silk, but a yellow must be tied in for the purpose when the body is done.
No. 14. The Iron Blue Dun.
This is one of the smallest of the ephemeridæ, but not the least useful. It lives only two or three days before changing its coat, when its body becomes almost white, and its wings transparent.