This is my tying of the Waterhen Bloa. This is one of the most famous Spider patterns.
Hook – Partridge barbless dry fly hook size 14. You can vary the hook gauge for different parts of the water column
Thread – Primrose yellow – here I use Kimono silk color number 301
Body – sparsely dubbed with water rat or European water vole. This material is no longer sold. I substituted Pine Squirrel raked off a skin to include both underfur and guard hairs.
Hackle – undercovert feather from a waterhen wing. Waterhen is available but difficult to get. A smoky gray is the color so a hen feather in that color is a sub. If you have drake mallard wings I like the overcovert as a sub.