Krejice are traditional flies from Bosnia. They imitate mayfly duns. Wings are made by using a jay feather which is great for this purpose. The colour, texture and softness of a jay feather makes these flies both beautiful and effective.
They mostly imitate species such as Serratella ignita (BWO) and various Baetis duns. On a larger hooks, these flies can work well as a Rhithrogena semicolorata imitations.
Krejice were originally designed as wet flies but can be fished as dry flies also. On a waters with heavy fishing pressure, where big fish have seen all the cdc, parachute and classic hackled patterns, they can really save the day.
I love to tie the body with tread and use polypropylene for ribs.
White-ish jay feathers can be used for spinners,
and brown and black will make a nice caddis wings.