From mid May up the mid July, caddis flies of Sericostoma personatum specie are hatching throughout the Balkans .
The body is black with green stripes, wings are very dark too.
In Montenegro and Bosnia, the insect is called The Blackie, although in Serbia most common name is The Greeny, because of it's green stripes.
Through the years, I found that chartreuse stripes works best for me on Lim river. If I want a nice, dead drift ride, I'll make a cdc version with no hackle and if I want to skate it over some calm pools, I'll use palmer fly.
Antron dubbing for the body and black crow feather for the back and the stomach of the fly.
Caught a lot of big graylings on this flies, including some longer than 50 centimeters, which are the Holy Grail for grayling fly fishermen.