Here are a few old bugs used by Czech fishermen for more than 20 years. Usually a trout bug is a fly with a little bit of scruffy dubbing , tinsel and one turn of soft hackle or hot spot dubbing behing the bead. These flies are so simple to tie, in fact too simple and for this reason almost all tiers avoid them. I do not know why we like to complicate everything and we forgot that simple things work very often better then those fancy ones.
Here is the classic model tied with copper bead and orange thorax and very popular in UK. Bill Eadie improved this model and he is considered his generator.
And here is a variation, with darker body , gold bead and pink thorax: